Disease Development Is Accompanied by Changes in Bacterial Protein Abundance and Functions in a Refined Model of Dextran Sulfate Sodium (DSS)-Induced Colitis

Using the acute dextran sulfate sodium
(DSS)-induced colitis model,
studies have demonstrated that intestinal inflammation is accompanied
by major changes in the composition of the intestinal microbiota.
Only little is known about the microbial changes and more importantly
their functional impact in the chronic DSS colitis model. We used
a refined model of chronic DSS-induced colitis that reflects typical
symptoms of the human disease without detrimental weight loss usually
observed in DSS models. We sampled cecum and colon content as well
as colon mucus from healthy and diseased mouse cohorts (n = 12) and applied 16S rRNA gene sequencing and metaproteomics. An
increase of Prevotella sp. in both colon content
and mucus was observed. Functional differences were observed between
sample types demonstrating the importance of separately sampling lumen
content and mucus. The abundance of Desulfovibrio, a sulfate-reducing bacterium, was positively associated with the
carbon metabolism. Lachnoclostridium was positively
correlated to both vitamin B6 and tryptophan metabolism. In summary,
functional changes in the distal colon caused by DSS treatment were
more pronounced in the mucus-associated microbiota than in the microbiota
present in the distal colon content.