Transfer of blood urea nitrogen to cecal microbial nitrogen is increased by fructo‐oligosaccharide feeding in guinea pigs

Abstract

The present study was conducted to determine the mechanism by which nitrogen (N) availability is improved by fructo-oligosaccharide (FOS) in guinea pigs. Adult male guinea pigs were fed a commercial pellet diet (50 g/day) with either 5% glucose or 5% FOS for 7 days in individual metabolism cages. After 7 days of feeding the diet, (15) N-urea was administered intravenously 1 h before slaughter under anesthesia. The amount and concentration of total, protein, bacterial, ammonia and urea N and the (15) N atom % excess were measured in blood, liver, gut contents and urine. The (15) N atom % excess of total and protein N, and the amount of total, protein and bacteria N and (15) N in the cecum were significantly increased by the consumption of FOS. Furthermore, the concentration and amount of short-chain fatty acids were significantly increased by the consumption of FOS. In contrast, the amount of urinary (15) N was significantly decreased by the consumption of FOS. These results suggest that consumption of FOS increases transfer of blood urea N into the large intestine for bacterial N synthesis, which is subsequently re-absorbed by cecotrophy, and contributes to the increase of N utilization in guinea pigs.

Comparative Analysis of Fecal Microbiota in Grasscutter (Thryonomys swinderianus) and Other Herbivorous Livestock in Ghana

“…The mucus-trap mechanism allows the flow of food particles that are larger than those transported by the wash-back type into the cecum [30]. It is suggested that the wash-back CSM seals the rabbit's cecum for microbiota fermentation [30][31][32]. In other words, rabbits might be able to selectively store microbiota, whereas other animals do not have such ability.…”

Gut Function-Enhancing Properties and Metabolic Effects of Dietary Indigestible Sugars in Rodents and Rabbits

“…The raised N in cecotrophs results from bacterial proliferation which is stimulated by iS in the cecum. The fermentation of iS induces excessive amounts of blood urea flowing into the cecum [ 132 ], which is transformed to ammonia by bacterial ureolytic activity [ 133 ] to contribute to bacterial N synthesis [ 128 , 134 ]. As a result, urinary excretion of N is shifted to fecal excretion [ 10 , 128 ].…”

Safety evaluation of α-galacto-oligosaccharides for use in infant formulas investigated in neonatal piglets

“…The reduction in BUN value may be due to the increased nitrogen utilization by a larger microbial population induced by oligosaccharide intake. 43 A significant increase in TRIGs was noted in treated males; however, because the TRIG value is within the historical control range for piglets of this age and strain (11.0-108.0 gm/dL), it is not considered clinically adverse. Additionally, no statistically significant changes in chemistry parameters were noted in females from the treated group compared to controls.…”