Hydrogen sulfide protects from colitis: a possible role in stabilizing gut microbiota (898.3)

Abstract

We hypothesised that hydrogen sulfide (H2S) modifies gut microbiota and resolves intestinal inflammation. Rats were gavaged with diallyl disulfide (DADs), and colitis was induced by dinitrobenzene sulfonic acid (DNBS). Colitis severity was assessed by macroscopical, biochemical, and histological analysis. Microbial genetic diversity was performed by denaturing gradient gel electrophoresis. Antimicrobial activity of DADs, NaHS and Na2S was evaluated by plating and growth assays. Human intestinal epithelial cell lines were used to assess expression levels of antimicrobial peptides by qRT‐PCR, western‐blotting and immunofluorescence.Administration of DADs increased the expression of cathelicidin, separated the microbiota from the host by a thick mucus barrier, and slightly altered microbial genetic diversity. Treatment of DNBS animals with an inhibitor of H2S‐producing enzyme provoked a more severe colitis, enhanced the presence of mucosa‐associated microbial aggregates, and altered mucus barrier. These inflammatory parameters were all reduced when DNBS‐treated animals were given DADs. In vitro, H2S‐releasing compounds inhibited the growth of four strains of gut bacteria. Additionally, H2S altered the level of expression of cathelicidin and trefoil factor‐3 in human epithelial cells.The findings shed a new light on the therapeutic potential of H2S delivery during the course of colitis.Grant Funding Source: Izaak Walton Killam PDF fellowship / University of Calgary Eye's High PDF fellowship