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The objective of the study was to evaluate the effect of the incorporation of spent coffee grounds in ice cream cones on the quality, sensory characteristics, and in vitro starch digestibility. The incorporation of spent coffee grounds in ice cream cones increased the content of dietary fiber and phenolic compounds. However, the quality and texture characteristics decreased with the addition of spent coffee grounds. The in vitro starch digestibility decreased significantly, resulting in a significant increase in resistant starch content. Fitting starch digestibility using the LOS-plot model revealed the presence of two sequential first-order digestion rates. Sensory analysis revealed that the panelists well accepted ice cream cones fortified with spent coffee grounds. The results suggest that spent coffee grounds are a potential ingredient for the formulation of food matrices with reduced starch digestibility, which contributes to the prevention of chronic degenerative diseases such as type II diabetes., Competing Interests: Declaration of competing interest The authors declare no conflict of interest. The results reported in this study are original and developed under no conflict of interest by all authors., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Considering the high abundance of bound polyphenols (BP) in whole grain dietary fiber (DF), this study utilized multi-omics approach to evaluate the impact of BP of defatted rice bran insoluble DF (RIDF) in modulating obesity. Mice on high-fat diet were gavage-administered RIDF, BP-removed or formulated RIDF. The results indicated that DF significantly reduced serum total cholesterol, triglycerides, high-density and low-density lipoprotein cholesterol levels. Moreover, hepatic lipid accumulation and damage induced by high-fat diet were significantly ameliorated with DF intervention. The presence of BP increased the abundance of beneficial bacteria g_Akkermansia and g_Butyricicocus, as well as the expression of butyric acid/propionic acid. Furthermore, the expression of hepatic lipids and lipid-like molecules was significantly decreased under the combined intervention of BP and DF, and this was accompanied by alterations in genes related to lipid, sterol, and cholesterol metabolic biological processes. These findings suggest that BP contribute to the anti-obesity effects of DF., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Oat (Avena sativa) processing generates a large amount of by-products, especially oat bran. These by-products are excellent sources of bioactive compounds such as polyphenols and essential fatty acids. Therefore, enhancing the extraction of these bioactive substances and incorporating them into the human diet is critical. This study investigates the effect of acid pretreatment on the solid-state fermentation of oat bran with Aspergillus niger, with an emphasis on the bioaccessibility of phenolic acids and lipid profile. The results showed a considerable increase in reducing sugars following acid pretreatment. On the sixth day, there was a notable increase in the total phenolic content, reaching 58.114 ± 0.09 mg GAE/g DW, and the vanillic acid level significantly rose to 77.419 ± 0.27 μg/g DW. The lipid profile study revealed changes ranging from 4.66 % in the control to 7.33 % on the sixth day of SSF. Aside from biochemical alterations, antioxidant activity measurement using the DPPH technique demonstrated the maximum scavenging activity on day 4 (83.33 %). This study highlights acid pretreatment's role in enhancing bioactive compound accessibility in solid-state fermentation and its importance for functional food development., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Clarification is required when the term "carbohydrate" is used interchangeably with "saccharide" and "glycan." Carbohydrate classification based on human digestive enzyme activities brings clarity to the energy supply function of digestible sugars and starch. However, categorizing structurally diverse non-digestible carbohydrates (NDCs) to make dietary intake recommendations for health promotion remains elusive. In this review, we present a summary of the strengths and weaknesses of the traditional dichotomic classifications of carbohydrates, which were introduced by food chemists, nutritionists, and microbiologists. In parallel, we discuss the current consensus on commonly used terms for NDCs such as "dietary fiber," "prebiotics," and "fermentable glycans" and highlight their inherent differences from the perspectives of gut microbiome. Moreover, we provide a historical perspective on the development of novel concepts such as microbiota-accessible carbohydrates, microbiota-directed fiber, targeted prebiotics, and glycobiome. Crucially, these novel concepts proposed by multidisciplinary scholars help to distinguish the interactions between diverse NDCs and the gut microbiome. In summary, the term NDCs created based on the inability of human digestive enzymes fails to denote their interactions with gut microbiome. Considering that the gut microbiome possesses sophisticated enzyme systems to harvest diverse NDCs, the subclassification of NDCs should be realigned to their metabolism by various gut microbes, particularly health-promoting microbes. Such rigorous categorizations facilitate the development of microbiome-targeted therapeutic strategies by incorporating specific types of NDCs., (© 2024 Institute of Food Technologists®.)

5-Heptadecylresorcinol (AR-C17), a homologue of alkylresorcinols (ARs) and mainly observed in cereal brans, has stronger physiological functions compared with its homologues. However, not only is its content rare but also the purification low. Besides, few researches on its digestion characteristics and bioavailability limits its maximum applications. Here, we mainly relied on solid-state fermentation, embedment, in vitro models to systematically evaluate processing technologies, digestion and absorption characteristics of AR-C17. We showed that the highest content of AR-C17 was 57.6 μg/g extracted from triticale bran fermented by Saccharomyces cerevisiae relying on ultrasound-assistance. Additionally, AR-C17 was chiefly absorbed in duodenum and jejunum, and its apparent absorption increased by around 2.1 times when quercetin was added as the synergistic agent, which was higher than other phenolics in bran extract. Furthermore, AR-C17 embedded by β-cyclodextrin avoided the decomposition of in strong acidic environment, enhancing the retention rate to 96 % in in vitro digestion. According to the results above, we mixed AR-C17 with the quercetin, and embedded the mixture by β-cyclodextrin, which maximized the apparent absorption of AR-C17, reaching 19.8 % when the ratio of quercetin and AR-C17 was 1:1., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The aim of this study was to extract water-soluble dietary fibers (WSDF skin ), pectin (PEC skin ), and xyloglucan (XG skin ) from hazelnut skin and to determine their impacts on colonic microbiota and metabolic function. WSDF skin , PEC skin , and XG skin were extracted by water, acid, and alkali treatments, respectively. Monosaccharide analysis revealed WSDF skin and PEC skin were dominated by uronic acids, while the XG skin was found to contain xyloglucan- and pectin-associated sugars. In vitro fecal fermentation analysis showed that WSDF skin , PEC skin , and XG skin are fermented to different microbial short-chain fatty acid profiles by identical microbiota. 16S rRNA sequencing demonstrated that PEC skin promoted Faecalibacterium prausnitzii and Lachnospiraceae related operational taxonomic units (OTUs), which are recognized as beneficial members of the human gut, whereas WSDF skin and XG skin stimulated Bacteroides OTUs. Interestingly, increased abundances of F. prausnitzii and Lachnospiraceae OTUs in PEC skin were higher than those in commercially available pectin. Finally, PEC skin and XG skin were tested in a biscuit model and the results showed that either PEC skin or XG skin can be incorporated into biscuit formulations without impacting physical, textural, and sensory properties of the final product. Overall, our results demonstrated that hazelnut skin, an industrial byproduct, can be utilized for the production of functional dietary fibers, especially pectin, to improve colonic health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Phenolics in bound form extensively exist in cereal dietary fiber, especially insoluble fiber, while their release profile in gastrointestinal tract and contribution to the potential positive effects of dietary fiber in modulating gut microbiota still needs to be disclosed. In this work, the composition of bound phenolics (BPs) in triticale insoluble dietary fiber (TIDF) was studied, and in vitro gastrointestinal digestion as well as colonic fermentation were performed to investigate BPs liberation and their role in regulating intestinal flora of TIDF. It turned out that most BPs were unaccessible in digestion but partly released continuously during fermentation. 16 s rRNA sequencing demonstrated that TIDF possessed prebiotic effects by promoting anti-inflammatory while inhibiting proinflammatory bacteria alongside boosting SCFAs production and antioxidative BPs contributed a lot to these effects. Results indicated that TIDF held capabilities to regulate intestinal flora and BPs were important functional components to the health benefits of cereal dietary fiber., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study aimed to evaluate the effect of extrusion and of open-pan cooking on whole germinated and non-germinated grains of pearl millet (Pennisetum glaucum L. R. Br.), on its chemical-nutritional composition and in vitro iron bioavailability. The experimental design consisted of three flours: non-germination open-pan cooked millet flour (NGOPCMF), germination open-pan cooked millet flour (GOPCMF), and extrusion cooked millet flour (ECMF). The ECMF increased the carbohydrates, iron, manganese, diosmin, and cyanidin and decreased the total dietary fiber, resistant starch, lipids, and total vitamin E, in relation to NGOPCMF. The GOPCMF increased the lysine and vitamin C and decreased the phytate, lipids, total phenolic, total vitamin E, and riboflavin concentration, in relation to NGOPCMF. Furthermore, germinated cooked millet flour and extruded millet flour improved iron availability in vitro compared to non-germinated cooked millet flour. GOPCMF and ECMF generally preserved the chemical-nutritional composition of pearl millet and improved in vitro iron bioavailability; therefore, they are nutritionally equivalent and can be used to develop pearl millet-based products., Competing Interests: Declaration of competing interest The authors affirm that they have no known conflicting financial interests or personal relationships that may have influenced the research presented in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Bodyweight loss and rumen microbial dysfunction of grazing sheep was a challenge for the sheep production industry during cold season, which were considered to correlated with under-roughage-feeding. Alfalfa is a good roughage supplementary for ruminants, which can improve grazing sheep bodyweight-loss and rumen microbial dysfunction during grass-withering period. This study evaluated the effects of alfalfa hay supplementary change dietary non-fibrous carbohydrate/neutral detergent fiber (NFC/NDF) ratios on rumen fermentation and microbial function of Gansu alpine fine wool sheep during extreme cold season. 120 ewes (3-4 yrs) with an average body weight of 28.71 ± 1.22 kg were allocated randomly into three treatments, and fed NFC/NDF of 1.92 (H group), 1.11 (M group), and 0.68 (L group), respectively. This study was conducted for 107 d, including 7 d of adaption to the diets. The rumen fermentation parameters and microbial characteristics were measured after the end of feeding trials. The results showed that the concentrations of sheep body weight, nitrogen components (Total-N, Soluble protein-N and Ammonia-N), blood biochemical indices (LDH, BUN and CHO) and ruminal volatile fatty acids (TVFA and propionate) significantly increased with an increase in the proportion of NFC/NDF ratios ( p  < .05), and the acetate and acetate/propionat ratio presented a contrary decreasing trend ( p  < .05). A total of 1018 OTUs were obtained with 97% consistency. Ruminococcus, Ruminococcaceae and Prevotella were observed as the predominant phyla in ruminal fluid microbiota. Higher NFC/NDF ratios with Alfalfa supplementary increased the richness and diversity of ruminal fluid microbiota, and decreased ruminal fluid microbiota beta-diversity. Using clusters of orthologous groups (COG), the ruminal fluid microbiota of alfalfa supplementary feeding showed low immune pathway and high carbohydrate metabolism pathway. In summary, the study suggested that there was an increasing tendency in dietary NFC/NDF ratio of 1.92 in body weight, ruminal fermentation, microbial community composition and fermentation characteristics through developing alfalfa supplementary system.

