Influence of feces from patients with ulcerative colitis on butyrate oxidation in rat colonocytes

An impaired oxidation of butyrate has been suggested as a causative factor of ulcerative colitis and, moreover, agents present in colonic luminal contents impair butyrate oxidation in both rat and human colonocytes. To evaluate the overall effect of feces on the production of CO2 and ketone bodies from butyrate oxidation in rat colonocytes, fecal homogenates from 10 healthy subjects and 10 patients with quiescent and 10 patients with active ulcerative colitis were sterile filtrated and added to rat colonocytes incubated with 2, 4, and 10 mmol/liter of stock butyrate, respectively. Addition of fecal filtrate from healthy subjects and patients with quiescent and active ulcerative colitis to colonocytes incubated with 2, 4, and 10 mmol/liter of stock butyrate, respectively, tended to decrease the production of CO2 from butyrate oxidation, whereas ketogenesis was unaffected. The decrease in CO2 production was not explained by the simultaneous addition of fecal short-chain fatty acids (SCFAs). However, a difference in the ability to decrease CO2 production was not found between filtrates from healthy subjects and patients with quiescent and active ulcerative colitis. In conclusion, feces from healthy subjects and patients with quiescent and active ulcerative colitis contain inhibitor(s) of the production of CO2 from butyrate oxidation in colonocytes. However, a specific inhibitory effect of feces from patients with ulcerative colitis on the production of CO2 could not be identified.