Gut Reaction: Can Probiotics Improve Wellbeing in Adults with Type 1 Diabetes? A Randomised, Parallel Arm, Placebo-Controlled Trial in Adults with Type 1 Diabetes

Abstract

Background: The challenging task of managing type 1 diabetes (T1D) incurs a significant behavioural and psychological burden. T1D is associated with an increased risk of depression and anxiety, which can negatively impact glycaemic control. With T1D incidence increasing each year, developing approaches to optimise glycaemic control and the psychological health of individuals with T1D is imperative. Accumulating evidence suggests that probiotics may be a novel therapy to improve depression and anxiety symptoms and glycaemic control in those with T1D through manipulating the gut microbiota and gut-brain axis. However, no studies have investigated probiotics’ effects on mood and glycaemic control in adults with T1D. Aim: The study aimed to investigate whether consuming probiotics could reduce symptoms of depression and anxiety and improve glycaemic control in adults with T1D. The study also explored the prevalence of depression, anxiety and stress symptoms in adults with T1D and their beliefs of probiotics. Method: The study was a 1:1 randomised, double-blind, parallel-arm placebo-controlled trial. A total of 74 adults (>18 years old) with T1D were recruited and randomised to consume either a probiotic (Lactobacillus rhamnosus HN001 at a dose of 6 x 109 cfu/day), or a placebo capsule, daily for 12-weeks. Outcome measures included depression, anxiety and stress symptoms, diabetes quality of life, and glycaemic control, and were assessed at baseline and after the 12-week intervention. Results: Analyses revealed that L. rhamnosus HN001 did not improve symptoms of depression, anxiety or stress, quality of life, or glycaemic control compared to placebo. Rather, all outcome measures displayed a significant improvement across the 12-week intervention, irrespective of group allocation. Those who reported more severe symptoms of depression, anxiety and stress at baseline did not show greater improvements following probiotic supplementation. Conclusion: Probiotics did not confer beneficial effects on mental health measures or glycaemic control compared to placebo and therefore cannot be recommended to adults with T1D at present. Further research is required to validate and build upon these findings to establish if different probiotic strains, dosages, and whether pre-existing levels of physiological and psychological health can impact the efficacy of probiotics in this population.