Grain bran dietary fiber (DF) has the effect of promoting intestinal health and is worth being studied. In the present study, the physicochemical properties and prevention effect of DF on ulcerative colitis (UC) were investigated. The results showed that the optimal extraction conditions were determined as α-amylase (350 U/g, 70 °C, pH 7.0, 2.5 h) and papain (100 U/g, 60 °C, pH 7.0, 1.5 h), resulting in a yield of 83.81% for DF. Moreover, DF exhibited unique physicochemical properties contributing to its preventive effects, as evidenced by its ability to mitigate symptoms such as hematochezia, immune inflammation, and impaired intestinal barrier in UC mice. The underlying mechanism can be attributed to the regulation of phenylalanine, tyrosine and tryptophan biosynthesis pathway and maintenance of intestinal microbial homeostasis. Therefore, our study suggests that grain bran DF holds potential for the prevention of UC, providing a basis for the development and utilization of grain bran., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microbiome-directed dietary interventions such as microbiota-directed fibers (MDFs) have a proven track record in eliciting responses in beneficial gut microbes and are increasingly being promoted as an effective strategy to improve animal production systems. Here we used initial metataxonomic data on fish gut microbiomes as well as a wealth of a priori mammalian microbiome knowledge on α-mannooligosaccharides (MOS) and β-mannan-derived MDFs to study effects of such feed supplements in Atlantic salmon (Salmo salar) and their impact on its gut microbiome composition and functionalities. Our multi-omic analysis revealed that the investigated MDFs (two α-mannans and an acetylated β-galactoglucomannan), at a dose of 0.2% in the diet, had negligible effects on both host gene expression, and gut microbiome structure and function under the studied conditions. While a subsequent trial using a higher (4%) dietary inclusion of β-mannan significantly shifted the gut microbiome composition, there were still no biologically relevant effects on salmon metabolism and physiology. Only a single Burkholderia-Caballeronia-Paraburkholderia (BCP) population demonstrated consistent and significant abundance shifts across both feeding trials, although with no evidence of β-mannan utilization capabilities or changes in gene transcripts for producing metabolites beneficial to the host. In light of these findings, we revisited our omics data to predict and outline previously unreported and potentially beneficial endogenous lactic acid bacteria that should be targeted with future, conceivably more suitable, MDF strategies for salmon., (© 2024. The Author(s).)

To enhance the use of wheat bran in chicken feed, a solid-state fermentation approach was used with Lactobacillus paracasei LAC28 and Pediococcus acidilactici BCC-1, along with arabinoxylan-specific degrading enzymes (xylanase, arabinofuranosidase, feruloyl esterase, XAF). The effects of the fermentation process were evaluated both in vitro and in vivo . In the in vitro study, XAF supplementation demonstrated superior performance, significantly reducing the pH of the fermented wheat bran (FWB) and increasing lactic, acetic, and butyric acid levels, total phenol content, and free radical scavenging capacity ( P < 0.05) compared to the XAF-free group. In the in vivo study, broilers were fed diets containing either unfermented wheat bran (UFWB) or FWB (fermented individually with LAC28 or BCC-1). Broilers fed FWB with BCC-1 exhibited significant improvements in body weight gain, intestinal morphology, and nutrient digestibility ( P < 0.05) compared to the control group. Moreover, the FWB established a healthier microbial community in the avian gastrointestinal tract. Overall, this study demonstrated the potential of combining XAF and bacteria to enhance wheat bran fermentation, benefiting broiler intestinal health and growth. This innovative approach holds promise as a cost-efficient and sustainable strategy to improve the nutritional quality of wheat bran for animal feed applications.

It is commonly accepted that dietary fibers are good for gut health. The effect of fibers on the diversity and metabolic activities of the cecal microflora, however, differ with the passage of time. Therefore, we investigated the time-series impacts of the pasture grazing system (a high dietary fiber source) on the cecal microbiome and short-chain fatty acids in Wanpu geese, comparing it to commercial feeding (a low dietary fiber source). The cecal microbiota composition and SCFA concentrations were evaluated by 16S rRNA gene sequencing and gas chromatography, respectively. We found that pasture produced a generally quick positive response to Bacteroidales, Lactobacillales, Gastranaerophilales (at 45 days), Lachnospirales, and Oscillospirales (at 60 days and 90 days) irrespective of Erysipelotrichales (at 45 days), Clostridia&#95;UCG-014 , RF39 (at 60 days), Christensenellales, and Peptostreptococcales-Tissierellales (at 90 days) in geese. Meanwhile, we found that Lactobacillales, Gastranaerophilales, Lachnospirales, and Oscillospirales were significantly correlated with short-chain fatty acids in pasture grazing geese. Indeed, the correlation of cecal microbiota with SCFAs led to altered microbial functions evinced by COG; KEGG pathway levels 1, 2, and 3; BugBase; and FAPROTAX databases. This study emphasizes the importance of dietary fiber sources in influencing beneficial impacts in regulating geese microbiota homeostasis and metabolic functions such as energy and lipid metabolism.IMPORTANCELow dietary fiber diet sources cause gut microbial and short-chain fatty acid alterations that lead to compromised animal health. The establishment of an artificial pasture grazing system at the expense of ryegrass is a good source of dietary fiber for geese. Our results described the importance of pasture in maintaining the gut microbiota, SCFAs, and potential microbial functions reported by COG; KEGG pathway levels 1, 2, and 3; BugBase; and FAPROTAX databases., Competing Interests: The authors declare no conflict of interest.

