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The oral administration of probiotics is nowadays recognized as a strategy to treat or prevent the consequences of unhealthy dietary habits. Here we analyze and compare the effects of the oral administration of vegetative cells or spores of Shouchella clausii SF174 in counteracting gut dysfunctions induced by 6 weeks of high fructose intake in a rat model. Gut microbiota composition, tight junction proteins, markers of inflammation and redox homeostasis were evaluated in ileum and colon in rats fed fructose rich diet and supplemented with cells or spores of Shouchella clausii SF174. Our results show that both spores and cells of SF174 were effective in preventing the fructose-induced metabolic damage to the gut, namely establishment of "leaky gut", inflammation and oxidative damage, thus preserving gut function. Our results also suggest that vegetative cells and germination-derived cells metabolize part of the ingested fructose at the ileum level., Competing Interests: Declarations of competing interests ER acts as a consultant for Gruppo Savio (Italy) that has the rights for the commercialization of strain SF174. Gruppo Savio (Italy) had no role in the design of the study, in the collection, analyses or interpretation of data or in the writing of the manuscript., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Increased levels of proteases, such as trypsin, in the distal intestine have been implicated in intestinal pathological conditions 1-3 . However, the players and mechanisms that underlie protease regulation in the intestinal lumen have remained unclear. Here we show that Paraprevotella strains isolated from the faecal microbiome of healthy human donors are potent trypsin-degrading commensals. Mechanistically, Paraprevotella recruit trypsin to the bacterial surface through type IX secretion system-dependent polysaccharide-anchoring proteins to promote trypsin autolysis. Paraprevotella colonization protects IgA from trypsin degradation and enhances the effectiveness of oral vaccines against Citrobacter rodentium. Moreover, Paraprevotella colonization inhibits lethal infection with murine hepatitis virus-2, a mouse coronavirus that is dependent on trypsin and trypsin-like proteases for entry into host cells 4,5 . Consistently, carriage of putative genes involved in trypsin degradation in the gut microbiome was associated with reduced severity of diarrhoea in patients with SARS-CoV-2 infection. Thus, trypsin-degrading commensal colonization may contribute to the maintenance of intestinal homeostasis and protection from pathogen infection., (© 2022. The Author(s).)

Ethnopharmacological Relevance: Eriobotrya japonica (Thunb.) Lindl leaf (EJL) is used as a traditional Chinese medicine. E. japonica is a member of the Rosaceae family. EJL suppresses cough and relieves asthma and is widely used to treat lung diseases. In the present study, guided by the traditional Chinese medicine theory of the exterior-interior relationship between the lungs and the large intestine, the pathogenesis of cough variant asthma (CVA) and the treatment mechanism of EJL on CVA were explored., Aim of the Study: This study aimed to explore the airway remodeling effects of EJL in CVA from the perspective of the intestinal flora and the matrix metallopeptidase 9/tissue inhibitor of metalloproteinases-1 (MMP-9/TIMP-1) pathway., Materials and Methods: The oleanolic acid and ursolic acid contents in EJL were measured by high-performance liquid chromatography (HPLC) to ensure the quality of EJL. BALB/c mice were used to establish a CVA model through ovalbumin (OVA) sensitization and atomization. EJL (at 5, 10, or 20 g/kg/day) was intragastrically administered. The body weight, ratio of total bronchial wall area (WAt) to bronchial basement membrane perimeter (Pbm) (WAt/Pbm), the number of coughs, and cough latency were measured. The pathological changes of the lung tissue were analyzed by hematoxylin and eosin (HE) staining. The expression of α-smooth muscle actin (α-SMA) was measured by immunohistochemistry (IHC). The expressions of MMP-9 and TIMP-1 were detected in the lung tissue by reverse transcription quantitative polymerase chain reaction (RT-PCR) and Western blot analysis. Additionally, an Illumina Hiseq platform was used for 16S ribosomal DNA (16S rDNA) high-throughput sequencing to detect the intestinal flora in feces samples., Results: The results confirmed the positive effects of EJL on CVA. After administration of EJL, the number of coughs and the WAt/Pbm ratio decreased, the cough latency was prolonged, body weight was increased, and the general status was better than that of the CVA model mice. HE staining revealed that EJL decreased inflammatory cell infiltration and improved the histopathological structure of the lung tissue. EJL also showed significant inhibitory effects on the expression of α-SMA, MMP-9, and TIMP-1 and normalized the intestinal flora to a certain extent., Conclusions: The results demonstrated that EJL alleviated airway remodeling of CVA mice, which might be related to the inhibition of the MMP-P/TIMP-1 pathway and the regulation of intestinal flora., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Arid plant communities provide variable diets that can affect digestive microbial communities of free-foraging ruminants. Thus, we used next-generation sequencing of 16S and 18S rDNA to characterize microbial communities in the rumen (regurgitated digesta) and large intestine (faeces) and diet composition of lactating creole goats from five flocks grazing in native plant communities in the Sonoran Desert in the rainy season. The bacterial communities in the rumen and large intestine of the five flocks had similar alpha diversity (Chao1, Shannon, and Simpson indices). However, bacterial community compositions were different: a bacterial community dominated by Proteobacteria in the rumen transitioned to a community dominated by Firmicutes in the large intestine. Bacterial communities of rumen were similar across flocks; similarly occurred with large-intestine communities. Archaea had a minimum presence in the goat digestive tract. We detected phylum Basidiomycota , Ascomycota , and Apicomplexa as the main fungi and protozoa. Analyses suggested different diet compositions; forbs and grasses composed the bulk of plants in the rumen and forbs and shrubs in faeces. Therefore, lactating goats consuming different diets in the Sonoran Desert in the rainy season share a similar core bacterial community in the rumen and another in the large intestine and present low archaeal communities.

Chlamydia in the genital tract is known to spread via the blood circulation system to the large intestine lumen to achieve long-lasting colonization. However, the precise pathways by which genital Chlamydia accesses the large intestine lumen remain unclear. The spleen was recently reported to be critical for chlamydial spreading. In the current study, it was found that following intravaginal inoculation with Chlamydia , mice with and without splenectomy both yielded infectious Chlamydia on rectal swabs, indicating that the spleen is not essential for genital Chlamydia to spread to the gastrointestinal tract. This conclusion was validated by the observation that intravenously inoculated Chlamydia was also detected on the rectal swabs of mice regardless of splenectomy. Careful comparison of the tissue distribution of live chlamydial organisms following intravenous inoculation revealed redundant pathways by which Chlamydia can reach the large intestine lumen. The intravenously inoculated Chlamydia was predominantly recruited to the spleen within 12 h and then detected in the stomach lumen by 24 h, in the intestinal lumen by 48 h, and on rectal swabs by 72 h. These observations suggest a potential spleen-to-stomach pathway for hematogenous Chlamydia to reach the large intestine lumen. This conclusion was supported by the observation made in mice under coprophagy-free condition. However, in the absence of spleen, hematogenous Chlamydia was predominantly recruited to the liver and then simultaneously detected in the intestinal tissue and lumen, suggesting a potential liver-to-intestine pathway for Chlamydia to reach the large intestine lumen. Thus, genital/hematogenous Chlamydia may reach the large intestine lumen via multiple redundant pathways.

Antibiotic resistance in bacterial pathogens is a growing problem for both human and veterinary medicine. Mobile genetic elements (MGEs) such as plasmids, transposons, and integrons enable the spread of antibiotic resistance genes (ARGs) among bacteria, and the overuse of antibiotics drives this process by providing the selection pressure for resistance genes to establish and persist in bacterial populations. Because bacteria, MGEs, and resistance genes can readily spread between different ecological compartments (e.g. soil, plants, animals, humans, wastewater), a "One Health" approach is needed to combat this problem. The equine hindgut is an understudied but potentially significant reservoir of ARGs and MGEs, since horses have close contact with humans, their manure is used in agriculture, they have a dense microbiome of both bacteria and fungi, and many antimicrobials used for equine treatment are also used in human medicine. Here, we collate information to date about resistance genes, plasmids, and class 1 integrons from equine-derived bacteria, we discuss why the equine hindgut deserves increased attention as a potential reservoir of ARGs, and we suggest ways to minimize the selection for ARGs in horses, in order to prevent their spread to the wider community.

