Exploring Longitudinal Gut Microbiome towards Metabolic Functional Changes Associated in Atopic Dermatitis in Early Childhood

Simple Summary Atopic dermatitis (AD) is a skin disease associated with changes in the gut microbiome early in life. We conducted a comprehensive study to investigate the gut microbiome of Thai children with AD compared to their healthy counterparts. Our study involved both longitudinal analysis, starting from 9 months of age until 30 months, and cross-sectional analysis, comparing patients in the same age group to explore temporal variation. Accordingly, differences were found in bacteria that are potentially identified to produce short-chain fatty acids, which are important for gut health. These children with AD also showed differences in certain metabolic activities related to vitamin production and host immune response. This study is the first challenge to track these gut bacteria and metabolic changes over time in Thai children with allergies. Understanding these differences can help us develop better treatments for AD and similar conditions, benefiting children’s health worldwide. Abstract Atopic dermatitis (AD) is a prevalent inflammatory skin disease that has been associated with changes in gut microbial composition in early life. However, there are limited longitudinal studies examining the gut microbiome in AD. This study aimed to explore taxonomy and metabolic functions across longitudinal gut microbiomes associated with AD in early childhood from 9 to 30 months of age using integrative data analysis within the Thai population. Our analysis revealed that gut microbiome diversity was not different between healthy and AD groups; however, significant taxonomic differences were observed. Key gut bacteria with short-chain fatty acids (SCFAs) production potentials, such as Anaerostipes , Butyricicoccus , Ruminococcus , and Lactobacillus species, showed a higher abundance in the AD group. In addition, metabolic alterations between the healthy and AD groups associated with vitamin production and host immune response, such as biosynthesis of menaquinol, succinate, and (Kdo)2-lipid A, were observed. This study serves as the first framework for monitoring longitudinal microbial imbalances and metabolic functions associated with allergic diseases in Thai children during early childhood.