Cette page a été traduite automatiquement et l'exactitude de la traduction n'est pas garantie. Veuillez vous référer au version anglaise pour un texte source.

A1-Free vs. Conventional Milk Metabolic Response Study

28 avril 2026 mis à jour par: Dennis A. Savaiano, Purdue University

A Randomized Crossover Study Evaluating Postprandial Glucose and Insulin Responses to A1-Free and Conventional Milk With and Without a Delayed Lactose Challenge in Healthy Adults

This study will examine how different types of milk affect blood sugar and insulin responses after eating. Specifically, the study compares milk that contains only A2 beta-casein protein (A1-free milk) to conventional milk, which contains both A1 and A2 proteins.

Participants will complete four study visits in which they will consume different milk-based beverages. These include lactose-containing milk and lactose-free milk followed by a lactose drink given later. Blood samples will be collected over several hours to measure glucose and insulin responses. Breath tests and questionnaires will also be used to assess digestion and gastrointestinal symptoms.

The goal of this study is to determine whether milk protein type influences metabolic responses and whether consuming lactose-free milk affects how the body processes lactose when it is consumed later.

Aperçu de l'étude

Statut

Pas encore de recrutement

Les conditions

Intervention / Traitement

Description détaillée

Postprandial glucose and insulin responses are important indicators of metabolic health, even in individuals without diagnosed metabolic disease. The rate and pattern of nutrient digestion and absorption can influence these responses, and emerging evidence suggests that differences in milk protein composition, specifically the presence or absence of A1 beta-casein, may alter gastrointestinal function and metabolic outcomes.

This study is a randomized, double-blind, crossover trial designed to evaluate the effects of A1-free milk compared to conventional milk on postprandial metabolic responses in healthy adults. Participants will complete four experimental conditions in random order: (1) lactose-containing A1-free milk, (2) lactose-containing conventional milk, (3) lactose-free A1-free milk followed by a delayed lactose challenge, and (4) lactose-free conventional milk followed by a delayed lactose challenge.

The inclusion of both lactose-containing and lactose-free conditions allows for evaluation of two complementary questions. First, direct comparisons between lactose-containing A1-free and conventional milk will assess whether milk protein composition influences postprandial glucose and insulin responses under typical consumption conditions. Second, the lactose-free preload conditions, combined with a standardized delayed lactose challenge, are designed to evaluate whether prior milk consumption modifies subsequent metabolic responses to lactose exposure. This approach provides insight into potential differences in digestive kinetics, including gastric emptying, nutrient delivery, and lactose digestion and absorption.

During each study visit, participants will consume a standardized milk-based intervention following an overnight fast. In the lactose-free conditions, a lactose beverage matched to the amount of lactose typically present in the milk will be administered 60 minutes after milk consumption. Blood samples will be collected at multiple timepoints over a postprandial period to measure glucose and insulin concentrations and characterize response patterns, including early-phase responses and overall exposure.

Secondary and exploratory outcomes include breath hydrogen testing as a non-invasive marker of carbohydrate fermentation and lactose maldigestion, as well as gastrointestinal symptom assessments using validated questionnaires. These measures will be used to provide additional context for interpreting metabolic responses across conditions.

The crossover design allows each participant to serve as their own control, improving statistical power and reducing variability. The findings from this study will help clarify whether differences in milk protein composition influence metabolic responses and whether prior exposure to lactose-free milk alters the body's handling of lactose consumed at a later time.

Type d'étude

Interventionnel

Inscription (Estimé)

35

Phase

  • N'est pas applicable

Contacts et emplacements

Cette section fournit les coordonnées de ceux qui mènent l'étude et des informations sur le lieu où cette étude est menée.

Coordonnées de l'étude

  • Nom: Laura A Robinson, PhD
  • Numéro de téléphone: 908-442-3688
  • E-mail: ldelvers@purud.edu

Critères de participation

Les chercheurs recherchent des personnes qui correspondent à une certaine description, appelée critères d'éligibilité. Certains exemples de ces critères sont l'état de santé général d'une personne ou des traitements antérieurs.

Critère d'éligibilité

Âges éligibles pour étudier

  • Adulte
  • Adulte plus âgé

Accepte les volontaires sains

Oui

La description

Inclusion Criteria:

  • Ability/desire to provide informed consent
  • Are between 18 and 65 years of age
  • Are generally healthy, with no known metabolic or gastrointestinal conditions that would affect digestion or metabolism
  • Are willing to consume milk-based beverages and lactose-containing drinks as part of the study
  • Are willing to fast overnight (approximately 10-12 hours) prior to study visits and follow study instructions (e.g., diet and activity restrictions)
  • Are willing to attend all study visits and complete all study procedures (blood draws, breath tests, urine samples, questionnaires)
  • Are able to understand and provide written informed consent in English.

