TNF and psoriasis: Besides, a randomized controlled trial found that continuous oral administration of Bifidobacteria infantis (B. infantis) 35,624 significantly improved the progression of psoriasis and reduced the expression of C-reactive protein and tumor necrosis factor (TNF)-α, showing that the immunomodulatory effects of the microbiota in humans are not limited to the mucosal immune system but extend to the systemic immune system (Groeger et al., 2013).