Ginsenoside Rg1 (Rg1) is traditional Chinese medicine with neuroprotective activity. Previous studies have demonstrated that Rg1 improves Alzheimer's disease (AD) and alters gut microbiology, but its mechanism remains to be elucidated, and thus far, its use in the treatment of AD has not been satisfactory. The present study investigated the improvement effects of Rg1 and its association with the microbiota of the large intestine. Following treatment with Rg1 in AD tree shrews, the treatment group demonstrated significantly shorter escape latency and crossed a platform more frequently in a water maze test. Western blotting demonstrated that Rg1 inhibited the expression of β-secretase 1, while increasing microtubule-associated protein 2 and Fox-3 in the hippocampus. Immunohistochemical analysis revealed that Rg1 decreased the expression of amyloid β, tau phosphorylated at serine 404 and pro-apoptotic factor Bax, while increasing the expression of Bcl-2 in the hippocampus and cortex. High throughput sequencing of 16S rRNA demonstrated that Rg1 altered the microbiota abundance of the large intestine. In conclusion, Rg1 affected the expression of apoptosis proteins, possessed a neuroprotective effect and may have a close association with the microbiota of large intestine by significantly reducing the abundance of Bacteroidetes and increasing the energy requirement of tree shrews.

Interactions between host and gut microbial communities are modulated by diets and play pivotal roles in immunological homeostasis and health. We show that exchanging the protein source in a high fat, high sugar, westernized diet from casein to whole-cell lysates of the non-commensal bacterium Methylococcus capsulatus Bath is sufficient to reverse western diet-induced changes in the gut microbiota to a state resembling that of lean, low fat diet-fed mice, both under mild thermal stress (T22 °C) and at thermoneutrality (T30 °C). Concomitant with microbiota changes, mice fed the Methylococcus-based western diet exhibit improved glucose regulation, reduced body and liver fat, and diminished hepatic immune infiltration. Intake of the Methylococcu-based diet markedly boosts Parabacteroides abundances in a manner depending on adaptive immunity, and upregulates triple positive (Foxp3 + RORγt + IL-17 + ) regulatory T cells in the small and large intestine. Collectively, these data point to the potential for leveraging the use of McB lysates to improve immunometabolic homeostasis.

Background: The microbiome is now known for its important role in whole-body homeostasis. A dysbiosis of the normal microbiota is correlated with metabolic disorders. In this sense, the search for compounds able to modulate the microbiome is needed. Resveratrol, a natural compound found in grapes seems to be a promising candidate., Objective: In this study, our motivation was to evaluate the effects of the association between Resveratrol and Lactococcus lactis, a probiotic, on the composition of the gastrointestinal microbiota and body weight of mice., Methods: Twenty female mice were divided into 4 groups: (1) standard diet, (2) standard diet plus Lactococcus lactis, (3) standard diet plus resveratrol, and (4) standard diet plus Lactococcus lactis and resveratrol. At the end of the treatment period, samples of blood, mucus, stomach, and small and large intestines were collected for analysis. Total levels of Immunoglobulin A and Immunoglobulin E, Lac+ and Lac- bacteria and Lactobacillus were measured., Results: The main results indicate that the association between resveratrol and probiotics was able to decrease mice body weight, as compared to the other groups, in addition to decrease the number of Lac- bacteria and increasing the number of Lac+ bacteria. The levels of secretory IgA were also decreased, compared to the animals treated with only probiotics or resveratrol., Conclusion: We observed potential synergism between Resveratrol and Lactococcus lactis mainly in modulating the stomach and intestinal microbiota., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The impact of human milk (HM) or dairy milk-based formula (MF) on the large intestine's metabolome was not investigated. Two-day old male piglets were randomly assigned to HM or MF diet (n = 26/group), from postnatal day (PND) 2 through 21 and weaned to a solid diet until PND 51. Piglets were euthanized at PND 21 and PND 51, luminal contents of the cecum, proximal (PC) and distal colons (DC), and rectum were collected and subjected to metabolomics analysis. Data analyses were performed using Metaboanalyst. In comparison to MF, the HM diet resulted in higher levels of fatty acids in the lumen of the cecum, PC, DC, and rectum at PND 21. Glutamic acid was greater in the lumen of cecum, PC, and DC relative to the MF group at PND 21. Also, spermidine was higher in the DC and rectal contents of HM relative to MF at PND 21. MF diet resulted in greater abundances of amino acids in the cecal lumen relative to HM diet at PND 21. Additionally, several sugar metabolites were higher in various regions of the distal gut of MF fed piglets relative to HM group at PND 21. In contrast, at PND 51, in various regions there were higher levels of erythritol, maltotriose, isomaltose in HM versus MF fed piglets. This suggests a post weaning shift in sugar metabolism that is impacted by neonatal diet. The data also suggest that infant diet type and host-microbiota interactions likely influence the lower gut metabolome., Competing Interests: The authors declare that the article was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Rosa, Matazel, Bowlin, Williams, Elolimy, Adams, Bode and Yeruva.)

Clostridioides difficile is an enteric bacterial pathogen that can a cause nosocomial infection leading to debilitating colitis. The development of a murine model of C. difficile infection has led to fundamental discoveries in disease pathogenesis and the host immune response to infection. Recently, C. difficile endogenously present in the microbiota of mice has been reported and was found to complicate interpretation of mouse studies. Here, we report a novel C. difficile strain, named NTCD-035, isolated from the microbiota of our mouse colony. The presence of NTCD-035 in mice prior to challenge with a highly pathogenic C. difficile strain (VPI10463) led to significantly reduced disease severity. Phylogenetic characterization derived from whole genome sequencing and PCR ribotyping identified the isolate as a novel clade 1, ribotype 035 strain that lacks the pathogenicity locus required to produce toxins. Deficiency in toxin production along with sporulation capacity and secondary bile acid sensitivity was confirmed using in vitro assays. Inoculation of germ-free mice with NTCD-035 did not cause morbidity despite the strain readily colonizing the large intestine. Implementation of a culture-based screening procedure enabled the identification of mice harboring C. difficile in their microbiota, the establishment of a C. difficile -free mouse colony, and a monitoring system to prevent future contamination. Taken together, these data provide a framework for screening mice for endogenously harbored C. difficile and support clinical findings that demonstrate the therapeutic potential of non-toxigenic strains in preventing C. difficile associated disease. Abbreviations : PaLoc - Pathogenicity locus, CFUs - Colony forming units, TcdA - toxin-A, TcdB - toxin-B, CdtA - binary toxin A, CdtB - binary toxin B, CdtR - binary toxin R, NTCD - non-toxigenic C. difficile .

Gut mucosal microbes evolved closest to the host, developing specialized local communities. There is, however, insufficient knowledge of these communities as most studies have employed sequencing technologies to investigate faecal microbiota only. This work used shotgun metagenomics of mucosal biopsies to explore the microbial communities' compositions of terminal ileum and large intestine in 5 healthy individuals. Functional annotations and genome-scale metabolic modelling of selected species were then employed to identify local functional enrichments. While faecal metagenomics provided a good approximation of the average gut mucosal microbiome composition, mucosal biopsies allowed detecting the subtle variations of local microbial communities. Given their significant enrichment in the mucosal microbiota, we highlight the roles of Bacteroides species and describe the antimicrobial resistance biogeography along the intestine. We also detail which species, at which locations, are involved with the tryptophan/indole pathway, whose malfunctioning has been linked to pathologies including inflammatory bowel disease. Our study thus provides invaluable resources for investigating mechanisms connecting gut microbiota and host pathophysiology.

