Fig. 1

Experimental design. A In hpg^−/− (wild-type) mice, the hypothalamic–pituitary–gonadal axis is functional. Gonadotropin-releasing hormone (GnRH) is secreted from the hypothalamus and stimulates production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from gonadotrope cells in the anterior pituitary. LH and FSH then regulate steroidogenesis and gametogenesis in the ovaries and testes which results in sexual development and reproductive competence. In hpg^+/+ mutant mice, GnRH is not produced due to a truncation in the Gnrh1 gene, resulting in hypogonadism. B The study included four experimental groups: female and male wild-type and mutant mice. N = number of mice per group. C Sampling of intestinal microbial communities was done in the duodenum, ileum, and cecum, both in the lumen and mucosa, resulting in 539 samples including fecal samples. Created with BioRender.com