a2 Milk for gut comfort Matthew Barnett, AgResearch Limited April 14 - PowerPoint PPT Presentation

a2 Milk™ for gut comfort Matthew Barnett, AgResearch Limited April 14 th 2016 Host Institution

Overview • a2 Milk™ – what’s the story? • Where does this project fit in? • What do we hope to achieve? • How are we going to do it?

a2 Milk™ – What’s the Story? • Bovine milk has >200 different proteins • One of these is β -casein, which comprises 25-30% of the total protein • There are several well-characterised variants in the β - casein gene • Some of these result in changes to the protein sequence, with possible functional consequences

a2 Milk™ – What’s the Story? • Originally, all cows produced only A2 β -casein • A1 β -casein mutation developed in some European dairy herds 5-10,000 years ago. This form is now the most widespread • Today, most milk contains a mix of A1 and A2 protein types • a2 milk™ products contain only the A2 form of β -casein

a2 Milk™ – What’s the Story? β -casomorphin-7 (BCM-7) Figure adapted from Gobbetti et al. (2002). Crit Rev Food Sci Nutr 42(3):223-39, and Jinsmaa & Yoshikawa (1999) Peptides 23(8):957-62

a2 Milk™ – What’s the Story? β -casomorphin-7 (BCM-7) Figure adapted from Gobbetti et al. (2002). Crit Rev Food Sci Nutr 42(3):223-39, and Jinsmaa & Yoshikawa (1999) Peptides 23(8):957-62

a2 Milk™ – What’s the Story? Human β -casein is like A2, not A1, bovine β -casein Human, goat and sheep β -casein proteins are comparable to A2 • (not A1) protein in terms of structure around BCM-7 release Only 1-10% of the theoretical human equivalent comes from in • vitro digestion of human β -casein Internal differences mean bovine BCM-7 is 10 x more potent • (opioid receptor binding) than the theoretical human equivalent T y r 6 0 - P r o 6 1 - P h e 6 2 - P r o 6 3 - G l y 6 4 - P r o 6 5 - l l e 6 6 - H i s 6 7 B o v i n e β - c a s e i n A 1 T y r 6 0 - P r o 6 1 - P h e 6 2 - P r o 6 3 - G l y 6 4 - P r o 6 5 - l l e 6 6 - P r o 6 7 B o v i n e β - c a s e i n A 2 T y r 5 1 - P r o 5 2 - P h e 5 3 - Va l 5 4 - G l u 5 5 - P r o 5 6 - l l e 5 7 - P r o 5 8 H u m a n β - c a s e i n

a2 Milk™ – What’s the Story? • Interest started with epidemiological studies indicating differential disease risk associated with A1 and A2 milk • More recent work in animals and humans has focused on immediate effects (e.g., digestive comfort) – Consumers care about the “now” – Generally accepted that a healthy gut means better overall health • Pre-clinical data shows differences resulting from consumption of standard milk (i.e., containing A1 β -casein) and a2 milk™ (free of A1 β -casein) – Intestinal transit 1 – Inflammatory response 1,2 1 Barnett et al. (2014). Int J Food Sci Nutr 65(6):720-7 2 Ul Haq et al. (2013). Eur J Nutr 53(4):1039-49

a2 Milk™ – What’s the Story? • Human clinical data 1 showing consumption of standard vs. a2 milk™ may lead to differences in – Intestinal comfort – Intestinal physiology – Cognitive behaviour • Mechanisms may relate to the release of different bioactive peptides – BCM-7 from A1 β -casein has been shown to trigger inflammation in human cells in vitro 2 – This needs to be consolidated by human studies 1 Jianqin et al. (2016). Nutrition Journal 15:35 2 Trivedi et al. (2014). J Nutr Biochem 25(10):1011-8

Where does this project fit in? • Many consumers in Asia consider themselves to be “lactose intolerant” • These consumers avoid consuming dairy products due to intestinal discomfort • Recent data suggest this discomfort may be due to inflammation in the small intestine, which may in turn be a response to A1 β -casein

Where does this project fit in? • Evidence of increased intestinal discomfort in response to A1 milk compared with A2 milk Jianqin et al. (2016). Nutrition Journal 15:35

Where does this project fit in? • Evidence of inflammation in response to A1 milk compared with A2 milk – Increased serum IL-4, IgG, IgE How can we build on this evidence? Jianqin et al. (2016). Nutrition Journal 15:35

What do we hope to achieve? • Generate evidence that some consumers who currently avoid dairy can tolerate a2 Milk™ • Better understand the mechanisms through which this (in)tolerance occurs • Contribute evidence for a health claim by the a2 Milk Company • -> Increased dairy consumption in China

How are we going to do it? • Test the hypothesis: “that a2 Milk™ does not induce adverse symptoms of gut discomfort in consumers with perceived lactose intolerance.”

How are we going to do it? Clinical studies, standard vs. a2 Milk™ • A range of outcome measures, including – Self-reported intestinal symptoms/mood/appetite – Imaging of small intestine – Plasma • Metabolites • Cytokines – Breath volatile metabolites

How are we going to do it? In vitro studies, purified and SGID A1 vs. A2 β -casein • How do these variants influence inflammatory Image by kaibara87 - originally posted to Flickr as Cell Culture, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=5618734 response? – Cytokine release from cells • TNF- α (pro-inflammatory) • IL-10 (anti-inflammatory) • IL-4 (pro-inflammatory) – miRNA release from cells • miRNAs related to inflammation

Outcomes • Demonstrate health benefits of a2 Milk™-based products for improving gut comfort • Contribute to the a2 Milk Company’s mission: “to pioneer the scientific understanding of a2 Milk™ so we can bring more people the pleasure and nutritional goodness that only comes from real and natural milk.”

Outcomes • Support the a2 Milk Company to submit a dossier for a high-level health claim that meets NZ regulations, and those in key international export markets. • Increased value to the NZ supply chain – Farmers – Processors – Ingredient manufacturers

Acknowledgements • HVN • The a2 Milk Company Limited • The University of Auckland • “a2 Milk™ for Gut Comfort” Team – Shalome Bassett, David Cameron-Smith, Andrew Clarke, Li Day, Karl Fraser, Amber Milan, Suzanne Simpson, Wayne Young

Cheers!