Phenylacetylglycine is a gut microbial metabolite that can activate β2AR. Phenylacetylglycine protects against cardiac injury caused by ischemia/reperfusion.In Vitro:Phenylacetylglycine (10-100 μM; 30 min before H/R injury) reduces disreoxygenation (H/R) injury-induced apoptosis and activates Gαi and Gαs signaling in neonatal mouse cardiomyocytes (NMCMs).