The Role of Gut Microbiota in Heart Failure: When Friends Become Enemies

Abstract

Heart failure is a complex health issue, with important consequences on the overall wellbeing of patients. It can occur both in acute and chronic forms and, in the latter, the immune system appears to play an important role in the pathogenesis of the disease. In particular, in the forms with preserved ejection fraction or with only mildly reduced ejection fraction, some specific associations with chronic inflammatory diseases have been observed. Another interesting aspect that is worth considering is the role of microbiota modulation, in this context: given the importance of microbiota in the modulation of immune responses, it is possible that changes in its composition may somewhat influence the progression and even the pathogenesis of heart failure. In this narrative review, we aim to examine the relationship between immunity and heart failure, with a special focus on the role of microbiota in this pathological condition.

Altered Expression of Intestinal Tight Junction Proteins in Heart Failure Patients with Reduced or Preserved Ejection Fraction: A Pathogenetic Mechanism of Intestinal Hyperpermeability

“…There is evidence in the literature that the dysbiosis of the gut microbiota is associated with high circulating TMAO concentrations due to a disrupted gut mucosal barrier and increased intestinal permeability [22,34]. TMAO activates signaling pathways such as TGF-β1/Smad3 and p65 NF-κB, leading to a decrease in energy metabolism and mitochondrial function, and impairs the tricarboxylic acid (TCA) cycle, ultimately adversely affecting myocardial contractile function and intracellular calcium processing, and consequently triggering cardiac hypertrophy and myocardial fibrosis [1,20,22].…”

“…According to the current pathogenetic aspects of chronic heart failure (HF), systemic inflammation plays a central role in the progression of the disease [1]. HF with reduced ejection fraction (HFrEF) leads to intestinal congestion, which subsequently impairs the integrity and function of the intestinal epithelial barrier and increases intestinal permeability [2].…”

Gut–Kidney–Heart: A Novel Trilogy

“…Specifically, HF determines changes in the composition of GM, with a loss of variety and an increase in pathogenic microorganisms such as Campylobacter spp., Salmonella spp., Shigella spp., Yersinia enterocolitica [68], Candida spp., and Chlamydia pneumoniae [69].…”

Factors Influencing Microbiota in Modulating Vaccine Immune Response: A Long Way to Go

“…The human microbiota, particularly the gut microbiota, interacts with the immune system in different ways, leading to either proinflammatory or anti-inflammatory activation [7,11]. This interplay takes place through various mechanisms, such as the production of bacterial metabolites with pro-/anti-inflammatory activity, the regulation of immune cell differentiation, the influence on the host's metabolism, and the modulation of intestinal permeability [7,10,15]. All of these factors can result in an imbalance when external or internal factors perturb the equilibrium in the GM community, inducing an impairment in its functional and compositional harmony called gut dysbiosis [16].…”