The effect of fiber source in enteral products on fecal weight, mineral balance, and growth rate in rats.

The effect of two fiber systems in enteral formulas on fecal output, mineral balance, weight gain, and cecal short-chain fatty acid production was studied in rats. Enteral products tested had either no fiber; soy fiber (3.4 g of total dietary fiber/8 fluid oz); a fiber blend containing 75% oat fiber, 17.5% gum arabic, and 7.5% carboxymethylcellulose (3.4 g of total dietary fiber/8 fluid oz); or the same blend at 4 g of total dietary fiber/8 fluid oz. Food, feces, and urine were analyzed for nitrogen, calcium, magnesium, iron, and zinc. Cecal contents were analyzed for short-chain fatty acids. Weight gain, intake, food efficiency, and nitrogen balance were unaffected by fiber source. Fecal weight was increased by the fiber blend (p < .05). Calcium and magnesium balances were similar for all groups fed fiber-containing products but were lower for the fiber-free group (p < .05). Iron balance was significantly lower for rats fed the fiber blend at 4 g/8 fluid oz as compared with the other treatment groups (p < .05). Cecal acetate, propionate, and total short-chain fatty acid concentrations for rats fed the soy-fiber diet were significantly higher than for the other three diets (p < .05). Rats fed the fiber blend at the higher level had a significantly higher percentage of butyrate production than rats fed the other three diets (p < .05).(ABSTRACT TRUNCATED AT 250 WORDS)