Fusarium mycotoxins are common contaminants in cereals and often co-occur with plant-derived mycotoxin sugar conjugates. Several of these modified mycotoxins are not degraded in the small intestine and hence carried through to the large intestine where microbial transformation may occur. This study aims to assess the gastrointestinal stability of the trichothecenes HT-2 toxin (HT-2), HT-2-β-glucoside (HT-2-Glc), diacetoxyscirpenol (DAS), DAS-α-glucoside (DAS-Glc) and fumonisin B1 (FB 1 ), N -(1-deoxy-d-fructos-1-yl) fumonisin-B 1 (NDF-FB 1 ). All tested modified mycotoxins were stable under upper gastrointestinal (GI) conditions. In faecal batch culture experiments, HT-2-Glc was hydrolysed efficiently and no further microbial biotransformation of HT-2 was observed. DAS-Glc hydrolysis was slow and DAS was de-acetylated to 15-monoacetoxyscripenol. NDF-FB 1 was hydrolysed at the slowest rate and FB 1 accumulation varied between donor samples. Our results demonstrate that all tested modified mycotoxins are stable in the upper GI tract and efficiently hydrolysed by human gut microbiota, thus potentially contributing to colonic toxicity. Hence the microbial biotransformation of any novel modified mycotoxins needs to be carefully evaluated.

Reactive arthritis, an autoimmune disorder, occurs following gastrointestinal infection with invasive enteric pathogens, such as Salmonella enterica. Curli, an extracellular, bacterial amyloid with cross beta-sheet structure can trigger inflammatory responses by stimulating pattern recognition receptors. Here we show that S. Typhimurium produces curli amyloids in the cecum and colon of mice after natural oral infection, in both acute and chronic infection models. Production of curli was associated with an increase in anti-dsDNA autoantibodies and joint inflammation in infected mice. The negative impacts on the host appeared to be dependent on invasive systemic exposure of curli to immune cells. We hypothesize that in vivo synthesis of curli contributes to known complications of enteric infections and suggest that cross-seeding interactions can occur between pathogen-produced amyloids and amyloidogenic proteins of the host., Competing Interests: The authors have declared that no competing interests exist.

Background: Nonalcoholic fatty liver disease (NAFLD) is considered to be associated with diet and gut dysbiosis. Excessive sucralose can induce gut dysbiosis and negatively affect host health. Maternal diet shapes the microbial communities of neonate and this effect continues in later life. We aimed to investigate the effects of maternal sucralose (MS) intake on the susceptibility of offspring to hepatic steatosis in adulthood., Methods: C57BL/6 pregnant mice were randomized into MS group (MS during gestation and lactation) and maternal control (MC) group (MC diet). After weaning, all offspring were fed a control diet until 8 weeks of age, and then treated with a high-fat diet (HFD) for 4 weeks. The intestinal development, mucosal barrier function, and gut microbiota were assessed in the 3-week-old offspring. Moreover, the severity of hepatic steatosis, serum biochemistry, lipid metabolism, and gut microbiota was then assessed in the 12th week., Results: MS significantly inhibited intestinal development and disrupted barrier function in 3-week-old offspring. MS also induced intestinal low-grade inflammation, significantly changed the compositions and diversity of gut microbiota including reducing butyrate-producing bacteria and cecal butyrate production with down-regulation of GPR43. Mechanically, blocking GPR43 blunted the anti-inflammatory effect of one of the butyrate-producing bacteria, Clostridium butyricum in vitro . After HFD treatment, MS exacerbated hepatic steatosis, and disturbed fatty acid biosynthesis and metabolism, accompanied by inducing gut dysbiosis compared with MC group., Conclusions: MS intake inhibits intestinal development, induces gut dysbiosis in offspring through down-regulation of GPR43, and exacerbates HFD-induced hepatic steatosis in adulthood.

Rapeseed meal is a sustainable feed ingredient that can be used as an alternative to imported soybean meal in European pig production. The gut microbiota plays an important role on pig physiology and health but the impact on microbiota of using rapeseed in diets is still not well known. In this study, 84 purebred Norwegian Landrace pigs with average initial weight of 25 kg were divided into two groups and fed for approximately three months with either a control diet containing soybean meal (CON) or a high-fiber experimental diet where 20% rapeseed meal (RSF) was included as an alternative to soybean meal in CON. The composition and function of microbiome in gut digesta samples were analyzed by performing 16S rRNA gene sequencing and culturing of bacteria. The microbiota diversity and composition were similar between the dietary treatments; however, relative abundance of a variety of bacterial groups and imputed functions of microbiome in the ileum and large intestine were altered when the pigs were fed with a rapeseed-based diet. It was notable that the immune-inducing bacterial group Mucispirillum and anti-inflammatory stimulating bacteria Lachnospira were more abundant in the ileum and large intestine of the RSF group, respectively. Moreover, there was a higher abundance of major amino acid fermenters and amylolytic bacteria in the CON group and a high abundance of putative short chain fatty acid producers in RSF group. In comparison with the CON group, the gut microbiome of RSF group possessed an enhanced potential for carbohydrate and energy metabolism and a reduced potential for bacterial pathogenicity-related pathways.

The intestinal microbiota plays an important role in the health and metabolism of the host. Next-generation sequencing technology has enabled the characterization of the gut microbiota of several animal species. We analyzed the intestinal microbiota in six different parts of the gastrointestinal tracts (GITs) of five Mongolian horses by sequencing the 16S rRNA gene V3-V4 hypervariable region. All horses were kept in the natural habitat of the Inner Mongolia grassland. Significant differences were observed among the microbiota compositions of the distinct GIT regions. In addition, while the microbial community structures of the small and large intestine were significantly different, those of the cecum and colon were similar. In the foregut, Firmicutes (65%) and Proteobacteria (23%) were the most abundant, while Firmicutes (45%) and Bacteroidetes (42%) were the most common in the hindgut. At the level of family, Ruminococcaceae (p = .203), Lachnospiraceae (p = .157), Rikenellaceae (p = .122), and Prevotellaceae (p = .068) were predominant in the hindgut, while the relative abundance of the Akkermansia genus (5.7%, p = .039) was higher in the ventral colon. In terms of the putative functions, the ratio of microbial abundance in the different parts of the GIT was similar, the result can help characterize the gut microbial structure of different animals., (© 2020 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Here, we investigated the prevalence of Salmonella enterica, with and without resistance to 17 common antimicrobial agents, in 706 green anoles (Anolis carolinensis) that were collected in Naha and Tomigusuku Cities, Okinawa Main Island, Japan, between 2009 and 2014. Salmonella strains, including S. enterica Weltevreden and Enteritidis serovars, were identified in the large intestinal content samples extracted from 15 (2.1%) of the analyzed green anoles. No antimicrobial resistance was detected. Thus, the present study demonstrates that although the prevalence of Salmonella and the risk of its transmission from the green anoles to humans or other animals on Okinawa Main Island are relatively low, the green anole population nevertheless represents a potential source of Salmonella infection that could affect human health in this region.

Both the gut and skin microbiotas have important functions for amphibians. The gut microbiota plays an important role in both the health and evolution of the host species, whereas the role of skin microbiota in disease resistance is particularly important for amphibians. Many studies have examined the effects of environmental factors on the skin and gut microbiotas, but no study has yet explored the similarities between the skin and gut microbiotas. In this study, the gut and skin microbiotas of Rana dybowskii in summer and winter were investigated via high-throughput Illumina sequencing. The results showed that the alpha diversity of gut and skin microbiotas decreased significantly from summer to winter. In both seasons, the microbial composition and structure differed significantly between the gut and skin, and the similarities between these microbiotas differed between seasons. The pairwise distances between the gut and skin microbiotas were greater in winter than in summer. The ratio of core OTUs and shared OTUs to the sum of the OTUs in the gut and skin microbiotas in summer was significantly higher than that in winter. The similarities between the gut and skin microbiotas are important for understanding amphibian ecology and life history.

