Bifidobacterium bifidum TMC3115 Can Characteristically Influence Glucose and Lipid Profile and Intestinal Microbiota in the Middle-Aged and Elderly.

Bifidobacterium bifidum TMC3115 strain (TMC3115) was orally administrated to 47 subjects with mild hyperglycaemia and dyslipidaemia aged 45 to 75 years for 3 weeks. Blood samples were collected before and after intervention for profiling plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol and triglyceride concentrations, as well as fasting blood glucose. Before and 3 and 4 weeks after intervention, the faecal samples were collected to analyse faecal microbiota using the sequencing of 16S rRNA genes with a next-generation sequencer. TMC3115 significantly decreased plasma TC and LDL-C levels of the tested subjects after intervention (P < 0.05). The frequencies of defaecation and faecal odour after the intervention and 1 week later were significantly better than at pre-intervention, respectively. TMC3115 administration increased Firmicutes, Bacteroides and Actinobacteria and decreases in Proteobacteria and Fusobacteria. There were significant increases in the proportions of Dorea and Lachnospira after the intervention (P < 0.05). TMC3115 also increased the level of Firmicutes and decreased that of Bacteroidetes 1 week after the intervention (P < 0.05). Serum triglycerides correlated negatively with the proportions of Bacteroidetes (R = - 0.21, P = 0.047) and Bacteroides (R = - 0.23, P = 0.029), while the relative abundance of Dialister of Firmicutes correlated negatively and significantly with the serum LDL-C (R = - 0.24, P = 0.022) and TC levels (R = - 0.22, P = 0.030). These results indicate that TMC3115 might exhibit beneficial effects on the serum cholesterol metabolism of subjects with dyslipidaemia through modulation of their intestinal microbiota. Trial registration: ChiCTR-OOC-16010271.