Gut microbiome (Cambridge, England)最新文献

Metabolic dietary patterns, including the Empirical Dietary Index for Hyperinsulinaemia (EDIH) and Empirical Dietary Inflammatory Pattern (EDIP), are known to impact multiple chronic diseases, but the role of the colonic microbiome in mediating such relationships is poorly understood. Among 1,610 adults with faecal 16S rRNA data in the TwinsUK cohort, we identified the microbiome profiles for EDIH and EDIP (from food frequency questionnaires) cross-sectionally using elastic net regression. We assessed the association of the dietary pattern-related microbiome profile scores with circulating biomarkers in multivariable-adjusted linear regression. In addition, we used PICRUSt2 to predict biological pathways associated with the enriched microbiome profiles, and further screened pathways for associations with the dietary scores in linear regression analyses. Microbiome profile scores developed with 32 (EDIH) and 15 (EDIP) genera were associated with higher insulin and homeostatic model assessment of insulin resistance. Six genera were associated with both dietary scores: Ruminococcaceae_UCG-008, Lachnospiraceae_UCG-008, Defluviitaleaceae_UCG-011 Anaeroplasma, inversely and Negativibacillus, Streptococcus, positively. Further, pathways in fatty acid biosynthesis, sugar acid degradation, and mevalonate metabolism were associated with insulinaemic and inflammatory diets. Dietary patterns that exert metabolic effects on insulin and inflammation may influence chronic disease risk by modulating gut microbial composition and function.

The gut microbiome is widely recognized for its significant contribution to maintaining human health across all life stages, from infancy to adulthood and beyond. This perspective article focuses on the impacts of well-supported microbiome research on global caesarean delivery rates, breastfeeding practices, and antimicrobial use. The article also explores the impact of dietary choices, particularly those involving ultra-processed foods, on the gut microbiota and their potential contribution to conditions like obesity, metabolic syndrome, and inflammatory diseases. This perspective aims to emphasize the need for updated guidelines and policy interventions to address the increasing global trends of caesarean deliveries, reduced breastfeeding, overuse of antibiotics, and consumption of highly processed foods to counter their adverse effects on gut health.

The latest Yakult Science Study Day was held virtually on 2 November 2023. Aimed at healthcare professionals, researchers, and students, a variety of experts explored the latest gut microbiome research and what it means in practice. The morning sessions discussed the role of the microbiome in health and disease, the rapid advancements in DNA sequencing and implications for personalised nutrition, the current state of evidence on health benefits associated with fermented foods, prebiotics and probiotics and the challenges involved in interpreting research in this area. The afternoon session considered the emerging research on the microbiota-gut-brain axis in mediating effects of food on mood, the bidirectional impact of menopause on the gut microbiota, and the interplay between the gut and skin with implications for the treatment of rare and common skin disorders. The session ended with an update on the use of faecal microbiota transplant in both research and clinical practice. Undoubtedly, the gut microbiome is emerging as a key conductor of human health, both in relation to gastrointestinal and non-gastrointestinal outcomes. As research continues to elucidate mechanisms of action and confirm their effects in human trials, the gut microbiome should be a key consideration within a holistic approach to health moving forward.

Streptococcus gallolyticus, subspecies gallolyticus (Sgg) is a gram-positive bacterium associated with infective endocarditis and colorectal cancer (CRC). Sgg has features that allow the bacterium to thrive in the colorectal tumor microenvironment and further progress the development of CRC to facilitate its survival. Sgg contains 3 pili that facilitate colonic cell adhesion and translocation through phase variation. Sgg also contains bile salt hydrolase and a bacteriocin called gallocin with substantially increased activity in bile acids, which facilitates its growth in the bile acid-rich adenomatous colorectal microenvironment. Sgg also uses tumor metabolites as an energy source. Sgg also possesses tannase, which metabolizes gallotannin to be used as a carbon source and reduces the anti-apoptotic effects of tannins, driving CRC progression. Sgg also interferes with a variety of oncogenic cell signaling pathways, including the Wnt/β-catenin pathway through mechanisms that are not fully elucidated. Increased β-catenin signaling also enhances adhesion via increased expression of the extracellular matrix and increases bile acid concentrations in the lumen through downregulation of an apical bile acid transporter. Finally, Sgg induces biotransformation of toxic substrates in CRC cells, which leads to formation of toxic intermediates and DNA adducts, promoting further progression of CRC.

