Daily administration of Limosilactobacillus mucosae DPC 6426 had negligible effects on blood lipids in mildly hypercholesterolaemic adults

Abstract Among the recommendations to prevent heart disease is the maintenance of normal blood cholesterol levels, through the consumption of a cardioprotective diet, and if necessary, the use of therapeutics such as statins. Alterations in the gut microbiota have previously been associated with the development of obesity, insulin resistance and increased risk of developing cardiovascular disease (CVD). Probiotics have since emerged as a potential therapeutic strategy, aimed at reversing the alterations to the gut microbiome. Indeed, we had previously found that ingestion of Limosilactobacillus mucosae DPC 6426 had significantly lowered both blood cholesterol and triglyceride levels in a pre-clinical apoE mouse model, as well as modulating the gut microbiota, suggesting strain-specific cardiometabolic potential. To investigate the translational relevance of these findings in humans, we conducted a randomised, double-blind, placebo-controlled clinical trial which assessed the effects of daily administration of the strain at a dose of 3.8 × 10 9 CFU/per day, in mildly hypercholesterolaemic adults, on blood lipid profiles and the gut microbiota composition. Results demonstrated, despite successful gastrointestinal transit and recovery of Lactobacillus spp., that Limosilactobacillus mucosae DPC 6426 was not superior to placebo in modifying blood lipid concentrations or the gut microbiota composition in healthy, mildly hypercholesterolaemic adults. Such findings highlight the complexity of translating probiotic-associated metabolic benefits from preclinical apoE mouse models to healthy human participants. Further investigations are warranted to ascertain whether the probiotic dose administered in this study was insufficient to translate from the pre-clinical apoE mouse model in such a human cohort.