CD4 and colitis: Another strategy by Yao and collaborators consists in a Bifidobacterium longum strain capable of secreting human IL-10 which was capable of alleviating inflammatory damage of colonic tissue in a DSS-induced mouse model by blocking the colitis-activated NF-κB pathways and upregulating CD4 + CD25 + Foxp3+ Treg in blood and mesenteric lymph nodes [27].