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The first complete cloning, purification and characterization of a proteolytic enzyme in Bifidobacterium animalis subsp. lactis to utilize milk proteins and milk-derived peptides are reported. The activity of B. animalis subsp. lactis endopeptidase (PepO) is found with oligopeptide substrates of many amino acid residues and the predominant peptide bond is on the N-terminal side of phenylalanine residues.

Antibiotics have contributed significantly to the improvement of animal health and to the availability of animal-derived foodstuffs. However, the routine use of antimicrobials in animal production has raised concerns not only about the potential presence of residues in foods but, particularly, about the development and spread of antibiotic-resistant bacteria that may compromise the treatment of animal and human infectious diseases. In this context, strategies to reduce antibiotic use and/or mitigate their collateral damage, especially the development of resistance and adverse effects on the host microbiota, must be developed. In this article, different strategies and lines of action or research are proposed to be applied within the framework of the Spanish National Plan for Antibiotic Resistance. [ABSTRACT FROM AUTHOR]

There is an increased interest in secondary plant metabolites, such as polyphenols and carotenoids, due to their proposed health benefits. Much attention has focused on their bioavailability, a prerequisite for further physiological functions. As human studies are time consuming, costly, and restricted by ethical concerns, in vitro models for investigating the effects of digestion on these compounds have been developed and employed to predict their release from the food matrix, bioaccessibility, and assess changes in their profiles prior to absorption. Most typically, models simulate digestion in the oral cavity, the stomach, the small intestine, and, occasionally, the large intestine. A plethora of models have been reported, the choice mostly driven by the type of phytochemical studied, whether the purpose is screening or studying under close physiological conditions, and the availability of the model systems. Unfortunately, the diversity of model conditions has hampered the ability to compare results across different studies. For example, there is substantial variability in the time of digestion, concentrations of salts, enzymes, and bile acids used, pH, the inclusion of various digestion stages; and whether chosen conditions are static (with fixed concentrations of enzymes, bile salts, digesta, and so on) or dynamic (varying concentrations of these constituents). This review presents an overview of models that have been employed to study the digestion of both lipophilic and hydrophilic phytochemicals, comparing digestive conditions in vitro and in vivo and, finally, suggests a set of parameters for static models that resemble physiological conditions. [ABSTRACT FROM AUTHOR]

Lactococcin A production in lactococci has recently been linked to a signal-sequence-independent secretory system consisting of a four-gene cluster. Lactococcus lactis subsp. lactis LLM23L-A1 has been obtained after Tn 5 mutagenesis of pLLM23, a plasmid containing the gene cluster responsible for lactococcin A production. In contrast to other Tn 5-generated mutants, strain LLM23L-A1 exhibited a 12-fold increase in lactococcin A production. Overproduction of lactococcin A was not linked to an increased pLLM23 copy number. Restriction-enzyme analysis indicated the site of Tn 5 insertion to be at the 3′ end of lcnD and upstream of the lcnA structural gene. From DNA sequencing, the Tn 5 insertion was located −79 bp upstream of the transcription start site of the lcnA and lciA genes, eliminating eight amino acids from the C-terminal end of lactococcin D. Northern blots revealed overproduction of a 500-base transcript in strain LLM23L-A1, which corresponded to that predicted from the positions of the lactococcin A operon transcriptional start site and the termination structures. This result suggests that the overproduction of lactococcin A in strain LLM23L-A1 is at the transcriptional level and provides further impetus for elucidating the complete regulatory mechanism for lactococcin A expression. [ABSTRACT FROM AUTHOR]

Cites a study examined the effects of various types of animal milk on the characteristics of cheeses, in an effort to optimize the process for making low fat cheeses using ultrafiltration. Information in the ultrafiltration process; Microbiological analyses of the cheeses; Details on the texture of the cheeses; Results of the study.

