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Abstract Disruption of the bone metabolic balance with advancing age leads to an escalating prevalence of bone‐related diseases, significantly compromising individuals’ quality of life. The gut microbiota actively participates in the regulation of bone metabolism, and perturbations in the gut microbiota can exacerbate bone diseases by compromising gut barrier integrity. Determining the microbial taxa involved in bone loss could offer valuable insights into the development of alternative therapies and nutritional interventions for disease management. Therefore, based on metagenomic and 16S ribosomal RNA data, this study analyzed the gut microbiota structure of 488 individuals with different bone masses (NC, normal; ON, osteopenia; OP, osteoporosis) to identify significant associations between the gut microbiota and bone loss. The results showed that at the genus and species levels, the microbiota diversity of the ON population increased, whereas that of the OP population decreased. Bacteroides were significantly enriched in the OP population, whereas the beneficial bacteria Bifidobacterium, Akkermansia, and lactobacilli decreased. Subsequent analyses revealed no significant variation in different bone populations in terms of Bifidobacterium levels, whereas lactobacilli exhibited diverse responses across distinct bone populations. The administration of lactobacilli effectively enhanced lumbar spine bone mineral density and modulated the gut microbiota structure in a population with unhealthy bone mass. This study contributes to the validation of the association between the gut microbiota and bone mass, enhances our understanding of the potential impact of probiotics (lactobacilli) on bone mass, and establishes a robust scientific basis for the application of probiotics in the regulation of bone mass.

Abstract Prevotella copri, which is divided into four clades, exerts bidirectional effects on host health. These effects include positive improvements in the allergy response and insulin sensitivity. However, P. copri sometimes has adverse effects on host health, and it has been found to be positively correlated with inflammation, insulin resistance, and diarrhea. The interaction between P. copri and these diseases is influenced by the host's diet. The capacity of P. copri to metabolize dietary glycans, as well as the effects of its degradation products, such as short‐chain fatty acids and succinic acid, appear to underlie its dual impact on the host. This duality suggests that manipulating the host's diet to increase the abundance of P. copri may be an effective strategy to improve disease outcomes. Here, we illustrate the characteristics and genetic traits of P. copri related to dietary metabolism are and summarize the health effects of P. copri on the host and methods to regulate its abundance, thus providing suggestions for the development and practical application of P. copri.

Long-term and/or excessive ethanol intake can lead to alcoholic liver disease (ALD). Gut dysbiosis contributes to a critical role in the pathogenesis of ALD. Here, we explored the impact of viable and dead Lacticaseibacillus rhamnosus CCFM1060 on the gut microbiota of alcohol-treated mice. The findings indicated that CCFM1060 V and D (viable and dead) administration improved the gut microbiota composition. Specifically, CCFM1060 D restored the abundance of butyric acid-producing bacteria, Alistipes, Lachnospiraceae, and Ruminococcaceae in ethanol-induced mice; CCFM1060 V improved the abundance of g_Dubsiela, g_Bifdobacterium, g_Ruminococcaceae_UCG_014_2, the SCFA-producing bacteria which were decreased in alcoholic hepatitis. Furthermore, the interventions improved the microstructure of the ileum, including the villi and crypts. They reinforced the intestinal barrier by increasing the RNA and protein expression of claudin-1, occludin, and ZO-1 in the colon. Also, they have been shown to enhance the liver’s antioxidant function by suppressing the synthesis of MDA and boosting the concentrations of GSH and SOD through the Nrf2/HO-1 pathway. In addition, interventions can suppress mice’s levels of TNF-α and IL-6, IL-1β in serum, presumably via the TRL4/MyD88/NF-κB pathway. Together, these results suggest that CCFM1060 can modulate the gut microbiota structure, reinforce the intestinal barrier, improve intestinal homeostasis, enhance liver antioxidant capacity, and mitigate inflammation response, eventually protecting the liver from ethanol-induced injury.

Abstract The pathogenesis of Parkinson's disease (PD) is closely related to the gut microbiota, and microecological therapies based on gut probiotics have received widespread attention, among which Bifidobacterium has been demonstrated to have a potential neuroprotective effect, but specific mechanisms have been lacking in the investigation. Here, we show that Bifidobacterium longum subsp. longum CCFM1029 significantly inhibited LPS‐induced inflammatory responses in microglia and alleviated 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐induced motor dysfunction, dopaminergic neuronal damage, and neuroinflammation in PD mice. Subsequently, the mechanism of action of CCFM1029 in PD was systematically elucidated by the neurochemical and biochemical analysis in PD mice, together with microbiomic and metabolomic analysis. It was found that CCFM1029 intervention restores dysbiosis in the gut microbiota linked to PD and reverses alterations in microbial metabolites. We established the interactions among the gut microbiota, metabolites, and brain by integrating behavioral and neurophysiological data with changes in the composition of the gut microbiota and metabolomic characteristics. We found that CCFM1029 intervention increases levels of the beneficial gut microbial metabolites indole‐3‐acrylic acid and short‐chain fatty acid (acetic and butyric acid) and decreases levels of the neuroinflammation‐associated metabolite N‐acetylhistamine. To summarize, our findings suggest CCFM1029 as a novel dietary supplement can prevent and mitigate the progression of PD through the microbiota‐gut‐brain axis.

Abstract Throughout the life span of a host, bifidobacteria have shown superior colonization and glycan abilities. Complex glycans, such as human milk oligosaccharides and plant glycans, that reach the colon are directly internalized by the transport system of bifidobacteria, cleaved into simple structures by extracellular glycosyl hydrolase, and transported to cells for fermentation. The glycan utilization of bifidobacteria introduces cross-feeding activities between bifidobacterial strains and other microbiota, which are influenced by host nutrition and regulate gut homeostasis. This review discusses bifidobacterial glycan utilization strategies, focusing on the cross-feeding involved in bifidobacteria and its potential health benefits. Furthermore, the impact of cross-feeding on the gut trophic niche of bifidobacteria and host health is also highlighted. This review provides novel insights into the interactions between microbe-microbe and host-microbe.

Little has been known about symbiotic relationships and host specificity for symbionts in the human gut microbiome so far. Bifidobacteria are a paragon of the symbiotic bacteria biota in the human gut. In this study, we characterized the population genetic structure of three bifidobacteria species from 58 healthy mother–infant pairs of three ethnic groups in China, geographically isolated, by Rep-PCR, multi-locus sequence analysis (MLSA), and in vitro carbohydrate utilization. One hundred strains tested were incorporated into 50 sequence types (STs), of which 29 STs, 17 STs, and 4 STs belong to B. longum subsp. longum, B. breve, and B. animalis subsp. lactis, respectively. The conspecific strains from the same mother–child pair were genetically very similar, supporting the vertical transmission of Bifidobacterium phylotypes from mother to offspring. In particular, results based on allele profiles and phylogeny showed that B. longum subsp. longum and B. breve exhibited considerable intraspecies genetic heterogeneity across three ethnic groups, and strains were clustered into ethnicity-specific lineages. Yet almost all strains of B. animalis subsp. lactis were incorporated into the same phylogenetic clade, regardless of ethnic origin. Our findings support the hypothesis of co-evolution between human gut symbionts and their respective populations, which is closely linked to the lifestyle of specific bacterial lineages. Hence, the natural and evolutionary history of Bifidobacterium species would be an additional consideration when selecting bifidobacterial strains for industrial and therapeutic applications.

Akkermansia muciniphila play an important in ameliorating obesity but is not allowed for direct consumption in most countries. To date, microbiota-directed foods selectively promote the targeted human gut microbes, providing a strategy for A. muciniphila enhancement. Multiple studies have indicated the potential regulation of the polyphenol on A. muciniphila. Therefore, a polyphenol screening based on A. muciniphila upregulation was performed in mice. Chlorogenic acid (CGA) exhibited a greater response to A. muciniphila upregulation. Furthermore, we found that CGA did not directly promote A. muciniphila growth or mucin secretion. Microbiome and metabolomics revealed that the increased abundance of A. muciniphila resulted from the inhibition of CGA on Desulfovibrio and Alistipes and the influence of docosahexaenoic acid, β-hydroxybutyrate, and N-acetyl-lactosamine. Finally, to confirm the regulation of CGA on A. muciniphila under disease conditions, high-fat diet-fed mice were established. The results showed CGA promoted A. muciniphila growth, and we expectedly found that CGA suppressed the augment in body weight of mice, significantly attenuated adipose tissue abnormality, provided liver protection and improved gut barrier integrity. These results suggest that CGA inhibits the development of obesity. Overall, our results indicate that microbiota-directed food is a promising approach for the treatment of obesity.

