The gut and intestinal bacteria in chronic heart failure.

Chronic heart failure (CHF) is now recognized as a multisystem disorder with increased sympathetic tone, hormonal derangements, an anabolic/catabolic imbalance, endothelial dysfunction, and systemic low-grade inflammation affecting various organ systems. Pro-inflammatory cytokines appear to play important roles in that context. There is increasing evidence for the gut to have a pathophysiological role for both chronic inflammation and malnutrition in CHF. Indeed, disturbed intestinal microcirculation and barrier function in CHF seem to trigger cytokine generation, thereby contributing to further impairment in cardiac function. On the other hand, myocardial dysfunction can induce microcirculatory injuries leading to a disruption in the intestinal barrier. This amplifies the inflammatory response. Furthermore, alterations of specific absorption functions of the intestinal mucosa in CHF may aggravate symptoms of cachexia. The increased number of adherent bacteria seen in patients with CHF and elevated systemic levels of anti-lipopolysaccharide immunoglobulin A underscore this fact. Therefore, the gut poses an interesting target for therapeutic interventions in patients with CHF.