Caseinomacropeptide (CMP), isolated from cow’s or combined ewe’s and goat’s sweet cheese whey, and whey protein concentrate (WPC), enhanced growth of Bifidobacterium lactis in milk. Supplementation of milk at 2% CMP increased counts of B. lactis by 1.5 log cycles after 24 h incubation at 37 °C when compared with unsupplemented milk, showing no differences between the two CMPs. The highest bacterial growth (9.1 log cfu ml−1) was obtained when milk was supplemented with 2% WPC. The growth-promoting activity shown by WPC could be due to its CMP and whey protein content. CMP and WPC could be utilised to complement milk in order to increase counts of bifidobacteria in probiotic fermented milks. [Copyright &y& Elsevier]

Abstract: A hygienized rennet paste (HRP) and a defined strain starter culture, including Lactobacillus casei subsp. casei IFPL as adjunct, were considered for manufacturing Majorero cheese, a Spanish traditional variety made from goat milk. Influence of both factors on physicochemical characteristics, proteolysis, rheological and sensory properties, was evaluated throughout the ripening. Cheeses produced either industrially (IL) or in artisanal manner (AL) were compared with the experimental lot (EL), which included HRP and IFPL starter in its manufacture. Results showed a low level of primary proteolysis, expressed by a low content of non-casein nitrogen (NCN), in experimental cheeses. Despite the slightly poor texture (hard and crumbly) related to the high TS and salt contents, a good general acceptability was attained for EL, with the best scores for aroma and flavour intensities achieved at 30 ripening days. In fact, the sensory panel detected the “piquant” flavour (typical of the artisanal cheese variety) in EL after 15 days of ripening. [Copyright &y& Elsevier]

Abstract: Several wild lactococcal strains were tested for their ability to produce aroma compounds during growth in milk. Strains were incubated alone and in combination with Lactococcus lactis IFPL730, which is characterized by showing α-keto acid decarboxylase activity. Volatile compounds from incubated milks were analyzed by means of solid-phase microextraction (SPME) and evaluated by gas chromatography–mass spectrometry (GC–MS). Incubated milks were also sniffed for sensory analysis to describe aroma attributes. The combination of L. lactis IFPL326 that showed the highest branched chain aminotransferase activity with IFPL730 contributed to the highest formation of leucine-derived volatile compounds, such as 3-methylbutanal, 3-methyl-1-butanol and 2-hydroxy-4-methyl pentanoic acid methyl ester. In addition, the milk incubated with this combination of strains was awarded, by the test panellists, the highest scores for “ripened cheese” attribute and aroma intensity. The results indicate that combination of L. lactis strains harbouring complementary catabolic routes can contribute to improved cheese aroma formation, the combined cultures with L. lactis IFPL730 resulting in higher volatile compound formation than isolate strains. [Copyright &y& Elsevier]

A set-type fermented milk manufactured from goat''s milk was developed. Optimal curd tension was achieved by supplementation of milk with skim milk powder and whey protein concentrate (WPC). Milk was fermented employing a commercial probiotic starter culture (ABT-2), which contained Streptococcus thermophilus ST-20Y, Lactobacillus acidophilus LA-5, and Bifidobacterium BB-12. Supplementation of milk with 3% WPC reduced fermentation time by 2 h due to the increase in viable counts of S. thermophilus and Bifidobacterium by 0.3 and 0.7 log units, respectively. Addition of WPC increased the protein content (1%) as well as potassium and magnesium content (0.3 and 0.02 g kg−1, respectively). Increase of the protein content led to an increase in the apparent viscosity and gel firmness of the product, and at the same time whey syneresis was reduced. As a consequence, the product received a high score for appearance, taste, aroma, texture and overall acceptance. [Copyright &y& Elsevier]

