Background

Bariatric surgery, specifically sleeve gastrectomy (SG), results in substantial sustained weight loss with improvement in cardiovascular diseases. We have previously published that rodent SG improves hypertension and diastolic function independent of weight loss associated with unique shifts in the gut microbiome. We therefore tested the hypothesis that the gut microbiome directly mediates the improvement in cardiovascular dysfunction by performing fecal material transfer (FMT) studies from surgical to naïve rats.

Methods

We performed SG (n=6) or Sham (n=7) surgery in obese, Zucker rats at 8 weeks of age. Stool was collected from these surgical donor rats for future FMT. Three recipient groups (n=7-8/group) received daily oral consumption of SG-FMT/Nutella, Sham-FMT/Nutella, or Nutella alone. Animals were followed post-operatively for the effect of FMT on body weight, food intake, body composition, glucose tolerance, blood pressure, cardiac function, and cardiomyocyte stress.

Results

SG-FMT did not alter body weight, food intake, body composition, glucose tolerance or diastolic function after 10 weeks. SG-FMT resulted in significantly lower blood pressures (124+-16 mmHg) compared to Sham-FMT (150+-10 mmHg, p=0.002) and Nutella groups (143+-12 mmHg, p=0.05), starting at 8 weeks of treatment. In vitro, SG-FMT plasma significantly reduced relative LDH secretion from H9 myoblasts compared to Sham-FMT (-32.8%, p<0.01) and Nutella groups (-15%, p<0.01) under metabolic-oxidative stress.

Conclusions

SG induces changes in the gut microbiome which are transferable to a naïve host to improve blood pressure and reduce cardiometabolic stress. This suggests that the gut microbiome is a mechanism for weight-loss independent, cardiovascular disease remission after SG.