CD4 and dermatitis: In our previous study, PEW reduces high-fat diet-induced obesity in mice via the regulation of gut microbiota (Wang et al., 2020), we hypothesize the gut microbiome regulation function of PEW may play a role in alleviating skin inflammation of AD and influencing CD4+ T cell differentiation, also, it is possible that PEW ameliorates AD via modulating effects of diets.