Effect of butyrate enemas on inflammation and antioxidant status in the colonic mucosa of patients with ulcerative colitis in remission.

BACKGROUND & AIMS: Butyrate, produced by colonic fermentation of dietary fibers is often hypothesized to beneficially affect colonic health. This study aims to assess the effects of butyrate on inflammation and oxidative stress in subjects with chronically mildly elevated parameters of inflammation and oxidative stress. METHODS: Thirty-five patients with ulcerative colitis in clinical remission daily administered 60ml rectal enemas containing 100mM sodium butyrate (n=17) or saline (n=18) during 20 days (NCT00696098). Before and after the intervention feces, blood and colonic mucosal biopsies were obtained. Parameters of antioxidant defense and oxidative damage, myeloperoxidase, several cytokines, fecal calprotectin and CRP were determined. RESULTS: Butyrate enemas induced minor effects on colonic inflammation and oxidative stress. Only a significant increase of the colonic IL-10/IL-12 ratio was found within butyrate-treated patients (p=0.02), and colonic concentrations of CCL5 were increased after butyrate compared to placebo treatment (p=0.03). Although in general butyrate did not affect colonic glutathione levels, the effects of butyrate enemas on total colonic glutathione appeared to be dependent on the level of inflammation. CONCLUSION: Although UC patients in remission were characterized by low-grade oxidative stress and inflammation, rectal butyrate enemas showed only minor effects on inflammatory and oxidative stress parameters