Fecal IgA production depends on colonization by a gut microbiota. However, the bacterial strains that drive gut IgA production remain largely unknown. Here, we assessed the IgA-inducing capacity of a diverse set of human gut microbial strains by monocolonizing mice with each strain. We identified Bacteroides ovatus as the species that best induced gut IgA production. However, this induction varied bimodally across different B. ovatus strains. The high IgA-inducing B. ovatus strains preferentially elicited more IgA production in the large intestine through the T cell-dependent B cell-activation pathway. Remarkably, a low-IgA phenotype in mice could be robustly and consistently converted into a high-IgA phenotype by transplanting a multiplex cocktail of high IgA-inducing B. ovatus strains but not individual ones. Our results highlight the critical importance of microbial strains in driving phenotype variation in the mucosal immune system and provide a strategy to robustly modify a gut immune phenotype, including IgA production., Competing Interests: Declaration of Interests J.J.F. serves as a consultant for Janssen Research & Development LLC. All remaining authors declare no conflict of interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Oil palm fruit is widely used for edible oils, but the health benefits of other components are relatively unknown. We examined if consuming a polyphenol-rich extract of the fruit, from a vegetation by-product of oil processing, which also contains fibre, has gastro-intestinal benefits in rats on a Western-type diet (WD). The oil palm preparation (OPP) was added to food (OPP-F) or drinking water (OPP-D) to provide 50 mg of gallic acid equivalents (GAE)/d and compared to effects of high amylose maize starch (HAMS; 30%) in the diet or green tea extract (GT; 50 mg GAE/d) in drinking water over 4 wk. OPP treatments induced some significant effects ( P < 0.05) compared to WD. OPP-D increased caecal digesta mass, caecal digesta concentrations of total SCFA, acetate and propionate (OPP-F increased caecal butyrate concentration), the numbers of mucus-producing goblet cells per colonic crypt, and caecal digesta abundance of some bacteria which may provide benefit to the host ( Faecalibacterium prausnitzii , Akkermansia muciniphila and Ruminococcus gnavus ). HAMS induced similar effects but with greater potency and had a broader impact on microbe populations, whereas GT had minimal impacts. These results suggest dietary OPP may benefit the large bowel., Competing Interests: There is a potential conflict of interest resulting from the involvement and authorship of representatives of the funder (MPOB) in this study.

The identification of natural bioactive compounds which can prevent the post-weaning growth check and enhance gastrointestinal health in the absence of in-feed medications is an urgent priority for the swine industry. The objective of this experiment was to determine the effects of increasing dietary inclusion levels of laminarin in the first 14 d post-weaning on pig growth performance and weaning associated intestinal dysfunction. At weaning, ninety-six pigs (8·4 (sd 1·09) kg) (meatline boars × (large white × landrace sows)) were blocked by live weight, litter and sex and randomly assigned to: (1) basal diet; (2) basal + 100 parts per million (ppm) laminarin; (3) basal + 200 ppm laminarin and (4) basal + 300 ppm laminarin (three pigs/pen). The appropriate quantity of a laminarin-rich extract (65 % laminarin) was added to the basal diet to achieve the above dietary inclusion levels of laminarin. After 14 d of supplementation, eight pigs from the basal group and the best-performing laminarin group were euthanised for sample collection. The 300 ppm laminarin group was selected as this group had higher ADFI compared with all other groups and higher ADG than the basal group (P < 0·05). Laminarin supplementation increased villus height in the duodenum and jejunum (P < 0·05). Laminarin supplementation increased the expression of SLC2A8/GLUT8 in the duodenum, SLC2A2/GLUT2, SLC2A7/GLUT7, SLC15A1/PEPT1 and FABP2 in the jejunum and SLC16A1/MCT1 in the colon. Laminarin supplementation reduced Enterobacteriaceae numbers in the caecum (P < 0·05) and increased lactobacilli numbers (P < 0·05), total volatile fatty acid concentrations and the molar proportions of butyrate (P < 0·01) in the colon. In conclusion, 300 ppm laminarin from a laminarin-rich extract has potential, as a dietary supplement, to improve performance and prevent post-weaning intestinal dysfunction.

Increasing evidence suggests that intestinal helminth infection can alter intestinal microbial communities with important impacts on the mammalian host. However, all of the studies to date utilize different techniques to study the microbiome and access different sites of the intestine with little consistency noted between studies. In the present study, we set out to perform a comprehensive analysis of the impact of intestinal helminth infection on the mammalian intestinal bacterial microbiome. For this purpose, we investigated the impact of experimental infection using the natural murine small intestinal helminth, Heligmosomoides polygyrus bakeri and examined possible alterations in both the mucous and luminal bacterial communities along the entire small and large intestine. We also explored the impact of common experimental variables including the parasite batch and pre-infection microbiome, on the outcome of helminth-bacterial interactions. This work provides evidence that helminth infection reproducibly alters intestinal microbial communities, with an impact of infection noted along the entire length of the intestine. Although the exact nature of helminth-induced alterations to the intestinal microbiome differed depending on the microbiome community structure present prior to infection, changes extended well beyond the introduction of new bacterial species by the infecting larvae. Moreover, striking similarities between different experiments were noted, including the consistent outgrowth of a bacterium belonging to the Peptostreptococcaceae family throughout the intestine., (Copyright © 2019 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.)

We studied the effect of combined antimicrobial therapy with amoxicillin, metronidazole, and clarithromycin on the severity of ischemia/reperfusion myocardial injury in Wistar rats with alimentary obesity and acute inflammation of the large intestine. General ischemia/reperfusion was reproduced on Langendorff-perfused isolated hearts and infarct size was estimated. Acute inflammation of the large intestine was accompanied by an increase in the blood levels of proinflammatory cytokines. The presence of obesity and acute inflammation of the large intestine did not significantly affect the infarct size in comparison with the control. Administration of antimicrobial drugs to animals with obesity and acute inflammation of the large intestine led to a significant increase in the infarct size, which should be considered when prescribing antimicrobial therapy to patients with comorbidity.

Goat milk and goat milk and inulin were used as encapsulating agents of Bifidobacterium BB-12 and applied in Frozen Yogurt (GF2 and GF3, respectively) in order to evaluate the antagonistic effect against Escherichia coli. GF1 is a control containing only Escherichia coli. Simulation of gastrointestinal digestion occurred sequentially. Quantification of Bifidobacterium BB-12 was performed using plate counting while E. coli count was compared with quantification by qPCR with viable and nonviable cell differentiation. The Bifidobacterium BB-12 count was <1.0, 9.23 and 9.11 log CFU g -1 for GF1, GF2 and GF3, respectively. In the ascending colon, all samples showed E. coli counts of approximately 5 log CFU g -1 by plate counting and by qPCR. Throughout the transverse (24 h) and descending colon (48 h) samples GF2 and GF3 showed decrease in E. coli number. GF3 showed higher decrease of E. coli in the descending colon because of inulin bifidogenic characteristic. The production of organic acids by bifidobacteria was directly related to the decrease in the E. coli count. In plate counts, E. coli was not detected for the GF3 sample in the descending colon. However, when quantified by qPCR the sample presented amplification that corresponded to 3 log CFU g -1 . In this way, it was possible to observe the phenomenon of the viable but not-culturable cells of E. coli. Finally, it is recommended the microcapsule produced with goat milk and the inulin for application in goat milk products, due to the better antagonist effect against E. coli., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The intestinal microbiota of the horse, an animal of huge economic and social importance worldwide, is essential to the health of the animal. Understanding the intestinal ecosystem and its dynamic interaction with diet and dietary supplements currently requires the use of experimental animals, with consequent welfare and financial constraints. Here, we describe the development and assessment, using multiple analytical platforms, of a three-vessel, continuous-flow, in vitro model of the equine hindgut. After inoculation of the model with fresh horse feces, the bacterial communities established in each vessel had a taxonomic distribution similar to that of the source animal. Short-chain fatty acid (SCFA) and branched-chain fatty acid (BCFA) production within the model at steady state was consistent with the expected bacterial function, although higher concentrations of some SCFA/BCFA relative to those in the ex vivo gut content were apparent. We demonstrate the intermodel repeatability and the ability of the model to capture some aspects of individual variation in bacterial community profiles. The findings of this proof-of-concept study, including recognition of the limitions of the model, support its future development as a tool for investigating the impact of disease, nutrition, dietary supplementation, and medication on the equine intestinal microbiota. IMPORTANCE The equine gut model that we have developed and describe has the potential to facilitate the exploration of how the equine gut microbiota is affected by diet, disease, and medication. It is a convenient, cost-effective, and welfare-friendly alternative to in vivo research models., (Copyright © 2019 American Society for Microbiology.)

