Puberty Starts in the Gut: Intestinal Clues to Early Puberty-Rethinking Biomarkers in Pediatric Endocrinology.

Central precocious puberty (CPP) may be influenced by gut microbiota through changes in short-chain fatty acids (SCFAs), β-glucuronidase activity, and enterohepatic estrogen recycling. This narrative review integrates current evidence from human and animal studies exploring microbial contributions to pubertal timing. Across multiple cohorts, CPP is associated with loss of SCFA-producing commensals, such as Bacteroides, and increased abundance of taxa like Alistipes, Ruminococcus, and Lachnoclostridium. These microbial shifts are linked to altered SCFA profiles, diminished anti-inflammatory and neuroendocrine modulation, and enhanced reabsorption of estrogens via microbial β-glucuronidase activity. Experimental models support a causal connection: gut dysbiosis accelerates pubertal onset, whereas microbiota-targeted interventions can restore hormonal balance and delay activation of the HPG axis. While some overlap with obesity-associated microbiota exists, the endocrine-specific microbial changes observed in CPP suggest partially distinct mechanisms. Overall, the gut microbiota emerges as both a modulator and potential biomarker of early pubertal onset. Its integration into pediatric endocrine frameworks could improve early risk assessment and guide future interventions, though further validation through standardized, longitudinal, and diverse population studies is still required.