Dietary fibres consist of a heterogeneous group of carbohydrate polymers which resist digestion by human gastrointestinal enzymes. Consumption of dietary fibre has been linked with innumerable health benefits encompassing the foundational pillars of metabolic health from obesity to hypertension, dyslipidaemia, and type 2 diabetes mellitus (T2DM), with many of these benefits linked with metabolites produced by the fermentation of fibre by gut microbes [1]. The potential of dietary fibre to provide a safe and effective nonpharmacologic complementary tool with which to combat the evolving consequences of the obesity epidemic has recently garnered tremendous attention in both medical literature and lay media alike. HIGHLIGHTS: Consumption of dietary fibre has been linked with innumerable health benefits encompassing the foundational pillars of metabolic health with many of these benefits linked with metabolites produced by the fermentation of fibre by gut microbes At the present time clinicians are faced with an impossible task in which there is rapidly mounting evidence for dietary fibres advancing metabolic health, but little practical options for healthcare providers other than to simply recommend patients consume more fibre. Benefits of fibre intake may perhaps be maximised in an individual by matching specific fibre consumption with existing microbial functional characteristics If dietary fibres could be demonstrated to act as successful adjuncts to sustain or improve standard of care therapies or even alleviate common gastrointestinal side effects associated with current treatments, they would be an invaluable tool in our metabolic health armamentarium. Neither Dr. Madsen or I have any financial conflicts of interest pertinent to the contents of this manuscript., (© 2024 The Author(s). Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

The aim of this study was to evaluated the impact of different fibre levels in alpaca diet on voluntary feed intake and apparent digestibility, and to estimate the digestibility of organic matter (OMD) from the content of crude protein (CP) in feces. The study was carried out with twelve alpacas (36.7 ± 6.4 kg body weight- BW), which were offered 4 treatments with different neutral detergent fiber content (NDF. T1: 40.3%; T2: 62%; T3: 68%; T4: 72%) under a switch back design. Absolute daily dry matter intake (DMI) was higher for T1 (678 g/d) than T4 (312 g/d) (p ≥ 005). NDF intake was similar between treatments when related to BW or MW (on average 1% BW and 22 g/kg MW. p ≥ 0.05). Water intake (L/kg DMI) was higher in T1 compared to the other treatments, with values ranging from 2.9 L/kg DMI(T1) to 2.8 L/kg DMI(T4), respectively (p ≤ 0.05). Digestibility of dry matter, organic matter and CP was higher in T1 than in the other treatments, with average values ranging from 72% for T1 to 32% for T4 (p ≤ 0.05). NDF digestibility was similar among treatments (p ≥ 0.05). The regression equation generated to predict OMD (y) was as follows: y = 0.360 + 0.08294*fecal CP (g/kg OM). Further studies will indicate whether faecal nitrogen can be used to estimate digestibility and hence diet quality in South American camelids., (© 2024. The Author(s).)

This study aimed to prepare soybean dregs dietary fibre (DF) using physically assisted chemical (KHMSO) modification and study its structure, function and vitro simulation experiments. The soluble dietary fibre (SDF) content in KHMSO increased and insoluble dietary fibre (IDF) content decreased. The modified DF surface becomes irregular and rough, and the results of XPS fitting indicated that the DF structure had different peak-splitting groups. The KHMSO-treated group had the lowest digestion rate in gastric fluid and the highest digestibility in intestine fluid. The OD 600 of fecal cultures was increased to 0.915, and the increased abundance of microbiota was associated with the metabolism of SCFAs, such as Lachnospiraceae, as well as the higher n-butyric acid in the KHMSO-treated group compared to the other groups and lower than the inulin, suggesting KHMSO might enhance the production of functional foods aimed at promoting intestinal health., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest in the publication of this manuscript. This study is original research that has not been published previously, and not under consideration for publication elsewhere., (Copyright © 2024. Published by Elsevier B.V.)

Edible fungi are emerging as a valuable dietary fiber source with health benefits, where their bioactivity hinges on their structure. This study targets the structure-activity relationship of soluble dietary fibers from Lentinus edodes (LESDF), Agaricus bisporus (ABSDF), and Hericium erinaceus (HESDF), focusing on their impact on gut microbiota and health. We explored the properties and structures of edible fungi, finding their soluble fibers affect metabolites and gut microbiota by increasing gas and lowering pH. Among these, HESDF demonstrated superior effects (pH: △1.4 ± 0.07; Gas production: △24.5 ± 0.4 mL). Furthermore, different types of edible fungi dietary fiber exhibited distinct capabilities in promoting the production of short-chain fatty acids by gut microorganisms. For instance, ABSDF exceled in acetic acid production (26.12 ± 0.35 mM) and propionic acid production (9.50 ± 0.13 mM), while HESDF stood out in butyric acid production (17.86 ± 0.09 mM). LESDF showed higher levels of Phascolarctobacterium, ABSDF had elevated levels of Ruminococcus, and HESDF displayed increased levels of Faecalibacterium. These results contribute to our understanding of how soluble dietary fiber from different edible fungi impacts gut microbiota and offers insights for the development and utilization of these fibers as functional food., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Exploring nutritional therapies that manipulate tryptophan metabolism to activate AhR signaling represents a promising approach for mitigating chronic colitis. Arabinoxylan is a bioactive constituent abundant in wheat bran. Here, we comprehensively investigated anti-colitis potentials of wheat bran arabinoxylan (WBAX), its synbiotic and postbiotic derived from WBAX and Limosilactobacillus reuteri WX-94 (i.e., a probiotic strain exhibiting tryptophan metabolic activity). WBAX fueled L. reuteri and promoted microbial conversion of tryptophan to AhR ligands during in vitro fermentation in the culture medium and in the fecal microbiota from type 2 diabetes. The WBAX postbiotic outperformed WBAX and its synbiotic in augmenting efficacy of tryptophan in restoring DSS-disturbed serum immune markers, colonic tight junction proteins and gene profiles involved in amino acid metabolism and FoxO signaling. The WBAX postbiotic remodeled gut microbiota and superiorly enhanced AhR ligands (i.e., indole metabolites and bile acids), alongside with elevation in colonic AhR and IL-22. Associations between genera and metabolites modified by the postbiotic and colitis in human were verified and strong binding capacities between metabolites and colitis-related targets were demonstrated by molecular docking. Our study advances the novel perspective of WBAX in manipulating tryptophan metabolism and anti-colitis potentials of WBAX postbiotic via promoting gut microbiota-dependent AhR signaling., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Hybrid Pennisetum, a top biomass energy source, faces usage limitations because of its scarce lactic acid bacteria and high fiber content. This study assessed the influence of rumen fluid pretreatment on hybrid Pennisetum's silage, with focus on silage duration and rumen fluid effects on quality and fiber decomposition. Advanced third-generation sequencing was used to track microbial diversity changes and revealed that rumen fluid considerably enhanced dry matter, crude protein, and water-soluble carbohydrates, thus improving fermentation quality to satisfactory pH levels (3.40-3.67). Ideal results, including the highest fiber breakdown and enzymatic efficiency (47.23 %), were obtained with 5 % rumen fluid in 60 days. The addition of rumen fluid changed the dominant species, including Paucilactobacillus vaccinostercus (0.00 % vs. 18.21 %) and Lactiplantibacillus plantarum (21.03 % vs. 47.02 %), and no Enterobacter was detected in the high-concentration treatments. Moreover, strong correlations were found between specific lactic acid bacteria and fermentation indicators, revealing the potential of achieving efficient and economically beneficial hybrid Pennisetum production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The present study deals with the production of cellulase-free endoxylanase by Aspergillus niger ISL-9 using wheat bran as a solid substrate. Endoxylanase was produced under a solid-state fermentation. Various growth parameters were optimized for the improved production of the enzyme. The Substrate level of 15 g was optimized as it provided the fungus with balanced aeration and nutrition. Among the six moisture contents investigated, Moisture Content 5 (MC5) was optimized (g/l: malt extract, 10; (NH 4 ) 2 HPO 4 , 2.5; urea, 1.0) and 10 mL of MC5 was found to give the highest production of endoxylanase. The pH and time of incubation were optimized to 6.2 and 48 h respectively. The Inoculum size of 2 mL (1.4 × 10 6 spores/mL) gave the maximum enzyme production. After optimization of these growth parameters, a significantly high endoxylanase activity of 21.87 U/g was achieved. Very negligible Carboxymethylcellulase (CMCase) activity was observed indicating the production of cellulase-free endoxylanase. The notable finding is that the endoxylanase activity was increased by 1.4-fold under optimized conditions (p ≤ 0.05). The overall comparison of kinetic parameters for enhanced production of endoxylanase by A. niger ISL-9 under Solid State Fermentation (SSF) was also studied. Different kinetic variables which included specific growth rate, product yield coefficients, volumetric rates and specific rates were observed at 48, 72 and 96 h incubation time and were compared for MC1 and MC5. Among the kinetic parameters, the most significant result was obtained with volumetric rate constant for product formation (Q p ) that was found to be optimum (1.89 U/h) at 72 h incubation period and a high value of Q p i.e.1.68 U/h was also observed at 48 h incubation period. Thus, the study demonstrates a cost-effective and environmentally sustainable process for xylanase production and exhibits scope towards successful industrial applications., (© 2024. The Author(s).)