A slow fermentation rate of dietary fiber could result in a steady metabolite production release and even distribution in the entire colon, increasing the likelihood of meeting the energy requirements of the distal colon. In the present study, we modulated the fermentation rate in an in vitro human fecal fermentation model by applying chemical cross-linking modification to a type 2 resistant starch [i.e., high-amylose maize starch (HAMS)]. Cross-linking modification decreased the gas production (an indicator of the fermentation rate) of HAMS throughout the whole fermentation progress. The butyrate production rate of cross-linked starches decreased gradually with the increase of the cross-linking degree. Certain beneficial gut microbiota such as genera of Blautia and Clostridiales members were remarkably promoted by starches with low and medium cross-linking degrees, whereas HAMS with a high cross-linking degree obviously promoted the abundance of Bacteroides uniformis and Ruminococcus bromii . This finding reveals that cross-linking modification effectively controls the fermentation rate and highlights the modulation metabolite profiles and gut microbiota composition through chemical modification.

In this work, 18 gluten-free flours (prepared from cereals, pseudocereals and legumes), differing in pigmentation, were screened for their phenolic profiles, cooked and, then, subjected to digestion and large intestinal fermentation in vitro. A combined targeted/untargeted metabolomic approach was used to elucidate the microbial biotransformation processes of polyphenols following digestion. This preliminary work demonstrated an increase in 3,5-dihydroxybenzoic acid (on average from 0.67 up to 1.30 μmol/g dry matter) throughout large intestinal fermentation of pseudocereals (esp. quinoa), due to their high alkylresorcinol contents. Isoflavones were converted into equol- or O-desmethylangolensin- derivatives, whereas anthocyanins were degraded into lower-molecular-weight phenolics (i.e., protocatechuic aldehyde and 4-hydroxybenzoic acid, with the latter exhibiting the highest increase over time). A decreasing trend was observed for antioxidant activities (i.e., FRAP and ORAC values) moving from digested to faecal fermented samples. These findings highlight that gluten-free flours are able to deliver bioaccessible polyphenols to the colon., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The glycosphingolipid, α-galactosylceramide (αGalCer), when presented by CD1d on antigen-presenting cells, efficiently activates invariant natural killer T ( i NKT) cells. Thereby, it modulates immune responses against tumors, microbial and viral infections, and autoimmune diseases. Recently, the production of αGalCer by Bacteroidetes from the human gut microbiome was elucidated. Using hydrophilic interaction chromatography coupled to MS 2 , we screened murine intestinal tracts to identify and quantify αGalCers, and we investigated the αGalCer response to different dietary and physiologic conditions. In both the cecum and the colon of mice, we found 1-15 pmol of αGalCer per milligram of protein; in contrast, mice lacking microbiota (germ-free mice) and fed identical diet did not harbor αGalCer. The identified αGalCer contained a β( R )-hydroxylated hexadecanoyl chain N -linked to C18-sphinganine, which differed from what has been reported with Bacteroides fragilis Unlike β-anomeric structures, but similar to αGalCers from B. fragilis , the synthetic form of the murine αGalCer induced i NKT cell activation in vitro. Last, we observed a decrease in αGalCer production in mice exposed to conditions that alter the composition of the gut microbiota, including Western type diet, colitis, and influenza A virus infection. Collectively, this study suggests that αGalCer is produced by commensals in the mouse intestine and reveals that stressful conditions causing dysbiosis alter its synthesis. The consequences of this altered production on i NKT cell-mediated local and systemic immune responses are worthy of future studies., (Copyright © 2019 von Gerichten et al.)

The gastrointestinal (GI) tract of vertebrates is inhabited by a vast array of organisms, i.e., the microbiota and macrobiota. The former is composed largely of commensal microorganisms, which play vital roles in host nutrition and maintenance of energy balance, in addition to supporting the development and function of the vertebrate immune system. By contrast, the macrobiota includes parasitic helminths, which are mostly considered detrimental to host health via a range of pathogenic effects that depend on parasite size, location in the GI tract, burden of infection, metabolic activity, and interactions with the host immune system. Sharing the same environment within the vertebrate host, the GI microbiota and parasitic helminths interact with each other, and the results of such interactions may impact, directly or indirectly, on host health and homeostasis. The complex relationships occurring between parasitic helminths and microbiota have long been neglected; however, recent studies point towards a role for these interactions in the overall pathophysiology of helminth disease, as well as in parasite-mediated suppression of inflammation. Whilst several discrepancies in qualitative and quantitative modifications in gut microbiota composition have been described based on host and helminth species under investigation, we argue that attention should be paid to the systems biology of the gut compartment under consideration, as variations in the abundances of the same population of bacteria inhabiting different niches of the GI tract may result in varying functional consequences for host physiology., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This study aimed to evaluate the potential of two new fat-protected butyrate or heptanoate salts to improve gut health and control post-weaning colibacillosis in weaning piglets challenged with enterotoxigenic Escherichia coli (ETEC) F4 + , particularly focusing on their impact on intestinal microbiota and fermentative activity along the gastrointestinal tract (GIT). Seventy-two 21-d-old pigs were fed a plain diet (CTR) or supplemented with sodium butyrate (BUT) or sodium heptanoate (HPT), both at 0.3%. After a week of adaptation, animals were orally challenged at days 8 and 9 with 5.8 · 10 9 and 6.6 · 10 10 cfu, respectively, and were euthanised on d 4 and d 8 post-inoculation (PI) ( n = 8) to collect blood, digesta and tissue samples and characterise microbial groups, pathogen loads (qPCR), fermentation, ileal histomorphometry and immune markers. Colonic microbiota was analysed by 16S rRNA gene MiSeq sequencing. Supplementing both acid salts did not compensate clinical challenge effects nor performance impairments and neither histomorphometry nor serum biomarkers. Changes in the gastric fermentative activity were registered, BUT reducing lactic acid concentrations (day 8 PI), and with HPT fewer animals presenting detectable concentrations of propionic, butyric and valeric acids. At ileum BUT increased acetic acid concentration (day 8 PI), and both additives reduced short-chain fatty acids (SCFA) in the colon. Increases in enterobacteria and coliforms counts in ileal digesta (day 4 PI, p < 0.10) and mucosa scrapes ( p < 0.05) were registered although E. coli F4 gene copies were unaffected. Regarding changes in the colonic microbiota (day 4 PI), Prevotellaceae and Prevotella were promoted with BUT supplementation whereas only minor groups were modified in HPT-treated animals. Summarising, although the pathogen loads or inflammatory mediators remained unresponsive, butyrate and heptanoate showed a significant impact on microbial fermentation along the whole GIT, being able to modify different bacterial groups at the colon. It could be hypothesised that these effects might be mediated by a carry-over effect of the changes observed in gastric fermentation, but possibly also to a better nutrient digestion in the foregut as a result of the reduced colonic SCFA concentrations.

Polybrominated diphenyl ethers (PBDEs) are persistent environmental toxicants associated with increased risk for metabolic syndrome. Intermediary metabolism is influenced by the intestinal microbiome. To test the hypothesis that PBDEs reduce host-beneficial intermediary metabolites in an intestinal microbiome-dependent manner, 9-week old male conventional (CV) and germ-free (GF) C57BL/6 mice were orally gavaged once daily with vehicle, BDE-47, or BDE-99 (100 μ mol/kg) for 4 days. Intestinal microbiome (16S rDNA sequencing), liver transcriptome (RNA-Seq), and intermediary metabolites in serum, liver, as well as small and large intestinal contents (SIC and LIC; LC-MS) were examined. Changes in intermediary metabolite abundances in serum, liver, and SIC, were observed under basal conditions (CV vs. GF mice) and by PBDE exposure. PBDEs altered the largest number of metabolites in the LIC; most were regulated by PBDEs in GF conditions. Importantly, intestinal microbiome was necessary for PBDE-mediated decreases in branched-chain and aromatic amino acid metabolites, including 3-indolepropionic acid, a tryptophan metabolite recently shown to be protective against inflammation and diabetes. Gene-metabolite networks revealed a positive association between the hepatic glycan synthesis gene α -1,6-mannosyltransferase (Alg12) mRNA and mannose, which are important for protein glycosylation. Glycome changes have been observed in patients with metabolic syndrome. In LIC of CV mice, 23 bacterial taxa were regulated by PBDEs. Correlations of certain taxa with distinct serum metabolites further highlight a modulatory role of the microbiome in mediating PBDE effects. In summary, PBDEs impact intermediary metabolism in an intestinal microbiome-dependent manner, suggesting that dysbiosis may contribute to PBDE-mediated toxicities that include metabolic syndrome., (Copyright © 2019 by The American Society for Pharmacology and Experimental Therapeutics.)

