a2 Milk™ for Gut Comfort

Research Team

Dr Matthew Barnett

Matthew is the lead for the research project a2 Milk for gut comfort, jointly funded by High-Value Nutrition and the a2 Milk Company. He has held a range of roles at AgResearch Ltd, including research associate and research scientist. Matthew is involved in a range of projects investigating the importance of nutrition for health throughout life.

ORCID ID: https://orcid.org/0000-0002-5186-5579 

Public Summary

Principal Investigator: Dr Matthew Barnett, AgResearch

Collaborating organisations: University of Auckland

Since February 2016, the “a2 Milk™ for Gut Comfort” HVN contestable project has sought to deliver scientific evidence for benefits of dairy products containing only the A2 β-casein protein on gut comfort. This is to enable a rapidly growing player in New Zealand’s dairy industry to further capture lucrative and growing dairy export markets (China and South-East Asia) in which there is a high incidence of intolerance to traditional dairy products. We aimed to demonstrate that A2 β-casein protein dairy products are well tolerated and can deliver the health benefits to consumers who might be expected to experience digestive discomfort in response to traditional dairy products that contain the A1 β-casein protein.

The project was the result of a close partnership between the research team and a key industry partner, the a2 Milk Company Limited (a2MC). This has ensured that the outcomes of the research have been made rapidly available to a2MC, and benefits have therefore been captured by one of the current key players in theNew Zealand dairy industry.

The research combined expertise in clinical trials and analysis of gastrointestinal function at the Liggins Institute, The University of Auckland and sophisticated biological sample analysis techniques from AgResearch. In the first of two registered clinical trials (the a2 Milk™ for Gut Comfort or “aMiGo” trial) it was demonstrated that short-term subjective feelings of gut discomfort in lactose intolerant young women were improved in response to A1 β-casein-free milk (a2 Milk™) compared to conventional milk. This was supported by the observation that breath hydrogen, a measure of lactose malabsorption, was reduced after a2 Milk™ ingestion, compared to conventional milk. This study was unique in that it also examined whether it is possible to be intolerant to milk without being lactose intolerant. The results identified “non-lactose dairy intolerance” which is characterised by a rapid onset set of subjective symptoms.  These symptoms were unaltered by the type of milk consumed.

Outcomes of the aMiGo clinical trial were reported at three international conferences: the Food & Nutrition Conference & Expo (FNCE) in Chicago, USA (Dr Amber Milan, October 2017), the Food Structures, Digestion and Health International Conference in Sydney, Australia (Professor David Cameron-Smith, October 2017), and the Asia-Pacific Conference on Clinical Nutrition in Adelaide, Australia (Dr Amber Milan, November 2017). There were also twelve media reports of the study outcomes (including The New Zealand Herald, Newshub, and Newstalk ZB). The first peer-reviewed journal publication describing outcomes for the aMiGo study was submitted in April 2019 to the American Journal of Clinical Nutrition (Impact Factor 6.549).

The second clinical study (a randomised, double-blind, crossover trial entitled “The role of inflammation in lactose malabsorption – a2 Milk™ for Gut Comfort Study”, or “Los aMiGos”) investigated the response to inclusion of A1 β-casein-free milk (a2 Milk™) and cheese in the diet, compared to consumption of conventional milk and cheese (containing a mix of A1 and A2 beta-casein). Unlike the aMiGo study which was a single-dose study in young women, the second study included young men and women, and was of two weeks’ duration, aiming to determine longer-term gut responses to the two dietary regimes, including perceived symptoms, inflammation, and changes in the intestinal microbiota. This study was completed in December 2018, and analyses are currently ongoing.

Overall, this research has contributed to a strong platform for market diversification in both developed and developing markets and has played a role in significant growth in demand for a2 Milk™ products, with consequent increased revenue for the New Zealand dairy sector in general. The project supports the overall mission of the High-Value Nutrition National Science Challenge by generating knowledge and capability that the New Zealand food and beverage industry can utilise to develop high-value foods with validated health outcomes and thus increase export revenues.

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