Butyrate increases cardiac output and causes vasorelaxation in a healthy porcine model.

Background: Butyrate, a short-chain fatty acid, has shown potential to improve left ventricular (LV) function and induce vasorelaxation in rodents. Butyrate may either be produced by the microbiome in the colon, be ingested or administered intravenously. This study aimed to evaluate effects of butyrate on cardiac output (CO) and associated hemodynamic variables in a porcine model.

Methods: In a randomized, blinded crossover study, ten healthy 60-kg pigs were given three hour infusions of 600 mM butyrate and equimolar sodium chloride (control). CO was measured by thermodilution via a pulmonary artery catheter. LV contractility was assessed using pressure-volume admittance catheterization. Additionally, isolated porcine coronary arteries were exposed to butyrate in a wire myograph to evaluate vasorelaxation.

Results: Butyrate infusion increased plasma butyrate concentration to 0.53 mM (95 % confidence interval (CI): 0.49 to 0.58 mM, P < 0.58 mM, P < 0.001) and CO by 1.6 L/min (95 % CI: 1.0 to 2.1 L/min, P < 0.001) compared with the control. Heart rate, LV ejection fraction, cardiac efficiency and dP/dtmax rose, while systemic vascular resistance, arterial elastance, mean arterial pressure and LV end-systolic volume decreased. Loadindependent LV contractility and stroke volume did not significantly differ. In the myograph, porcine coronary arteries relaxed in response to butyrate in a concentration-dependent manner.

Conclusion: Butyrate increases cardiac output and lowers vascular resistance in a large animal model, through increased HR and systemic vasorelaxation. Load-independent LV contractility was not significantly altered. We observed indices of increased end-organ perfusion. These potentially beneficial cardiovascular properties of butyrate should be further studied.