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

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.

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.

Eligibility Criteria:
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.