This study focuses on the resilience of gut microbiota during a five-month multi-interventional nutrition trial. The modulatory effects of beta-glucan, rye bran and two dietary fiber mixtures on the fecal pH and compositional changes of the microbiome of healthy subjects were studied. To analyze the stability of intestinal microbiota, we collected an extensive dataset of sequential fecal samples (23-29 from each participant) during a week of the base, beta-glucan consumption and wash-out periods accompanied by the collection of daily food diary data. Microbiota analyses were also conducted after the end of each fiber intake and wash-out period, along with measurements of fecal organic acids and pH. Based on the dominant bacterial taxa, two prevalent microbiota types were identified. The Prevotella-type microbiota responded more to the tested dietary fibers, while the Bacteroides-type microbiota was the least affected. Three microbiota types could not be clustered and behaved differently. Although we noted individual effects of definite fibers on participants' gut microbiota and metabolic profile, relative abundances of bacteria remained stable in the base period (z-scores - 2.2 to 2.3). In most cases, the bacterial abundances of the final samples remained within the normal fluctuation range stressing out the resilience of healthy microbiota. The pH of all fecal samples varied between 6.1 and 8.3 and was associated with the concentration of organic acids and microbial composition. The effect of dietary fibers on the metabolism of fecal microbiota clearly depended on the individual microbiota type. Combining the analysis of gut microbiota with knowledge of the properties of dietary fibers would provide a powerful strategy for nutrition guidance and disease prevention., (© 2024. The Author(s).)

Background: Dietary fibers can alter microbial metabolic output in support of healthy immune function; however, the impact of distinct fiber sources and immunomodulatory effects beyond short-chain fatty acid production are underexplored. In an effort to discern the effects of diverse fibers on host immunity, we employed five distinct rodent diets with varying fiber content and source in specific-pathogen-free, gnotobiotic (containing a 14-member synthetic human gut microbiota), and germ-free mice., Results: Broad-scale metabolomics analysis of cecal contents revealed that fiber deprivation consistently reduced the concentrations of microbiota-produced B vitamins. This phenomenon was not always explained by reduced biosynthesis, rather, metatranscriptomic analyses pointed toward increased microbial usage of certain B vitamins under fiber-free conditions, ultimately resulting in a net reduction of host-available B vitamins. Broad immunophenotyping indicated that the local gut effector immune populations and activated T cells accumulate in a microbiota-dependent manner. Supplementation with the prebiotic inulin recovered the availability of microbially produced B vitamins and restored immune homeostasis., Conclusions: Our findings highlight the potential to use defined fiber polysaccharides to boost microbiota-derived B vitamin availability in an animal model and to regulate local innate and adaptive immune populations of the host. Video abstract., (© 2024. The Author(s).)

Pectic polysaccharides can beneficially shape the human microbiota. However, individual variability in the microbial response, especially the response between normal-weight (NW) and overweight (OW) people, is rarely understood. Therefore, we performed batch fermentation using inulin (INU), commercial pectin (CP), and pectic polysaccharides extracted from goji berry (GPP) and raspberry (RPP) by microbiota from five normal-weight (NW) and five overweight (OW) donors. The degree of specificity of fiber was negatively correlated to its fermentable rate and microbial response. Meanwhile, we found that microbiota from OW donors had a stronger fiber-degrading capacity than NW donors. The result of correlation between individual basal microbiota and the fermentable rate indicated Dialister , Megamonas , Oscillospiraceae&#95;NK4A214 , Prevotella , Ruminococcus , and unidentified&#95;Muribaculaceae may be the key bacteria. In summary, we highlighted a new perspective regarding the interactive relationship between different fibers and fecal microbiota from different donors that may be helpful to design fiber interventions for individuals with different microbiota.

While innumerous associative microbiome studies have been published, mechanistic links between the microbiome and host physiology remain much scarcer. In Cell Host & Microbe, Shen et al. report the effect of soluble dietary fibers in alcohol-related liver disease. Through microbiome remodeling, dietary fiber triggers upregulation of liver ornithine aminotransferase and a subsequent reduction in hepatic damage., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This study innovatively employed solid-state fermentation (SSF) to evaluate chitinase induction in Trichoderma harzianum . Solid-state fermentation minimizes water usage, a crucial global resource, and was applied using shrimp waste chitin and a mixture of commercial chitin with wheat bran as substrates. Shrimp waste and wheat bran were pretreated and characterized for SSF, and the fungus's utilization of the substrates was assessed using spectrophotometric and microscopic methods. The resulting enzymes' ability to produce chitooligosaccharides (COS) mixtures was studied. Wheat bran/commercial chitin demonstrated superior performance, with a 1.8-fold increase in chitinase activity (76.3 U/mg protein) compared to shrimp waste chitin (41.8 U/mg protein). Additionally, the COS mixture obtained from wheat bran/commercial chitin showed a higher concentration of reducing sugars, reaching 87.85 mM, compared to shrimp waste chitin (14.87 mM). The COS profile from wheat bran/commercial chitin included monomers to heptamers, while the profile from shrimp waste chitin was predominantly composed of monomers. These results highlight the advantages of SSF for chitinase induction and COS production in T. harzianum , offering potential applications as dietary fiber, antioxidants, and antimicrobial agents. The findings contribute to by-product valorization, waste reduction, and the sustainable generation of valuable products through SSF-based enzyme production.

