The carriers of IL-1β rs16944 single nucleotide polymorphism (related to high proinflammatory cytokine levels, depression, and neurodegenerative diseases) presented a moderate risk of having anxiety at baseline (43 vs. 11.4% in non-carriers), but the administration of probiotics helped in decreasing the HAMA score in this subgroup, while in the non-carriers the effect of probiotics was not significant (34). Here, IL1B is linked to depressive disorder.