Further, most of the drugs used in HF, including β-blockers, angiotensin receptor blockers, angiotensin-converting enzyme inhibitors, calcium channel blockers, statins, and the more recently introduced SGLT2 inhibitors [155], can alter the gut microbiota composition [149,156,157], which in turn may modify drug action and ultimately affect HF management. The gene discussed is ACE; the disease is hydrops fetalis.