Stachyose is a prebiotic that traditionally extracted from plants, such as vegetable. It has been demonstrated to alleviate intestinal inflammation by regulating gut microbiota, but the mechanism has been unclear. This research aims to detect the potential mechanism of stachyose in alleviating the severity of ulcerative colitis (UC). The results indicated that the administration of stachyose could recover the body weight, protect against the colonic tissue damage, reduce the pro-inflammatory cytokines levels, and reverse the histological abnormalities in UC mice. Oral stachyose could restore DSS-induced disturbance in intestinal bacteria. Besides, the metabolome result of serum samples showed that stachyose treatment significantly altered serum metabolites against inflammatory responses in colitis mice. Also, a significant correlation can be found between 23 metabolite biomarkers and 18 differential genera. Our results provided a strong foundation for the future study of the protective role of stachyose in maintaining intestinal homeostasis.

The mechanism of metabolites produced by lactic acid bacteria in mediating microbial interactions has been difficult to ascertain. This study comparatively evaluated the antimicrobial effect of the novel bacterium Pediococcus acidilactici CCFM18 and explored the global chemical view of its interactions with indicator bacteria. P. acidilactici CCFM18 had sufficiently strong antimicrobial activity to effectively inhibit the growth of the indicator bacteria and enhance their intracellular reactive oxygen species (ROS) level. The emerging technique of matrix-assisted laser desorption ionization–time-of-flight (MALDI-TOF) imaging mass spectrometry indicated that P. acidilactici CCFM18 increased the production of pediocin PA-1 and the penocin A profile during its interaction with the indicator bacteria, thus differing from P. acidilactici CCFM28 (a commonly used laboratory strain). Strikingly, the production of coagulin A was triggered only by signaling molecules made by the competing strain L. thermophilus, suggesting an idiosyncratic response from P. acidilactici CCFM18. Bioinformatic mining of the P. acidilactici CCFM18 draft genome sequence revealed gene loci that code for the complex secondary metabolites analyzed via MSI. Taken together, these results illustrate that chemical interactions between P. acidilactici CCFM18 and indicator bacteria exhibit high complexity and specificity and can drive P. acidilactici CCFM18 to produce different secondary metabolites.

An increasing number of studies have indicated that gut microbiota and its metabolites are crucial in the development of hyperlipidemia. Bifidobacterium longum (B. longum) CCFM1077 has been shown to have lipid-lowering effects in animals. This study aimed to evaluate the potential of B. longum CCFM1077 in lowering the lipid levels in patients with hyperlipidemia and investigate the effect of this bacterium on serum lipid abnormalities, gut microbiota, and fecal metabolites in these patients. This study was a six-week, randomized, double-blind, and placebo-controlled pilot clinical trial. Subjects with hyperlipidemia (N = 62) were randomly assigned to receive placebo (N = 31) or B. longum CCFM1077 (1 × 1010 colony-forming units (CFUs) per day; N = 31). Serum lipid levels including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), total triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) were examined at the baseline and interventional endpoints. Changes in the gut microbiota composition and diversity were measured based on 16S ribosomal RNA (rRNA) sequencing of the V3–V4 region at the end of the intervention period. Non-targeted metabolomics of the feces was performed using ultra-performance liquid chromatography (UPLC)-Q-Exactive Orbitrap/mass spectrometer. Oral administration of B. longum CCFM1077 for six weeks significantly decreased the serum levels of TC (p

This meta-analysis of randomized controlled trials aimed to evaluate the effects of probiotic supplementation on glucose homeostasis in patients with polycystic ovary syndrome (PCOS). The meta-analysis was performed in accordance with the Cochrane Handbook guidelines and relevant the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement criteria. Of 825 identified reports, 11 randomized clinical trials were included in the meta-analysis. An analysis of pooled extracted data revealed that supplementation with probiotics significantly decreased fasting blood glucose (FBG, n = 7; standardized mean difference (SMD) = −0.40; 95 % confidence interval (CI): −2.02, −0.02; P = 0.04) and insulin levels (n = 6; SMD = −0.57; 95 % CI: −0.89, −0.25; P = 0.0004) and the homeostatic model assessment of insulin resistance (n = 7; SMD = −0.64; 95 % CI: −0.96, −0.31; P = 0.0001) while increasing the quantitative insulin sensitivity check index (QUICKI, n = 5; SMD = 0.58; 95 % CI: 0.08, 1.09; P = 0.02) in patients with PCOS. The FBG-reducing effect decreased as the baseline body mass index (BMI) and mean age of the participants increased. Indeed, a greater number of bacterial species and a higher bacterial dose were shown to reduce QUICKI effectively. The systematic review indicated that probiotic supplementation may help to control glucose homeostasis in adults with polycystic ovarian syndrome.

Sporolactobacillus is a genus of lactic acid bacteria, which can be widely found in soil. According to NCBI, only 20 strains of the genus Sporolactobacillus have been identified through phenotypic and genotypic analysis, indicating their relatively low numbers compared to other lactic acid bacteria. Currently, there is a growing interest in isolating and studying Sporolactobacillus, particularly focusing on its physiological characteristics and conducting in vitro experiments. This paper provides a review of the sources and physiological characteristics of Sporolactobacillus, along with genotype analysis, carbohydrate metabolism traits, and potential antibacterial properties. It also delves into basic physiological characteristics, lactic acid production, and applications, offering insights for the future utilization of Sporolactobacillus and laying a foundation for exploring its potential applications.

Recent studies have revealed the potency of probiotics in alleviating metabolic diseases associated with intestinal barrier dysfunction. However, an efficient model for screening probiotic strains against specific metabolic diseases has not been well developed. In the present study, a Caco-2 cell monolayer membrane model treated with tumor necrosis factor (TNF)-α or alcohol was used to evaluate the effect of 139 Lactobacillus strains on intestinal barrier function in vitro. We then selected 11 Lactobacillus strains with different regulatory abilities on the gut barrier to determine their effect against ovariectomy-induced osteoporosis or chronic alcoholic liver injury in vivo. Our results showed that the Pearson coefficient between the data of cell and animal models were 0.82 and −0.97 for the protection of probiotics against osteoporosis and alcoholic liver disease, respectively, suggesting the reliability of the cell model to simulate the in vivo protective effects of probiotics. This study established a potential in vitro approach based on a Caco-2 cell monolayer membrane model for the efficient screening of potential probiotics against specific metabolic diseases such as osteoporosis and chronic alcoholic liver disease.

ABSTRACTCholestasis is a condition characterized by the abnormal production or excretion of bile, and it can be induced by a variety of causes, the factors of which are extremely complex. Although great progress has been made in understanding cholestasis pathogenesis, the specific mechanisms remain unclear. Therefore, it is important to understand and distinguish cholestasis from different etiologies, which will also provide indispensable theoretical support for the development of corresponding therapeutic drugs. At present, the treatment of cholestasis mainly involves several bile acids (BAs) and their derivatives, most of which are in the clinical stage of development. Multiple lines of evidence indicate that ecological disorders of the gut microbiota are strongly related to the occurrence of cholestasis, in which BAs also play a pivotal role. Recent studies indicate that probiotics seem to have certain effects on cholestasis, but further confirmation from clinical trials is required. This paper reviews the etiology of and therapeutic strategies for cholestasis; summarizes the similarities and differences in inducement, symptoms, and mechanisms of related diseases; and provides information about the latest pharmacological therapies currently available and those under research for cholestasis. We also reviewed the highly intertwined relationship between gut microbiota-BA-cholestasis, revealing the potential role and possible mechanism of probiotics in the treatment of cholestasis.

