Comparative data between eczema and control group.xlsx

The gut microbiota plays a crucial role in infant health, but its disruptions in eczema remain unclear. In this cross-sectional study, we compared the gut microbiota and metabolite profiles of infants with eczema and healthy controls, revealing reduced acidogenic and acidophilic commensals, altered short-chain fatty acids, impaired intestinal acidification, and disrupted microbial networks. Lower total bile acids and <i>Lactobacillus</i> counts suggested delayed bile acid maturation. Based on these findings, we propose a Dual Driving Force Hypothesis, where high lactate initiates microbiota succession, followed by bile acids. Lactate accumulation is essential for intergenerational microbiota reproducibility, and acidogenic bacteria serve as key immune stimuli. Reduced microbial exposure due to excessive hygiene may delay lactate accumulation, impair microbiota maturation, and weaken immune development. Our findings support the hygiene hypothesis and highlight microbiome-targeted strategies for eczema prevention and intervention.