Effects of A2 Milk on Gastrointestinal Function in Non-lactose Milk Intolerance

Study Overview
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Brief Summary
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There is increasing evidence that a number of people experience moderate milk intolerance characterised by increased gas production, bloating and abdominal cramp, which can neither be attributed to lactose intolerance, nor to milk protein allergy. Milk digestion can lead to the formation of bioactive peptides, one of which derived from a mutated gene variant (A1) coding for milk beta-casein has been associated with increased gastrointestinal inflammation and poor gastrointestinal function. In this study, we hypothesise that consumption of non-mutated A2 milk will improve gastrointestinal symptoms in non-lactose milk intolerant individuals.

Detailed Description
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Non-lactose milk intolerance is a condition that has not been defined clinically yet but the current literature reports existence of subjects who are moderately milk intolerant and whose intolerance can neither be attributed to a defect in lactose intolerance, nor to milk protein allergy. Yet, they experience at least one or two of the following symptoms following milk consumption: gases, bloating, abdominal cramp. It is known that the A1gene variant coding for beta-casein leads to the production of a bioactive peptide with opioid activity named betacasomorphin 7 (BCM7). This peptide has been associated with several metabolic health disorders including diabetes, elevated cardiovascular risk and stimulation of pro-inflammatory signals. Recently, it was reported that non-lactose milk intolerant subjects did not experience such symptoms when consuming milk containing the non-mutated A2 gene variant coding for beta-casein. In this study, we hypothesise that consumption of A2 milk will improve gastrointestinal symptoms in non-lactose milk intolerant individuals. The primary outcome of this study will be the reduction of gastrointestinal inflammation following a course of A2 milk consumption.

Official Title
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Effects of A2 Milk on Gastrointestinal Function of Volunteers Affected by Non-lactose Milk Intolerance

Conditions
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Milk Intolerance

Intervention / Treatment
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* Dietary Supplement: A2 milk 100
* Dietary Supplement: A2 milk 150
* Dietary Supplement: A2 milk 200
* Dietary Supplement: A2 milk 250
* Dietary Supplement: A1/A2 milk 100
* Dietary Supplement: A1/A2 milk 150
* Dietary Supplement: A1/A2 milk 200
* Dietary Supplement: A1/A2 milk 250


