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 bowel function and nutritional status of elderly men. Methods: Seven older male subjects participated in this study that consisted 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 defecation, enema use and bloating were monitored daily. Fecal characteristics such as wet and dry stool weights, stool moisture, pH and short-chain fatty acid contents were determined on five-day fecal composites collected in each period. Feces were further fractionated into plant, bacterial and soluble fractions to determine the bases for the increase in stool weight. Nutritional status of subjects was assessed with anthropometric parameters, nutrient intake and biochemical measurements. Results: Incorporation of IO significantly increased the defecation frequency, wet stool output and dry stool weight by twofold, 70% and 55%, respectively. Fecal acetate and propionate concentrations significantly increased by nearly two and a half fold with IO supplement. The increase in stool bulk was mainly attributed by increased bacterial mass. Mean serum sodium concentration decreased in the experimental period while other blood characteristics did not change significantly. Anthropometric parameters and nutrient intake remained constant throughout the study. Conclusions: Consumption of IO effectively improved bowel movement, stool output and microbial fermentation in the colon without any adverse effect observed in this study. Therefore, supplementation of IO into ordinary low fiber dirts may be practical in relieving constipation in the elderly population.