Probiotics have attracted growing interest in recent decades due to their multiple health benefits. The synergistic relationship between probiotics and prebiotics can enhance the production of metabolites called postbiotics, which are gaining increasing importance because of their beneficial functions in the gastrointestinal tract and their influence on different organs and tissues. Notable among the postbiotics is gamma-aminobutyric acid, which plays an essential role in the prevention of neural disease, type 1 diabetes, cancer, immunological disorders and asthma. Generally, gamma-aminobutyric acid is produced by lactic acid bacteria, which under certain conditions can produce a high amount of this amino acid. The food industry has leveraged this capacity to develop functional foods enriched with gamma-aminobutyric acid.