Interactions between human gut microbiota and dietary fibres (DF) are influenced by the complexity and diversity of both individual microbiota and sources of DF. Based on 480 in vitro fermentations, a full factorial experiment was performed with six faecal inocula representing two enterotypes and three DF sources with nanometer, micrometer, and millimeter length-scales (apple pectin, apple cell walls and apple particles) at two concentrations. Increasing DF size reduced substrate disappearance and fermentation rates but not biomass growth. Concentrated DF enhanced butyrate production and lactate cross-feeding. Enterotype differentiated final microbial compositions but not biomass or fermentation metabolite profiles. Individual donor microbiota differences did not influence DF type or concentration effects but were manifested in the promotion of different functional microbes within each population with the capacity to degrade the DF substrates. Overall, consistent effects (independent of donor microbiota variation) of DF type and concentration on kinetics of substrate degradation, microbial biomass production, gas kinetics and metabolite profiles were found, which can form the basis for informed design of DF for desired rates/sites and consequences of gut fermentation. These results add further evidence to the concept that, despite variations between individuals, the human gut microbiota represents a community with conserved emergent properties., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Adlay bran is known for its nutrient-rich profile and multifunctional properties, and steam explosion (SE) is an emerging physical modification technique. However, the specific effects of SE on the activity composition and antioxidant capacity of adlay bran soluble dietary fiber (SDF) during in vitro digestion, as well as its influence on gut microbiota during in vitro fermentation, remain inadequately understood. This paper reports the in vitro digestion and fermentation characteristics of soluble dietary fiber from adlay bran modified by SE (SE-SDF). Compared with the untreated samples (0-SDF), most of the phenolic compounds and antioxidant capacity were significantly increased in the SE-SDF digests. Additionally, SE was beneficial for adlay bran SDF to increase the content of acetic acid, propionic acid and total short-chain fatty acids (SCFAs) in fermentation broth during in vitro fermentation. SE-SDF could promote the growth of beneficial bacteria while inhibiting the proliferation of pathogenic microbes. Our research indicates that SE-SDF shows strong antioxidant properties after in vitro digestion and plays a pivotal role in regulating gut microbiota during in vitro fermentation, ultimately enhancing human intestinal health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Lignocellulose constitutes the primary component of dietary fiber. We assessed how fermenting bamboo shoot residue with the medicinal white-rot fungus Inonotus obliquus affected the yield, composition, and functional attributes of dietary fiber by altering bamboo shoot residue lignocellulose's spatial structure and composition. I. obliquus secretes lignocellulolytic enzymes, which effectively enhance the degradation of holocellulose and lignin by 87.8% and 25.5%, respectively. Fermentation led to a more porous structure and reduced crystallinity. The yield of soluble dietary fiber increased from 5.1 g/100 g raw BSR to 7.1 g/100 g 9-day-fermented bamboo shoot residue. The total soluble sugar content of dietary fiber significantly increased from 9.2% to 13.8%, which improved the hydration, oil holding capacity, in vitro cholesterol, sodium cholate, and nitrite adsorption properties of dietary fiber from bamboo shoot residue. These findings confirm that I. obliquus biotransformation is promising for enhancing dietary fiber yield and quality., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A total of 378 Cobb-500 male broilers were used to evaluate the effects of 2 fiber sources, differing in hydration capacity and fermentability, on gastrointestinal tract development, apparent ileal digestibility and performance from 1 to 42d of age. There were 9 replicates per each of the 3 dietary treatments, all in mash form: a wheat-soybean control (CON) diet, CON diet diluted with 1.5% of wood lignocellulose (LC diet) as a non-fermentable insoluble fiber with high hydration capacity; and CON diluted with 1.5% of a mixture of fibers (ISFC diet) containing both lignified insoluble fiber and a prebiotic soluble fiber fraction from fructooligosaccharides. Additionally, the fermentability of both fiber sources (LC and ISFC) was determined by in vitro using cecal inoculum from broilers fed the experimental diets. Both LC and ISFC treatments impaired by 4% feed conversion ratio only during the first 7d (P = 0.003) compared with CON group. In the grower period (21-42d), the ISFC group showed the best growth (P = 0.039), and at 42d tended to show the highest body weight (P = 0.095). This agrees well with the highest ileal dry matter (P = 0.033) and organic matter (P = 0.043) digestibility observed in ISFC group and the similar trend observed for ileal protein digestibility (P = 0.099) at 42d. Also, at 42 d, absolute and relative (% body weight) digestive tract weights (P ≤ 0.041) and empty gizzard weights (P ≤ 0.034) were greater for LC and ISFC groups compared to CON. The cecal molar proportion of valeratewas greatest in ISFC group (P = 0.039). In vitro gas production was higher for ISFC than for LC substrate when using either a diet-adapted or non-adapted cecal inoculum (P < 0.05). These results show the interest in combining IF with prebiotic highly fermentable fiber, such as fructooligosaccharides, in broilers to improve nutrient digestibility and finishing performance., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Grape pomace (GP) and pecan shell (PS) are two by-products rich in phenolic compounds (PC), and dietary fiber (DF) that may be considered for the development of functional baked foods. In this study, four formulations with different GP:PS ratios (F1(8%:5%), F2(5%:5%), F3(5%:2%), F4(0%:5%), and control bread (CB)) were elaborated and characterized (physiochemical and phytochemical content). Also, their inner structure (SEM), changes in their FTIR functional group's vibrations, and the bioaccessibility of PC and sugars, including an in vitro glycemic index, were analyzed. Results showed that all GP:PS formulations had higher mineral, protein, DF (total, soluble, and insoluble), and PC content than CB. Additionally, PC and non-starch polysaccharides affected gluten and starch absorbance and pores distribution. In vitro digestion model showed a reduction in the glycemic index for all formulations, compared to CB. These findings highlight the possible health benefits of by-products and their interactions in baked goods., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Apple pomace, an abundant agricultural by-product with low utilization rates, often leads to environmental pollution if not properly managed. This study aimed to enhance the nutritional value of apple pomace by comparing the effects of solid-state fermentation using complex probiotics and cellulase preparation. Additionally, the study investigated the dynamic changes in various components throughout the fermentation process with complex probiotics. The results of single-strain solid-state fermentation tests indicated that Lactiplantibacillus plantarum DPH, Saccharomyces cerevisiae SC9, and Bacillus subtilis C9 were the optimal strains for fermenting the most effective substrate combination, comprising 73 % apple pomace and 20 % millet bran. The strains (complex probiotics) and a cellulase preparation were used for the solid-state fermentation of the apple pomace mixture for nine days, respectively. The contents of acid detergent fiber, neutral detergent fiber, hemicellulose, and insoluble dietary fiber decreased by up to 9.99 %, 9.59 %, 23.21 %, and 14.34 %, respectively. In contrast, the content of soluble dietary fiber significantly increased by up to 29.74 %. Both methods reduced cellulose crystallinity and modified the substrate's surface structure, resulting in a looser arrangement. Fermentation with complex probiotics for three or six days increased the abundance of lactic acid bacteria, which comprised >87 % of the total microbial population. Concurrently, the abundance of detrimental bacteria, such as Salmonella, Acetobacter, Escherichia, and Pantoea, significantly decreased. Furthermore, fermentation with complex probiotics for six or nine days enhanced antioxidant properties, leading to a significant increase in beneficial metabolites, including amino acids, organic acids, gamma-aminobutyric acid, serotonin. In conclusion, complex probiotics can effectively substitute for cellulase preparation in the solid-state fermentation of apple pomace, with a six-day fermentation period yielding optimal results. This study provides valuable insights into enhancing the value of apple pomace in the feed industry and the effective application of agro-industrial by-products., Competing Interests: Declaration of competing interest The authors declare to have no competing financial interests or personal relationships that could appear to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Insoluble dietary fiber (IDF) isolated through co-fermented bran from probiotics may improve starch gel-based foods. This work aimed to elucidate the comprehensive impact of different IDF samples (CK, unfermented; NF, natively fermented; YF, yeast fermented; LF, Lactobacillus plantarum fermented; and MF, mix-fermented) and their addition ratios (0.3-0.9%) on gel structure-property function. Results indicated that IDF introduction altered the starch pasting behavior (decreased the viscosity and advanced the pasting time). Also, YF, LF, and MF showed less effect on gel multiscale morphology (SEM and CLSM); however, their excessively high ratio resulted in network structure deterioration. Moreover, FT-IR, XRD, and Raman characterization identified the composite gels interaction mechanisms mainly by hydrogen bonding forces, van der Waals forces, water competition, and physical entanglement. This modulation improved the composite gel water distribution, rheological/stress-strain behavior, textural properties, color, stability, and digestive characteristics. The obtained findings may shed light on the construction and development of whole-grain gel-based food products with new perspectives., Competing Interests: Declaration of competing interest The authors declare no financial or other conflicts of interest in this work, the data of this work has not been published elsewhere., (Copyright © 2024. Published by Elsevier Ltd.)