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI: 20-35kg/m2 Glucose<7mmol/l (not diagnosed with diabetes) Total cholesterol<7mmol/l Triacylglycerol<4mmol/l Normal liver and kidney function Regular milk drinker with self-reported intolerance to commercial milk. Suffered from mild to moderate digestive discomfort after milk consumption. Have normal blood pressure 120/80 mmHg (BP <160/90 mmHg can be accepted) during quiet respiration. Agree not to take any medication, supplements and other dairy products including acidophilus milk Be willing to comply with all the requirements and procedures of the study. Agree to sign the informed consent form; Agree not to enrol in another interventional clinical research study while participating in this study. Fully understand the nature, objective, benefit and the potential risks and side effects of the study. Exclusion Criteria: Females who are pregnant or planning to be a pregnant and lactating. Have known dairy allergy. Have stopped drinking milk for the last 6 month. Have history of lactose intolerance Have history of faecal impaction. Received antibiotics in the previous six months Smoker Anemia Trying to lose weight by following a diet or exercise regimen designed for weight loss, or taking any drug influencing appetite and any drug for weight loss for the last three months. Have participated in similar dairy or probiotics-containing product's clinical trials within 3 months before the screening. Currently taking medicines for cardiovascular or metabolic disease. History of alcohol or drug misuse. Have history of or be diagnosed of any of the following diseases that may affect the study results: gastrointestinal disorders, hepatopathy, nephropathy, endocrine disease, blood disorders, respiratory, cardiovascular diseases and known on-going allergy such as asthma. Currently suffering from any gastrointestinal disorders or gastrointestinal disease, including irritable bowel syndrome, colitis, ulcerative colitis, celiac disease, irritable bowel syndrome (IBS); Had hospitalizations within 3 months before screening; Currently drug frequency user of that may affect the gastrointestinal function or immune system. As judged by investigator. Who take medication at least the last 6-month. Who do excessive exercise not as part of a weight-loss regime, e.g. athletes.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 56 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: A1/A2 milk<br>Commercial conventional A1/A2 semi-skimmed fresh pasteurised cow milk. Progressive intake of intervention milk as follows: Days 1 and 2: 100 mL twice a day Days 3 and 4: 150 mL twice a day Days 5 and 6: 200 mL twice a day Days 7 to 14: 250 mL twice a day | Dietary Supplement: A1/A2 milk 100<br>* Days 1 and 2: 100 mL A1/A2 milk twice a day<br>Dietary Supplement: A1/A2 milk 150<br>* Days 3 and 4: 150 mL A1/A2 milk twice a day<br>Dietary Supplement: A1/A2 milk 200<br>* Days 5 and 6: 200 mL A1/A2 milk twice a day<br>Dietary Supplement: A1/A2 milk 250<br>* Days 7 to14: 250 mL A1/A2 milk twice a day<br>|
| Active Comparator: A2 milk<br>Commercial A2 semi-skimmed fresh pasteurised cow milk. Progressive intake of intervention milk as follows: Days 1 and 2: 100 mL twice a day Days 3 and 4: 150 mL twice a day Days 5 and 6: 200 mL twice a day Days 7 to 14: 250 mL twice a day | Dietary Supplement: A2 milk 100<br>* Days 1 and 2: 100 mL A2 milk twice a day<br>Dietary Supplement: A2 milk 150<br>* Days 3 and 4: 150 mL A2 milk twice a day<br>Dietary Supplement: A2 milk 200<br>* Days 5 and 6: 200 mL A2 milk twice a day<br>Dietary Supplement: A2 milk 250<br>* Days 7 to 14: 250 mL A2 milk twice a day<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in gastrointestinal inflammation indicated by fecal calprotectin | Measurement of fecal calprotectin (ug/g feces) | baseline, 14 days, 28 days, 42 days and 56 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in NMR-based urinary metabolic profiles | Measured using High Resolution 700MHz proton NMR spectroscopy (Bruker) (no unit) | baseline, 14 days, 28 days, 42 days and 56 days | 
| Change in NMR-based plasma metabolic profiles | Measured using High Resolution 700MHz proton NMR spectroscopy (Bruker) (no unit) | baseline, 14 days, 28 days, 42 days and 56 days | 
| Change in NMR-based fecal metabolic profiles | Measured using High Resolution 700MHz proton NMR spectroscopy (Bruker) (no unit) | baseline, 14 days, 28 days, 42 days and 56 days | 
| Change in gut microbiota ecosystem assessed by sequencing the 16S rDNA extracted from feces | Measures relative abundance of bacterial taxa | baseline, 14 days, 28 days, 42 days and 56 days | 
| Change in systemic inflammation indicated by circulating levels of high sensitivity C-reactive protein | hs-CRP in mg/L | baseline, 14 days, 28 days, 42 days and 56 days | 
| Change in gastrointestinal function assessed using visual analogue scale for GI symptoms | Measures gases, bloating, abdominal cramps, diarrhoea, headache, constipation, nausea and rash | 14 days | 
| Height (in m) used to detect change in BMI (kg/m^2) |  | baseline | 
| Weight (in kg) used to detect change in BMI (kg/m^2) |  | baseline, 14 days, 28 days, 42 days and 56 days | 
| Change in systolic blood pressure in mmHg |  | baseline, 14 days, 28 days, 42 days and 56 days | 
| Change in diastolic blood pressure in mmHg |  | baseline, 14 days, 28 days, 42 days and 56 days | 
| Diagnostic of lactose intolerance by breath hydrogen concentration following ingestion of 25g lactose in 250 mL water |  | screening visit, 14 days, 42 days and 56 days | 
| Diagnostic of lactose intolerance by breath methane concentration following ingestion of 25g lactose in 250 mL water |  | screening visit, 14 days, 42 days and 56 days | 
| Self-reported change in gut transit time |  | 14 days, 42 days and 56 days | 
| Monitoring of changes in psychological behaviour assessed by TMT |  | baseline, 14 days, 28 days, 42 days and 56 days | 
| Monitoring of changes in psychological behaviour assessed by Letter Memory Test |  | baseline, 14 days, 28 days, 42 days and 56 days | 
| Monitoring of changes in psychological behaviour assessed by Flanger Test |  | baseline, 14 days, 28 days, 42 days and 56 days | 
| Monitoring of changes in mood measured by PANAS questionnaire |  | baseline, 14 days, 28 days, 42 days and 56 days | 
| Change in stool consistency using the Bristol stool chart |  | baseline, 14 days, 28 days, 42 days and 56 days |