Decreased colonization of fecal C lostridium coccoides/ E ubacterium rectale species from ulcerative colitis patients in an in vitro dynamic gut model with mucin environment.

The mucus layer in the colon, acting as a barrier to prevent invasion of pathogens, is thinner and discontinuous in patients with ulcerative colitis ( UC). A recent developed in vitro dynamic gut model, the M- SHIME, was used to compare long-term colonization of the mucin layer by the microbiota from six healthy volunteers ( HV) and six UC patients and thus distinguish the mucin adhered from the luminal microbiota. Although under the same nutritional conditions, short-chain fatty acid production by the luminal communities from UC patients showed a tendency toward a lower butyrate production. A more in-depth community analysis of those microbial groups known to produce butyrate revealed that the diversity of the C lostridium coccoides/ E ubacterium rectale and C lostridium leptum group, and counts of F aecalibacterium prausnitzii were lower in the luminal fractions of the UC samples. Counts of R oseburia spp. were lower in the mucosal fractions of the UC samples. q PCR analysis for butyryl- Co A:acetate Co A transferase, responsible for butyrate production, displayed a lower abundance in both the luminal and mucosal fractions of the UC samples. The M- SHIME model revealed depletion in butyrate producing microbial communities not restricted to the luminal but also in the mucosal samples from UC patients compared to HV. [ABSTRACT FROM AUTHOR]