Megasphaera elsdenii has been correlated with gas production by human faecal microbiota during fermentation. The objective of this study was to determine the role of M. elsdenii in gas production by the microbiome. Kidney beans and sweet potatoes were subjected to in vitro digestion and dialysis followed by fermentation with ten faecal microbiomes: three with detectable M. elsdenii (Me_D) and seven with no detectable M. elsdenii (Me_ND). Me_D microbiomes produced more gas than the Me_ND microbiomes (p < 0.001). Me_D microbiomes produced more gas during fermentation of sweet potatoes than kidney beans (p < 0.001), while the opposite was true for the Me_ND microbiomes (p < 0.001). Among amplicon sequence variants that were associated with gas production, M. elsdenii had the strongest association (p < 0.001). Me_D microbiomes consumed more acetate and produced more butyrate than Me_ND microbiomes (p < 0.001). Gas production by M. elsdenii was confirmed by fermentation of sweet potatoes and acetate with human and rumen M. elsdenii isolates. The human isolate produced gas on sweet potatoes and acetate. This study suggests that M. elsdenii may be involved in gas production during the fermentation of flatulogenic foods through utilisation of undigestible substrates or cross-feeding on acetate.

The host-intestinal microbiome interaction has gained much scientific attention in the past two decades, boosted by advances in DNA sequencing and cultivation techniques. An accumulating amount of evidence shows that gut microbes play crucial roles in gut homeostasis, immune system education, and are associated with quality-of-life indicators. Beneficial health factors are associated with the digestion of dietary fibres in the colon and the subsequent production of short-chain fatty acids, including acetate, propionate, and butyrate. Coprococcus is a butyrate-producing genus in the phylum Firmicutes, and its abundance is inversely correlated with several neuropsychological and neurodegenerative disorders. Case-control studies provide strong evidence of decreased abundance of Coprococcus spp. in depressed individuals. The species Coprococcus eutactus has the unique capacity to use two separate pathways for butyrate synthesis and has been found to be depleted in children with delayed language development and adults with Parkinson's disease. The combined literature on Coprococcus and the gut microbiota-brain axis points towards enhanced butyrate production and reduced colonisation of pathogenic clades as factors explaining its association with health effects. The genus Coprococcus is a promising candidate for a mental health biomarker and an interesting lead for novel dietary-based preventive therapies for specific neurological disorders.

Risk of bias assessment is a critical step of any meta-analysis or systematic review. Given the low sample count of many microbiome studies, especially observational or cohort studies involving human subjects, many microbiome studies have low power. This increases the importance of performing meta-analysis and systematic review for microbiome research in order to enhance the relevance and applicability of microbiome results. This work proposes a method based on the ROBINS-I tool to systematically consider sources of bias in microbiome research seeking to perform meta-analysis or systematic review for microbiome studies.

We carried out a comparative analysis between the bacterial microbiota composition of zoo-housed western lowland gorillas and their wild counterparts through 16S rRNA gene amplicon sequencing. In addition, we characterised the carbohydrate-active and methanogenic potential of the zoo-housed gorilla (ZHG) microbiome through shotgun metagenomics and RNA sequencing. The ZHG microbiota showed increased alpha diversity in terms of bacterial species richness and a distinct composition from that of the wild gorilla microbiota, including a loss of abundant fibre-degrading and hydrogenic Chloroflexi. Metagenomic analysis of the CAZyome indicated predominant oligosaccharide-degrading activity, while RNA sequencing revealed diverse cellulase and hemi-cellulase activities in the ZHG gut, contributing to a total of 268 identified carbohydrate-active enzymes. Metatranscriptome analysis revealed a substantial contribution of 38% of the transcripts from anaerobic fungi and archaea to the gorilla microbiome. This activity originates from cellulose-degrading and hydrogenic fungal species belonging to the class Neocallimastigomycetes, as well as from methylotrophic and hydrogenotrophic methanogenic archaea belonging to the classes Thermoplasmata and Methanobacteria, respectively. Our study shows the added value of RNA sequencing in a multiomics approach and highlights the contribution of eukaryotic and archaeal activities to the gut microbiome of gorillas.