Digestive DiscomfortNCT06763185
A1 Beta-casein-free Milk in Milk-intolerant Participants
A study testing Dietary Supplement: conventional cow's milk consumption, and then A1PF milk consumption and Dietary Supplement: A1PF milk consumption, and then conventional cow's milk consumption in people with Digestive Discomfort, run by a2 Milk Company Ltd. at 1 site in United States.
Trial summary
This was a single-site, double-blind, randomised, controlled, crossover study, which aimed to compare the effects of conventional cow's milk (CON, containing both A1- and A2-types of beta-casein) versus milk free of A1-type beta-casein (A1PF milk) on gastrointestinal (GI) physiology and symptoms of digestive… Read more about this study
- Who is it for?
- Ages 18 to 68 years
- Conditions the study is for
- Digestive Discomfort
- What is being tested?
- Dietary Supplement: conventional cow's milk consumption, and then A1PF milk consumption and Dietary Supplement: A1PF milk consumption, and then conventional cow's milk consumption
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 54 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Apr 2017to 27 Mar 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 68 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male or female participants aged 18 to 68 years
- Irregularly consumed milk
- Had self-reported mild-to-moderate digestive discomfort after milk consumption
- Had normal electrocardiograms and blood pressure during quiet respiration
Who cannot join
- Known allergies to dairy products
- Severe milk intolerance
- A history of faecal impaction
- Having suffered from GI disorders (e.g., irritable bowel syndrome, colitis, ulcerative colitis, or coeliac disease)
- Currently being administered drugs for cardiovascular or metabolic disease
- Trying to lose weight by following a diet or exercise regimen
- Took any appetite or weight loss drugs for the previous three months
Trial locations and contacts
1 site in 1 country.
United States1 site
Pennington Biomedical Research Center
Baton Rouge, Louisiana, 70808
About this study
Official title: Comparative Effects of Conventional Cow's Milk Versus Milk Free of A1-type Beta-casein on Gastrointestinal Physiology and Symptoms of Digestive Discomfort in Participants Intolerant to Conventional Cow's Milk: a Randomised Controlled Trial
This was a single-site, double-blind, randomised, controlled, crossover study, which aimed to compare the effects of conventional cow's milk (CON, containing both A1- and A2-types of beta-casein) versus milk free of A1-type beta-casein (A1PF milk) on gastrointestinal (GI) physiology and symptoms of digestive discomfort in non-regular milk drinkers with self-reported intolerance to conventional cow's milk. The study location was the Pennington Biomedical Research Center in Louisiana, USA. The study comprised a 2-week washout period, 2 weeks of milk consumption, crossover, a second 2-week washout period, and a second 2-week period of milk consumption. Eligible participants were stratified by sex to achieve an approximate 1:1 male to female ratio and were randomised to receive conventional cow's milk (sequence 1) or A1PF milk (sequence 2) during the first period of milk consumption. During the second period of milk consumption, participant groups underwent crossover to receive the alternate study milk.
Milk was consumed three times per day after meals, with 250 mL provided at each administration. During washout periods, participants were required to avoid all dairy products and use only rice milk to replace any normal dairy intake, and to avoid foods with very high fermentable oligosaccharides, disaccharides, monosaccharides, and polyols content, to avoid potential confounding of the symptoms experienced. Any medication, nutritional supplements, dairy products, acidophilus milk, or probiotics were prohibited during the study.
The study protocol and all related documentation were approved by the Pennington Biomedical Research Center Institution Review Board. The study was conducted in accordance with the principles of the Declaration of Helsinki and the Good Clinical Practice Guidelines of the International Conference on Harmonisation. All participants provided written informed consent prior to initiating any study procedures.
