Mo2033 Butyrate or Glutamine Enemas Prevent Inflammation and Fibrosis in Experimental Diversion Colitis

Abstract

Background and aims: Diversion colitis is a relatively common complication of colostomy involving the excluded colon's segment. Although the pathogenesis of the chronic inflammatory process remains unclear, the lack of luminal nutrients is believed to play a major role in the development of the disease. Therefore, we tested whether essential colonocyte nutrients, such as butyrate or glutamine could attenuate the inflammation in a model of diversion colitis. Methods: Forty eight male Wistar SPF rats were randomly distributed in 4 groups of 12 rats each. Animals were submitted to a Hartmann's end colostomy, and treated with enemas containing glutamine, butyrate, or saline. Enemas were administered twice a week in the excluded segment of the colon from the 4th to the 12th week after the surgical procedure. Follow-up video-colonoscopy was performed every 4 weeks, during 12 weeks. Afterwards, animals of all groups, including a normal control group were sacrificed either on the 8th week or the 12th week. The effects of treatment were evaluated using videoendoscopic and histologic scores, Picrosirius, Periodic Acid of Schiff and TUNEL staining, and also measuring the production of IL-1β, TNF-α and TGF-β in organ cultures, by ELISA. Results: Colonoscopies of the diverted segment, on 8th and 12th weeks, showed mucosa with hyperemia, increased number of vessels, spontaneous bleeding and mucus discharge, with the peak of the inflammatory activity in the 8th week. Treatment with either glutamine or butyrate prevented a significant increase in both colonoscopic (P < 0.01) and histological (P < 0.01) inflammatory scores, and stabilized the densities of collagen fibers in tissue (P < 0.02), the number of goblet cells (P <0.04), and the rate of apoptosis within the epithelium (P < 0.04) to normal low values, compared to the high values of the untreated inflamed tissues. Butyrate and glutamine enemas significantly abrogated the increased production of IL-1β and TGF-β (butyrate), and also of TNF-α (butyrate and glutamine) from tissue explants of surgically diverted colon, and levels were kept within the normal ranges following treatment. Conclusion: Topical administration of either glutamine or butyrate provides mucosal protection against the development of inflammation in the diverted colonic segment after colostomy. These results strongly suggest that the lack of specific luminal nutrients can induce inflammation, and support the potential utilization of glutamine or butyrate enemas for the treatment and possibly the prevention of human diversion colitis.