FECAL SHORT-CHAIN FATTY-ACIDS IN CHILDREN WITH INFLAMMATORY BOWEL-DISEASE

Nutrition of colonic epithelial cells (colonocytes) is maintained by l uminal short-chain fatty acids (SCFAs), chiefly by n-butyrate. The imp ortance of SCFAs for the maintenance of colonic epithelium has been de monstrated in animal models of colitis produced by rectal instillation of an inhibitor of SCFA oxidation and in patients with diversion coli tis in whom a segment of colonic epithelium was deprived of contact wi th luminal SCFAs. We measured fecal SCFAs and lactate in children with ulcerative colitis (UC; n = 17) and with Crohn's disease with ileocol onic involvement (CD; n = 22) and age-matched controls (n = 12) by a v acuum-distillation, gas chromatographic method. Fecal SCFA concentrati ons were correlated with scores of clinical disease activity. Patients with UC and CD had a decrease in the fecal concentration of acetate ( p < 0.05) and an increase in n-butyrate (p < 0.01) compared with contr ols. No significant changes in fecal lactate were seen. A comparison o f inactive- or mild-UC patients with moderate- or severe-UC patients y ielded major differences in SCFA concentrations with n-butyrate increa sed in inactive and mild UC well above control values and total SCFA a nd acetate decreased in moderate and severe UC below control levels. R aised concentrations of fecal n-butyrate may reflect impaired utilizat ion of this SCFA in the colon of patients with mild UC and Crohn's dis ease with colonic involvement. Whether this defect is primary or secon dary to inhibitors in the colonic lumen, due to impaired transport of n-butyrate into the cell or defective metabolism within the cell, or s pecific to inflammatory bowel, disease remains to be explored.