Gut Microbiota and Related Metabolites in Children With Egg White Sensitization

Background: We hypothesized that food sensitization in children could be linked to specific gut microbiota. The objective of this study is to assess a group of children with egg white sensitization (ES) from the microbiological and biochemical-metabolic standpoint, applying the microbiota and metabolomics approach to studying the intestinal contents of the feces. Methods: Twenty-eight toddlers with ES (mean age 13.08 months) and 24 healthy controls (mean age 12.85 months) were recruited for feces collection, serum IgE measurement, gut microbiota and metabolomics analysis. Individual microbial diversity and composition were analyzed via targeting the 16S rRNA gene hypervariable V3–V5 regions. The metabolite profiles of human feces were explored by ¹H nuclear magnetic resonance. Results: Children with ES exhibited relatively high levels of Firmicutes at the phylum level and relatively low levels of Bacteroidetes. Moreover, children with ES exhibited significantly reduced overall gut microbiota diversity and richness compared with healthy children. At the family level, we observed significant increases in the numbers of Clostridiaceae, Lachnospiraceae, Pasteurellaceae and Ruminococcaceae in children with ES. Egg white sensitivity increases orotic acid, nicotinate, methyl succinate, urocanic acid, xanthine, amino acids (tyrosine, lysine, tryptophan, phenylalanine) and short-chain fatty acids (n-butyrate, valerate) levels according to the results of metabolomics analysis. Conclusions: In summary, some specific families and genera (dysbiosis) are enriched in the gut microbiota, and increases in the mean concentrations of organic compounds in the fecal metabolite profile are associated with ES in children. These findings may provide evidence of potential strategies to control the development of ES or other atopies by modifying the gut microbiota.