Effects of short chain fatty acids on mucosal proliferation and inflammation of ileal pouches in patients with ulcerative colitis and familial polyposis.

PURPOSE: To verify whether short chain fatty acids (SCFA) alter the proliferative and endoscopic pattern of the mucosa in ileal pouches of ulcerative colitis (UC) or familial adenomatous polyposis (FAP) patients. METHODS: We studied patients after proctocolectomy carrying a pelvic ileal pouch for FAP or UC (noncanalized pouches in 10 UC and 4 FAP patients and canalized pouches in 6 UC and 5 FAP patients). Patients with noncanalized pouches were treated twice daily for one week with 30 ml of a SCFA solution (60 mM sodium acetate, 30 mM sodium propionate, 40 mM sodium butyrate, and 22 mM sodium chloride, pH 7); patients with canalized pouches were treated with the same solution twice daily for two weeks. Pouch mucosal biopsies were collected before and after SCFA. Mucosal proliferation was assessed by incorporation of [3H]thymidine in vitro and autoradiography. RESULTS: In UC patients proliferation did not vary in noncanalized pouches but was significantly reduced in canalized pouches after SCFA. In FAP patients SCFA did not alter proliferation. No significant effects of SCFA were observed on daily defecation frequency, endoscopic appearance, or histopathology of the pouches. CONCLUSIONS: SCFA do not control inflammation and clinical functions but reduce cell proliferation in UC patients. On the contrary, FAP patients are refractory to SCFA.