Exclusion Criteria:

  • You have a known allergy to milk or dairy products
  • You are currently pregnant, planning to become pregnant, or breastfeeding
  • You currently smoke or have used tobacco or nicotine-containing products within the past 3 months
  • You have a history of excessive alcohol use within the past 30 days
  • You have been diagnosed with diabetes (Type 1 or Type 2), prediabetes, or other metabolic conditions that affect glucose or insulin responses (such as insulin resistance, metabolic syndrome, or polycystic ovary syndrome [PCOS])
  • You have a history of gastrointestinal conditions that may affect digestion or absorption (such as inflammatory bowel disease, Crohn's disease, ulcerative colitis, celiac disease, or severe irritable bowel syndrome)
  • You have had gastrointestinal surgery that alters normal digestive function (such as bariatric surgery or gastric bypass)
  • You have other medical conditions that may affect digestion or interfere with study results (such as Past or present: Organ transplant, chronic pancreatitis, pancreatic insufficiency, symptomatic biliary disease, Celiac disease, chronic constipation, diverticulosis, inflammatory bowel disease (IBD), ulcerative colitis (UC), Crohn's disease (CD), small intestine bacterial overgrowth syndrome (SIBO), gastroparesis, gastro-esophageal reflux disease (GERD), Irritable Bowel Syndrome (IBS) or any other medical condition with symptoms that could confound collection of adverse events.)
  • You have used medications or supplements known to affect glucose metabolism, digestion, or gastrointestinal function within the following timeframes prior to enrollment:
  • Within 4 weeks: insulin, metformin, GLP-1 receptor agonists, corticosteroids, digestive enzymes, fiber supplements, and all oral or IV antibiotics
  • Within 2 weeks: bismuth-containing compounds (e.g., Pepto-Bismol) and proton pump inhibitors or acid suppressors (e.g., omeprazole [Prilosec], lansoprazole [Prevacid], esomeprazole [Nexium], pantoprazole [Protonix], rabeprazole [Aciphex])
  • Within 1 week: laxatives and stool softeners (e.g., Miralax, Colace, senna, lactulose, Citrucel, Metamucil, Fibercon), probiotics and prebiotics, gastrointestinal motility agents (e.g., Reglan, Linzess, Amitiza), and antidiarrheal medications (e.g., loperamide [Imodium], Lomotil)
  • You have had a recent infection within the past 30 days
  • You have been diagnosed with Human Immunodeficiency Virus (HIV), hepatitis B, or hepatitis C
  • You are currently undergoing chemotherapy
  • Height: ___ Weight: ___ BMI: ___ Weighing <16.5 kg or Body mass index > 35 kg/m2
  • You have participated in another clinical trial or used an investigational product within the past 30 days
  • You have any other condition that, as determined by the study team, would make participation unsafe or interfere with study results

Plan d'étude

Cette section fournit des détails sur le plan d'étude, y compris la façon dont l'étude est conçue et ce que l'étude mesure.

Comment l'étude est-elle conçue ?

Détails de conception

  • Objectif principal: Autre
  • Répartition: Randomisé
  • Modèle interventionnel: Affectation croisée
  • Masquage: Tripler

Armes et Interventions

Groupe de participants / Bras
Intervention / Traitement
Expérimental: Lactose-Containing A1-Free Milk
Participants consume lactose-containing A1-free milk during one study visit. Blood, breath hydrogen, urine, and gastrointestinal symptom measures are collected over the 180 minute postprandial period.
Complément alimentaire: Lactose-Containing A1-Free Milk
A lactose-containing milk beverage containing A2 beta-casein and no A1 beta-casein, consumed during one experimental study visit.
Autres noms:
  • Lait A2
  • A1-free milk
Expérimental: Lactose-Containing Conventional Milk
Participants consume lactose-containing conventional milk containing both A1 and A2 beta-casein during one study visit. Blood, breath hydrogen, urine, and gastrointestinal symptom measures are collected over the 180 minute postprandial period.
Complément alimentaire: Lactose-Containing Conventional Milk
A lactose-containing conventional milk beverage containing both A1 and A2 beta-casein, consumed during one experimental study visit.
Autres noms:
  • Lait conventionnel
  • A1/A2 milk
Expérimental: Lactose-Free A1-Free Milk With Delayed Lactose Drink
Participants consume lactose-free A1-free milk followed by a lactose drink administered 60 minutes after milk consumption. Blood, breath hydrogen, and gastrointestinal symptom measures are collected over the 180 minute postprandial period.
Complément alimentaire: Lactose-Free A1-Free Milk With Delayed Lactose Drink
A lactose-free A1-free milk beverage consumed at the start of the study visit, followed by a lactose drink administered 60 minutes after milk consumption. The lactose drink is matched to the amount of lactose expected in the milk serving.
Expérimental: Lactose-Free Conventional Milk With Delayed Lactose Drink
Participants consume lactose-free conventional milk containing both A1 and A2 beta-casein followed by a lactose drink administered 60 minutes after milk consumption. Blood, breath hydrogen, and gastrointestinal symptom measures are collected over the 180 minute postprandial period.
Complément alimentaire: Lactose-Free Conventional Milk With Delayed Lactose Drink
A lactose-free conventional milk beverage containing both A1 and A2 beta-casein consumed at the start of the study visit, followed by a lactose drink administered 60 minutes after milk consumption. The lactose drink is matched to the amount of lactose expected in the milk serving.

