RecruitingACTRN12622000755730

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

Effect of milk containing only a2 beta-casein protein plus lactoferrin on immunity and inflammatory markers, gastrointestinal function, and cognitive function as compared to conventional milk which contains a2 and a1 beta-casein and no lactoferrin, in healthy young adults.

Sponsor

Nutrition Research Australia

Enrollment

50 participants

Start Date

Jun 6, 2022

Study Type

Interventional

Conditions

Immune Function Cognition Gastrointestinal Microbiome

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). Another component of milk, lactoferrin, is thought to have immuno-modulating properties (Kell, 2020). When consumed orally, lactoferrin is mostly absorbed, with a small amount reaching the lower bowel (Yamuchi, 2006). In humans, orally consumed bovine lactoferrin has improved systemic and gut immunity (Sachdeva, 2009; Yamuchi, 2006). We hypothesise that consumption of A2 milk, in conjunction with lactoferrin, will reduce markers of inflammation in healthy individuals. This study will test the effect of A2-only beta-casein milk fortified with bovine lactoferrin, as compared to A1/A2 beta-casein containing milk without lactoferrin fortification 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 plus lactoferrin, or cow's milk containing both A1/A2 beta-casein without lactoferrin 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).

Eligibility

Sex: Both males and femalesMin Age: 18 YearssMax Age: 40 Yearss

Inclusion Criteria12

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 Criteria28

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

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Interventions

250mL cow's milk containing A2/A2 beta-casein proteins, + 100mg bovine lactoferrin. 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.