The primary purpose of this study is to assess the effect of co-ingestion of microbial proteases and whey protein concentrate (WPC) on postprandial plasma amino acid concentrations in healthy adult participants compared to WPC with placebo. The secondary purpose is to assess the effect of co-ingestion of microbial proteases and WPC on postprandial glycemic response, subjective appetite sensations, gut-derived appetite regulating hormones, ad libitum meal intake, and gastrointestinal tolerability in healthy adult participants compared to WPC with placebo.
A within-subject crossover design will be used for this randomized, double-blind, placebo-controlled study in health adults to assess the efficacy of a microbial protease mixture (from Aspergillus species) on enhancing postprandial aminoacidemia after consumption of a whey protein shake. There are two treatment groups in this crossover trial, including one microbial protease group and one placebo group. A total of 24 participants will be enrolled and undergo both treatment phases with a minimum 7-day washout. The study will last no less than 8 days and up to 72 days for each participant, including screening, washout, and end of study (EOS) visit. The study will include a screening visit (Visit 1) followed by a screening period lasting up to 30 days, the phase 1 aminoacidemia trial on Day 1 (Visit 2), minimum 7-day washout with a window of +35 days, followed by the phase 2 aminoacidemia trial (EOS Visit 3, Day 8 +35 days). During the aminoacidemia trials, participants will arrive to the clinic in a fasted state, and 31.9 grams whey protein concentrate (WPC) in 300 mL water with microbial proteases or placebo will be administered. Blood will be collected at baseline and 11 postprandial timepoints across 4 hours for plasma amino acid, glucose, and insulin quantitation. Blood will also be utilized for quantitation of the anorexigenic, satiety-related peptide hormones glucagon-like peptide 1 (GLP-1) and peptide YY (PYY), and the orexigenic peptide hormone ghrelin. Additionally, changes in appetite sensations will be assessed by visual analog score (VAS) responses to 5 questions at baseline, directly after consumption of study products, and postprandially every half hour. Palatability of the study products will be assessed by 5-item Palatability Questionnaire. Gastrointestinal tolerability will be assessed by 8-item modified Gastrointestinal Tolerance Questionnaire (mGITQ) at the end of the 4-hour aminoacidemia trial. To further investigate appetite and satiety, an test meal will be provided at 4 hours for the determination of energy intake, followed by a final appetite VAS questionnaire immediately after the test meal. The maximum time to finish the test meal is 30 minutes. To account for the potential influence of menstrual cycle timing on the outcomes of interest, female subjects will be instructed to contact the clinic on day 1 of their menses so that Visit 2 (Day 1) can be scheduled at the end of menses, but still during the follicular phase of their menstrual cycle. The follicular phase is defined as days 1-14, where day 1 is the first day of menses. Therefore, Visit 2 (Day 1) and Visit 3 for female participants will occur approximately 3-5 days after start of menses, but on or before day 14 of the follicular phase (+4 day window), unless Visit 3 can be scheduled within the same follicular phase as Visit 2, with an at least 7-day washout. The study will include a total of three in-person visit days: screening (Visit 1), phase 1 (Visit 2), and phase 2/EOS (Visit 3). Study endpoints include postprandial plasma amino acid concentrations, postprandial plasma glucose and insulin concentrations, and postprandial plasma GLP-1, PYY, and ghrelin concentrations. Endpoints also include appetite VAS scores, ad libitum meal consumption, mGITQ scores, vital signs, anthropometric measures, and reports of adverse events, which will be assessed at all clinic visits.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
TRIPLE
Enrollment
24
One dose of P3 - WHEY will be combined with 31.9 grams whey protein concentrate in 300 mL water and consumed within 5 minutes at the start of each of the aminoacidemia trials.
One dose of placebo maltodextrain will be combined with 31.9 grams whey protein concentrate in 300 mL water and consumed within 5 minutes at the start of each of the aminoacidemia trials.
McGill University, Currie Gymnasium (Exercise Metabolism and Nutrition Research Laboratory)
Montreal, Quebec, Canada
Early (0-2 h) postprandial plasma total amino acid concentration incremental area-under-the-curve (P3 - WHEY vs. placebo treatment)
Free leucine, isoleucine, valine, histidine, lysine, methionine, phenylalanine, threonine, tryptophan, arginine, glutamine, glycine, alanine, serine, glutamic acid, aspartic acid, asparagine, tyrosine, cysteine, proline (combined) (µmol·L\^(-1)·120 min)
Time frame: 2 hours
Early (0-2 h) postprandial plasma essential amino acid concentration incremental area-under-the-curve
Free leucine, isoleucine, valine, histidine, lysine, methionine, phenylalanine, threonine, tryptophan (combined) (µmol·L\^(-1)·120 min)
Time frame: 2 hours
Early (0-2 h) postprandial plasma branched chain amino acid concentration incremental area-under-the-curve
Free leucine, isoleucine, valine (combined) (µmol·L\^(-1)·120 min)
Time frame: 2 hours
Early (0-2 h) postprandial plasma leucine concentration incremental area-under-the-curve
Free leucine (µmol·L\^(-1)·120 min)
Time frame: 2 hours
Total (0-4 h) postprandial plasma total amino acid concentration incremental area-under-the-curve