Que mesure l'étude ?

Principaux critères de jugement

Mesure des résultats
Description de la mesure
Délai
Postprandial Plasma Insulin Incremental Area Under the Curve (iAUC)
Délai: 0 to 180 minutes post-intervention during each study visit
Incremental area under the curve (iAUC) for plasma insulin concentrations following consumption of each study condition, measured from serial blood samples collected via an indwelling catheter.
0 to 180 minutes post-intervention during each study visit
Postprandial Plasma Glucose Incremental Area Under the Curve (iAUC)
Délai: 0 to 180 minutes post-intervention during each study visit
Incremental area under the curve (iAUC) for plasma glucose concentrations following consumption of each study condition, measured from serial blood samples collected via an indwelling catheter.
0 to 180 minutes post-intervention during each study visit

Mesures de résultats secondaires

Mesure des résultats
Description de la mesure
Délai
Early-Phase Postprandial Glucose and Insulin Response
Délai: 0 to 60 minutes post-intervention
Early-phase postprandial response assessed by incremental area under the curve (iAUC) for plasma glucose and insulin concentrations.
0 to 60 minutes post-intervention
Time to Peak Plasma Glucose and Insulin Concentrations (Tmax)
Délai: 0 to 180 minutes post-intervention
Time required to reach peak plasma glucose and insulin concentrations following each study condition.
0 to 180 minutes post-intervention
Circulating Metabolite Responses
Délai: 0, 30, 60, and 120 minutes
Postprandial changes in circulating metabolites, including amino acids and acylcarnitines, measured from plasma samples to assess metabolic responses.
0, 30, 60, and 120 minutes
Breath Hydrogen Concentrations
Délai: Baseline and every 30 minutes from 0 to 180 minutes post-intervention
Breath hydrogen levels measured as a non-invasive marker of carbohydrate fermentation and lactose maldigestion.
Baseline and every 30 minutes from 0 to 180 minutes post-intervention
Gastrointestinal Symptom Scores
Délai: Baseline and at 60, 120, and 180 minutes post-intervention
Self-reported gastrointestinal symptoms (e.g., bloating, gas, abdominal discomfort) assessed using visual analog scale and Likert-type questionnaires.
Baseline and at 60, 120, and 180 minutes post-intervention
Urinary Galactose Concentrations
Délai: Baseline and 180 minutes post intervention
Urinary galactose concentrations measured as an marker of lactose metabolism.
Baseline and 180 minutes post intervention

Collaborateurs et enquêteurs

C'est ici que vous trouverez les personnes et les organisations impliquées dans cette étude.

Parrainer

Purdue University

Les enquêteurs

  • Chercheur principal: Dennis A Savaiano, PhD, Purdue University

Publications et liens utiles

La personne responsable de la saisie des informations sur l'étude fournit volontairement ces publications. Il peut s'agir de tout ce qui concerne l'étude.

Publications générales

Dates d'enregistrement des études

Ces dates suivent la progression des dossiers d'étude et des soumissions de résultats sommaires à ClinicalTrials.gov. Les dossiers d'étude et les résultats rapportés sont examinés par la Bibliothèque nationale de médecine (NLM) pour s'assurer qu'ils répondent à des normes de contrôle de qualité spécifiques avant d'être publiés sur le site Web public.

Dates principales de l'étude

Début de l'étude (Estimé)

15 juin 2026

Achèvement primaire (Estimé)

31 octobre 2026

Achèvement de l'étude (Estimé)

31 janvier 2027

Dates d'inscription aux études

Première soumission

28 avril 2026

Première soumission répondant aux critères de contrôle qualité

28 avril 2026

Première publication (Réel)

5 mai 2026

Mises à jour des dossiers d'étude

Dernière mise à jour publiée (Réel)

5 mai 2026

Dernière mise à jour soumise répondant aux critères de contrôle qualité

28 avril 2026

Dernière vérification

1 avril 2026

Plus d'information

Termes liés à cette étude

Mots clés

Autres numéros d'identification d'étude

  • IRB 2026-00000555

Plan pour les données individuelles des participants (IPD)

Prévoyez-vous de partager les données individuelles des participants (DPI) ?

NON

Informations sur les médicaments et les dispositifs, documents d'étude

Étudie un produit pharmaceutique réglementé par la FDA américaine

Non

Étudie un produit d'appareil réglementé par la FDA américaine

Non

Ces informations ont été extraites directement du site Web clinicaltrials.gov sans aucune modification. Si vous avez des demandes de modification, de suppression ou de mise à jour des détails de votre étude, veuillez contacter register@clinicaltrials.gov. Dès qu'un changement est mis en œuvre sur clinicaltrials.gov, il sera également mis à jour automatiquement sur notre site Web .

S'abonner