Abstract Inflammatory bowel diseases (IBDs) are chronic inflammatory diseases of the gastrointestinal tract that have become a global health burden. Studies have revealed that Latilactobacillus sakei can effectively alleviate various immune diseases, including colitis, rheumatoid arthritis, and metabolic disorders. Here, we obtained 72 strains of L. sakei from 120 fermentation and fecal samples across China. In total, 16 strains from different sources were initially screened in an in vitro Caco‐2 model induced by dextran sulfate sodium. Subsequently, six strains (four exhibiting effectiveness and two exhibiting ineffectiveness) were selected for further validation in an in vivo colitis mouse model. The results demonstrated that L. sakei strains exhibited varying degrees of amelioration of the colitis disease process. Notably, L. sakei CCFM1267, the most effective strain, significantly restored colon length and tight‐junction protein expression, and reduced the levels of cytokines and associated inflammatory enzymes. Moreover, L. sakei CCFM1267 upregulated the abundance of Enterorhabdus, Alloprevotella, and Roseburia, leading to increased levels of acetic acid and propionic acid. Conversely, the other four strains (L. sakei QJSSZ1L4, QJSSZ4L10, QGZZYRHMT1L6, and QGZZYRHMT2L6) only exhibited a partial remission effect, while L. sakei QJSNT1L10 displayed minimal impact. Therefore, L. sakei CCFM1267 and QJSNT1L10 were selected for further exploration of the mechanisms underlying their differential mitigating effects. Comparative genomics analysis revealed significant variations between the two strains, particularly in genes associated with carbohydrate‐active enzymes, such as the glycoside hydrolase family, which potentially contribute to the diverse profiles of short‐chain fatty acids in vivo. Additionally, metabolome analysis demonstrated that acetylcholine and indole‐3‐acetic acid were the main differentiating metabolites of the two strains. Therefore, the strains of L. sakei exhibited varying degrees of effectiveness in alleviating IBD‐related symptoms, and the possible reasons for these variations were attributed to discrepancies in the carbohydrate‐active enzymes and metabolites among the strains.

Emerging evidence shows that some Lactobacillus fermentum (L. fermentum) strains can contribute to the prevention and treatment of ulcerative colitis (UC). In this study, 105 isolates of L. fermentum strains were separated from fecal samples of populations in different regions in China and their draft genomes were sequenced. Pan-genomic and phylogenetic characterizations of these strains and four model strains (L. fermentum 3872, CECT5716, IFO3956, and VRI003) were performed. Phylogenetic analysis indicated that there was no significant adaptive evolution between the genomes of L. fermentum strains and the geographical location, sex, ethnicity, and age of the hosts. Three L. fermentum strains (FWXBH115, FGDLZR121, and FXJCJ61) from different branches of the phylogenetic tree and strain type L. fermentum CECT5716 were selected and their anti-inflammatory and immune modulatory activities in a dextran sulphate sodium (DSS)-induced colitis mouse model were further investigated. Both L. fermentum FXJCJ61 and CECT5716 significantly alleviated UC by reducing all colitis-associated histological indices, maintaining mucosal integrity, and stimulating replenishment of short-chain fatty acids (SCFAs), while the other two strains failed to offer similar protection. The anti-inflammatory mechanisms of L. fermentum FXJCJ61 and CECT5716 were related to the inhibition of nuclear factor kappa-B (NF-κB) signaling pathway activation and enhancement of interleukin 10 (IL-10) production. Comparative genomic analysis of these strains identified candidate genes that may contribute to the anti-inflammatory effects of specific L. fermentum strains.

Studies have determined the immunomodulatory activities of cell-surface polysaccharides of lactic acid bacteria (LAB) and Bacteroides; however, the mechanisms, synthesis, regulation, structure, and functional links have not been systematically discussed. We first introduce the structure of the capsular polysaccharides (CPSs) of commonly studied probiotics and Bacteroides. Wzx-Wzy dependent and ATP-binding cassette (ABC) transporter-dependent pathways are the two main biosynthesis and secretion of CPS pathways. The genes known to be associated with these two pathways are mainly those associated with priming glycosyltransferase (pGT); a variable number of genes encoding for different glycosyl transferases (GTs); Wzx/Wzy-encoding enzymes related to flippases and polymerases; and ABC-transporter genes. In addition, the effects of CPSs on host immunity as well as their related underlying mechanisms are described. Surface polysaccharides on probiotics can serve as a mask to aid in their escape from attacks from the host’s immune system. In turn, they also exhibit immunomodulatory activities, such as strengthening the functions of macrophages, promoting the maturation of antigen-presenting cells, and inducing regulatory T cells. All of these effects of cell-surface polysaccharides exhibit their significant protective properties in immunocompromised diseases, such as colitis, arthritis, and dermatitis. Finally, we focused on their structure and functional links.

Abstract Purpose Bifidobacterium is an important probiotic used in food and medicine production. The probiotic properties of bifidobacteria are strain specific, so it is necessary to evaluate the probiotic properties of bifidobacteria isolated from specific populations, especially when developing products suitable for specific populations. The objective of this study was to evaluate the probiotic potential and safety of bifidobacteria isolated from healthy Uyghur infants from northwestern China. Methods In this study, antimicrobial activity, antibiotic sensitivity, hemolytic, acid and bile tolerance, hydrophobicity, co-aggregation, auto-aggregation, and antioxidant activity were evaluated. Results Based on antagonistic activity spectrum against seven intestinal pathogenic bacteria, 14 excellent strains were initially selected. Among 14 strains, four bifidobacteria strains (BF17-4, BF52-1, BF87-3, and BF88-5) were superior to strain Lactobacillus rhamnosus GG in cell surface hydrophobicity and auto-aggregation percentages and close to strain GG in co-aggregation with Escherichia coli EPEC O127: K63 (CICC 10411). The antioxidant activities of each of the 14 bifidobacteria strains varied with the cell components. Most of the strains were sensitive to all the antimicrobials tested, except kanamycin and amikacin. Conclusion BF17-4 and BF52-1 are good candidates for further in vivo studies and further used in functional foods.

People are increasingly aware of the role of vegetarian diets in modulating human gut microbial abundance and intestinal physiology. A plant-based diet is thought to benefit host health by contributing to establish a diverse and stable microbiome. In addition, microbe-derived metabolites of specific nutrients known to be abundant in vegetarian diets (such as indigestible carbohydrates, arginine, and others) are important to promote effective intestinal immune responses, maintain intestinal barrier function, and protect against pathogens. This review explores the characteristics of the gut microbiome formed by vegetarian diets and the effects of diet-associated nutrients on intestinal microbial abundance. The interactions between the microbe-derived metabolites of vegetarian diet-associated nutrients and intestinal physiology are also discussed.

This study was performed to determine the effects of bacteriocin-producing and non-bacteriocin-producing Pediococcus acidilactici strains on the immune system and intestinal flora of normal mice. Two P. acidilactici strains with antibacterial activity (P. acidilactici CCFM28 and CCFM18) were obtained based on the inhibition-zone assay. The produced components were identified as bacteriocins through protease treatment, pH adjustment and hydrogen peroxide treatment. Bacteriocin-producing and non-bacteriocin-producing P. acidilactici strains (P. acidilactici CCFM28, CCFM18 and NT17-3) caused significant changes in serum immune factors and intestinal flora of normal mice. After 14 days of intervention, the relative abundance of Firmicutes was significantly decreased, but that of Proteobacteria was significantly increased at the phylum level. At the genus level, the administration of three P. acidilactici strains resulted in the downregulation of Blautia and the upregulation of Ruminococcus and Lactobacillus. Furthermore, there were also different regulations on some probiotic strains, such as Bifidobacterium, Coprococcus and Akkermansia, which were closely related to the antibacterial ability of the bacteriocin and the type of strain. The results indicated that the intervention of different P. acidilactici strains could differently change the structure of intestinal flora in normal mice, which provided theoretical guidance for the selective use of bacteriocin-producing strains for health regulation in the future.