- Conditions
- Digestive Discomfort
- Being tested
- Dietary Supplement: conventional cow's milk consumption, and then A1PF milk consumption, Dietary Supplement: A1PF milk consumption, and then conventional cow's milk consumption
- Keywords
- milk free of A1-type beta-casein, conventional cow's milk, gastrointestinal symptoms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Dietary Supplement: conventional cow's milk consumption, and then A1PF milk consumptionOther
Milk was consumed three times per day after meals, with 250 mL provided at each administration. During washout periods, participants were required to avoid all dairy products and use only rice milk.
Dietary Supplement: A1PF milk consumption, and then conventional cow's milk consumptionOther
Milk was consumed three times per day after meals, with 250 mL provided at each administration. During washout periods, participants were required to avoid all dairy products and use only rice milk.
| Study group | Role | What they receive |
|---|---|---|
| Sequence 1 | Other | Sequence 1: a 2-week washout period, 2 weeks of conventional cow's milk consumption, crossover, a second 2-week washout period, and a second 2-week period of A1PF milk consumption. Receives: Other: Dietary Supplement: conventional cow's milk consumption, and then A1PF milk consumption |
| Sequence 2 | Other | Sequence 2: a 2-week washout period, 2 weeks of A1PF milk consumption, crossover, a second 2-week washout period, and a second 2-week period of conventional cow's milk consumption. Receives: Other: Dietary Supplement: A1PF milk consumption, and then conventional cow's milk consumption |
What is being measured
The primary outcome is the main question the study is designed to answer.
Severity of bloating, abdominal pain, gas, borborygmus, eructation, and diarrhoea measured via Visual Analogue Scale (VAS)
VAS: 0 = never; 1 = rarely; 2 = frequently; 3 = all the time
Measured: At day 28 and day 56 (day 1 is study start)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jan 2025
- Study start28 Apr 2017
- Primary completion27 Mar 2019
- Study completion27 Mar 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Digestive DiscomfortStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 54 participants (actual)
Sponsor and investigators
- Lead sponsor
- a2 Milk Company Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06763185
- Sponsor's protocol ID
- 1016-065 Milk
- Status last verified
- Jan 2025
- First submitted
- 11 Dec 2024
- Last updated
- 8 Jan 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Greenway FL, Hsia DS, Rebello CJ. Comparative effects of conventional cow's milk versus milk free of A1-type beta-casein on gastrointestinal physiology and symptoms of digestive discomfort in participants intolerant to conventional cow's milk: a pilot randomised controlled trial. Nutr J. 2026 Feb 4;25(1):28. doi: 10.1186/s12937-026-01288-9.
PubMed 41634798
Study at a glance
From the registry record, last updated by the sponsor on 8 Jan 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparative Effects of Conventional Cow's Milk Versus Milk Free of A1-type Beta-casein on Gastrointestinal Physiology and Symptoms of Digestive Discomfort in Participants Intolerant to Conventional Cow's Milk: a Randomised Controlled Trial
- ClinicalTrials.gov ID
- NCT06763185
- Acronym / sponsor ID
- 1016-065 Milk
- Conditions
- Digestive Discomfort
- Keywords
- milk free of A1-type beta-casein, conventional cow's milk, gastrointestinal symptoms
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 54 participants (actual)
- Lead sponsor
- a2 Milk Company Ltd.Industry (pharma, biotech, devices)
- Study start
- 28 Apr 2017 (actual)
- Primary completion
- 27 Mar 2019 (actual)
- Study completion
- 27 Mar 2019 (actual)
- First posted
- 8 Jan 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This was a single-site, double-blind, randomised, controlled, crossover study, which aimed to compare the effects of conventional cow's milk (CON, containing both A1- and A2-types of beta-casein) versus milk free of A1-type beta-casein (A1PF milk) on gastrointestinal (GI) physiology and symptoms of digestive discomfort in non-regular milk drinkers with self-reported intolerance to conventional cow's milk. The study location was the Pennington Biomedical Research Center in Louisiana, USA. The study comprised a 2-week washout period, 2 weeks of milk consumption, crossover, a second 2-week washout period, and a second 2-week period of milk consumption. Eligible participants were stratified by sex to achieve an approximate 1:1 male to female ratio and were randomised to receive conventional cow's milk (sequence 1) or A1PF milk (sequence 2) during the first period of milk consumption. During the second period of milk consumption, participant groups underwent crossover to receive the alternate study milk.
