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). Here, XDH is linked to depressive disorder.