Introduction: The roles of Bacteroides species in alleviating inflammation and intestinal injury has been widely demonstrated, but few studies have focused on the roles of Bacteroides vulgatus. Objectives: In this study, four B. vulgatus strains were selected, based on their genomic characteristics, to assess their ability to alleviate lipopolysaccharide (LPS)-induced acute intestinal injury in C57BL/6J mice. Methods: Alterations in the intestinal microbiota, intestinal epithelial permeability, cytokine level, short-chain fatty acid (SCFA) concentration, and immune responses were investigated following LPS-induced acute intestinal injury in C57BL/6J mice. Results: Severe histological damage and a significant change in cytokine expression was observed in the mouse colon tissues 24 h after LPS administration. Oral administration of different B. vulgatus strains showed different effects on the assessed parameters of the mice; particularly, only the administration of B. vulgatus FTJS7K1 was able to protect the architectural integrity of the intestinal epithelium. B. vulgatus FTJS7K1 also negated the LPS-induced changes in cytokine mRNA expression in the colon tissues, and in the proportion of regulatory T cells in the mesenteric lymph node. Compared with the LPS group, the B. vulgatus FTJS7K1 group showed significantly increased abundance of Lactobacillus, Akkermansia, and Bifidobacterium, and decreased abundance of Faecalibaculum. The B. vulgatus FTJS7K1 group also showed significantly increased concentration of SCFAs in fecal samples. The results of genomic analysis showed that these protective roles of B. vulgatus FTJS7K1 may be mediated through specific genes associated with defense mechanisms and metabolism (e.g., the secretion of SCFAs). Conclusions: Our findings suggest that the protective role of B. vulgatus FTJS7K1 appear to be via modulation of cytokine production in the colon tissue and regulation of the structure of the gut microbiota. These results provide support for the screening of the Bacteroides genus for next-generation probiotics.

This research was to estimate the curative effect of garlic supplement on non-alcoholic fatty liver disease (NAFLD), a total of and five clinical studies (randomized controlled trials (RCTs) and nine preclinical studies was included. The effect size of clinical trials was determined by standardized mean difference (SMD) with 95 % confidence interval (CI). Meta-analysis of enrolled 139 patients receiving garlic powder revealed a significant improvement of NAFLD, which include ALT: 95 % CI, −11.75 to − 6.24; P

Abstract Background Probiotics have been used to regulate the gut microbiota and physiology in various contexts, but their precise mechanisms of action remain unclear. Results By population genomic analysis of 418 Bifidobacterium longum strains, including 143 newly sequenced in this study, three geographically distinct gene pools/populations, BLAsia1, BLAsia2, and BLothers, were identified. Genes involved in cell wall biosynthesis, particularly peptidoglycan biosynthesis, varied considerably among the core genomes of the different populations, but accessory genes that contributed to the carbohydrate metabolism were significantly distinct. Although active transmission was observed inter-host, inter-country, inter-city, intra-community, and intra-family, a single B. longum clone seemed to reside within each individual. A significant negative association was observed between host age and relative abundance of B. longum, while there was a strong positive association between host age and strain genotype [e.g., single nucleotide polymorphisms in the arginine biosynthesis pathway]. Further animal experiments performed with the B. longum isolates via using a d-galactose-induced aging mouse model supported these associations, in which B. longum strains with different genotypes in arginine biosynthesis pathway showed divergent abilities on protecting against host aging possibly via their different abilities to modify the metabolism of gut microbes. Conclusions This is the first known example of research on the evolutionary history and transmission of this probiotic species. Our results propose a new mechanistic insight for promoting host longevity via the informed use of specific probiotics or molecules. Video abstract

Irritable bowel syndrome with diarrhea (IBS-D) is chronic intestinal dysfunction with diarrhea and other complicated clinical symptoms, and it has a great impact on the daily life and mental state of patients. Some studies have reported that ingestion of probiotics can significantly alleviate a variety of intestinal diseases. The purpose of this study was to investigate the IBS-D-alleviating effects of a probiotic strain, Lactobacillus plantarum (L. plantarum) CCFM8610, with multiple health-promoting effects. The study was a 12-week, randomized, double-blind, placebo-controlled, pilot clinical trial. Seventy-five patients were randomly assigned to receive the placebo, oligosaccharides, or L. plantarum CCFM8610 (1 × 1010 colony-forming units (CFU) per day), with a 2-week run-in period, an 8-week intervention period, and a 2-week follow-up observation period. The patients’ clinical symptoms and quality of life were examined by the IBS symptom severity scale (IBS-SSS) and the IBS quality of life scale (IBS-QOL). Changes in gut microbiota composition and diversity were measured at the end of the intervention period. The oral administration of L. plantarum CCFM8610 significantly decreased the IBS-SSS and IBS-QOL scores, reduced IBS-D symptom severity, recovered gut microbiota diversity, decreased the relative abundance of bloating-related genus Methanobrevibacter, and increased the relative abundance of butyric acid-producing genera, including Anaerostipes, Anaerotruncus, Bifidobacterium, Butyricimonas, and Odoribacter. These findings suggest that ingestion of L. plantarum CCFM8610 can significantly alleviate clinical symptoms and gut microbiota dysbiosis in IBS-D patients. The IBS-D-alleviating effect of L. plantarum CCFM8610 may be related to the increase in the relative abundance of butyric acid-producing genera in the intestine.

Abstract Background Bifidobacteria are important probiotics; some of the beneficial effects of bifidobacteria are achieved by the hydrolysis of glycans in the human gut. However, because the diet of breastfed infants typically lacks plant-derived glycans, in the gut environment of mothers and their breastfed infants, the mother will intake a variety of plant-derived glycans, such as from onions and bananas, through her diet. Under this assumption, we are interested in whether the same species of bifidobacteria isolated from mother-infant pairs present a distinction in their hydrolysis of plant-derived carbohydrates. Results Among the 36 Bifidobacterium strains, bifidobacterial carbohydrate utilization showed two trends related to the intestinal environment where the bacteria lived. Compared with infant-type bifidobacterial strains, adult-type bifidobacterial strains preferred to use plant-derived glycans. Of these strains, 10 isolates, 2 Bifidobacterium pseudocatenulatum (B. pseudocatenulatum), 2 Bifidobacterium pseudolongum (B. pseudolongum), 2 Bifidobacterium bifidum (B. bifidum), 2 Bifidobacterium breve (B. breve), and 2 Bifidobacterium longum (B. longum), were shared between the mother-infant pairs. Moreover, the repetitive sequence-based polymerase chain reaction (rep-PCR) results illustrated that B. pseudolongum and B. bifidum showed genotypic similarities of 95.3 and 98.2%, respectively. Combined with the carbohydrate fermentation study, these results indicated that the adult-type strains have a stronger ability to use plant-derived glycans than infant-type strains. Our work suggests that bifidobacterial carbohydrate metabolism differences resulted in the selective adaptation to the distinct intestinal environment of an adult or breastfed infant. Conclusions The present study revealed that the different gut environments can lead to the differences in the polysaccharide utilization in the same strains of bifidobacterial strains, suggesting a further goal of investigating the exact expression of certain enzymes in response to specific carbon sources.

Abstract Background Overactive bladder is defined as “urgency, with or without urge incontinence, usually with frequency and nocturia”. Electroacupuncture may be a safe and an effective alternative therapy for overactive bladder, but the evidence is limited. Methods We will conduct a three-arm, non-inferiority, multi-centre randomized controlled clinical trial. A total of 420 patients with moderate and severe overactive bladder will be randomly assigned to one of three groups: the electroacupuncture group (N = 140), sham electroacupuncture group (N = 140), and solifenacin group (N = 140). The primary outcome will be the change in the overactive bladder symptom score from baseline to the end of the 12-week treatment. The secondary outcomes will include the proportion of participants with a decrease in the overactive bladder symptom score ≥ 3 at weeks 4, 8, 12, 20, and 32; the change in average 24 h values of urination, nocturnal urination, urgency incontinence and urgency episodes from baseline to weeks 4, 8, 12, 20 and 32, and so forth. The adverse events will be recorded. Statistical analysis will include covariance analysis, nonparametric tests and descriptive statistics. Discussion This study will answer the question of whether electroacupuncture is effective and non-inferior to solifenacin for improving the symptoms of overactive bladder patients. Trial registration Chinese clinical trial registry ( ChiCTR1800019928 ).

