title: 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.
authors: Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
authors: Kiyonori
authors: K
authors: Kawasaki
authors: Xiao
authors: X
authors: Min
authors: Xiao
authors: X
authors: Li
authors: Ena
authors: E
authors: Hasegawa
authors: Ei
authors: E
authors: Sakaguchi
mesh_terms: D000641:Ammonia / Q000378:metabolism; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D001419:Bacteria / Q000302:isolation & purification / Q000378:metabolism; D001806:Blood Urea Nitrogen; D002432:Cecum / Q000378:metabolism* / Q000382:microbiology*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005632:Fructose / Q000008:administration & dosage* / Q000494:pharmacology; D005947:Glucose / Q000008:administration & dosage; D006168:Guinea Pigs / Q000378:metabolism*; D007408:Intestinal Absorption / Q000187:drug effects; D008297:Male; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D009844:Oligosaccharides / Q000008:administration & dosage* / Q000494:pharmacology; D011506:Proteins / Q000378:metabolism; D014018:Tissue Distribution; D014508:Urea / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D005232:Fatty Acids, Volatile; D009566:Nitrates; D009844:Oligosaccharides; D011506:Proteins; D005632:Fructose; D000641:Ammonia; D014508:Urea; C530477:urea nitrate; D005947:Glucose; D009584:Nitrogen
keywords: 15N-urea; cecum; fructo-oligosaccharide; guinea pig; nitrogen utilization