Metagenomics Investigation on Baby Diaper Area Microbiome and Its Association with Skin pH and Dermatitis in the Diapered Area

Dermatitis in the diapered area (DDA) is the most common skin condition in infants and can cause significant pain and discomfort, leading to disturbed sleep, changes in temperament, and heightened concern and anxiety for caregivers. This study investigates the relationship between skin pH, microbiome composition, and DDA severity in 158 infants from China, the US, and Germany, focusing on the buttocks, perianal, and thigh regions. Significant variations in DNA biomass and microbiota profiles were noted. <i>Escherichia coli</i> and <i>Veillonella atypica</i> were linked to higher rash scores and elevated skin pH, while <i>Bifidobacterium longum</i> showed a negative correlation with buttocks pH and rash severity but not with perianal rash. Correlation patterns emerged for other species, like <i>Enterococcus faecalis</i>, between perianal and buttocks rashes. Functional analysis identified key categories, including lipid and fatty acid metabolism, cofactor, amino acid, and carbohydrate metabolism, homeostasis and osmolarity stress, and microbial virulence and oxidative stress response, which are vital for skin health, DDA, and pH regulation in infants. These findings underscore the importance of maintaining a mildly acidic skin pH and minimizing fecal and urine residues for optimal infant skin health, suggesting that microbiota significantly influence DDA development, and provide insights for future preventive strategies and therapeutic interventions.