THE INFLUENCE OF A PRESERVED COLON ON THE ABSORPTION OF MEDIUM-CHAIN FAT IN PATIENTS WITH SMALL-BOWEL RESECTION

Background-Medium chain C8-C10 triglycerides (MCTs) improve fat absorp tion in short bowel patients. Effects on overall energy absorption rem ain unknown . Aims-To determine whether MCTs and medium chain fatty ac ids (MCFAs) are absorbed in the colon like the short chain fatty acids (SCFAs) or are lost in faeces similarly to long chain fatty acids (LC FAs). Methods-Nine small bowel resected patients without and 10 with a colon in continuity excreted 2-6 MJ/day and were randomised and cross ed over between two high fat diets (10 MJ/day, 50% as fat), based on e ither long chain triglycerides (LCT) alone or equal quantities of LCT and MCT. Results-Patients with a colon absorbed C8-C10 fatty acids con siderably better than patients without a colon at similar and extreme levels of LCFA malabsorption; the colonic impact on absorption of C14- 18 fatty acids was negligible. MCT redoubled fat (MCT+LCT) absorption from 23% to 58% in patients with a colon, and increased overall bomb c alorimetric energy absorption from 46% to 58%. The increase in fat abs orption 37% to 46% in patients without a colon did not improve overall energy absorption because malabsorption of carbohydrate and protein i ncreased. Conclusion-In small bowel resected patients, the colon seems to serve as a digestive organ for medium chain fat, probably absorbed as MCFAs, perhaps because like the SCFAs, they are water soluble. Onl y patients with a colon gained from MCT treatment.