The rate of aging can be determined, among other factors, by the diet during childhood and adolescence. Many additives are currently added to food, including carrageenan (E-407), a thickener derived from red algae. Although the acceptable daily intake for carrageenan is periodically re-evaluated, children show the highest levels of exposure with unknown potential effects on the aging process and longevity. Therefore, the aim of the present study is to know the effects in young mice of carrageenan intake, at the maximum level exposure scenario surveyed in children, on the homeostatic (nervous and immune) systems, the redox-inflammatory state and the repercussion that this may have on the aging and longevity of the animals. Swiss mice of 2 months of age (equivalent to 8 years old children) were used and 4 experimental groups were created (N = 10 animals/group): females and males that ingested carrageenan (540 mg/kg of κ-carrageenan in 200 μL of drinking water by pipette tip administration) and control females and males that took 200 μL of water, daily for 15 days. After that time, a battery of behavioral tests was performed, and peritoneal leukocytes were extracted to assess different immune functions and their redox and inflammatory state. These tests were repeated when the mice reached adulthood (7 months) and old age (18 months). Fecal microbiota was analyzed at the same sampling times. The results showed that animals that ingested carrageenan presented elevated levels of anxiety, impaired immune function and increased oxidative-inflammatory stress, with these effects extending into adulthood and old age and leading to reduced longevity in these mice. Overall, observed microbiota changes were related more to the aging process than the carrageenan intake. In conclusion, the exposure to high doses of the food additive carrageenan in childhood may contribute to an impairment of homeostasis, and consequently of health, with an increased oxidative-inflammatory stress, which implies an accelerated aging process, leading to a lower longevity., 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.)

Introduction: Resentment towards the Chinese population was perceived during the first months of the pandemic because the pandemic/disease started in that country., Objective: To determine the factors associated with the perception of resentment towards the Chinese in Latin America during the first wave of the COVID-19 pandemic., Methodology: Analytical cross-sectional study conducted during the second semester of the pandemic in more than a dozen countries. Four questions were asked about the perception of resentment towards the Chinese (Cronbach's Alpha: 0.88); those with the highest scores on the sum of the four questions were considered to have "more resentment towards the Chinese," and descriptive and analytical statistics were obtained., Results: Of the 7721 respondents, in the multivariate analysis, it was found that there was a difference according to the country; compared to Peru, those who had more resentment towards the Chinese were those residing in Paraguay (aPR: 1.29; 95%CI: 1.17-1.42; p-value < 0.001) and Bolivia (aPR: 1.52; 95%CI: 1.37-1.68; p-value < 0.001), while Chile (aPR: 0.78; 95%CI: 0.69-0.88; p-value < 0.001) had less resentment: 0.69-0.88; p-value < 0.001), Mexico (aPR: 0.68; 95%CI: 0.57-0.80; p-value < 0.001), Panama (aPR: 0.71; 95%CI: 0.59-0.86; p-value < 0.001) and Costa Rica (aPR: 0.64; 95%CI: 0.49-0.85; p-value = 0.002)., Discussion: There was a significant difference in resentment for each country., Competing Interests: Declarations. Ethics approval and consent to participate: The study was approved with resolution N°0014–2022-UPAO by the ethics committee of the Antenor Orrego Private University. Consent for publication: Since it was conducted during the pandemic, the data were collected online, which precluded informed consent; however, the purpose of the study is mentioned at the beginning of the online questionnaire. No personal details were requested from participants to ensure anonymity. The ethical principles of the Declaration of Helsinki conducted this research. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

The safety of the carrageenan (CGN) consumption as a food additive is under debate, with negative effects being associated with the products of hydrolysis of CGN. Moreover, there is an increasing need to integrate gut microbiome analysis in the scientific risk assessment of food additives. The objective of this study was to test the effects of CGN consumption on the gut microbiota and the intestinal homeostasis of young male and female mice. Female and male ICR-CD1 mice (8 weeks old) orally received 540 mg kg -1 day -1 of CGN, representing the maximum-level exposure assessment scenario surveyed for children, over the course of two weeks. Fecal material and peritoneal immune cells were analyzed to determine changes in the fecal microbiota, based on the analysis of bacterial 16S rRNA gene amplicon sequences and short-chain fatty acid (SCFA) concentrations, and some immune functions and redox parameters of peritoneal leukocytes. Non-significant microbiota taxonomical changes associated with CGN intake were found in the mouse stools, resulting the housing time in an increase in bacterial groups belonging to the Bacteroidota phylum. The PICRUSt2 functional predictions showed an overall increase in functional clusters of orthologous genes (COGs) involved in carbohydrate transport and metabolism. A significant increase in the cytotoxicity of fecal supernatants was observed in CGN-fed mice, which correlated with worsening of immune functions and oxidative parameters. The altered immunity and oxidative stress observed in young mice after the consumption of CGN, along with the fecal cytotoxicity shown towards intestinal epithelial cells, may be associated with the gut microbiota's capacity to degrade CGN. The characterization of the gut microbiota's ability to hydrolyze CGN should be included in the risk assessment of this food additive.

