[Effect of gum guar in diet on nitrogen balance, protein metabolism and food transit time in rats].
The addition of 5% gum guar to a diet containing 10% casein did not change the overall N retention of young rats but induced a significant shift in the N excretion from urine to feces, resulting in a markedly decreased apparent protein digestibility. The increase in total fecal dry matter over control values accounted for only 30% of the ingested gum guar implying that 70% was absorbed, possibly after being degraded by intestinal micro-organisms. The elimination of 14C activity following oral application of 14C protein indicated an accelerated turnover of amino acids during the first 3 h. After 25 h no difference between experimental and control animals was evident with respect to 14C activity remaining in the carcass. The transit time of food, as determined by neutron activation analysis of an Ytterbium marker, was somewhat decreased in the presence of gum guar.