Lactobacillus acidophilus, L. casei, L. reuteri, B. bifidum and Streptococcus thermophilus were demonstrated to be associated with CD4+Foxp3+ Treg up-regulation in inflamed regions, Th1, Th2 and Th17 cytokine downregulation and increased IL-10 and TGF-β expression levels in the IBD, atopic dermatitis (AD) and rheumatoid arthritis (RA) animal models [112]. Here, CD4 is linked to rheumatoid arthritis.