In vivo study of colonic fermentation of carbohydrate in infants

Dietary carbohydrate in the colon is fermented and converted into short-chain fatty acids. We studied the fate of carbohydrate that arrives in the colon under circumstances similar to those that occur during an episode of diarrhea and determined whether a quantitative correlation exists among certain indicators of colonic fermentation of carbohydrate arriving in the large bowel. A stable-isotope method was used to estimate carbon scavenging by the colon. Fourteen infants with severe malnutrition and history of watery stools and/or increased numbers of stools in the preceding 20 days were studied. Infants underwent nasocecal intubation and a 60-min infusion of 0.5 g/kg glucose containing 5 mg/kg of 13C-glucose. Stools were assessed for carbohydrate-fermenting bacteria, acetate, glucose, and 13C abundance; blood was assessed for acetate; and breath was assessed for hydrogen. Some of the infants eliminated the infusate per anus within 30 min of the infusion (group I; n = 5), while others did so 120 min or more after the infusion (Group II; n = 9). The volume of fecal output after the intracecal infusion differed significantly between group I and group II (57 +/- 13 vs. 24 +/- 4 ml; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)