Abstract The gut microbiota can significantly affect the function of the intestinal barrier. Some intestinal probiotics (such as Lactobacillus, Bifidobacteria, a few Escherichia coli strains, and a new generation of probiotics including Bacteroides thetaiotaomicron and Akkermansia muciniphila) can maintain intestinal epithelial homeostasis and promote health. This review first summarizes probiotics’ regulation of the intestinal epithelium via their surface compounds. Surface layer proteins, flagella, pili and capsular polysaccharides constitute microbial-associated molecular patterns and specifically bind to pattern recognition receptors, which can regulate signaling pathways to produce cytokines or inhibit apoptosis, thereby attenuating inflammation and enhancing the function of the gut epithelium. The review also explains the effects of metabolites (such as secreted proteins, organic acids, indole, extracellular vesicles and bacteriocins) of probiotics on host receptors and the mechanisms by which these metabolites regulate gut epithelial barrier function. Previous reviews summarized the role of the surface macromolecules or metabolites of gut microbes (including both probiotics and pathogens) in human health. However, these reviews were mostly focused on the interactions between these substances and the intestinal mucosal immune system. In the current review, we only focused on probiotics and discussed the molecular interaction between these bacteria and the gut epithelial barrier.

The maternal gut is thought to be the principal source of potential probiotic bacteria in the infant gut during the lactation stage. It is not clear whether facultative symbiont lactobacilli strictly follow vertical transmission from mother to infant and display the ethnic specificity in terms of species and strain composition in mother–infant cohorts. In the present study, a total of 16 former Lactobacillus species (365 strains) and 11 species (280 strains) were retrieved from 31 healthy mother–infant pairs of two ethnic groups, which have never intermarried, respectively. The result showed that the composition and number of Lactobacillus species between the two ethnic groups varied. Among 106 Lacticaseibacillus paracasei strains isolated, 64 representative strains were classified into 27 sequence types (ST) by means of multilocus sequence typing (MLST), of which 20 STs derived from 33 Uighur strains and 7 STs from 31 Li strains, and no homologous recombination event of genes was detected between strains of different ethnic groups. A go-EBURST analysis revealed that except for a few mother–infant pairs in which more than one STs were detected, L. paracasei isolates from the same mother–infant pair were found to be monophyletic in most cases, confirming vertical transfer of Lactobacillus at the strain level. More notably, L. paracasei isolates from the same ethnic group were more likely than strains from another to be incorporated into a specific phylogenetic clade or clonal complex (CC) with similar metabolic profile of glycan, supporting the hypothesis of ethnic specificity to a large degree. Our study provides evidence for the development of personalized probiotic tailored to very homogenous localized populations from the perspective of maternal and child health.

Background. The beneficial effects of probiotic supplementation standard antibiotic therapies for Helicobacter pylori infection have been verified, but the ability of probiotic monotherapy to eradicate H. pylori remains unclear. Aim. To evaluate the accuracy and efficacy of specific Lactobacillus strains against H. pylori infection. Methods. Seventy-eight patients with H. pylori infection were treated with strain L. crispatus G14-5M (L. crispatus CCFM1118) or L. helveticus M2-09-R02-S146 (L. helveticus CCFM1121) or L. plantarum CCFM8610 at a dose of 2 g twice daily for one month. 14C-urea breath test, the gastrointestinal symptom rating scale, serum pepsinogen concentrations, and serum cytokine concentrations of patients were measured at baseline and end-of-trial to analyze the effect of the Lactobacillus strains in eradicating H. pylori infection and reducing gastrointestinal discomfort in patients. In addition, the composition and abundance of the intestinal microbiota of patients were also measured at end-of-trial. Results. The 14C-urea breath test value of the three Lactobacillus treatment groups had decreased significantly, and the eradication rate of H. pylori had increased by the end of the trial. In particular, the eradication rate in the G14-5M treatment group was significantly higher than the placebo group (70.59% vs. 15.38%, P=0.0039), indicating that one-month administration of the G14-5M regimen was sufficient to eradicate H. pylori infection. The ingestion of Lactobacillus strains also ameliorated the gastrointestinal symptom rating scale scores, and the serum interleukin-8 concentrations of H. pylori-infected patients appeared to modulate the gut microbiota of patients. However, none of the Lactobacillus strains had a significant effect on general blood physiological characteristics, serum tumor necrosis factor α concentrations, or serum pepsinogen concentrations in the patients. Conclusion. Three Lactobacillus strains significantly alleviate the gastrointestinal discomfort and the gastric inflammatory response of H. pylori-infected patients. The activity of probiotics in eradicating H. pyloriinfection may be species/strain specific.

Taurine, an abundant free amino acid, plays multiple roles in the body, including bile acid conjugation, osmoregulation, oxidative stress, and inflammation prevention. Although the relationship between taurine and the gut has been briefly described, the effects of taurine on the reconstitution of intestinal flora homeostasis under conditions of gut dysbiosis and underlying mechanisms remain unclear. This study examined the effects of taurine on the intestinal flora and homeostasis of healthy mice and mice with dysbiosis caused by antibiotic treatment and pathogenic bacterial infections. The results showed that taurine supplementation could significantly regulate intestinal microflora, alter fecal bile acid composition, reverse the decrease in Lactobacillus abundance, boost intestinal immunity in response to antibiotic exposure, resist colonization by Citrobacter rodentium, and enhance the diversity of flora during infection. Our results indicate that taurine has the potential to shape the gut microbiota of mice and positively affect the restoration of intestinal homeostasis. Thus, taurine can be utilized as a targeted regulator to re-establish a normal microenvironment and to treat or prevent gut dysbiosis.

Human gut microbiota interfere with host development and aging. Bifidobacterium is a microbial genus found in the human digestive tract that has probiotic activities such as improving constipation and enhancing immunity. The species and numbers present change with age, but there has been limited research on probiotic gut microbiota at specific ages. This study analyzed the distribution of 610 bifidobacteria in subjects in several age groups (0−17, 18−65, and 66−108 y) using 486 fecal samples and determined the distribution of glycoside hydrolases based on genetic analysis of strains representing 85% of the Bifidobacterium species abundance in each age group. 6’-Sialyllactose is a major component of acidic breast milk oligosaccharides, which can promote human neurogenesis and bifidobacteria growth. Using genotypic and phenotypic association analysis, we investigated the utilization of 6’-sialyllactose by six B. bifidum strains isolated from subjects 0–17 and 18–65 y. A comparative genomic analysis of the six B. bifidum strains revealed differences in genomic features across age groups. Finally, the safety of these strains was evaluated by antibiotic gene and drug resistance phenotype analysis. Our results reveal that the distribution of glycoside hydrolase genes in B. bifidum varies with age, thus affecting the phenotypic results. This provides important insights for the design and application of probiotic products for different ages.

Inflammatory bowel disease (IBD) is a heterogeneous group of diseases associated with chronic inflammation of the intestinal tract, and is highly prevalent worldwide. Although its origin is not yet fully understood, new evidence emphasizes that environmental factors, especially dietary factors and intestinal microbiota disorders are key triggers of IBD. Probiotics, such as Lactobacillaceae spp., play an essential role in human health as they exert beneficial effects on the composition of the human gastrointestinal microbial community and immune system. Probiotic-based therapies have been shown to be effective in alleviating IBD. Among these, Lactobacillaceae rhamnosus is one of the most widely used strains. L. rhamnosus is widely present in the intestines of healthy individuals; it regulates the intestinal immune system and reduces inflammation through a variety of mechanisms. The purpose of this study was to identify scientific evidence related to L. rhamnosus and IBD, review and summarize the results, and discuss the possible mechanisms of action as a starting point for future research on IBD treatment.

