TGFB1 and Arthritis: The effect of probiotics on oral tolerance induction has been shown with L. casei. So et al. showed in a rat model of experimental arthritis that oral administration of L. casei suppresses arthritic inflammation by increasing the ratio of Foxp3+ CD4+ T cells, and increasing the secretion of IL-10 and TGF-β by CD4+ T cells [41].