The intestinal mucosa as a habitat of the gut microbiota and a rational target for probiotic functionality and safety

Deep metagenomic characterization of gut microbial community and function in preeclampsia

“…Its abundance has been associated with type 2 diabetes (T2D), rheumatoid arthritis ( Chen et al., 2016 ), and cholesterol metabolism ( Chen et al., 2016 ). Collinsella contributes to the pathogenesis in rheumatoid arthritis by increasing gut permeability, reducing the expression of tight junction proteins in epithelial cells, and inducing the expression of IL-17 cytokines ( Chen et al., 2016 ), which may result in the pathologic effects by recruitment of neutrophils and activation of NF-kB signaling ( Derrien et al., 2009 ). The increased gut permeability leads to leakage of bacteria and endotoxins from the gut lumen to the mesenteric lymph nodes and portal circulation, which will stimulate peritoneal, intestinal and hepatic macrophages ( Kim et al., 2006 ) to release numerous inducer cytokines of PE ( Lv et al., 2019 ; Chen et al., 2020 ).…”

Intestinal microbiota and anastomotic leakage of stapled colorectal anastomoses: a pilot study

“…The Roseburia genus in particular is a well-known butyrate producer, which, similar to Faecalibacteria, is associated with protection against inflammatory bowel diseases [ 18 ]. However, a large fraction of the Lachnospiraceae reads was identified on the species level to be of mucin-degrading Lachnospiraceae ( R. obeum , R. gnavus and R. torques ) [ 19 , 20 ]. The abundance of these mucin-degrading bacteria is commonly observed to be elevated in various inflammatory bowel diseases, such as Crohn’s disease, ulcerative colitis or irritable bowel syndrome [ 21 – 24 ].…”

Mucin-bacterial interactions in the human oral cavity and digestive tract

“…Recently, the use of a targeted cultivation approach allowed the isolation of a novel microorganism, Akkermansia muciniphila, capable of growth on mucin as sole carbon and nitrogen source. 93 This is the first intestinal member belonging to the recently discovered Verrucomicrobia phylum. Members of this bacterial phylum have been detected using molecular techniques in a variety of ecosystems, including soil, Clostridium cocleatum β-galactosidase, β-N-acetylglucosaminidase, α-N-acetylgalactosaminidase, neuraminidase 170…”

“…Further studies based on construction of 16S rRNA genes of enriched fecal mucin-degrading bacteria revealed the diversity of mucolytic consortia. 93 Mucolytic bacteria were enriched from fecal samples inoculated on a mucin-limited medium and monitored by denaturing gel gradient electrophoresis of 16S rRNA gene amplicons. This molecular fingerprint approach showed that the profiles from different subjects were highly diverse, with a similarity index of 57.4 ± 9.2%, indicating that the mucin-degrading bacterial community is roughly similar within the whole 2 These numbers (percentages) represent the protein coding genes that encode a putative signal peptide.…”

“…The 16S rRNA gene sequences that showed similarities higher than 98% to known database entries were related to the Gram-positive genera Clostridium and Ruminococcus (Clostridium clusters IV, XIVa and XVIII), whereas the remaining ones were related to species belonging to Verrucomicrobia and Proteobacteria. 93 In addition, recently Leitch et al studied the colonization of insoluble substrates including pig gastric mucin by fecal bacteria in an anaerobic in vitro continuous flow system. They showed by a cloning-and sequencing strategy and FISH based on 16S rRNA gene, that Bifidobacteria were the principal species (Bif.…”