Effects of a diverse prebiotic fibre supplement on HbA1c, insulin sensitivity, and inflammatory biomarkers in pre-diabetes: a randomised placebo-controlled clinical trial

Prebiotic fibre represents a promising and efficacious treatment to manage pre-diabetes, acting via complementary pathways involving the gut microbiome and viscosity-related properties. In this study, we evaluated the effect of using a diverse prebiotic fibre supplement on glycaemic, lipid, and inflammatory biomarkers in patients with pre-diabetes. Sixty-six patients diagnosed with pre-diabetes (yet not receiving glucose-lowering medications) were randomised into treatment (n = 33) and placebo (n = 33) interventions. Participants in the treatment arm consumed 20g per day of a diverse prebiotic fibre supplement and participants in the placebo arm consumed 2g per day of cellulose for 24 weeks. A total of 51 and 48 participants completed the week 16 and week 24 visits, respectively. The intervention was well-tolerated, with a high average adherence rate across groups. Our results extend upon previous work, showing a significant change in glycated haemoglobin (HbA1c) in the treatment group, but only in participants with lower baseline HbA1c levels (<6% HbA1c). Within the whole cohort, we showed significant improvements in insulin sensitivity, fasting plasma insulin, and C-reactive protein in the treatment group compared with the placebo. We did not observe any between-group differences in lipid profiles or other inflammatory cytokines. Together, our results show support for the beneficial effects of a diverse prebiotic fibre supplement on physiologically relevant biomarkers in pre-diabetes. ### Competing Interest Statement C.V Hall and T. Gurry are employees/shareholders of Myota GmbH. ### Clinical Trial NCT05593926 ### Funding Statement This project was sponsored and funded by Myota GmbH. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by Berkshire B NHS Human Research Ethics Committee in the United Kingdom (reference: 22/SC/0363). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Underlying data presented in the study are available upon reasonable request to the authors