Effects of isomalto-oligosaccharides on bowel functions and indicators of nutritional status in constipated elderly men

Objectives: To evaluate effects of isomalto-oligosaccharides (IO) on the bo wel function and nutritional status of elderly men. Methods: Seven older male subjects participated in this study that consiste d of a 30-day control low fiber period followed by a 30-day IO-supplemented (10 g active components) experimental period. Bowel functions such as defec ation, enema use and bloating were monitored daily. Fecal characteristics s uch as wet and dry stool weights, stool moisture, pH and short-chain fatty acid contents were determined on five-day fecal composites collected in eac h period. Feces were further fractionated into plant, bacterial and soluble fractions to determine the bases for the increase in stool weight. Nutriti onal status of subjects was assessed with anthropometric parameters, nutrie nt intake and biochemical measurements. Results: Incorporation of IO significantly increased the defecation frequen cy, wet stool output and dry stool weight by twofold, 70% and 55%, respecti vely. Fecal acetate and propionate concentrations significantly increased b y nearly two and a half fold with IO supplement. The increase in stool bulk was mainly attributed by increased bacterial mass. Mean serum sodium conce ntration decreased in the experimental period while other blood characteris tics did not change significantly. Anthropometric parameters and nutrient i ntake remained constant throughout the study. Conclusions: Consumption of IO effectively improved bowel movement, stool o utput and microbial fermentation in the colon without any adverse effect ob served in this study. Therefore, supplementation of IO into ordinary low fi ber dirts may be practical in relieving constipation in the elderly populat ion.