Both rice bran (RB) rancidity and dephenolization could affect the structural characteristics and phenolics composition of rice bran protein (RBP), thereby affecting RBP digestibility. The synergistic effects of RB rancidity and dephenolization on RBP digestibility were investigated. Excessive RB rancidity (RB stored for 10 d) and non-dephenolization reduced RBP digestibility, while moderate RB rancidity (RB stored for 1 d) combined with dephenolization improved RBP digestibility to a maximum of 74.19%. Dephenolization reduced the antioxidant capacities of RBP digestive products. The digestibility of non-dephenolized RBP (NDRBP) was significantly (P < 0.05) related with its carbonyl content, surface hydrophobicity, and ζ-potential. The digestibility of dephenolized RBP (DRBP) was significantly related with its β-sheet structure content, surface hydrophobicity, ζ-potential, and average particle size. Overall, moderate RB rancidity combined with dephenolization enhanced RBP digestibility by reducing the non-competitive inhibition of endogenous phenolics on protease and regulating the spatial structural characteristics of RBP., Competing Interests: Declaration of competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The low-grade matcha is rich in insoluble dietary fiber. Trichoderma viride was used to increase the soluble dietary fiber to improve its functional properties. The soluble dietary fiber content increased from 6.74% to 15.24%. Pectin, hemicellulose, maltose, d-xylose, and glucose contents increased by 63.35% and 11.54%, 2.18, 0.11, and 7.04 mg/g, respectively. Trichoderma viride fermentation disrupted the dense structure of insoluble dietary fiber, resulting in a honeycomb structure and improving crystallinity by 22.75%. These structural changes led to an improved cation exchange capacity from 1.69 to 4.22 mmol/g, an increase in the inhibitory effect of α-amylase from 47.38% to 72.04%, and a 2.13-fold in the ferrous ion scavenging ability, and the IC 50 values of superoxide anion was reduced from 7.00 to 1.54 mg/mL, respectively. Therefore, Trichoderma viride fermentation is an excellent method for improving the quality of dietary fiber in matcha processing by-products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Inadequate dietary fiber (DF) intake is associated with several human diseases. Bread is commonly consumed, and its DF content can be increased by incorporating defatted rice bran (DRB)., Objective: This first human study on DRB-fortified bread primarily aims to assess the effect of DRB-fortified bread on the relative abundance of a composite of key microbial genera and species in fecal samples. Secondary outcomes include clinical (cardiovascular risk profile), patient-reported (daily bread consumption and bowel movement, gut comfort, general well-being, and total DF intake), biological (fecal microbiota gene abundances, and fecal and plasma metabolites), and physiome (whole-gut and regional transit time and gas fermentation profiles) outcomes in healthy adults with low DF intake., Methods: This is a 2-armed, placebo-controlled, double-blinded, crossover randomized controlled trial. The study duration is 14 weeks: 2 weeks of lead-in, 4 weeks of intervention per phase, 2 weeks of washout, and 2 weeks of follow-up. Overall, 60 healthy adults with low DF intake (<18 g [female individuals] or <22 g [male individuals] per day) were recruited in Christchurch, New Zealand, between June and December 2022. Randomly assigned participants consumed 3 (female individuals) or 4 (male individuals) slices of DRB-fortified bread per day and then placebo bread, and vice versa. The DRB-fortified bread provided 8 g (female individuals) or 10.6 g (male individuals) of total DF, whereas the placebo (a matched commercial white toast bread) provided 2.7 g (female individuals) or 3.6 g (male individuals) of total DF. Before and after each intervention phase, participants provided fecal and blood samples to assess biological responses; completed a 3-day food diary to assess usual intakes and web-based questionnaires to assess gut comfort, general and mental well-being, daily bread intake, and bowel movement via an app; underwent anthropometry and blood pressure measurements; and drank blue food dye to assess whole-gut transit time. Additionally, 25% (15/60) of the participants ingested Atmo gas-sensing capsules to assess colonic gas fermentation profile and whole-gut and regional transit time. Mean differences from baseline will be compared between the DRB and placebo groups, as well as within groups (after the intervention vs baseline). For metabolome analyses, comparisons will be made within and between groups using postintervention values., Results: Preliminary analysis included 56 participants (n=33, 59% female; n=23, 41% male). Due to the large dataset, data analysis was planned to be fully completed by the last quarter of 2024, with full results expected to be published in peer-reviewed journals by the end of 2024., Conclusions: This first human study offers insights into the prospect of consuming DRB-fortified bread to effectively modulate health-promoting gut microbes, their metabolism, and DF intake in healthy adults with low DF intake., Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12622000884707; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=383814., International Registered Report Identifier (irrid): DERR1-10.2196/59227., (©Hwei Min Ng, Jasjot Maggo, Catherine Louisa Wall, Simone Brigit Bayer, Warren C McNabb, Jane Adair Mullaney, Meika Foster, Diana L Cabrera, Karl Fraser, Janine Cooney, Tania Trower, Catrin S Günther, Chris Frampton, Richard Blair Gearry, Nicole Clemence Roy. Originally published in JMIR Research Protocols (https://www.researchprotocols.org), 29.08.2024.)

Microbial aggregation mainly occurs on the intestinal epithelium, mucosal layer and undigested food particles in the gastrointestinal tract (GIT). Undigested food particles are usually insoluble dietary fiber (IDF), which can be easily obtained through daily diet, but there are few studies investigating whether the gut bacteria adhering to undigested food particles can form multi-species biofilms. In this study, we prepared mono- and multi-species biofilms using 18 core gut bacteria via a dynamic fermentation method, and it was found that multi-species composed of nine core gut bacteria (M9) showed the best biofilm formation ability. Cell counts of the nine bacteria in multi-species biofilms were 9.36, 11.85, 10.17, 9.93, 12.88, 11.39, 10.089, 9.06, and 13.21 Log 10 CFU mL -1 . M9 was tightly connected and regularly stacked on wheat fiber and had larger particle sizes than mono-species biofilms. M9 retained biofilm formation ability under pH and bile salt stresses. A human feces invasion experiment demonstrated that M9 can stably adhere to wheat fiber under the interference of complex gut bacteria, and the M9 multi-species biofilm had positions that can be filled by various gut bacteria. Metabolome results indicated that the M9 multi-species biofilm had more metabolic productions and more complex interspecies interactions than mono-species biofilms. This study provides a dynamic fermentation method to prepare multi-species biofilms on wheat fiber in vitro . It will also offer a research basis for clarifying whether gut bacteria can utilize IDF to form biofilm structures in vivo and the possible interspecific interactions and physiological functions of bacteria in biofilms.

Members of the mammalian gut microbiota metabolize diverse complex carbohydrates that are not digested by the host, which are collectively labeled "dietary fiber." While the enzymes and transporters that each strain uses to establish a nutrient niche in the gut are often exquisitely specific, the relationship between carbohydrate structure and microbial ecology is imperfectly understood. The present study takes advantage of recent advances in complex carbohydrate structure determination to test the effects of fiber monosaccharide composition on microbial fermentation. Fifty-five fibers with varied monosaccharide composition were fermented by a pooled feline fecal inoculum in a modified MiniBioReactor array system over a period of 72 hours. The content of the monosaccharides glucose and xylose was significantly associated with the reduction of pH during fermentation, which was also predictable from the concentrations of the short-chain fatty acids lactic acid, propionic acid, and the signaling molecule indole-3-acetic acid. Microbiome diversity and composition were also predictable from monosaccharide content and SCFA concentration. In particular, the concentrations of lactic acid and propionic acid correlated with final alpha diversity and were significantly associated with the relative abundance of several of the genera, including Lactobacillus and Dubosiella . Our results suggest that monosaccharide composition offers a generalizable method to compare any dietary fiber of interest and uncover links between diet, gut microbiota, and metabolite production., Importance: The survival of a microbial species in the gut depends on the availability of the nutrients necessary for that species to survive. Carbohydrates in the form of non-host digestible fiber are of particular importance, and the set of genes possessed by each species for carbohydrate consumption can vary considerably. Here, differences in the monosaccharides that are the building blocks of fiber are considered for their impact on both the survival of different species of microbes and on the levels of microbial fermentation products produced. This work demonstrates that foods with similar monosaccharide content will have consistent effects on the survival of microbial species and on the production of microbial fermentation products., Competing Interests: D.A.M., J.B.G., and C.B.L. are cofounders of Infinant Health, a probiotic company, and One.Bio, a company advancing novel bioactive glycans. None of these companies had any role in the conceptualization, design, analysis, or preparation of the manuscript.

