Gut microbiota profiles in Korean children with growth hormone deficiency: a case-control study.

BACKGROUND: The gut microbiota plays an important role in childhood growth and metabolic regulation and may interact with the growth hormone (GH)-insulin-like growth factor-1 axis. However, the gut microbiota characteristics in children with GH deficiency (GHD) are poorly understood. PURPOSE: This study aimed to compare the gut microbiota composition and predict the functional profiles of Korean children with GHD and those growing normally. METHODS: In this pilot case-control study, fecal samples were collected from children with biochemically confirmed GHD and age- and sex-matched healthy controls. Gut microbiota composition was analyzed using 16S rRNA gene sequencing. Microbial alpha and beta diversities, taxonomic compositions, and differentially abundant taxa were evaluated. Functional profiles of the gut microbiome were predicted using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States based on the Kyoto Encyclopedia of Genes and Genomes database. RESULTS: A total of 34 children (11 with GHD, 23 healthy controls) were included in the study. Alpha diversity indices did not differ significantly between groups, whereas beta diversity indices demonstrated a significant intergroup difference (permutational multivariate analysis of variance, P=0.003). At the phylum level, the GHD group showed a higher relative abundance of Proteobacteria and lower abundance of Bacteroidetes. At lower taxonomic levels, taxa including Enterobacteriaceae, Enterobacter, and Citrobacter, which are often associated with dysbiosis, were enriched in the GHD group, whereas beneficial taxa such as Bacteroides and Ruminococcaceae family members were reduced. A functional prediction analysis revealed enrichment of pathways related to adenosine triphosphate-binding cassette transporters, phosphotransferase systems, quorum sensing, and bacterial motility in children with GHD. CONCLUSION: Children with GHD showed altered gut microbiota composition and predicted microbial functional pathways despite similar overall microbial diversity. These findings suggest a potential association between gut microbiota alterations and GHD and warrant further investigation in larger well-designed studies.