IL2 and rheumatoid arthritis: When RA-induced animal models were fed Lactobacillus casei, it led to improvised health conditions by reduction in levels of pro-inflammatory cytokines such as IL-1β, IL-2, IL-6, IL-12, and IL-17, IFN-γ, and TNF-α, while upregulating the secretion of regulatory cytokines like IL-10 and TGF-β (149–152).