ARS | Publication request: Supplementing glutamate to partial enteral nutrition slows gastric emptying rate in preterm pigs

Submitted to: Pediatric Academic Society
Publication Type: Abstract Only
Publication Acceptance Date: April 14, 2011
Publication Date: April 30, 2011
Citation: Bauchart-Thevret, C., Stoll, B., Benight, N., Olutoye, O., Burrin, D.G. 2011. Supplementing glutamate to partial enteral nutrition slows gastric emptying rate in preterm pigs [abstract]. In: Proceedings of the 2011 Annual Conference of the Pediatric Academic Society and the Asian Society for Pediatric Research. Session: Gastroenterology, April 30-May 3, 2011, Denver, Colorado. 2924.307.

Technical Abstract: Premature infants frequently present with gastroduodenal motor dysfunction, which is manifest clinically as feeding intolerance resulting from slow gastric emptying. Glutamate (GLU) is the major excitatory neurotransmitter in the body and multiple GLU receptors and transporters have been found in the gut and enteric nervous system. Emerging evidence suggest that GLU may play a functional role in promoting gastric emptying and digestion. However, the importance of dietary GLU on gastric motor function in the developing gut is unknown. The objective of this study was to determine whether supplementing GLU to partial enteral nutrition can stimulate gastric emptying in preterm pigs. Ten-d preterm, parenterally-fed pigs received partial enteral nutrition (25 percent) as 4 orogastric feeds every 6 h as milk-based formula supplemented with monosodium glutamate (MSG) at 0, 2, 4 and 6 times the basal GLU intake (117 mg/kg per feed)(n=5-8 pigs/group) for 7 d. Whole-body respiratory calorimetry and (13)C-octanoic acid breath test were performed on d 3, 5, 7 and 9 of life. Body weight gain, stomach and intestine weights and arterial plasma GLU and glutamine concentrations were not different between the MSG groups. However, GLU and aspartate concentrations were 3-4 times higher in the portal vs. arterial plasma in all treatment groups, suggesting a significant net portal absorption. In addition, portal GLU concentration was significantly higher while portal arginine concentration was significantly lower in pigs fed the MSG 4 and 6 doses. There was no treatment effect on VO[2] uptake, VCO[2] production, respiratory exchange ratio and heat production. At d 9 (Table), we found lower (P<0.05) breath (13)CO[2] enrichments and (13)CO[2] production, percent of (13)CO[2] recovery/h and cumulative percent recovery of (13)C-octanoic acid in MSG-4 and MSG-6 vs. MSG-0 groups. The average lag time (T[lag]) and gastric half emptying time (T[1/2]) between all treatment groups were 121 and 188 min, respectively. Regression analysis showed that T[lag] and T[1/2] were increased (P<0.05) by MSG dose. In conclusion our results suggest that adding glutamate to partial enteral nutrition slows the gastric emptying rate but does not affect intestinal mucosal growth in premature pigs.