On the other hand, in inflammatory skin diseases such as atopic dermatitis and rosacea, Dialister is reported to act in a protective manner, because it produces propionic acid, induces regulatory T-cells, and controls inflammation by suppressing the production of inflammatory cytokines such as IL-6 and TNF [34], suggesting that the presence of Dialister species indicates the intensity of inflammation, but whether it is a cause or a consequence remains unclear at this stage. This evidence concerns the gene TNF and rosacea.