Milk was consumed three times per day after meals, with 250 mL provided at each administration. During washout periods, participants were required to avoid all dairy products and use only rice milk to replace any normal dairy intake, and to avoid foods with very high fermentable oligosaccharides, disaccharides, monosaccharides, and polyols content, to avoid potential confounding of the symptoms experienced. Any medication, nutritional supplements, dairy products, acidophilus milk, or probiotics were prohibited during the study.
The study protocol and all related documentation were approved by the Pennington Biomedical Research Center Institution Review Board. The study was conducted in accordance with the principles of the Declaration of Helsinki and the Good Clinical Practice Guidelines of the International Conference on Harmonisation. All participants provided written informed consent prior to initiating any study procedures.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, care provider)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sequence 1 | Other | Other: Dietary Supplement: conventional cow's milk consumption, and then A1PF milk consumptionSequence 1: a 2-week washout period, 2 weeks of conventional cow's milk consumption, crossover, a second 2-week washout period, and a second 2-week period of A1PF milk consumption. |
| Sequence 2 | Other | Other: Dietary Supplement: A1PF milk consumption, and then conventional cow's milk consumptionSequence 2: a 2-week washout period, 2 weeks of A1PF milk consumption, crossover, a second 2-week washout period, and a second 2-week period of conventional cow's milk consumption. |
Who may qualify
- Ages
- 18 to 68 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Male or female participants aged 18 to 68 years
- Irregularly consumed milk
- Had self-reported mild-to-moderate digestive discomfort after milk consumption
- Had normal electrocardiograms and blood pressure during quiet respiration
Key exclusion criteria (7 listed)
- Known allergies to dairy products
- Severe milk intolerance
- A history of faecal impaction
- Having suffered from GI disorders (e.g., irritable bowel syndrome, colitis, ulcerative colitis, or coeliac disease)
- Currently being administered drugs for cardiovascular or metabolic disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Dietary Supplement: conventional cow's milk consumption, and then A1PF milk consumptionMilk was consumed three times per day after meals, with 250 mL provided at each administration. During washout periods, participants were required to avoid all dairy products and use only rice milk. | Other | Sequence 1 |
| Dietary Supplement: A1PF milk consumption, and then conventional cow's milk consumptionMilk was consumed three times per day after meals, with 250 mL provided at each administration. During washout periods, participants were required to avoid all dairy products and use only rice milk. | Other | Sequence 2 |
Primary outcome
Severity of bloating, abdominal pain, gas, borborygmus, eructation, and diarrhoea measured via Visual Analogue Scale (VAS)
Time frame: At day 28 and day 56 (day 1 is study start)
VAS: 0 = never; 1 = rarely; 2 = frequently; 3 = all the time
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jan 2025.
- Derived from this study: PubMed 41634798Greenway FL, Hsia DS, Rebello CJ. Comparative effects of conventional cow's milk versus milk free of A1-type beta-casein on gastrointestinal physiology and symptoms of digestive discomfort in participants intolerant to conventional cow's milk: a pilot randomised controlled trial. Nutr J. 2026 Feb 4;25(1):28. doi: 10.1186/s12937-026-01288-9.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Dietary Supplement: conventional cow's milk consumption, and then A1PF milk consumption and Dietary Supplement: A1PF milk consumption, and then conventional cow's milk consumption in people with Digestive Discomfort, run by a2 Milk Company Ltd. at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 8 Jan 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Severity of bloating, abdominal pain, gas, borborygmus, eructation, and diarrhoea measured via Visual Analogue Scale (VAS) (time frame: At day 28 and day 56 (day 1 is study start)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06763185, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Jan 2025.