ObjectiveTo explore the distribution and differences in the intestinal microbiota in girls with obesity-related precocious puberty and the relationship between intestinal microbiota and obesity-related precocious puberty.Methods16 S rRNA gene amplicons from fecal samples from girls with precocious puberty and obesity-complicated precocious puberty and healthy children were sequenced to define microbial taxa.ResultsThe α- and β-diversity indices of the microbiome significantly differed among the three groups. At the phylum level, the proportions of Firmicutes, Actinobacteriota, Bacteroidota, Bacteria, Campylobacterota, and Acidobacteriota were different. At the genus level, there were differences in Bifidobacterium, Bacteroides, Anaerostipes, Fusicatenibacter, Klebsiella, Lachnospiraceae, ErysipelotrichaceaeUCG-003, Prevotella9, Ruminococcus gnavus group, and Lachnoclostridium. Additionally, Bifidobacterium, Anaerostipes, Bacteroides, Candidatus Microthrix, Eubacterium hallii group, Klebsiella, and Erysipelotrichaceae UCG-003 were identified as bacterial biomarkers by LEfSe. Furthermore, Sellimonas, Intestinibacter, Anaerostipes, Ruminococcus gnavus group, and Oscillibacter were identified as the differential biomarkers by random forest. A receiver operating characteristic (ROC) curve was used to evaluate the biomarkers with high predictive value for obesity-related precocious puberty. Spearman correlation analysis confirmed that Anaerostipes levels were negatively correlated with body weight, body mass index (BMI), bone age, luteinizing hormone, follicle-stimulating hormone, and estradiol.ConclusionsThere was a significant correlation between obesity-associated precocious puberty and gut microbiota, especially the functional characteristics of the microbiome and its interactions, which can provide a theoretical basis for the clinical intervention of obesity and precocious puberty through the microbiome.