Background: Dietary fibers (DFs) may influence the structural, nutritional and techno-functional properties of starch within food systems. Moreover, DFs have favorable effects on the digestive system and potentially a lower glycemic index. These potential benefits may change depending on DF type. Starch processed in the presence of soluble and insoluble fibers can undergo different structural and functional changes, and the present study investigated the effects of short-chain and long-chain inulin and cellulose on the structural and digestive properties of wheat starch., Results: The combined use of differential scanning calorimetry, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) provided insights into the structural changes in starch and inulin at different levels. Short-chain and long-chain inulin had higher water retention capacity and a potential to limit starch gelatinization. The FTIR results revealed an interaction between starch and inulin. Scanning electron microscopy analysis showed morphological changes in starch and inulin after the hydrothermal treatment. Cellulose fiber was not affected by the hydrothermal treatment and had no influence on starch behavior. The structural differences observed through XRD, FTIR and scanning electron microscopy analyses between starch with and without inulin fibers did not significantly impact starch digestibility, except for the dilution effect caused by adding DFs., Conclusion: The present study highlights the importance of utilizing different analytical tools to assess changes in food samples at different scales. Although short-chain and long-chain inulin could potentially limit starch gelatinization, the duration of the heat treatment (90 °C for 10 min) was sufficient to ensure complete starch gelatinization. The dilution effect caused by adding fibers was the primary reason for the effect on starch digestibility. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Background: Millet bran (MB), a byproduct of millet production, is rich in functional components but it is underutilized. In recent years, researchers have shown that fermentation can improve the biological activity of cereals and their byproducts. This study used Bacillus natto to ferment millet bran to improve its added value and broaden the application of MB. The bioactive component content, physicochemical properties, and functional activity of millet bran extract (MBE) from fermented millet bran were determined., Results: After fermentation, the soluble dietary fiber (SDF) content increased by 92.0%, the β-glucan content by 164.4%, the polypeptide content by 111.4%, the polyphenol content by 32.5%, the flavone content by 16.4%, and the total amino acid content by 95.4%. Scanning electron microscopy revealed that the microscopic morphology of MBE changed from complete and dense blocks to loosely porous shapes after fermentation. After fermentation, the solubility, water-holding capacity, and viscosity significantly increased and the particle size decreased. Moreover, the glucose adsorption capacity (2.1 mmol g -1 ), glucose dialysis retardation index (75.3%), and α-glucosidase inhibitory (71.4%, mixed reversible inhibition) activity of the fermented MBE (FMBE) were greater than those of the unfermented MBE (0.99 mmol g -1 , 32.1%, and 35.1%, respectively). The FMBE presented better cholesterol and sodium cholate (SC) adsorption properties and the adsorption was considered inhomogeneous surface adsorption., Conclusion: Fermentation increased the bioactive component content and improved the physicochemical properties of MBE, thereby improving its hypoglycemic and hypolipidemic properties. This study not only resolves the problem of millet bran waste but also encourages the development of higher value-added application methods for millet bran. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

The gut microbiota and diet-induced changes in microbiome composition have been linked to various liver diseases, although the specific microbes and mechanisms remain understudied. Alcohol-related liver disease (ALD) is one such disease with limited therapeutic options due to its complex pathogenesis. We demonstrate that a diet rich in soluble dietary fiber increases the abundance of Bacteroides acidifaciens (B. acidifaciens) and alleviates alcohol-induced liver injury in mice. B. acidifaciens treatment alone ameliorates liver injury through a bile salt hydrolase that generates unconjugated bile acids to activate intestinal farnesoid X receptor (FXR) and its downstream target, fibroblast growth factor-15 (FGF15). FGF15 promotes hepatocyte expression of ornithine aminotransferase (OAT), which facilitates the metabolism of accumulated ornithine in the liver into glutamate, thereby providing sufficient glutamate for ammonia detoxification via the glutamine synthesis pathway. Collectively, these findings uncover a potential therapeutic strategy for ALD involving dietary fiber supplementation and B. acidifaciens., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Isomalto/malto-polysaccharides (IMMPs) are a novel type of soluble dietary fibres with a prebiotic potential promoting growth of beneficial microbes in the gut. However, the mode of action of IMMPs remains unknown. Previous studies on IMMPs showed an increase in total bacteria, especially lactobacilli, and higher production of short chain fatty acids (SCFA) when IMMPs were fed to rats or used during in vitro fermentation. Here we used metatranscriptomics to investigate how IMMPs with different amounts of α - (1 → 6) glycosidic linkages affected microbial function during incubation with human fecal inoculum. We showed that active microbial community dynamics during fermentation varied depending on the type of IMMP used and that the observed changes were reflected in the community gene expression profiles. Based on metatranscriptome analysis, members of Bacteroides, Lactobacillus and Bifidobacterium were the predominant degraders of IMMPs, and the increased gene expression in these bacteria correlated with high amounts of α - (1 → 6) glycosidic linkages. We also noted an increase in relative abundance of these bacteria and an activation of pathways involved in SCFA synthesis. Our findings could provide a baseline for more targeted approaches in designing prebiotics for specific bacteria and to achieve more controlled modulation of microbial activity towards desired health outcomes., (© 2024. The Author(s).)

Alcohol-associated liver disease is a leading cause of chronic liver conditions, yet there are limited effective therapies. In this issue of Cell Host & Microbe, Shen et al. demonstrate that soluble dietary fiber enhances intestinal Bacteroides acidifaciens, which ameliorates alcohol-associated liver injury in mice by activating hepatic ornithine aminotransferase., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

1. A stimbiotic (STB) is any feed additive that stimulates caeca fibre fermentation, although the additive itself contributes little to the caeca short-chain fatty acid (SCFA) production. A 42 d experiment investigated the interactive effects of STB and wheat bran (WB) in broiler chickens receiving maize or wheat-based diets.2. The treatments were arranged in a 2 × 2 × 2 factorial (eight replicates each), the dietary factors being diet (maize-SBM or wheat-SBM), STB (with or without) and WB (0 or 50 g/kg). Jejunal tissue, gizzard, jejunal and ileal digesta and caecal contents were collected on d 18 and 42.3. Gizzard pH tended to decrease with STB ( p  = 0.06) supplementation and was lower in birds fed wheat- compared to maize-based diets on d 18 ( p  < 0.05). Birds receiving diets with WB had higher jejunum pH on d 18 ( p  < 0.05).4. Total short-chain fatty acids (SCFA) in the caeca on d 18 and isobutyrate on d 42 were higher ( p  < 0.05) for maize compared with wheat-based diets. However, on d 42, acetate, butyrate and total SCFA were higher ( p  < 0.05) for wheat-based compared with maize-based diets.5. On d 18, STB and WB inclusion increased villi height (VH; p  < 0.05) and VH to crypt depth ratio (VH/CD), respectively ( p  < 0.05). On d 42, VH ( p  < 0.05) and VH/CD were higher in wheat-based diets ( p  < 0.05). The VH/CD ratio was lower with STB supplementation ( p  < 0.05). Marker-corrected pentose oligosaccharides (Pent) 4 and (Pent) 5 concentrations in the ileal digesta were reduced ( p  < 0.05) with STB supplementation. In addition, STB decreased (Pent) 3 concentration in maize-, but not wheat-based diets ( p  < 0.05).6. In conclusion, both WB and STB influenced gastrointestinal pH and jejunum histomorphology of broilers without increasing oligosaccharide concentration in the ileum and SCFA in the caeca.