Background & Aims: This review examines to what extent high-protein diets (HPD), which may favor body weight loss and improve metabolic outcomes in overweight and obese individuals, may also impact the gut environment, shaping the microbiota and the host-microbe (co)metabolic pathways and products, possibly affecting large intestine mucosa homeostasis., Methods: PubMed-referenced publications were analyzed with an emphasis on dietary intervention studies involving human volunteers in order to clarify the beneficial vs. deleterious effects of HPD in terms of both metabolic and gut-related health parameters; taking into account the interactions with the gut microbiota., Results: HPD generally decrease body weight and improve blood metabolic parameters, but also modify the fecal and urinary contents in various bacterial metabolites and co-metabolites. The effects of HPD on the intestinal microbiota composition appear rather heterogeneous depending on the type of dietary intervention. Recently, HPD consumption was shown to modify the expression of genes playing key roles in homeostatic processes in the rectal mucosa, without evidence of intestinal inflammation. Importantly, the effects of HPD on the gut were dependent on the protein source (i.e. from plant or animal sources), a result which should be considered for further investigations., Conclusion: Although HPD appear to be efficient for weight loss, the effects of HPD on microbiota-derived metabolites and gene expression in the gut raise new questions on the impact of HPD on the large intestine mucosa homeostasis leading the authors to recommend some caution regarding the utilization of HPD, notably in a recurrent and/or long-term ways., (Copyright © 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Yogurt is a popular product worldwide partly because of the health-promoting effects of the probiotics that it contains. Probiotics with high survivability constitute a promising direction for fortified yogurt products. This study aimed to prepare Bifidobacterium breve-loaded yogurt with the bacteria surviving transit to the lower part of small intestine or colon. Bifidobacterium breve beads were prepared through an ion-crosslinking method using low methoxyl pectin as the encapsulating material. Features such as encapsulation efficiency and stability during storage and passage through the simulated gastrointestinal tract were studied in vitro. A commercial starter was used for yogurt fermentation, and B. breve with or without encapsulation was added as a probiotic supplement with the starter or 3 to 4 h after fermentation. The effects of B. breve beads on yogurt characteristics were evaluated after different fermentation processes: BC, milk fermented with marketed yogurt starter; UBFF, unencapsulated B. breve added to fresh milk and then fermented; EBFF, encapsulated B. breve added to fresh milk and then fermented; UBAF, unencapsulated B. breve added after fermentation with the starter; and EBAF, encapsulated B. breve beads added 3 to 4 h after fermentation with the starter. Evaluation was based on texture, electronic nose, and electronic tongue analyses. The particle size analysis of B. breve beads showed that they were uniform, mostly spherical, 1 to 1.5 mm in diameter with encapsulating efficiency higher than 99%. Following treatment with the simulated gastrointestinal tract conditions, the number of B. breve decreased by 1.76 and 4.82 log cfu/g for B. breve beads and unencapsulated B. breve, respectively. The EBAF group showed the lowest viscosity (2,235.67 cP) at d 0, and the lower postfermentation degree was reflected by the slow increase in yogurt viscosity. All groups kept a relatively stable pH during storage. The cohesiveness values of the EBAF and UBAF groups were significantly higher than those of the other groups. The trends in texture changes within the BC, UBFF, and EBFF groups were similar, and the UBAF and EBAF groups showed similar trends. In conclusion, B. breve beads showed good stability in vitro and improved yogurt characteristics by increasing the survival rate of the encapsulated cells. Good compatibility of low methoxyl pectin beads with yogurt was also observed., (Copyright © 2019 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The genital tract pathogen Chlamydia trachomatis is frequently detected in the gastrointestinal tract, but the host immunity that regulates chlamydial colonization in the gut remains unclear. In a Chlamydia muridarum -C57 mouse model, chlamydial organisms are cleared from the genital tract in ∼4 weeks, but the genital organisms can spread to the gastrointestinal tract. We found that the gastrointestinal chlamydial organisms were cleared from the small intestine by day 28, paralleling their infection course in the genital tract, but persisted in the large intestine for long periods. Mice deficient in α/β T cells or CD4 + T cells but not CD8 + T cells showed chlamydial persistence in the small intestine, indicating a critical role for CD4 + T cells in clearing Chlamydia from the small intestine. The CD4 + T cell-dependent clearance is likely mediated by gamma interferon (IFN-γ), since mice deficient in IFN-γ but not interleukin 22 (IL-22) signaling pathways rescued chlamydial colonization in the small intestine. Furthermore, exogenous IFN-γ was sufficient for clearing Chlamydia from the small intestine but not the large intestine. Mice deficient in developing Chlamydia -specific Th1 immunity showed chlamydial persistence in the small intestine. Finally, IFN-γ-producing CD4 + but not CD8 + T cells from immunized donor mice were sufficient for eliminating Chlamydia from the small intestine but not the large intestine of recipient mice. Thus, we have demonstrated a critical role for Th1 immunity in clearing Chlamydia from the small intestine but not the large intestine, indicating that chlamydial colonization in different regions of the gastrointestinal tract is regulated by distinct immune mechanisms., (Copyright © 2019 American Society for Microbiology.)

High red meat intake is associated with the risk of colorectal cancer (CRC), whereas dietary fibers, such as resistant starch (RS) seemed to protect against CRC. The aim of this study was to determine whether high-amylose potato starch (HAPS), high-amylose maize starch (HAMS), and butyrylated high-amylose maize starch (HAMSB)-produced by an organocatalytic route-could oppose the negative effects of a high-protein meat diet (HPM), in terms of fermentation pattern, cecal microbial composition, and colonic biomarkers of CRC. Rats were fed a HPM diet or an HPM diet where 10% of the maize starch was substituted with either HAPS, HAMS, or HAMSB, for 4 weeks. Feces, cecum digesta, and colonic tissue were obtained for biochemical, microbial, gene expression (oncogenic microRNA), and immuno-histochemical (O 6 -methyl-2-deoxyguanosine (O 6 MeG) adduct) analysis. The HAMS and HAMSB diets shifted the fecal fermentation pattern from protein towards carbohydrate metabolism. The HAMSB diet also substantially increased fecal butyrate concentration and the pool, compared with the other diets. All three RS treatments altered the cecal microbial composition in a diet specific manner. HAPS and HAMSB showed CRC preventive effects, based on the reduced colonic oncogenic miR17-92 cluster miRNA expression, but there was no significant diet-induced differences in the colonic O 6 MeG adduct levels. Overall, HAMSB consumption showed the most potential for limiting the negative effects of a high-meat diet.

Background: Methane emissions from pigs account for 10% of total methane production from livestock in China. Methane emissions not only contribute to global warming, as it has 25 times the global warming potential (GWP) of CO 2 , but also represent approximately 0.1~3.3% of digestive energy loss. Methanogens also play an important role in maintaining the balance of the gut microbiome. The large intestines are the main habitat for the microbiome in pigs. Thus, to better understand the mechanism of methane production and mitigation, generic-specific and physio-ecological characteristics (including redox potential (Eh), pH and volatile fatty acids (VFAs)) and methanogens in the large intestine of pig were studied in this paper. Thirty DLY finishing pigs with the same diet and feeding conditions were selected for this experiment., Result: A total of 219 clones were examined using the methyl coenzyme reductase subunit A gene (mcrA) and assigned to 43 operational taxonomic units (OTUs) based on a 97% species-level identity criterion. The family Methanobacteriaceae was the dominant methanogen in colonic digesta of finishing pigs, accounting for approximately 70.6% of the identified methanogens, and comprised mainly the genera Methanobrevibacter (57%) and Methanosphaera (14%). The order Methanomassiliicoccales, classified as an uncultured taxonomy, accounted for 15.07%. The methanogenic archaeon WGK1 and unclassified Methanomicrobiales belonging to the order of Methanomicrobiales accounted for 4.57 and 1.37%, respectively. The Eh was negative and within the range - 297.00~423.00 mV and the pH was within the range 5.04~6.97 in the large intestine. The populations of total methanogens and Methanobacteriales were stable in different parts of the large intestine according to real-time PCR., Conclusion: The major methanogen in the large intestine of finishing pigs was Methanobrevibacter. The seventh order Methanomassiliicoccales and species Methanosphaera stadtmanae present in the large intestine of pigs might contribute to the transfer of hydrogen and fewer methane emissions. The redox potential (Eh) was higher in the large intestine of finishing pigs, which had a positive correlation with the population of Methanobacteriale.

