The Role Of Gut Microbiome Secreted Short Chain Fatty Acids In The Development Of Heart Failure With Preserved Ejection Fraction HFpEF

More than 50% of patients with heart failure are diagnosed with heart failure with preserved ejection fraction (HFpEF), and 80% of them are obese. It is a prominent disease with no available treatments. It is characterized by diastolic dysfunction that involves increase in left ventricle stiffness and decrease in its relaxation during diastole. To better understand the pathogenesis of obesity associated HFpEF, our studies focus on the early asymptomatic changes in cardiac mechanics that occurs before the increases in intracardiac pressure. Therefore, we have developed an obesity associated mouse model that we called pre-HFpEF where mice were fed either Normal Chow or Western Diet for 14 weeks. Our echocardiography measurements indicated the presence of early cardiac dysfunction consistent with obesity associated pre-HFpEF phenotype. Mice on WD had decrease in Global Longitudinal Strain (%GLS) and Longitudinal strain rate reverse (LSRr) indicating early signs of systolic and diastolic dysfunction, as well as increase in left ventricle anterior and posterior wall thickness during diastole (LVAWd, LVPWd). Obesity is also known to cause microbiome imbalance, which plays a significant role in the development of cardiovascular diseases through changes in short chains fatty acids, which are products of dietary fiber fermentation by the gut bacteria. In order to study the association between gut microbiome imbalance and HFpEF development, we treated our obese pre-HFpEF mice with fecal matter transplantation (FMT) from either lean or obese mice, and we found that FMT from lean mice led to significant improvements in systolic and diastolic dysfunction by increasing %GLS and LSRr and preventing hypertrophy by decreasing LVAWd and LVPWd. In addition, WD reduced butyrate producing bacteria, however circulating levels of butyrate were significantly increased with lean FMT treatment. Using an in-vitro approach to mimic WD we found butyrate treatment to inhibit the activation of NLRP3 inflammasome and NF-KB. Therefore, since FMT treatment improved cardiac dysfunction in obesity associated pre-HFpEF mice, and that butyrate is increased after FMT and can play a role in metabolic homeostasis, we predict that butyrate could be an important player in FMT improvements through cardiac metabolic regulation and cardiac inflammation suppression