Changes in Gut Microbiome Structure and Function of Rats with Isoproterenol-Induced Heart Failure

: Recently, the potential role of gut microbiome (GM) in cardiovascular diseases has been revealed. Heart failure (HF) is one of the most prevalent cardiovascular diseases worldwide; however, whether GM dysbiosis participates in the development of HF remains largely unknown. This study aimed to investigate the specific changes in GM composition and function in isoproterenol (ISO)-induced HF in rats.The rats were divided into C (control), 4w-HF (ISO, 2.5 mg/kg/day for 4 weeks, intraperitoneally), and 2w-HF (ISO, 2.5 mg/kg/day for 2 weeks, intraperitoneally) groups. The cardiac structure and function in rats were assessed, and metagenomic analyses were then performed. Compared with the healthy control group, we found that the Shannon diversity index and microbial gene count in the 4w-HF and 2w-HF groups was drastically decreased. High-throughput sequencing showed that the three groups differed in intestinal bacterial community composition. Overgrowth of bacteria, such as Prevotella, was observed in the 4w-HF group, with reduced growth of bacteria, such as Roseburia, Lactobacillus, and Butyrivibrio, associated with healthy status compared with the C group on the genus level. Concomitant with the alteration of GM composition, underrepresentation of health-linked microbial function was observed in both the 4w-HF and 2w-HF groups compared with the C group.Iso-induced HF rats showed a significant decrease in the diversity and richness of the intestinal microbiome, with a downregulation of the key intestinal bacterial groups and overgrowth of bacteria considered to be involved in inflammatory responses as well as a decrease in health-linked microbial function. Our data indicated that altered GM may be a potential player in the pathogenesis and progression of HF.