Esta página foi traduzida automaticamente e a precisão da tradução não é garantida. Por favor, consulte o versão em inglês para um texto fonte.

A1-Free vs. Conventional Milk Metabolic Response Study

28 de abril de 2026 atualizado por: 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.

Visão geral do estudo

Descrição detalhada

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.

Tipo de estudo

Intervencional

Inscrição (Estimado)

35

Estágio

  • Não aplicável

Contactos e Locais

Esta seção fornece os detalhes de contato para aqueles que conduzem o estudo e informações sobre onde este estudo está sendo realizado.

Contato de estudo

  • Nome: Laura A Robinson, PhD
  • Número de telefone: 908-442-3688
  • E-mail: ldelvers@purud.edu

Critérios de participação

Os pesquisadores procuram pessoas que se encaixem em uma determinada descrição, chamada de critérios de elegibilidade. Alguns exemplos desses critérios são a condição geral de saúde de uma pessoa ou tratamentos anteriores.

Critérios de elegibilidade

Idades elegíveis para estudo

  • Adulto
  • Adulto mais velho

Aceita Voluntários Saudáveis

Sim

Descrição

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

Plano de estudo

Esta seção fornece detalhes do plano de estudo, incluindo como o estudo é projetado e o que o estudo está medindo.

Como o estudo é projetado?

Detalhes do projeto

  • Finalidade Principal: Outro
  • Alocação: Randomizado
  • Modelo Intervencional: Atribuição cruzada
  • Mascaramento: Triplo

Armas e Intervenções

Grupo de Participantes / Braço
Intervenção / Tratamento
Experimental: 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.
A lactose-containing milk beverage containing A2 beta-casein and no A1 beta-casein, consumed during one experimental study visit.
Outros nomes:
  • Leite A2
  • A1-free milk
Experimental: 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.
A lactose-containing conventional milk beverage containing both A1 and A2 beta-casein, consumed during one experimental study visit.
Outros nomes:
  • Leite convencional
  • A1/A2 milk
Experimental: 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.
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.
Experimental: 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.
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.

O que o estudo está medindo?

Medidas de resultados primários

Medida de resultado
Descrição da medida
Prazo
Postprandial Plasma Insulin Incremental Area Under the Curve (iAUC)
Prazo: 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)
Prazo: 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

Medidas de resultados secundários

Medida de resultado
Descrição da medida
Prazo
Early-Phase Postprandial Glucose and Insulin Response
Prazo: 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)
Prazo: 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
Prazo: 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
Prazo: 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
Prazo: 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
Prazo: Baseline and 180 minutes post intervention
Urinary galactose concentrations measured as an marker of lactose metabolism.
Baseline and 180 minutes post intervention

Colaboradores e Investigadores

É aqui que você encontrará pessoas e organizações envolvidas com este estudo.

Patrocinador

Investigadores

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

Publicações e links úteis

A pessoa responsável por inserir informações sobre o estudo fornece voluntariamente essas publicações. Estes podem ser sobre qualquer coisa relacionada ao estudo.

Publicações Gerais

Datas de registro do estudo

Essas datas acompanham o progresso do registro do estudo e os envios de resumo dos resultados para ClinicalTrials.gov. Os registros do estudo e os resultados relatados são revisados ​​pela National Library of Medicine (NLM) para garantir que atendam aos padrões específicos de controle de qualidade antes de serem publicados no site público.

Datas Principais do Estudo

Início do estudo (Estimado)

15 de junho de 2026

Conclusão Primária (Estimado)

31 de outubro de 2026

Conclusão do estudo (Estimado)

31 de janeiro de 2027

Datas de inscrição no estudo

Enviado pela primeira vez

28 de abril de 2026

Enviado pela primeira vez que atendeu aos critérios de CQ

28 de abril de 2026

Primeira postagem (Real)

5 de maio de 2026

Atualizações de registro de estudo

Última Atualização Postada (Real)

5 de maio de 2026

Última atualização enviada que atendeu aos critérios de controle de qualidade

28 de abril de 2026

Última verificação

1 de abril de 2026

Mais Informações

Termos relacionados a este estudo

Plano para dados de participantes individuais (IPD)

Planeja compartilhar dados de participantes individuais (IPD)?

NÃO

Informações sobre medicamentos e dispositivos, documentos de estudo

Estuda um medicamento regulamentado pela FDA dos EUA

Não

Estuda um produto de dispositivo regulamentado pela FDA dos EUA

Não

Essas informações foram obtidas diretamente do site clinicaltrials.gov sem nenhuma alteração. Se você tiver alguma solicitação para alterar, remover ou atualizar os detalhes do seu estudo, entre em contato com register@clinicaltrials.gov. Assim que uma alteração for implementada em clinicaltrials.gov, ela também será atualizada automaticamente em nosso site .

Se inscrever