Project description:The interplay between the intestinal microbiota and host is critical to intestinal ontogeny and homeostasis. MicroRNAs (miRNAs) may be an underlying link. Intestinal miRNAs are microbiota-dependent and when shed in the lumen, affect resident microorganisms. Yet, longitudinal relationships between intestinal tissue miRNAs, luminal miRNAs, and luminal microorganisms have not been elucidated, especially in early life. Here, we investigated the postnatal cecal miRNA and microbiota populations, their relationship, and their impact on intestinal maturation in specific and opportunistic pathogen free mice; we also assessed if they can be modified by an intervention with allochthonous probiotic lactobacilli. We report that cecal and cecal content miRNA and microbiota signatures are temporally regulated, correlated, and modifiable by probiotics with implications for intestinal maturation. These findings help with understanding causal relationships within the gut ecosystem and provide a basis for preventing and managing their alterations in diseases throughout life.
Project description:Pu-erh tea has attracted increasing attention worldwide because of its special flavor and health effects, but its impact on composition and function of the gut microbiota remains unclear. The aim of this study was to investigate effects of aqueous extracts of fermented (ripe) and non-fermented (raw) Pu-erh teas on the composition and function of intestinal microbiota of rats with diet-induced obesity. We conducted a comparative metagenomic and metaproteomic investigation of the microbial communities in cecal samples taken from obese rats administrated with or without extracts of raw and ripe Pu-erh tea. By analyzing the composition and diversity of 16S rRNA amplicons and expression profiles of 814 distinct proteins, we found that, despite differences in the chemical compositions of the raw and ripe Pu-erh tea, administration of either at two different doses (0.15 and 0.40 g/Kg body weight), significantly (P<0.05) increased community diversity, and changed the composition of the cecal microbiota by increasing the relative abundances of Firmicutes and decreasing those of Bacteroidetes. Community metabolic processes including sucrose metabolism, glycolysis, syntheses of proteins, rRNA and antibiotics were significantly (P<0.05), or had a tendency (0.10<P<0.05) to be, promoted by enriching relevant enzymes. Furthermore, evidences from population, molecular and metabolic levels have shown that polyphenols of raw Pu-erh tea and their metabolites can promote potentially the growth of Akkermansia municiphila by stimulating the type II and III secretion system protein, elongation factor Tu, and glyceraldehyde-3-phosphate dehydrogenase. This study has provided new evidences for the prebiotic effects of Pu-erh tea.
Project description:The study investigated the impact of environment on the composition of the gut microbiota and mucosal immune development and function at gut surfaces in early and adult life. Piglets of similar genotype were reared in indoor and outdoor environments and in an experimental isolator facility. Mucosa-adherent microbial diversity in the pig ileum was characterized by sequence analysis of 16S rRNA gene libraries. Host-specific gene responses in gut ileal tissues to differences in microbial composition were investigated using Affymetrix microarray technology and Real-time PCR. Experiment Overall Design: Animals were reared on the sow at an outdoor or indoor facility. Additional piglets from the indoor facility were transferred to individual isolator units at 24 hours of age, and given a daily dose of antibiotic cocktail for the duration of the study. Piglets were weaned at day 28. From day 29 onwards, piglets were fed creep feed ad libitum. Ileal tissue samples were excised from N=6 piglets per group at day 5, 28 and 56.
Project description:The human gut microbiota is crucial for degrading dietary fibres from the diet. However, some of these bacteria can also degrade host glycans, such as mucins, the main component of the protective gut mucus layer. Specific microbiota species and mucin degradation patterns are associated with inflammatory processes in the colon. Yet, it remains unclear how the utilization of mucin glycans affects the degradation of dietary fibres by the human microbiota. Here, we used three dietary fibres (apple pectin, β-glucan and xylan) to study in vitro the dynamics of colon mucin and dietary fibre degradation by the human faecal microbiota. The dietary fibres showed clearly distinguishing modulatory effects on faecal microbiota composition. The utilization of colon mucin in cultures led to alterations in microbiota composition and metabolites. Metaproteome analysis showed the central role of the Bacteroides in degradation of complex fibres while Akkermansia muciniphila was the main degrader of colonic mucin. This work demonstrates the intricacy of complex glycan metabolism by the gut microbiota and how the utilization of host glycans leads to alterations in the metabolism of dietary fibres. Metaproteomics analysis of this data reveals the functional activities of the bacteria in consortia, by this contributing to a better understanding of the complex metabolic pathways within the human microbiota that can be manipulated to maximise beneficial microbiota-host interactions.