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Australian Immunity Trial (Trial B): The effect of milk proteins on immune function in healthy young adults

Effect of milk containing only a2 beta-casein protein on immunity and inflammatory markers, gastrointestinal function, and cognitive function as compared to conventional milk which contains a2 and a1 beta-casein, in healthy young adults.

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ANZCTR
Registry ID
ACTRN12622000757718
Acronym
AIM trial
Enrollment
22
Registered
2022-05-27
Start date
2022-06-06
Completion date
2023-05-03
Last updated
2022-08-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

There is some evidence that A2 beta-casein versus A1/A2 beta-casein milk has beneficial effects on immunity, inflammation, gut health, and cognition function through multiple blinded RCTs (Trivedi 2017; Jianqin 2015; Ho 2014; Deth 2015). We hypothesise that consumption of A2 milk will reduce markers of inflammation and improve gut health and cognitive performance in healthy individuals. This study will test the effect of A2-only beta-casein milk as compared to A1/A2 beta-casein containing milk in a double-blind, randomised controlled trial. Healthy young adults will be randomised to recieve either cow's milk containing only A2 beta-casein protein, or cow's milk containing both A1/A2 beta-casein for 14 days. Participants will be asked to complete questionnaires, have a blood sample collected, and provide a faecal sample at the start and end of each intervention period. Participants will also be asked to follow a standardised diet for the entire study and will have their main meals provided, including during a run-in period (14 days), during each intervention period (2 x 14 days), and washout period between interventions (14 days).

Interventions

250mL cow's milk containing A2/A2 beta-casein proteins. Milk will be consumed once per day for 14 days, with a 14-day run-in period, plus 14-day washout period. Participants will drink the milk as part of a test breakfast daily. Breakfast will consist of 250mL milk, weet-bix + a banana, or 250mL milk, wholemeal toast with margarine and spread (e.g. jam), and a banana. Participants will be asked to avoid animal-based milk drinks during the run-in and wash-out periods. Compliance to the protocol

250mL cow's milk containing A2/A2 beta-casein proteins. Milk will be consumed once per day for 14 days, with a 14-day run-in period, plus 14-day washout period. Participants will drink the milk as part of a test breakfast daily. Breakfast will consist of 250mL milk, weet-bix + a banana, or 250mL milk, wholemeal toast with margarine and spread (e.g. jam), and a banana. Participants will be asked to avoid animal-based milk drinks during the run-in and wash-out periods. Compliance to the protocol will be measured through a survey administered weekly, and visual inspection of empty UHT milk tetra paks by the study co-ordinator.

Sponsors

Nutrition Research Australia
Lead SponsorOther Collaborative groups

Study design

Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Prevention
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
Yes

Inclusion criteria

Humans. Aged 18-40 years inclusive. Any sex or gender. BMI: 18.5-30kg/m2 inclusive. Can speak and read English. Consume cow’s milk 3 or more times per week, with at least 250ml consumed in one day. Agree to limit alcohol consumption to a maximum of 2 standard drinks per day during the study period. Agree to limit caffeine to two caffeinated beverages per day (one in the morning and one in the afternoon) during the study period. Agree to avoid nicotine (e.g., via cigarettes, vape, patch, or gum) during the study period. Agree to avoid prebiotic and probiotic supplements during the study period. Agree to avoid artificial sweeteners during the study period. Live in a stable residence and are able to receive and safely store weekly food deliveries throughout the intervention period.

Exclusion criteria

Unable to provide informed consent. Participant enrolled in or previously completed any AIM trial studies Diagnosed with a chronic disease, including autoimmune conditions, kidney or liver disease, cardiovascular disease, and diabetes. Diagnosed with one or more of the following mental health conditions: - Major depressive disorder, - Psychotic disorder such as schizophrenia, - Anorexia nervosa, - Bulimia nervosa, - Substance abuse disorder, - Bipolar disorder, - Personality disorder. History of elevated blood pressure (>140/90mmHg) at rest on 2 or more subsequent occasions, or told by a doctor that the participant has “high blood pressure” or “hypertension”. Experienced infectious disease, injury, or trauma in the past 6-months which led to hospitalisation, systemic (oral) steroid, or oral antibiotic prescription. Pregnant, breastfeeding, or attempting to become pregnant. Received a tetanus toxoid vaccination within the past 5-years. Received any other vaccination not previously mentioned in the past 6-months. Hospitalised within the past 3-months for any reason. Use of prescribed or recreational drugs, including steroids, CBD or cannabis, NSAIDs, proton-pump-inhibitors, or antihistamines within the past 2-months. - Paracetamol and ibuprofen are permitted. - Over-the-counter prescriptions permitted unless otherwise listed above or known to impact immunity and systemic inflammation. Change of oral contraception within past 6-months or planned change within the study period. Tobacco used within the past 2-years. Known or self-diagnosed allergy or intolerance to any food or ingredient. Seasonal allergy, e.g., rhinitis. Irritable bowel syndrome (self-diagnosis is valid). On a self- or healthcare professional prescribed diet (e.g., Paleo diet, vegan, gluten free diet, low sodium diet, FODMAPS diet). - Red meat vegetarian, lacto-ovo vegetarian, and pescatarian are permitted. Participated in a biomedical or medical study in the past 3-months; including participation in any AIM trials

Outcome results

None listed

Source: ANZCTR · Data processed: Feb 4, 2026