Probiotics are valuable microorganisms effective in reducing malnutrition-related infections in children. In this work, a collection of lactobacilli strains representative of traditional Andean fermented beverages was in vitro screened for their capability to survive the gastrointestinal transit, to adhere to the intestinal epithelium and to compete under simulated conditions of the child gut microbiota. The results allowed the selection of the riboflavin overproducing strain Lactiplantibacillus plantarum CECT 9435 based on its good rate of survival under in vitro gastrointestinal conditions when included in a food matrix representing the fortified food supplement Incaparina. The strain also showed good adhesion to HT29 cells producing mucus and outstanding performance in E. coli competition for the adhesion to this epithelial cell line. L. plantarum CECT 9435 gut performance was also evaluated in the child intestinal microbiota simulated in a dynamic gut model (BFBL simulator). The viability of the probiotic candidate in the gut conditions was high during the 7-day intervention period, reaching over 1 × 10 7 counts in each of the reactors simulating the three colonic regions. The transient viability of L. plantarum CECT 9435 within the child gut microbiota and its adhesion capacity to intestinal cells could facilitate the strain potential benefits as probiotic added to fortified supplementary foods destined to malnourished children., (© 2024. The Author(s).)

The gut microbiota should be included in the scientific processes of risk assessment of food additives. Xylitol is a sweetener that shows low digestibility and intestinal absorption, implying that a high proportion of consumed xylitol could reach the colonic microbiota. The present study has evaluated the dose-dependent effects of xylitol intake on the composition and the metabolic activity of the child gut-microbiota. The study was conducted in a dynamic simulator of the colonic microbiota (BFBL Gut Simulator) inoculated with a child pooled faecal sample and supplemented three times per day, for 7 days, with increasing xylitol concentrations (1 g/L, 3 g/L and 5 g/L). Sequencing of 16S rRNA gene amplicons and group-specific quantitative PCR indicated a xylitol dose-response effect on the abundance of Lachnospiraceae, particularly the genera Blautia, Anaerostipes and Roseburia. The microbial changes observed with xylitol corresponded with a dose-dependant effect on the butyrate concentration that, in parallel, favoured an increase in epithelial integrity of Caco-2 cells. The study represents a detailed observation of the bacterial taxa that are the main contributors to the metabolism of xylitol by the child gut microbiota and the results could be relevant in the risk assessment re-evaluation of xylitol as a sweetener., 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.)

Opuntia ficus-indica var. Colorada fruit is an important source of indicaxanthin, a betalain with antioxidant, anti-inflammatory, and neuromodulatory potential, proven in both in vitro and in vivo models. Other betalains and phenolic compounds with bioactive activities have also been identified in Colorada fruit extracts. These compounds may degrade by their exposure to different environmental factors, so in the present research, two double emulsion systems (W 1 /O/W 2 ) were elaborated using Tween 20 (TW) and sodium caseinate (SC) as surfactants to encapsulate Colorada fruit pulp extracts, with the aim of enhancing their stability during storage. Encapsulation efficiencies of up to 97.3 ± 2.7%, particle sizes between 236 ± 4 and 3373 ± 64 nm, and zeta potential values of up to ∣46.2∣ ± 0.3 mV were obtained. In addition, the evaluation of the in vitro gastro-intestinal stability and bioaccessibility of the main individual bioactives was carried out by standardized INFOGEST© protocol, obtaining the highest values for the encapsulated extract bioactives in comparison with the non-encapsulated extract (control). Especially, TW double emulsion showed bioaccessibility values of up to 82.8 ± 1.5% for the main bioactives (indicaxanthin, piscidic acid, and isorhamnetin glucoxyl-rhamnosyl-pentoside 2 (IG2)), indicating a promising potential for its use as a functional natural colorant ingredient.

