ESPE Abstracts

Key words: precocious puberty; idiopathic central precocious puberty; premature thelarche; gut microbiota; HPG axis

Background: The incidence of precocious puberty and obesity has increased significantly after the COVID-19 epidemic, and the specific cause is not clear. There seems to be a causal relationship between obesity and idiopathic central precocious puberty. A few studies have shown that the changes of gut microbiota (GM) in children with precocious puberty are similar to those in obese children, and there is no further exploration. It has not been reported whether there is the imbalance of GM in normal body mass index（BMI） girls with idiopathic central precocious puberty（ICPP）and the change of GM in ICPP children before and after gonadotropin-releasing hormone analog (GnRHa) treatment.

Method: The study subjects include 6-9 years old girls with normal BMI, who were diagnosed and Follow- up in the Department of Endocrinology, Genetics and Metabolism of Children's Hospital Affiliated to Zhengzhou University from December 2021 to June 2022, and were divided into CPP group （30 cases） and PT group（30 cases）. 28 Age-matched healthy girls with normal BMI were control group. 10 Girls in the CPP group who received GnRHa treatment were selected, and divided into pre-treatment group and post -therapy group. All subjects collected their fresh fecal samples, and 16S rRNA gene sequencing was used to analyze gut microbiota.

Results: Alpha diversity of PT group was higher than that of HC group, and there were significant differences in Beta diversity between CPP group and HC group, PT group and HC group (P<0.05). The CPP group and PT group both had significantly higher relative abundance of Alloprevotella (P<0.05). The GM of post-treatment girls were different with pre-treatment girls, and the GM of post-treatment girls were similar to that of healthy children. Luteinizing hormone and follicle stimulating hormone levels were negatively correlated with Veronococcus (P<0.05). Follicle stimulating hormone levels were positively correlated with rumen coccus (P<0.05). Estradiol was positively correlated with Chlorocurium, Bacillus and Acinetobacter (P<0.05), and negatively correlated with Clostridium (P<0.05).

Conclusion: Girls with normal BMI and precocious puberty also have intestinal flora disorder, it was mainly manifested in the species difference of GM compared with the healthy control group. The changes of sex hormones have an impact on the structure of GM. There is a causal interaction between the hypothalamic-pituitary-gonadal axis (HPGA) and GM, which is worthy of further investigation.