Sports nutrition products are developed and targeted mainly for athletes to improve their nutrient intake, performance, and muscle growth. The fastest growing consumer groups for these products are recreational sportspeople and lifestyle users. Although athletes may have elevated physiological protein requirements and they may benefit from dietary supplements, the evidence regarding the role of dietary protein and supplements in the nutrition of recreational sportspeople and sedentary populations is somewhat complex and contradictory. In high-protein diets, more undigested protein-derived constituents end up in the large intestine compared to moderate or low-protein diets, and hence, more bacterial amino acid metabolism takes place in the colon, having both positive and negative systemic and metabolic effects on the host. The aim of the present review is to summarize the impact of the high-protein products and diets on nutrition and health, in sportspeople and in sedentary consumers. We are opening the debate about the current protein intake recommendations, with an emphasis on evidence-based effects on intestinal microbiota and personalized guidelines regarding protein and amino acid supplementation in sportspeople and lifestyle consumers.

Background: Adherent and invasive Escherichia coli (AIEC) is preferentially associated with ileal Crohn's disease (CD). The role of AIEC in the development of inflammation and its regional tropism is unresolved. The presence of long polar fimbriae (LPF) in 71% of ileal CD AIEC suggests a role for LPF in the tropism and virulence of AIEC. The aim of our study is to determine if AIEC, with or without LpfA, induces intestinal inflammation in monoassociated IL-10-/- mice., Methods: We compared murine AIEC strains NC101 (phylogroup B2, LpfA-) and CUMT8 (phylogroup B1, LpfA+), and isogenic mutant CUMT8 lacking lpfA154, with a non-AIEC (E. coli K12), evaluating histologic inflammation, bacterial colonization, mucosal adherence and invasion, and immune activation., Results: IL-10-/- mice monoassociated with AIEC (either CUMT8, CUMT8:ΔlpfA, or NC101) but not K12 developed diffuse small intestinal and colonic inflammation. There was no difference in the magnitude and distribution of inflammation in mice colonized with CUMT8:ΔlpfA compared with wild-type CUMT8. Bacterial colonization was similar for all E. coli strains. Fluorescence in situ hybridization revealed mucosal adherence and tissue invasion by AIEC but not K12. Production of the cytokines IL-12/23 p40 by the intestinal tissue and IFN-γ and IL-17 by CD4 T cells correlated with inflammation., Conclusions: IL-10-/- mice monoassociated with murine AIEC irrespective of LpfA expression developed chronic inflammation accompanied by IL-12/23 p40 production in the small and large intestines and IFN-γ/IL-17 production by CD4 T cells that model the interplay between enteric pathosymbionts, host susceptibility, and enhanced immune responses in people with IBD., (© 2018 Crohn’s & Colitis Foundation. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Bacteria can circumvent the effect of antibiotics by transitioning to a poorly understood physiological state that does not involve conventional genetic elements of resistance. Here we examine antibiotic susceptibility with a Class A β-lactamase+ invasive strain of Klebsiella pneumoniae that was isolated from a lethal outbreak within laboratory colonies of Chlorocebus aethiops sabaeus monkeys. Bacterial responses to the ribosomal synthesis inhibitors streptomycin and doxycycline resulted in distinct proteomic adjustments that facilitated decreased susceptibility to each antibiotic. Drug-specific changes to proteomes included proteins for receptor-mediated membrane transport and sugar utilization, central metabolism, and capsule production, whereas mechanisms common to both antibiotics included elevated scavenging of reactive oxygen species and turnover of misfolded proteins. Resistance to combined antibiotics presented integrated adjustments to protein levels as well as unique drug-specific proteomic features. Our results demonstrate that dampening of Klebsiella pneumoniae susceptibility involves global remodeling of the bacterial proteome to counter the effects of antibiotics and stabilize growth., (© 2019 Keasey et al.)

The gut microbiome regulates important host metabolic pathways including xenobiotic metabolism and intermediary metabolism, such as the conversion of primary bile acids (BAs) into secondary BAs. The nuclear receptors pregnane X receptor (PXR) and constitutive androstane receptor (CAR) are well-known regulators for xenobiotic biotransformation in liver. However, little is known regarding the potential effects of PXR and CAR on the composition and function of the gut microbiome. To test our hypothesis that activation of PXR and CAR regulates gut microbiota and secondary BA synthesis, 9-week-old male conventional and germ-free mice were orally gavaged with corn oil, PXR agonist PCN (75 mg/kg), or CAR agonist TCPOBOP (3 mg/kg) once daily for 4 days. PCN and TCPOBOP decreased two taxa in the Bifidobacterium genus, which corresponded with decreased gene abundance of the BA-deconjugating enzyme bile salt hydrolase. In liver and small intestinal content of germ-free mice, there was a TCPOBOP-mediated increase in total, primary, and conjugated BAs corresponding with increased Cyp7a1 mRNA. Bifidobacterium, Dorea, Peptociccaceae, Anaeroplasma, and Ruminococcus positively correlated with T-UDCA in LIC, but negatively correlated with T-CDCA in serum. In conclusion, PXR and CAR activation downregulates BA-metabolizing bacteria in the intestine and modulates BA homeostasis in a gut microbiota-dependent manner., (© The Author(s) 2018. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The gastrointestinal tract is abundantly colonized by microbes, yet the translocation of oral species to the intestine is considered a rare aberrant event, and a hallmark of disease. By studying salivary and fecal microbial strain populations of 310 species in 470 individuals from five countries, we found that transmission to, and subsequent colonization of, the large intestine by oral microbes is common and extensive among healthy individuals. We found evidence for a vast majority of oral species to be transferable, with increased levels of transmission in colorectal cancer and rheumatoid arthritis patients and, more generally, for species described as opportunistic pathogens. This establishes the oral cavity as an endogenous reservoir for gut microbial strains, and oral-fecal transmission as an important process that shapes the gastrointestinal microbiome in health and disease., Competing Interests: TS, MH, LC, SL, PC, AV, JW, OM, RA, EB, Cd, IS, AH, SS, GZ, PW, PB No competing interests declared, (© 2019, Schmidt et al.)

Nondigestible carbohydrates (NDCs) are fermentation substrates in the colon after escaping digestion in the upper gastrointestinal tract. Among NDCs, resistant starch is not hydrolyzed by pancreatic amylases but can be degraded by enzymes produced by large intestinal bacteria, including clostridia, bacteroides, and bifidobacteria. Nonstarch polysaccharides, such as pectin, guar gum, alginate, arabinoxylan, and inulin fructans, and nondigestible oligosaccharides and their derivatives, can also be fermented by beneficial bacteria in the large intestine. Butyrate is one of the most important metabolites produced through gastrointestinal microbial fermentation and functions as a major energy source for colonocytes by directly affecting the growth and differentiation of colonocytes. Moreover, butyrate has various physiological effects, including enhancement of intestinal barrier function and mucosal immunity. In this review, several representative NDCs are introduced, and their chemical components, structures, and physiological functions, including promotion of the proliferation of butyrate-producing bacteria and enhancement of butyrate production, are discussed. We also describe the strategies for achieving directional accumulation of colonic butyrate based on endogenous generation mechanisms.

