Takeshi Fujieda

Postruminal supply of amino acids enhances ghrelin secretion and lipid metabolism in feed-deprived sheep

Single amino acids (AA) feeding is gaining more attention for their functional roles beyond nutritional needs. This study aimed to describe the endocrine and metabolic responses to a single AA administration (at 10% of MP for maintenance) in 48xa0hr fasted sheep (nxa0=xa04) receiving, over continued 4xa0hr, a duodenal infusate of saline (control), glutamate (Glu), glutamine (Gln), lysine HCl (Lys), threonine (Thr), or valine (Val) in a 4 by 6 Youden square design with weekly intervals. Blood samples were collected at 0, 15, 30, 60, 120, 180, and 240xa0min relative to the infusion onset, and plasma AA, glucose, β-hydroxybutyric acid (BHBA), nonesterified fatty acids (NEFA), ghrelin, insulin, glucagon, and insulin-like growth factor 1 (IGF-1) concentrations were measured. The results showed that the duodenal supply of Glu, Gln, Lys, Thr, and Val enhanced ghrelin release. Administration of Glu, Gln, and Val declined plasma BHBA concentrations, whereas plasma NEFA levels were decreased with Gln and Thr. Insulin concentration was greater with Thr, glucagon levels were increased with Lys, Thr, Val, and Glu, whereas IGF-1 levels were enhanced with Gln, Lys, and Thr supply. Thus, selective AA feeding can positively adjust the endocrine status and counteract the feed restriction-induced lipid mobilization.

Heat-killed cell preparation of Corynebacterium glutamicum stimulates the immune activity and improves survival of mice against enterohemorrhagic Escherichia coli

Fermentation by Corynebacterium glutamicum is used by various industries to produce L-Glutamate, and the heat-killed cell preparation of this bacterium (HCCG) is a by-product of the fermentation process. In present study, we evaluated the immunostimulating and survival effects against enterohemorrhagic Escherichia coli (STEC) infection of HCCG. HCCG significantly stimulated in vitro IgA and interleukin-12 p70 production in murine Peyer’s patch cells and peritoneal macrophages, respectively. Oral administration of 10 mg/kg body weight (BW) of HCCG for seven consecutive days stimulated IgA concentration in murine cecal digesta. Mice were orally administered HCCG for 17 consecutive days (d0–d17), and challenged with STEC on d4 to d6. Survival of mice tended to improve by 100 mg/kg BW of HCCG administration compared with those in control group. In conclusion, HCCG supplementation was found to prevent STEC infection in mice, and thus it may have the potential to stimulate the immune status of mammals. Graphical abstract Cell wall preparation of Corynebacterium glutamicum prevented of pathogenic E.coli infection through enhancement of immune function such as IgA secretion in the intestine.