We sought to determine if 28 days of probiotic supplementation influenced the plasma amino acid (AA) response to acute whey protein feeding.
Methods: Twenty-two recreationally active men (n = 11; 24.3 ± 3.2 yrs; 89.3 ± 7.2 kg) and women (n = 11; 23.0 ± 2.8 yrs; 70.2 ± 15.2 kg) participated in this double-blind, placebo-controlled, randomized study. Before (PRE) and after 28 days of supplementation (POST), participants reported to the lab following a 10-hr fast and provided a resting blood draw (0 min), then subsequently consumed 25 g of whey protein. Blood samples were collected at 15-min intervals for 2 h post-consumption (15-120 min) and later analyzed for plasma leucine, branched-chain AA (BCAA), essential AA (EAA), and total AA (TAA). Participants received a probiotic (PROB) consisting of 1 x10-9 colony forming units (CFU) Bacillus subtilis DE111 (n = 11) or a maltodextrin placebo (PL) (n = 11) for 28 days. Plasma AA response and area under the curve (AUC) values were analyzed via repeated measures analysis of variance.
Results: Our analysis indicated no significant (p < 0.05) differential responses for plasma leucine, BCAA, EAA, or TAA between PROB and PL from PRE to POST. AUC analysis revealed no group × time interaction for plasma leucine (p = 0.524), BCAA (p = 0.345), EAA (p = 0.512), and TAA (p = 0.712).
Conclusion: These data indicate that 28 days of Bacillus subtilis DE111 does not affect plasma AA appearance following acute whey protein ingestion.
Keywords: BCAA; absorption; gut; leucine; microbiome; protein synthesis.