Transplant of gut microbiota ameliorates metabolic and heart disorders in rats fed with a hypercaloric diet by modulating microbial metabolism and diversity.

Metabolic syndrome (MS) is a cluster of metabolic disorders which have a tight correlation with dysbiosis of gut microbiota (GM) that have to be treated to avoid higher risks for health. In this work, probiotics obtained from healthy cultured GM were provided to rats with metabolic syndrome (MSR) as therapy in treating MS through the correction of dysbiosis. MSR showed obesity, high blood pressure, abnormal blood chemistry parameters and high heart rate respect to control rats (CNTR). Cultivated GM from feces of MSR in media favoring anaerobic species, showed dysbiosis as judged by differences in the 16S rRNA metabarcoding analysis and by affected intermediary metabolism (methane and SCFA production, nutrients consumption and enzyme activities) compared to CNTR. The metabarcoding analysis of cultured healthy GM identified 211 species, which were further transplanted alive in MSR once a week for 9 weeks. Thereafter, in transplanted MSR the excess of Clostridium and Lactobacillus diminished, while Prevotella, Eubacterium, Faecalibacterium and methanogens, among others increased, leading to the recovery of the microbial metabolic capacity. The presence of butyric acid-producing bacteria in the transplanted GM correlated with increased levels of anti-inflammatory cytokines. Therefore, transplanted MSR recovered the normal levels of weight, blood glucose, triglycerides and cholesterol as well as the heart function. Data suggested that the great diversity of species contained in the GM transplanted restored the microbial metabolism, consuming excessive nutrients and secondary metabolites produced by MS. The use of cultivated GM as probiotics may be a safer alternative for the treatment of different diseases.