The epidemiological, experimental, and clinical studies have revealed that many kinds of probiotics (particularly Lactobacillus and Bifidobacterium), prebiotics (e.g., dietary fiber, GOS, B-GOS®, and alpha-lactalbumin), synbiotics, postbiotics (e.g., SCFAs), dairy products, spices (e.g., Zanthoxylum bungeanum, curcumin, and capsaicin), fruits, vegetables, and medicinal herbs could prevent and manage the mental disorders by modulating intestinal microbiota, including increasing beneficial gut microbiota and reducing harmful gut microbiota. The gene discussed is LALBA; the disease is psychiatric disorder.