ACUTE EFFECTS OF ORAL MICROBIAL PROTEASE CO-INGESTION WITH WHEY PROTEIN ON POSTPRANDIAL PLASMA AMINO ACID CONCENTRATIONS, APPETITE, AND SATIETY IN HEALTHY ADULTS

Author(s): HUANG, Y., BELL, Z.W.1, ALHAMWI, A.1, SAUVAGEAU, B.1, GARDY, S.1, KARUTH-IBARZ, T.1, HANNAIAN, S.J.1, CORREA, J.1, GRITSAS, A.1, GARVEY, S.M.2, ABOU SAWAN, S.3, MORAIS, J.1, CHURCHWARD-VENNE, T.A.1, Institution: MCGILL UNIVERSITY, Country: CANADA, Abstract-ID: 1916

INTRODUCTION:
Proteases are enzymes that catalyze the breakdown of proteins into smaller peptides and amino acids. Protease supplementation may be a candidate approach to enhance amino acid digestion and absorption from dietary protein. The present study aimed to evaluate the effects of a mixture of 3 microbial protease preparations (P3) on postprandial plasma amino acid concentrations when co-ingested with whey protein concentrate (WPC), compared to a maltodextrin placebo, in healthy young adults. Secondary aims were to assess the effect of WPC co-ingestion with P3 versus placebo on postprandial plasma glucose, insulin, and gut-derived appetite regulatory hormone (GLP-1, PYY, and ghrelin) concentrations, perceived appetite sensations, and ad libitum meal energy intake.
METHODS:
In this randomized, double-blinded, placebo-controlled crossover study, 12 males and 12 females (BMI: 23.6 (2.9) kg/m2; age: 25 (3) years [mean (SD)]) consumed WPC (25 g protein) with P3 or placebo. Plasma glucose, insulin, amino acid, and gut-derived appetite regulatory hormone concentrations were assessed at baseline, and throughout a 240-min postprandial period. Perceived appetite sensations were assessed by visual analog scale (VAS) questionnaires. An ad libitum meal was provided immediately following each trial to determine energy intake. The incremental area-under-the-curve (iAUC) and ad libitum energy intake data was compared between treatments using a mixed model ANCOVA, adjusting for treatment period, treatment sequence, and sex. Time-course data were analyzed via a mixed model repeated measures approach adjusting for baseline values, treatment period, treatment sequence, and sex. All hypothesis tests were two sided and performed at the alpha = 0.05 significance level.
RESULTS:
Adjusted mean postprandial plasma 60-min iAUC was 14% greater for plasma essential amino acids (EAA) (Treatment: P = 0.025) and 15% greater for branched-chain amino acids (BCAA) (Treatment: P = 0.021) with P3 versus placebo, with no significant differences for total amino acids or leucine (all P > 0.05). Adjusted mean postprandial plasma ghrelin was 12% lower (Treatment: P < 0.001), while adjusted mean VAS-derived fullness (Treatment: P = 0.025) and satiation (Interaction: t = 30–150 min; all P < 0.05) were greater with P3 versus placebo. Adjusted mean postprandial plasma glucose, insulin, GLP-1 and PYY, as well as ad libitum meal energy intake were not different between treatments (all P > 0.05).
CONCLUSION:
Co-ingestion of WPC with P3 increases postprandial plasma 60-min iAUC for EAA and BCAA concentrations, decreases plasma ghrelin concentration, and increases perceptions of fullness and satiation compared to co-ingestion of WPC with a placebo in young, healthy adults. Microbial protease supplementation may represent a practical strategy to further increase postprandial plasma amino acid availability and enhance satiety after dietary protein intake. This trial was prospectively registered at ClinicalTrials.gov (NCT05957185).