Background: Anaerobic colonic flora are necessary for the fermentation of fiber into short-chain fatty acids and constitute the bulk of fecal mass. Lack of dietary fiber in most enteral feedings, compounded by antibiotic therapy, suppresses normal colonic metabolism, resulting in diarrhea. Pectin, a water-soluble fiber, stimulates epithelial growth in the colon and thus reduces diarrhea.
Methods: Forty-four critically ill patients receiving enteral nutrition and antibiotic therapy were randomized to receive fiber-containing or fiber-free tube feedings and pectin or placebo. Data on frequency, consistency, and volume of fecal output; energy (caloric) intake; and administration of specific medications were collected for 9 days. Diarrhea was defined as 2 or more days with scores of 12 or higher on the Hart and Dobb diarrhea scale.
Results: Subjects in the 4 groups did not differ significantly in age, sex, severity of illness, or energy intake. Twelve subjects (27.3%) experienced diarrhea. Significantly fewer subjects in the fiber-free/placebo and fiber/pectin groups experienced diarrhea than did subjects in the fiber/placebo group (P = .02). On the basis of repeated-measures analysis of variance of daily mean scores, the severity of diarrhea did not differ significantly among the study groups over time (P = .16).
Conclusions: The reduced rate of diarrhea found in this study may be related to the stringent definition of diarrhea used. The therapeutic dose of pectin for reducing diarrhea needs further exploration. The trend was toward less diarrhea in the fiber/pectin group, but the study needs to be replicated with a larger sample.