3-phenylpropionic acid

3-phenylpropionic acid is a naturally occurring short-chain carboxylic acid and a gut microbial metabolite derived from dietary polyphenols, phenylalanine, and ferulic acid. It is produced by bacteria such as *Clostridium sporogenes* and *Desulfovibrio piger*. This compound exhibits diverse biological activities, including antimicrobial effects against pathogens like *Salmonella enterica* and *Salmonella pullorum*. It has been shown to reverse insulin resistance and obesity-associated metabolic dysfunction by activating hepatic AMP-activated protein kinase α (AMPKα), leading to insulin-sensitizing and anti-steatotic effects. Furthermore, 3-phenylpropionic acid attenuates intestinal inflammation and damage through the AhR/IL-22/STAT-3 signaling axis and promotes myotube hypertrophy by modulating the Foxo3/NAD+ pathway, inhibiting protein degradation and promoting protein acetylation. It is also implicated in neurological functions, with associations found between its levels and social behavior, ADHD symptoms, and executive function in children. Additionally, it plays a role in plant defense and is used as a fragrance ingredient.