Background: This meta-analysis aims to elucidate the role of probiotics in regulating the blood lipid profiles of adults with overweight or obesity. Method: The Pubmed, Cochrane Library, Scopus and Web of Science were used to search for relevant randomized controlled trials (RCTs) published before August 2021. The effects of probiotic intervention were assessed by total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels. The outcome data were synthesized by using standardized mean differences (SMDs). Results: Totally 18 articles involving 823 subjects were included in this study. The results showed that probiotic consumption markedly decreased the levels of TC (SMD) [95% confidence interval (CI)] = −0.18 [−0.29, −0.07], TG [95% CI] = −0.14 [−0.25, −0.03] and LDL-C [95% CI] = −0.12 [−0.24, −0.01]. Conclusion: This meta-analysis showed that probiotics have the potential to alleviate lipid abnormalities in overweight or obese adults.

Popular edible mushrooms Ganoderma lucidum and Gloeostereum incarnatum can improve physical health as a prebiotic and positively alter intestinal microbiota. Our research investigated the prebiotic effects of Ganoderma lucidum and Gloeostereum incarnatum on colon inflammation through G. lucidum water extraction polysaccharides (GLP), G. incarnatum water extraction polysaccharides (GIP), G. lucidum ethanol extraction (GLE), and G. incarnatum ethanol extraction (GIE) administered in mice after 7 days of dextran sulphate sodium (DSS) administration. Among the extracts, GLE showed reduced mortality rates, prevention of weight loss, mitigated colon length shortening, and decreased disease activity indices and histological scores. COX-2, MPO, and iNOS activities and the inflammatory cytokines’ expressions were determined to demonstrate the inhibition inflammation by GLE. Meanwhile, GLE upregulated the levels of MUC2, ZO-1, claudin-3, and occluding to protect the intestinal barrier. Furthermore, GLE modulated the composition of gut microbiota disturbed by DSS, as it decreased the abundance of Bacteroides, Staphylococcus, and Escherichia_Shigella, and increased Turicibacter and Bifidobacterium. Through cell experiment, GLE had a positive influence on adherens junction, tight junction, and TRAF6/MyD88/NF-κB signaling pathways. In conclusion, GLE supplementation promotes DSS-induced colitis recovery by regulating inflammatory cytokines, preserving the intestinal mucosal barrier, positively modulating microbiota changes, and positively influences immune response in TRAF6/MyD88/NF-κB signaling pathways.

Acute liver injury has multiple causes and can result in liver failure. In this study, we evaluated the hepatoprotective ability of cyanidin (Cy) and investigated its associated mechanisms. Cy administration significantly and dose-dependently ameliorated acute liver injury induced by carbon tetrachloride (CCl4). High-dose Cy showed effects comparable to those achieved by the positive control (silymarin). Severe oxidative stress and inflammatory responses in the liver tissue induced by CCl4 were significantly mitigated by Cy supplementation. The total antioxidant capacity and the activity of superoxide dismutase, catalase, and glutathione peroxidase were increased and the content of malondialdehyde, lipid peroxide, tumor necrosis factor α, interleukin-1β, and interleukin-6 were decreased. Additionally, the Nrf2 and NF-κB signaling pathways, which regulate antioxidative and inflammatory responses, were analyzed using quantitative real-time polymerase chain reaction and western blot assay. Cy treatment not only increased Nrf2 transcription and expression but also decreased NF-κB signaling. Moreover, molecular docking simulation indicated that Cy had high affinity for Keap1 and NF-κB/p65, which may promote nuclear translocation of Nrf2 and inhibit that of NF-κB. In summary, Cy treatment exerted antioxidative and anti-inflammatory effects and ameliorated liver injury by increasing Nrf2 and inhibiting the NF-κB pathway, demonstrating the potential of Cy as a therapeutic agent in liver injury.

Polyethylene glycol (PEG) is one of the most commonly used bowel cleansing methods. Although the safety of PEG for bowel cleansing has been proven, its impact on intestinal microbiota has not been clearly explained, especially in terms of the dynamic changes in intestinal microbiota after PEG bowel cleansing, and there are no consistent results. In this study, stool samples were collected from 12 participants at six time points before and after bowel cleansing. We obtained data on the microbiota of these samples using 16S rRNA gene sequencing and analysis. The data revealed that the structure and composition of the microbiota changed greatly approximately 7 d after intestinal cleansing. The analysis of the dynamic changes in the microbiota showed that the change was most significant at day 3, but the internal structure of the microbiota was similar to that before bowel cleansing. A comparison of the most significantly changed microbiota at different time points before and after bowel cleansing revealed four bacteria: Bacteroides, Roseburia, Eubacterium, and Bifidobacterium. We also established a humanized mouse model to simulate human bowel cleansing using PEG. The results showed that the mouse model achieved similar effects to human bowel cleansing, but its recovery speed was one stage earlier than that of humans. These findings suggest that the intestinal microbiota after bowel cleansing initially underwent a short-term change and then actively returned to its initial status. The results on key bacteria and establishment of mouse models can provide a reference for subsequent research on bowel cleansing.

Under bile salt treatment, strains display significant differences in their tolerance ability, suggesting the existence of diverse resistance mechanisms in Lactobacillus; however, the genes involved in this protective process are not fully understood. In this study, novel target genes associated with bile salt tolerance in Lactobacillus were identified using comparative genomics for PCR detection and the rapid screening of tolerant strains. The bile salt tolerance of 107 lactobacilli isolated from different origins was assessed, and 26 strains with comparatively large differences were selected for further comparative genomic analysis. Tolerant strains had 112 specific genes that were enriched in the phosphotransferase system, the two-component system, carbohydrate metabolism, and the ATP-binding cassette transporter. Six genes from Lactobacillus were cloned into the inducible lactobacillal expression vector pSIP403. Overexpression in the host strain increased its tolerance ability by 11.86–18.08%. The novel genes identified here can be used as targets to design primers for the rapid screening of bile salt-tolerant lactobacilli. Altogether, these results deepen our understanding of bile salt tolerance mechanisms in Lactobacillus and provide a basis for further rapid assessments of tolerant strains.

Limosilactobacillus fermentum is ubiquitous in traditional fermented vegetables, meat products, and the human gut. It is regarded as a “generally recognized as safe” organism by the US Food and Drug Administration. So far, the genetic features and evolutionary strategies of L. fermentum from the human gut and food remain unknown. In this study, comparative genomic analysis of 224 L. fermentum strains isolated from food and human gut (164 L. fermentum strains isolated from human gut was sequenced in our lab) was performed to access genetic diversity and explore genomic features associated with environment. A total of 20,505 gene families were contained by 224 L. fermentum strains and these strains separated mainly into six clades in phylogenetic tree connected with their origin. Food source L. fermentum strains carried more carbohydrate active enzyme genes (belonging to glycosyltransferase family 2, glycoside hydrolase family 43_11, and glycoside hydrolase family 68) compared with that of human gut and L. fermentum derived from food showed higher ability to degrade xylulose and ribose. Moreover, the number of genes encoding otr(A), tetA(46), lmrB, poxtA, and efrB were more abundant in food source L. fermentum, which was consistent with the number of CRISPR spacers and prophages in L. fermentum of food source. This study provides new insight into the adaption of L. fermentum to the food and intestinal tract of humans, suggesting that the genomic evolution of L. fermentum was to some extent driven by environmental stress.

Recently, a bidirectional relationship between dietary lead (Pb) exposure and gut changes has been identified. Pb causes gut dysbacteriosis and destroys gut physiological homeostasis, causing a series of oxidative stress, immune-inflammatory reactions and increased permeability of the intestinal barrier. Pb-induced gut dysbiosis and physiological disorders are related to impairments in nutrient absorption, essential element homeostasis, lipid metabolism, and nervous system, which can in turn influence Pb transport and metabolism. Dietary supplements such as probiotics, prebiotics, minerals, and antioxidants could be a potential strategy to alleviate Pb toxicity. They can protect the gut barrier, promote Pb discharge, and regulate oxidative stress and essential metal levels, which likely depend on the gut microbiota. Thus, dietary supplements, especially probiotics and prebiotics, are a new and safe strategy to prevent and alleviate Pb poisoning in the future.

