Two other strains of Lactobacillus, L. rhamnosus CCFM1228 and L. paracasei CCFM1229, can alleviate anxiety- and depression-related behaviors in animal models, which may be achieved by regulating the activity of xanthine oxidase (XO) in brain (Xu M. et al., 2022). The gene discussed is XDH; the disease is major depressive disorder.