To investigate the morphological changes of insoluble fiber and their effects on microbiota modulation, particularly Bacteroides, rice bran insoluble fibers were extruded at different feed moisture levels (E20, E40, and E60). The physicochemical properties and SEM revealed that E20 exhibited the highest water holding capacity and displayed the most fragmented edges. E40 had the highest swelling holding capacity and displayed the most lamellar gaps. E60 showed minimal change in physicochemical properties but had a rough surface. After 48h fermentation, E40 showed the highest levels of Bacteroides and SCFAs. E20 and E60 resulted in a modest increase in Bacteroides abundance. SEM showed that bacteria were attached to fragmented edges, loosened lamellar gaps, and rough surfaces of the extruded insoluble fibers. The results suggested that Bacteroides gained a competitive advantage within the extrusion treatment created structural changes. Extrusion treatment can be used to generate specific niches favorable for Bacteroides., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Consumption of wheat bran is associated with health benefits. However, the insoluble cell layer fiber and considerable levels of anti-nutritional factors limit bioavailability of wheat bran, which can be effectively improved through fermentation. To comprehensively elucidate the precise biotransformation and health benefits mechanisms underlying wheat bran fermentation. This review investigates current fermentation biotechnology for wheat bran, nutritional effects of fermented wheat bran, mechanisms by which fermented wheat bran induces health benefits, and the application of fermented wheat bran in food systems. The potential strategies to improve fermented wheat bran and existing limitations on its application are also covered. Current findings support that microorganisms produce enzymes that degrade the cell wall fiber of wheat bran during the fermentation, releasing nutrients and producing new active substances while degrading anti-nutrient factors in order to effectively improve nutrient bioavailability, enhance antioxidant activity, and regulate gut microbes for health effects. Fermentation has been an effective way to degrade cell wall fiber, thereby improving nutrition and quality of whole grain or bran-rich food products. Currently, there is a lack of standardization in fermentation and human intervention studies. In conclusion, understanding effects of fermentation on wheat bran should guide the development and application of bran-rich products., Competing Interests: Declaration of competing interest The authors declare that they do not have any conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tryptophan is catabolized by gut microorganisms resulting in a wide range of metabolites implicated in both beneficial and adverse host effects. How gut microbial tryptophan metabolism is directed towards indole, associated with chronic kidney disease, or towards protective indolelactic acid (ILA) and indolepropionic acid (IPA) is unclear. Here we used in vitro culturing and animal experiments to assess gut microbial competition for tryptophan and the resulting metabolites in a controlled three-species defined community and in complex undefined human faecal communities. The generation of specific tryptophan-derived metabolites was not predominantly determined by the abundance of tryptophan-metabolizing bacteria, but rather by substrate-dependent regulation of specific metabolic pathways. Indole-producing Escherichia coli and ILA- and IPA-producing Clostridium sporogenes competed for tryptophan within the three-species community in vitro and in vivo. Importantly, fibre-degrading Bacteroides thetaiotaomicron affected this competition by cross-feeding monosaccharides to E. coli. This inhibited indole production through catabolite repression, thus making more tryptophan available to C. sporogenes, resulting in increased ILA and IPA production. The fibre-dependent reduction in indole was confirmed using human faecal cultures and faecal-microbiota-transplanted gnotobiotic mice. Our findings explain why consumption of fermentable fibres suppresses indole production but promotes the generation of other tryptophan metabolites associated with health benefits., (© 2024. The Author(s).)

Lignin is a polyphenolic polymer that is an important factor in limiting fiber digestibility by ruminants. The objective of the current study was to evaluate lignin's effects on whole animal energy utilization in diets similar in NDF content. A low-lignin (LoLig) diet was formulated to contain 32.5% NDF (DM basis) and 9.59% lignin (NDF basis) and the high-lignin (HiLig) diet was formulated to contain 31.0% NDF (DM basis) and 13.3% lignin (NDF basis). These diets were randomly assigned and fed to 12 late-lactation (mean ± SD; 214 ± 14.9 DIM) multiparous Jersey cows (mean ± SD; 435 ± 13.9 kg) in a 2-period crossover design. Cows fed the LoLig treatment consumed more DM than cows on the HiLig diet (mean ± SD; 19.9 vs. 18.7 ± 0.645 kg/d) and the LoLig diet was concurrently of a greater gross energy concentration (mean ± SEM; 4.27 vs. 4.23 ± 0.03 Mcal/kg). As expected, increasing the concentration of lignin resulted in a reduction in total-tract NDF digestibility (45.5% vs. 40.4% ± 0.742%). Increasing lignin also resulted in a reduction in the digestibility of starch (97.7 vs. 96.3 ± 0.420) and CP (65.0 vs. 60.0 ± 0.829). Lignin also decreased the concentration of digestible energy (2.83 vs. 2.63 ± 0.04 Mcal/kg) and ME (2.52 vs. 2.36 ± 0.05 Mcal/kg), but the concentration of NE L was similar (1.81 vs. 1.75 ± 0.06 Mcal/kg). Increasing the concentration of lignin also reduced yields of ECM (33.7 vs. 30.0 ± 0.838 kg/d), milk protein (1.00 vs. 0.843 ± 0.027 kg/d), and milk fat (1.30 vs. 1.19 ± 0.058 kg/d). Decreasing the dietary lignin concentration did not affect daily methane emissions, averaging 391 ± 29.6 L/d. Results of this study indicate that feeding a diet greater in lignin decreases the digestibility of nutrients and provides less energy for production responses and that energy supplied from digestible NDF may be less than predicted by some nutrition models., (© 2024, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Soluble dietary fibre (SDF) has gained growing interest because of its multiple functional and nutritional benefits. In the current study, the effect of SDF extracted from eucheuma seaweed on both the physicochemical properties and the released metabolites of yellow cakes was evaluated systematically. The results revealed that the addition of SDF induced increases in specific gravity, specific volume and water content of yellow cakes, and caused a decrease in weight loss and changes in texture and colour. In addition, sensory evaluation showed that up to 10 % substitution of flour with SDF was acceptable. In vitro digestion of cakes demonstrated that flour substitution with SDF at different levels (8 %-14 %) significantly reduced the release of glucose, ranging from 11.24 % to 29.12 %. In addition to the increased apparent viscosity of the cake digesta, the metabolite analysis based on nuclear magnetic resonance spectroscopy identified a total of 29 metabolites, including amino acids, fatty acids and sugars. Notably, the addition of SDF reduced the release of amino acids and fatty acids after digestion. These findings suggested that seaweed SDF was a potential substitute for some food components, which would provide functional benefits to the digestive characteristics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Dietary fibers have attracted much attention due to their multiple benefits on gut health. In this work, the protective mechanism of dietary fiber from sweetpotato residues (SRDF) on the high-fat diet (HFD)-induced intestinal barrier injury was investigated using microbiome-metabolomics-based approach. The physicochemical property analysis demonstrated a thermal stability below 200 °C and porous pectin-polysaccharide structure of SRDF with high in vitro functional activities. The biochemical analysis indicated that SRDF significantly ameliorated intestinal barrier function by improving intestinal morphology and permeability and inhibiting inflammatory response. Microbiome analysis demonstrated that SRDF significantly reversed the HFD-induced dysbacteriosis, decreased the ratio of Firmicutes/Bacteroides and enhanced the relative abundance of probiotics, such as Muribaculaceae and Bifidobacteriaceae. Metabolomics analysis showed that SRDF also significantly altered the metabolic profile in the colon, wherein the differential metabolites were mainly involved in amino acid metabolism (especially tryptophan). Pearson correlation coefficient identified the beneficial relationship between intestinal microbiome and metabolome induced by SRDF. The limitation of this study was that the mouse model may not fully replicate the human intestinal responses due to the difference between the standard environmental conditions and natural world. Generally, our results implied the great potential of SRDF as a functional food ingredient., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

At the interface between the outside world and the self, the intestine is the first organ receiving nutritional information. One intestinal function, gluconeogenesis, is activated by various nutrients, particularly diets enriched in fiber or protein, and thus results in glucose production in the portal vein in the post-absorptive period. The detection of portal glucose induces a nervous signal controlling the activity of the central nuclei involved in the regulation of metabolism and emotional behavior. Induction of intestinal gluconeogenesis is necessary for the beneficial effects of fiber or protein-enriched diets on metabolism and emotional behavior. Through its ability to translate nutritional information from the diet to the brain's regulatory centers, intestinal gluconeogenesis plays an essential role in maintaining physiological balance., (Copyright © 2024 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)