Probiotics and wellbeing in adults with type 1 diabetes

This study is a randomised, double-blind, placebo-controlled trial investigating the effects of probiotic versus placebo capsules on depression, anxiety, stress, health-related quality of life, and glycaemic control (HbA1c) among adults with T1D in the Auckland region over the course of 12 weeks. Beliefs around probiotic supplementation will also be examined. Eighty participants will be recruited from Auckland, Counties Manakau and/or Waitemata District Health Board diabetes outpatient clinics. Participants will also be recruited from online T1D communities (E.g. Facebook support groups). The probiotic capsules are Lactobacillus rhamnosus HN001, at a dose of 6x109 CFU/day (1 capsule/day). After providing written informed consent, participants will complete baseline questionnaires in clinic or using the secure website REDCap. Participants’ HbA1c levels will be accessed through their medical records. Participants will then be randomised to receive probiotic or placebo capsules for 12 weeks and will be given a bottle of capsules and be asked to take one capsule each day. Participants will be sent a text message every two weeks reminding them to take their capsules. Outcome measures will be assessed at baseline (in clinic) and at the 12 weeks follow-up using online questionnaires. After the 12-week follow-up, 6-10 participants will be invited to attend a focus group and/or interviews to discuss their views on taking probiotics and possible barriers (e.g. cost). This qualitative component will also allow us to explore more in-depth views from Maori participants, who are unlikely to be equally represented in the quantitative data due to T1D being more prevalent in European New Zealanders. With a sample size of 80, we hope to recruit approximately eight Maori participants, out of which we estimate 4-6 will be able to attend the focus group and/or interviews.