After transplantation of fecal flora from patients with different grades of atopic dermatitis (AD) into the intestines of mice and sensitizing the mice to AD, it was found that mice inoculated with gut flora from patients with high grades had more pronounced dermatitis symptoms and higher serum expression levels of the pro-inflammatory factors IL-1β, TNF-α, IL-4, IL-5, and IL-6 [67]. Here, TNF is linked to Alzheimer disease.