Free leucine, isoleucine, valine, histidine, lysine, methionine, phenylalanine, threonine, tryptophan, arginine, glutamine, glycine, alanine, serine, glutamic acid, aspartic acid, asparagine, tyrosine, cysteine, proline (combined) (µmol·L\^(-1)·240 min)
Time frame: 4 hours
Total (0-4 h) postprandial plasma essential amino acid concentration incremental area-under-the-curve
Free leucine, isoleucine, valine, histidine, lysine, methionine, phenylalanine, threonine, tryptophan (combined) (µmol·L\^(-1)·240 min)
Time frame: 4 hours
Total (0-4 h) postprandial plasma branched chain amino acid concentration incremental area-under-the-curve
Free leucine, isoleucine, valine (combined) (µmol·L\^(-1)·240 min)
Time frame: 4 hours
Total (0-4 h) postprandial plasma leucine concentration incremental area-under-the-curve
Free leucine (µmol·L\^(-1)·240 min)
Time frame: 4 hours
Postprandial plasma amino acid concentration, absolute change from baseline to 45 minutes
Total amino acids, essential amino acids, branched chain amino acids, leucine (µmol/L)
Time frame: 45 minutes
Postprandial plasma amino acid concentration, baseline-adjusted change from baseline to 45 minutes
Total amino acids, essential amino acids, branched chain amino acids, leucine (µmol/L)
Time frame: 45 minutes
Postprandial plasma amino acid concentration, absolute change from baseline to 60 minutes
Total amino acids, essential amino acids, branched chain amino acids, leucine (µmol/L)
Time frame: 60 minutes
Postprandial plasma amino acid concentration, baseline-adjusted change from baseline to 60 minutes
Total amino acids, essential amino acids, branched chain amino acids, leucine (µmol/L)
Time frame: 60 minutes
Postprandial plasma amino acid maximum concentration
Total amino acids, essential amino acids, branched chain amino acids, leucine (µmol/L)
Time frame: 4 hours
Postprandial plasma amino acid time to peak concentration
Total amino acids, essential amino acids, branched chain amino acids, leucine (minutes)
Time frame: 4 hours
Postprandial plasma glucose concentration incremental area-under-the-curve
Plasma glucose (mmol·L\^(-1)·240 min)
Time frame: 4 hours
Postprandial plasma insulin concentration incremental area-under-the-curve
Plasma insulin (mmol·L\^(-1)·240 min)
Time frame: 4 hours
Postprandial appetite sensation scores
Participants will be asked to complete visual analog scales (VAS) for measurements of appetite sensations at 10 timepoints (t = 0, 30, 60, 90, 120, 150, 180, 210, 240, and 270 min). Five sensations related to appetite are queried by VAS (i.e., "How hungry are you?", "How full are you?", "How satiated are you?", "How strong is your desire to eat?" on a scale from "Not at all" to "Extremely"; and "How much do you think you could (or would want to) eat right now" on a scale from "nothing at all" to "a very large amount"). Outcomes are measured in millimeters (mm) along a 100-mm horizontal line.
Time frame: 4.5 hours
Postprandial appetite sensation incremental-area-under-the-curve
Participants will be asked to complete visual analog scales (VAS) for measurements of appetite sensations at 9 timepoints (t = 0, 30, 60, 90, 120, 150, 180, 210, 240). Five sensations related to appetite are queried by VAS (i.e., "How hungry are you?", "How full are you?", "How satiated are you?", "How strong is your desire to eat?" on a scale from "Not at all" to "Extremely"; and "How much do you think you could (or would want to) eat right now" on a scale from "nothing at all" to "a very large amount"). Responses are measured in mm·240 min.
Time frame: 4 hours
Total (0-4 h) postprandial plasma glucagon-like peptide 1 incremental-area-under-the-curve
Plasma glucagon-like peptide 1 (pg ·L\^(-1)·240 min)
Time frame: 4 hours
Total (0-4 h) postprandial plasma peptide YY incremental-area-under-the-curve
Plasma peptide YY (pg·L\^(-1)·240 min)
Time frame: 4 hours
Total (0-4 h) postprandial plasma ghrelin incremental-area-under-the-curve
Plasma ghrelin (pg·L\^(-1)·240 min)
Time frame: 4 hours
Ad libitum meal energy intake
The ad libitum test meal will contain 562 kJ per 100 g with 20% energy from protein, 65% energy from carbohydrate, and 15% energy from fat. The participants will be provided with approximately 1 kg of the test meal on a plate with utensils. Participants will be instructed to "eat as much or as little as desired until feeling "comfortably full" within 30 minutes. The meal will be weighed before consumption and remaining contents will be weighed after achieving comfortable fullness to calculate the energy intake. The outcome will be measure in kilojoules (kJ).
Time frame: 4.5 hours
5-Item Palatability Questionnaire scores
Visual analog score (VAS) outcomes are measured in millimeters (mm) along a 100-mm horizontal line. The most positive and most negative ratings are anchored at each end of the line. The VAS statements on palatability include: (1) "Visual appeal". Responses can range from "Good" to "Bad"; (2) "Smell". Responses can range from "Good" to "Bad"; (3) "Taste". Responses can range from "Good" to "Bad"; (4) "Aftertaste". Responses can range from "Much" to "None"; and (5) "Palatability". Responses can range from "Good" to "Bad".
Time frame: 4 hours
8-Item Modified Gastrointestinal Tolerance Questionnaire scores
Participants will be asked to complete an 8-item modified Gastrointestinal Tolerance Questionnaire at the conclusion of each aminoacidemia trial (t = 4 hours). Gastrointestinal symptoms including abdominal bloating/distension, burping, gas/flatulence, borborygmus/stomach rumbling, abdominal cramping, reflux (heartburn), nausea, and vomiting, will be ranked on a 4-point scale ranging from "none" to "severe".
Time frame: 4 hours
Incidence of adverse events
Number of participants with adverse events
Time frame: 72 days
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