The purpose of the work is to determine the spectrum, quantity and frequency of occurrence of microorganisms in the oral fluid and large intestine in healthy young men under changes of living conditions. A survey was conducted of 14 nonresident young men, students of the 1st and 2nd courses, studying at Tver State Medical University, which included questions about the place of birth, living conditions, the presence of chronic diseases and the frequency of their exacerbations over the past year, water and food regimes, physical exertion, the presence of bad habits and emotional stress, etc. The oral fluid and feces were examined to determine the spectrum and amount of microbiota of the upper and lower parts of the gastrointestinal tract. As the result of the survey, it was found that the living conditions of all young men significantly worsened among second-year students than freshmen. It was revealed that colon microbiota in sophomores characterized by less diverse than those of first-year, despite of a marked increase in the number of opportunistic pathogens (Stаphylocоccus spp., Strерtocoсcus spp., Clоstridium spp., Васillus spp., Кlebsiеlla spp.) over resident microbes. It was found the decrease in the number and frequency of occurrence of all microbial representatives in the oral microbiota of 2nd year students in comparison with first-year. It was proved that the deterioration of living conditions of nonresident students led to the increase in the number of second-year students with dysbiotic changes in the intestinal microbiota from 86% to 100%, mainly due to the increase in the number of persons with dysbiosis of II and III degree., Competing Interests: The authors declare no conflict of interest.

The aim of this study was to determine if there are quantitative differences in Candida fungi between pediatric patients with Crohn's disease (before and after exclusive enteral nutrition (EEN), and the biologic therapy with anti-tumor necrosis factor alpha - (IFX)), and healthy controls. DNA was isolated from fecal samples and PCR was used to determine the number of fungal cells. Both therapeutic interventions resulted in a statistically significant decrease in Pediatric Crohn's Disease Activity Index. The numbers of Candida decreased during both therapeutic intervention but the difference was statistically significant for the IFX intervention only ( p = 0.045). Moreover, fungi population in both study groups declined during intervention when compared to the control group but the difference was significant before treatment only in the IFX group ( p = 0.013). The total distribution of Candida with both IFX and EEN as well as in the control group differed significantly ( p = 0.01) before treatment only. No correlation between the numbers of Candida and disease activity as well as the following biochemical parameters: serum iron concentration, protein or glucose level were found. It cannot be ruled out that, in combination with genetic and immunological disorders, fungi can contribute to the initiation of the disease process and perpetuation of active inflammation., The aim of this study was to determine if there are quantitative differences in Candida fungi between pediatric patients with Crohn’s disease (before and after exclusive enteral nutrition (EEN), and the biologic therapy with anti-tumor necrosis factor alpha – (IFX)), and healthy controls. DNA was isolated from fecal samples and PCR was used to determine the number of fungal cells. Both therapeutic interventions resulted in a statistically significant decrease in Pediatric Crohn’s Disease Activity Index. The numbers of Candida decreased during both therapeutic intervention but the difference was statistically significant for the IFX intervention only ( p = 0.045). Moreover, fungi population in both study groups declined during intervention when compared to the control group but the difference was significant before treatment only in the IFX group ( p = 0.013). The total distribution of Candida with both IFX and EEN as well as in the control group differed significantly ( p = 0.01) before treatment only. No correlation between the numbers of Candida and disease activity as well as the following biochemical parameters: serum iron concentration, protein or glucose level were found. It cannot be ruled out that, in combination with genetic and immunological disorders, fungi can contribute to the initiation of the disease process and perpetuation of active inflammation.

Resource limitation is a fundamental factor governing the composition and function of ecological communities. However, the role of resource supply in structuring the intestinal microbiome has not been established and represents a challenge for mammals that rely on microbial symbionts for digestion: too little supply might starve the microbiome while too much might starve the host. We present evidence that microbiota occupy a habitat that is limited in total nitrogen supply within the large intestines of 30 mammal species. Lowering dietary protein levels in mice reduced their faecal concentrations of bacteria. A gradient of stoichiometry along the length of the gut was consistent with the hypothesis that intestinal nitrogen limitation results from host absorption of dietary nutrients. Nitrogen availability is also likely to be shaped by host-microbe interactions: levels of host-secreted nitrogen were altered in germ-free mice and when bacterial loads were reduced via experimental antibiotic treatment. Single-cell spectrometry revealed that members of the phylum Bacteroidetes consumed nitrogen in the large intestine more readily than other commensal taxa did. Our findings support a model where nitrogen limitation arises from preferential host use of dietary nutrients. We speculate that this resource limitation could enable hosts to regulate microbial communities in the large intestine. Commensal microbiota may have adapted to nitrogen-limited settings, suggesting one reason why excess dietary protein has been associated with degraded gut-microbial ecosystems.

Background: Resistant starch (RS) has been studied for its ability to serve as a substrate for the microbiota present in the human large intestine and for its beneficial physiological effects. The aim of this study was to screen and select novel strains of lactic acid bacteria (LAB) in the genus Bifidobacterium isolated from human fecal samples for further application as probiotics relying on their utilization of RS3, a prebiotic., Results: LAB were isolated from human fecal samples, based on their ability to utilize RS3 as a carbon source. Consequently, two LAB were identified as Bifidobacterium adolescentis based on morphological, physiological and biochemical properties, and molecular biological analysis. The RS3-utilizing ability of these isolates was shown by the rapid decrease in pH of RS3-MRS media and by the pinhole traces on the surface of RS3 particles. Isolated B. adolescentis JSC2 was shown to be negative for β-glucuronidase, suggesting that it would be safe for human use, and was found to be tolerant towards the acidic, bile-salt environment., Conclusion: This synbiotics approach of B. adolescentis JCS2, an RS-utilizing probiotics, coupled with RS utilization, is expected to enhance RS utilization in the food industry and be beneficial for the promotion of human health. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

The diversity of the methanogenic archaea associated with the six segments of the horse and donkey hindgut (caecum, right ventral colon, left ventral colon, left dorsal colon, right dorsal colon, and rectum) was analyzed using 16S rDNA gene clone library. A total of 641 positive clones, 321 from the horse and 320 from the donkey hindgut, were examined by the RFLP, revealing 9 different ribotypes, 8 in the horse and 5 in the donkey hindgut. In both the animals Methanobacteriales (Methanobrevibacter-like sequences) and Methanomicrobiales (Methanocorpusculum-like sequences) were detected as the dominant orders followed by the uncultured Methanomassiliicoccales. The composition of the equine archaeal community was found to be dependent on the gut region. In both the two animals no Methanobrevibacter-like clones were detected in the caeca, which were instead inhabited by the Methanocorpusculum-like archeons. The Methanosarcinales were found only in distal regions of the horse hindgut., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

We hypothesized that water-soluble cellulose acetate (WSCA) could be useful tool for the delivery of short-chain fatty acids to the large intestine. Rats were fed a control diet or a diet containing graded levels of WSCA for up to 21 days. Consuming WSCA dose-dependently increased large-bowel acetate and propionate concentrations through the bacterial fermentation. When WSCA was used as substrate, acetyl esterase activity in the cecal bacteria was detected solely in rats fed WSCA, in which the activity increased over time accompanied by an increased number of Bacteroides xylanisolvens. Consuming WSCA at a 4% level increased the goblet cell numbers and mucin contents in the cecum and lowered plasma cholesterol concentrations, which tended to correlate with the portal plasma concentrations of propionate. The results suggest that bacterial fermentation of WSCA is characterized by the greater production of acetate and propionate, which may contribute to the physiologic alterations.

Binding of cholera toxin subunit B (CTB) to its receptor and toxin transport into the intestinal epithelial cells are the causative events for the potentially lethal disease cholera. The five sugar mono-sialo ganglioside GM1 is the cell surface receptor for cholera toxin B-subunit. CTB binding was determined by use of immobilized GM1 to microtiter plates and by immunohistochemistry. Sections from the human colon and the human soft palate were incubated with FITC-conjugated CTB and with anti-MUC2. Both the luminal surface of the intestine and the secretory goblet cells exhibited strong binding. Addition of simple carbohydrates and milk to the incubation medium showed that a combination of lactose and non-fat dry milk was potent inhibitors of toxin- and mucin binding. Both CTB and ant-MUC2 stained to the cytoplasm (mucin granules) in the goblet cells from the human soft palate. In the colon CTB stained the entire cytoplasm of the goblet cells while anti-MUC2 detected only the supranuclear region of some cells, suggesting carbohydrate heterogeneity between goblet cell mucin granules in different regions of the human body. Both CTB- and MUC2 binding were inhibited when GM1 was added to the incubation medium. It is proposed that the human colonic goblet cells play a role in the secretory diarrhea in patients with cholera and that milk might have a prophylactic or therapeutic application in the management of cholera., (Copyright © 2018 Elsevier Ltd. All rights reserved.)