Effects of Alpha-Ketoglutarate on Glutamine Metabolism in Piglet Enterocytes in Vivo and in Vitro.
Level 5 - mechanism / opinion, no new human data
Preclinical animal and in vitro study without human participants.
PubMed 27018713 · doi:10.1021/acs.jafc.6b00433
What was done
Twenty-one piglets weaned at 28 days (initial body weight 6.0 ± 0.2 kg) were randomly allocated to three groups (n = 7 per group): a basal corn-soybean meal diet (CON), the basal diet with 1% alpha-ketoglutarate (AKG), or the basal diet with 1% L-glutamine (GLN). Additionally, intestinal porcine epithelial cells (IPEC-1) were cultured with 0.5, 2, and 3 mM AKG to evaluate glutamine metabolism in vitro.
What was found
There were no significant differences across the three groups in initial body weight, final body weight, or average daily feed intake (P > 0.05). Average daily gain (P = 0.013) and gain:feed ratio (P = 0.041) were significantly greater in the AKG group than in the CON and GLN groups. Both AKG and GLN increased jejunal villus length, mucosal thickness, crypt depth, and mRNA expression of jejunal and ileal amino acid transporters compared with CON (P < 0.05). Serum concentrations of Asp, Glu, Val, Ile, Tyr, Phe, Lys, and Arg were lower in the AKG and GLN groups compared to CON (no exact numerical values provided in the abstract). In vitro, AKG dose-dependently decreased net glutamine utilization and the formation of ammonia, Glu, Ala, and Asp by IPEC-1 cells (P < 0.05).
Why it matters
This study indicates that alpha-ketoglutarate can substitute for glutamine in supporting intestinal mucosal integrity and amino acid utilization in early-weaned animals.
Limits
The study was conducted in piglets and cultured porcine epithelial cells, limiting direct applicability to human nutrition. Sample size was small (21 piglets total, 7 per group), and the abstract lacks exact numerical values and effect sizes for morphology measurements, serum amino acid concentrations, and transporter mRNA expression levels.
Cited by
- supports Intestinal epithelial cells utilize glutamine, converting it to alpha-ketoglutarate as an energy source.