Meniere's disease (MD) is a disorder of the inner ear characterized by chronic episodes of vertigo, tinnitus, increased aural pressure, and sensorineural hearing loss. Causes of MD are unknown, but endolymphatic hydrops is a hallmark. In addition, 5%-15% of MD cases have been identified as familial. Whole-genome sequencing studies of individuals with familial MD identified DTNA and FAM136A as candidate genes for autosomal dominant inheritance of MD. Although the exact roles of these genes in MD are unknown, FAM136A encodes a mitochondrial protein, and DTNA encodes a cytoskeletal protein involved in synapse formation and maintenance, important for maintaining the blood-brain barrier. It is also associated with a particular aquaporin. We tested vestibular and auditory function in dtna and fam136a knockout (KO) mice, using RotaRod and startle reflex-based clicker tests, respectively. Three-factor analysis of variance (ANOVA) results indicated that sex, age, and genotype were significantly correlated with reduced mean latencies to fall ("latencies") for male dtna KO mice, while only age was a significant factor for fam136a KO mice. Fam136a KO mice lost their hearing months before WTs (9-11 months vs. 15-20 months). In male dtna KO mice, divergence in mean latencies compared with other genotypes was first evident at 4 months of age, with older males having an even greater decrease. Our results indicate that fam136a gene mutations generate hearing problems, while dtna gene mutations produce balance deficits. Both mouse models should help to elucidate hearing loss and balance-related symptoms associated with MD., (© 2023 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

This study aimed to explore the anti-inflammatory and gut microbiota modulation potentials of flavonoid-rich fraction (PFF) extracted from Passiflora foetida fruits. The results showed that PFF markedly reduced the production of nitric oxide (NO), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) in LPS-stimulated RAW 264.7 cells. Meanwhile, PFF treatment also effectively decreased the phosphorylation levels of MAPK, PI3K/Akt, and NF-κB signaling-pathway-related proteins (ERK, JNK, p38, Akt, and p65). Moreover, PFF had an impact on microbial composition and metabolites in a four-stage dynamic simulator of human gut microbiota (BFBL gut model). Specifically, PFF exhibited the growth-promoting ability of several beneficial bacteria, including Bifidobacterium , Enterococcus , Lactobacillus , and Roseburia , and short-chain fatty acid (SCFA) generation ability in gut microbiota. In addition, spectroscopic data revealed that PFF mainly contained five flavonoid compounds, which may be bioactive compounds with anti-inflammatory and gut microbiota modulation potentials. Therefore, PFF could be utilized as a natural anti-inflammatory agent or supplement to health products.

Understanding the individual factors that modulate flavor perception is a central issue for the development of personalized diets strategies to fight obesity. This study aimed to investigate differences in flavor perception between adults with normal weight and those with obesity, as well as some potential biological factors related to these differences. To do that, liking and flavor perception intensity were measured against retronasal olfactory (pineapple, butter, tropical and chocolate) and taste attributes (sweetness, umami and bitter) in 77 individuals grouped as normalweight or obese, according to their body mass index (BMI). Unstimulated saliva was collected from all participants and characterized in terms of salivary flow, total protein content, total antioxidant capacity, total esterase activity and bacterial composition through 16S rDNA amplicon sequencing. The results showed that participants displayed differences in flavor perception according to their BMI group. Thus, the group with obesity showed significant lower liking and intensity scores for low calorie related food aroma (pineapple and tropical), lower taste intensity scores for sweet and umami, and a higher acceptability for umami than the group with normal weight. Significant differences between BMI groups were observed for salivary biochemical variables and specific bacterial taxa, some of which were significantly correlated to flavor intensity. This work suggests for the first time the existence of an oral-brain axis that might contribute to the development or perpetuation of obesity, which opens new and interesting avenues of research., 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 © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)