Edible mushrooms as valuable health foods have potential beneficial effects, and these beneficial activities are connected with the modulation of gut microbiota. In this review, we discuss the regulation of gut microbiota by edible mushroom. Ganoderma lucidum increases Bacteroides/Firmicutes ratio, and promote the growth of anti-inflammatory and short-chain fatty acid (SCFA) producing bacteria. Hericium erinaceus maintains intestinal barrier integrity, and increases the diversity and richness of gut microbiota. Lentinula edodes act as a prebiotic, increases SCFA-producing bacteria and regulates the proportion of Bacteroides/Firmicutes. Grifola frondosa increases the ratio of Bacteroides/Firmicutes, the growth of anti-inflammatory and SCFA-producing bacteria. We also discuss the effects of different edible mushrooms on the gut microbiota in different diseases and introduce a perspective application of mushrooms as adjuvant therapies for modulating gut microbiota in clinical treatments. Summarized, the statement in modulation of gut microbiota composition by edible mushrooms will provide a new perspective for further research.

Akkermansia muciniphila is a commensal bacterium of the gut mucus layer. Although both in vitro and in vivo data have shown that A. muciniphila strains exhibit strain-specific modulation of gut functions, its ability to moderate immunity to ulcerative colitis have not been verified. We selected three isolated human A. muciniphila strains (FSDLZ39M14, FSDLZ36M5 and FSDLZ20M4) and the A. muciniphila type strain ATCC BAA-835 to examine the effects of different A. muciniphila strains on dextran sulfate sodium-induced colitis. All of the A. muciniphila strains were cultured anaerobically in brain heart infusion medium supplemented with 0.25% type II mucin from porcine stomach. To create animal models, colitis was established in C57BL/6 mice which randomly divided into six groups with 10 mice in each group by adding 3% dextran sulfate sodium to drinking water for 7 days. A. muciniphila strains were orally administered to the mice at a dose of 1 × 109 CFU. Only A. muciniphila FSDLZ36M5 exerted significant protection against ulcerative colitis (UC) by increasing the colon length, restoring body weight, decreasing gut permeability and promoting anti-inflammatory cytokine expression. However, the other strains (FSDLZ39M14, ATCC BAA-835 and FSDLZ20M4) failed to provide these effects. Notably, A. muciniphila FSDLZ20M4 showed a tendency to exacerbate inflammation according to several indicators. Gut microbiota sequencing showed that A. muciniphila FSDLZ36M5 supplementation recovered the gut microbiota of mice to a similar state to that of the control group. A comparative genomic analysis demonstrated that the positive effects of A. muciniphila FSDLZ36M5 compared with the FSDLZ20M4 strain may be associated with specific functional genes that are involved in immune defense mechanisms and protein synthesis. Our results verify the efficacy of A. muciniphila in improving UC and provide gene targets for the efficient and rapid screening of A. muciniphila strains with UC-alleviating effects.

The present study evaluated the protection of Lactiplantibacillus plantarum CCFM8661, a candidate probiotic with excellent benzopyrene (B[a]P)-binding capacity in vitro, against B[a]P-induced toxicity in the colon and brain of mice. Mice that received B[a]P alone served as the model group. Each mouse in the L. plantarum treatment groups were administered 2×109 colony forming unit (CFU) of L. plantarum strains once daily, followed by an oral dose of B[a]P at 50 mg/kg body weight. Behavior, biochemical indicators in the colon and brain tissue, and the gut microbiota composition and short-chain fatty acid (SCFA) levels in the gut were investigated. Compared to the treatment in the model group, CCFM8661 treatment effectively reduced oxidative stress in the brain, improved behavioral performance, increased intestinal barrier integrity, and alleviated histopathological changes in mice. Moreover, CCFM8661 increased the gut microbiota diversity and abundance of Ruminococcus and Lachnospiraceae and reduced the abundance of pro-inflammatory Turicibacter spp. Additionally, the production of SCFAs was significantly increased by L. plantarum CCFM8661. Our results suggest that CCFM8661 is effective against acute B[a]P-induced toxicity in mice and that it can be considered as an effective and easy dietary intervention against B[a]P toxicity.

Abstract Background There are still a large variety of microorganisms among aquatic animals, especially probiotic lactic acid bacteria in cold water fishes at high latitudes have not been fully developed. Hence, the present study aims to evaluate the probiotic potential of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes (Xinjiang) and select candidates to be used as new food preservative agents and/or probiotic additives in feeding of aquaculture. Results A total of 43 Lactobacillus spp. were isolated from 16 kinds of intestinal tract of cold-water fishes. They were characterized by phenotypic methods, identified using Rep-PCR and 16S rRNA gene sequencing as four species: Lactobacillus sakei (22 isolates), Lactobacillus plantarum (16 isolates), Lactobacillus casei (4 isolates) and Lactobacillus paracasei (1 isolate). The in vitro tests included survival in low pH and bile, antimicrobial activity (against Escherichia coli, Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enterica subsp. enterica, Listeria monocytogenes, and Listeria innocua), resistance to 15 antibiotics and hemolytic tests. Among all 43 lactobacilli isolates, the 22 isolates showed a wide range of antimicrobial activity against 6 different pathogenic strains. There were twenty isolates growing at optimal temperature ranging 16~20 °C, which were initially considered to be cold-adapted strains. Two (2) Lb. sakei strains and 2 Lb. plantarum strains demonstrated the highest survivability after 4 h of exposure at pH 2.0. Most of the tested strains cannot be cultured after exposed into 0.5% bile solution for 4 h, while 2 Lb. plantarum strains (E-HLM-3, CQ-CGC-2) and 1 Lb. sakei strain M-DGM-2 survived even at 2% bile concentration. In addition, the safety assessment showed that 22 strains without any detectable hemolytic activity and resistant to glycopeptides (vancomycin, teicoplanin), levofloxacin, aztreonam, amikacin and oxacillin, while all the studied lactobacilli showed sensitivity to or semi-tolerant to other antibiotics. Conclusions Based on all the experiments, 3 strains, including E-HLM-3, CQ-CGC-2, and M-DGM-2 might be a candidate of choice for using in the food preservative agents and/or probiotic additives in feeding of aquaculture.

Breast milk acts as an intermediary for the transfer of functionally important commensal bacteria from mother to infant, especially for Bifidobacterium that can colonize the infant gut. However, the vast majority of rRNA amplicon-based studies reported the conspicuous intercohort and interindividual variation for the prevalence of Bifidobacterium in breast milk. In order to elucidate whether Bifidobacterium phylotypes persistently co-occured at the species or strain level in mother–breast milk–infant triads, we analyzed collectively the next-generation sequencing (NGS) datasets of bacterial 16S rRNA gene and the Bifidobacterium-specific groEL gene from maternal feces, breast milk, and infant feces in a small yet very homogeneous cohort of 25 healthy Uyghur mother–infant pairs (lactation for 7–720 days) in Kashgar, Xinjiang, China. Overall, 16S rRNA gene analysis showed that microbiome in the newborn gut was closer to that of breast milk in the first 4 months of lactation, and subsequently showed an obvious trend of adulthood at 6–12 months. Based on the BLAST accurate taxonomic result of the representative sequences of all ASVs (amplicon sequencing variants), only three sets of ASVs could be clearly assigned into Bifidobacterium species, whereas the remaining eight sets of ASVs corresponded to four indefinite Bifidobacterium species group. By contrast, the groEL gene dataset was partitioned into 376 ASVs, at least belonging to 13 well-known Bifidobacterium species or subspecies, of which 15 ASVs, annotated to seven well-known Bifidobacterium species or subspecies, showed triadic synchronism in most 23 mother–infant pairs tested. However, several other rare bifidobacterial phylotypes, which were frequently encountered in animals, were found to display no correspondence of the presence between the three ecosystems of mother–infant pairs. Our test results were obviously to support the hypothesis that breast milk acts as an intermediary for the transfer of probiotic commensal bacteria from mother to infant, especially for endosymbiotic Bifidobacterium that can colonize the infant gut. Some oxygen-insensitive exogenous Bifidobacterium phylotypes with a cosmopolitan lifestyle may be indirectly transferred to breast milk and the infant’s intestinal tract through environmental contamination. Thus, the groEL gene proved to be a very effective target for the depth resolution of Bifidobacterium community by high-throughput sequencing technologies.

