Milk Consumption on Digestive Comfort. (A2-DIGEST)

April 5, 2022 updated by: Jean-Michel Lecerf, Institut Pasteur de Lille

Effect of Milk Consumption, Containing A2 β-caseins Only, on Digestive Comfort. A Randomized and Double-blind Study

Lactose, naturally present in milk, can cause digestive discomfort. Delactosed milk is currently the only one alternative to cow's milk for intolerant people. As some of them do not digest milk, it was completely remove from their diet. However, are they really intolerant to lactose or intolerant to milk (or to another of its compounds)? Do β-caseins play a role in this intolerance? β-caseins are proteins naturally present in milk. Two types of β-caseins were identified: A1 and A2. These types differ according to the genetic profile of the cow and depend on the breed. The rare clinical studies interested in this topic suggest that:

  1. consumption of milk A1 versus consumption of milk A2 can lead to: softer stools, delayed transit, as well as pro-inflammatory effects in some individuals,
  2. consumption of A2 milk significantly reduces gastrointestinal symptoms and improves digestive comfort in lactose intolerant people.

Thus, it would be interesting to be able to assess the effect of a consumption of A2A2 milk type compared to A1A2 milk type, both on the parameters of digestive comfort and on inflammatory parameters.

Study Overview

Status

Completed

Conditions

Detailed Description

The study will be carried out on healthy volunteers, aged 18 to 65 and self-declared sensitive, even intolerant to the consumption of milk.

The main objective of the study is to assess the impact of milk β-caseins (A2A2 vs A1A2) on the digestive comfort felt during the consumption of milk in subjects declaring that they do not tolerate milk.

Study Type

Interventional

Enrollment (Actual)

50

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Nord
      • Lille, Nord, France, 59019
        • NutrInvest - Institut Pasteur de Lille

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Man or woman;
  • 18 to 65 years old;
  • Declaring to have sensitivity or intolerance when consuming cow's milk;
  • Agreeing to follow the constraints generated by the study;
  • Having signed the informed consent form;
  • Social insured.

Exclusion Criteria:

  • Subject with an allergy to cow's milk proteins;
  • Subject suffering from a severe eating disorder (anorexia, bulimia, binge eating);
  • Subject with chronic pathology interfering with the parameters studied during this study (inflammatory intestinal disease, celiac disease);
  • Subject suffering from acute intestinal infection at the time of inclusion (gastroenteritis, etc.);
  • Subject with immunodeficiency or any other serious pathology (cancer, hemopathy);
  • Pregnant or planning to be pregnant during the study period;
  • Subject participating in another clinical study or in period of exclusion from another study;
  • Subject deprived of liberty;
  • Subject under judicial protection measure;
  • Whose main investigator or a qualified co-investigator judges that the state of health or the concomitant treatments are not compatible with the good progress of the clinical study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: OTHER
  • Allocation: RANDOMIZED
  • Interventional Model: CROSSOVER
  • Masking: DOUBLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
OTHER: Milk A1A2
Group (A1 → A2) receiving control milk A1A2 in period 1 then the milk evaluated A2A2 in period 2

Before each start of consumption of the products under study, a wash-out period of 2 weeks (no consumption of milk) must be observed by the subjects.

25 subjects will consume A1A2 milk for 2 weeks (period 1), then they will consume A2A2 milk for 2 weeks (period 2).

During each consumption period, various questionnaires will be completed by the subjects: frequency and consistency of stool, analog visual scales on digestive comfort and dietary surveys. Stool collections will also be carried out.

OTHER: Milk A2A2
Group (A2 → A1) receiving the milk evaluated A2A2 in period 1 then the control milk A1A2 in period 2

Before each start of consumption of the products under study, a wash-out period of 2 weeks (no consumption of milk) must be observed by the subjects.

25 subjects will consume A2A2 milk for 2 weeks (period 1), then they will consume A1A2 milk for 2 weeks (period 2).

During each consumption period, various questionnaires will be completed by the subjects: frequency and consistency of stool, analog visual scales on digestive comfort and dietary surveys. Stool collections will also be carried out.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Analog visual scales
Time Frame: 4 weeks

Digestive comfort will be assessed daily by the average of the following analog visual scales (score : 0 to 10), completed within 30 min to 3 hours after consumption of the daily dose of milk, depending on the usual occurrence of symptoms in individuals:

  • I have bloating
  • I have abdominal pain
  • I have flatulence (gas)
  • I have borborygmas (gurgling)
  • I have reflux (return, rise)
  • Overall, I estimate my digestive comfort.

The average of these 6 analog visual scales, called Global Digestive Discomfort (IDG), will therefore be available every day for 14 days; the final variable analyzed will be the average of these 14 IDG values, and will be called Global Average Digestive Discomfort (IDGM).

4 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Analysis of the average per period of each analog visual scales independently
Time Frame: 4 weeks
The analogue visual scales will be completed daily during each period of milk consumption (4 weeks)
4 weeks
Difference Calprotectin at the end of the period - Calprotectin at V0 (measured in mg/kg)
Time Frame: 4 weeks
Stool collections are made during inclusion visits, V1 follow-up and V3 end of study.
4 weeks
For each of the inflammatory markers (CRP us, IL-1β, TNF-α, IL-6) : difference between value at the end of the period and value at V0
Time Frame: 4 weeks

Blood samples are taken during inclusion visits, V1 follow-up and V3 end of study.

All of the inflammatory markers are measured in pg/ml.

4 weeks
Average stool frequencies and consistencies
Time Frame: 4 weeks

This questionnaires will be completed daily during each period of milk consumption (4 weeks).

Bristol scale: stool type 1 (separate hard balls) to stool type 7 (watery, structureless stools)

4 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

July 20, 2020

Primary Completion (ACTUAL)

April 14, 2021

Study Completion (ACTUAL)

June 1, 2021

Study Registration Dates

First Submitted

July 9, 2020

First Submitted That Met QC Criteria

July 9, 2020

First Posted (ACTUAL)

July 13, 2020

Study Record Updates

Last Update Posted (ACTUAL)

April 12, 2022

Last Update Submitted That Met QC Criteria

April 5, 2022

Last Verified

April 1, 2022

More Information

Terms related to this study

Other Study ID Numbers

  • 2020-A00185-34

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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