A randomised double-blind placebo-controlled trial of a probiotic combination for manipulating the gut microbiota and managing metabolic syndrome

An increasing number of studies indicate that the occurrence of metabolic syndrome is significantly influenced by the host's gut microbiota and its metabolites. This study evaluated the potential application of a combination of Bifidobacterium adolescentis CCFM8630 and Lactobacillus reuteri CCFM8631 for the clinical remission of metabolic syndrome. This research comprised 40 individuals with metabolic syndrome, 21 of whom were in the probiotic intervention group and 19 in the placebo control group. The intervention duration was 11 weeks and involved the daily intake of 1 × 1010 CFU of a probiotic combination comprising Bifidobacterium adolescentis CCFM8630 and Lactobacillus reuteri CCFM8631. The serum biochemical indexes of the participants before and after the intervention were measured. After the intervention, faecal samples were collected to comprehensively analyse the gut microbiota of the participants by high-throughput sequencing and the faecal concentrations of target short-chain fatty acids by gas chromatography–mass spectrometry. The results showed that the 11-week probiotic intervention significantly reduced fasting blood glucose, fasting insulin, triglyceride, and low-density lipoprotein cholesterol concentrations in patients with metabolic syndrome and significantly increased the abundance of Bacteroidetes and some genera that produce short-chain fatty acids by regulating the abundance of gut microbial taxa that are strongly correlated with the clinical indicators of metabolic syndrome. These results demonstrated the beneficial effects of the probiotic combination on the clinical remission of metabolic syndrome, suggesting its potential application as an adjuvant strategy for the clinical treatment of metabolic syndrome in the future and laying a foundation for the further study of the mechanism of action of probiotics in alleviating metabolic syndrome.