Constipation is a prevalent gastrointestinal disorder that seriously reduces the quality of life. Clinical studies have shown that a great change or severe imbalance occurs in the intestinal microbiota of people with constipation. This study explored whether bacteriocin-producing and non-bacteriocin-producing Pediococcus acidilactici strains resulted in differences in the alleviation of constipation and changes in the fecal flora in BALB/c mice. The constipation-related indicators, gastrointestinal regulatory peptides and gut microbiota were identified to evaluate their alleviating effects and underlying mechanisms. The time to the first black-stool defecation and the gastrointestinal transit rate in constipated mice were found to be somewhat improved by four P. acidilactici strains (P > 0.05). Moreover, there were significant differences in the level of most gastrointestinal regulatory peptides in the serum, as well as in the composition and abundance of intestinal microbiota in different groups (P < 0.05). At the phylum level, the relative abundance of Firmicutes was significantly increased, but those of Bacteroidetes and Proteobacteria were significantly reduced after the administration of four P. acidilactici strains for 14 d (P < 0.05). The levels of Bacteroides and genera from Enterobacteriaceae were significantly decreased, whereas Bifidobacterium and Lactobacillus were upregulated when bacteriocin-producing P. acidilactici CCFM18 and CCFM28 strains were provided in the diet (P < 0.05). The results indicated that although constipation-related symptoms were alleviated to only a limited degree, the administration of four P. acidilactici strains effectively regulated the gut flora and provided a potential health benefit to the host, especially the bacteriocin-producing P. acidilactici strains.

Lactobacillus plantarum, a widely used probiotic in the food industry, exists in diverse habitats, which has led to its niche-specific genetic evolution. However, the relationship between this type of genetic evolution and the bacterial phenotype remains unclear. Here, six L. plantarum strains derived from paocai and human feces were analyzed at the genomic and phenotypic levels to investigate the features of adaptive evolution in different habitats. A comparative genomic analysis showed that 93 metabolism-related genes underwent structural variations (SVs) during adaptive evolution, including genes responsible for carbohydrate, lipid, amino acid, inorganic ion and coenzyme transport and metabolism, and energy production and conversion. Notably, seven virulence factor-related genes in strains from both habitats showed SVs — similar to the pattern found in the orthologous virulence genes of pathogenic bacteria shared similar niches, suggesting the possibility of horizontal gene transfer. These genomic variations further influenced the metabolic abilities of strains and their interactions with the commensal microbiota in the host intestine. Compared with the strains from feces, those from paocai exhibited a shorter stagnation period and a higher growth rate in a diluted paocai solution because of variations in functional genes. In addition, opposite correlations were identified between the relative abundances of L. plantarum strains and the genus Bifidobacterium in two media inoculated with strains from the two habitats. Overall, our findings revealed that the niche-specific genetic evolution of L. plantarum strains is associated with their fermentation abilities and physiological functions in host gut health. This knowledge can help guiding the exploration and application of probiotics from the specific niches-based probiotic exploitation.

Among the nutrients available to the human gut microbiota, the complex carbohydrates and glycosaminoglycans are important sources of carbon for some of the species of human gut microbiota. Glycosaminoglycan (heparin) from the host is a highly preferred carbohydrate for Bacteroides. To explore how gut microbiota can effectively use heparin as a carbon source for growth, we conducted a screening of the Carbohydrate-Active enzymes (CAZymes) database for lytic enzymes of the PL13 family and Research Center of Food Biotechnology at School of Food Science and Technology of Jiangnan University database of Bacteroides to identify novel glycosaminoglycan-degrading bacterial strains. Four Bacteroides species (Bacteroides eggerthii, Bacteroides clarus, Bacteroides nordii, and Bacteroides finegoldii) that degraded heparin were selected for further studies. Analysis of the polysaccharide utilization sites of the four strains revealed that all of them harbored enzyme encoding genes of the PL13 family. Functional analysis revealed the activity of CAZymes in a medium containing heparin as the sole carbon source, suggesting their potential to degrade heparin and support growth. The four enzymes were heterologous expressed, and their enzymatic properties, kinetics, and thermal stability were determined. The lytic enzyme of B. nordii had high enzymatic activity and thermal stability. The features that cause this high thermal stability were elucidated based on an examination of the three-dimensional structure of the protein. Our findings provide an important theoretical basis for the application of glycosaminoglycans and glycosaminoglycan-degrading enzymes in the medical and biotechnology industries, and an important scientific basis for precision nutrition and medical intervention studies using gut microbiota or enzymes as targets.

Cadmium (Cd) is a toxic metal inducing a range of adverse effects on organs including liver and kidneys. However, the underlying molecular mechanisms of Cd-induced intestinal toxicity through dietary intake is poorly studied. This study evaluated the toxic effects of Cd on intestinal physiology and confirmed the effectiveness of the protective mechanism of the probiotic Lactobacillus plantarum CCFM8610 against chronic Cd toxicity. After treatment with Cd, the HT-29 cell line was subjected to iTRAQ analysis, which revealed that changes in the proteomic profiles after Cd exposure were related to pathways involved in the stress response and carbohydrate metabolism. The results of an animal trial also indicated that 10 weeks of Cd exposure decreased the fecal water content and contractile response of colonic muscle strips in mice, and delayed the excretion time of the first black feces. L. plantarum CCFM8610 treatment provided protective effects against these Cd-induced intestinal motility dysfunctions by recovering the levels of neurotransmitters, including substance P, acetyl cholinesterase, vasoactive intestinal peptide, 5-hydroxytryptamine, calcitonin gene-related peptide, and nitric oxide, and suppressing the cellular stress response in mice (e.g., the inhibition of mitogen-activated protein kinase pathways). The administration of this probiotic was also observed to reduce Cd levels in the tissues and blood of the mice. Our results suggest a newly identified protective mechanism of probiotics against Cd toxicity that involves the recovery of intestinal motility and increase in fecal cadmium excretion.

The maternal gut is the principal source of commensal bacteria in the infant gut during the lactation stage, where breast milk acts as an intermediary for the transfer of potential probiotic bacteria consortia, including Lactobacillus. This study aimed to characterize the bacterial communities in human milk, maternal, and infant feces in a small yet very homogeneous cohort of 25 healthy mother–infant pairs in northwestern China (n = 25, infant age from 7 days to 2 years), with special emphasis on the cooccurrence and vertical transfer of Lactobacillus phylotypes at the species or strain level in mother-breast milk-infant triads. Accurate sequencing analysis revealed that among 73 Lactobacillus zero-radius operational classification units (ZOTUs) identified, 58 belonging to 18 recognized species or species groups were distributed in all three types of samples. Lactobacillus ruminis, L. mucosae and L. gasseri-johnsonii as true residents were the most represented in all three ecosystems, whereas the content of Lactobacillus phylotypes commonly developed as probiotics was not dominant. While the numbers of Lactobacillus species in breast milk and infant feces were greater than that in maternal feces, principal coordinates analysis (PCoA) based on beta diversity, coupled with the frequency of isolates determined by culture methods, showed that the Lactobacillus community in the infant gut was more similar to that in the maternal gut than to that in breast milk, suggesting that the gut is niche selective for Lactobacillus populations. In addition, identical strains of L. ruminis, L. paracasei, L. mucosae and L. salivarius were isolated from multiple mother–infant pairs, supporting the hypothesis that vertical transfer of bacteria via breastfeeding contributes to the initial establishment of the microbiota in the developing infant intestine.

Hepatic antioxidative substances are critical indicators to characterize the degree of oxidative stress in the body. The overall effects of probiotic administration on hepatic superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-PX) activity and malondialdehyde (MDA) content were systematically evaluated through determining standardised mean difference (SMD). As a result, the meta-analysis of 23 research papers involving five kinds of oxidative stress models revealed that probiotic intervention significantly increased the levels of SOD by 114% (95% confidence interval (CI): 0.70, 1.59; P