Thauera can regulate circulating androgen levels in male mice

Gut microbiota has been considered a major regulator of sex steroids metabolism in vertebrate, although the corresponding mechanisms and bacterial taxa remain elusive. Thauera sp. strain GDN1 can degrade major androgens under both oxic and denitrifying conditions. Here, we gavaged mice with strain GDN1, and monitor the colonization and androgen degradation activities of strain GDN1 in the moue gut. We detected apparent increase in strain GDN population in mouse feces during continuous administration (twice per week). Four weeks after the first oral administration, we detected anaerobic androgenic metabolite 17beta-hydroxy-1-oxo-2,3-seco-androstan-3-oic acid (2,3-SAOA) in the fecal extracts, along with the colonization of strain GDN1 in mouse cecum and the expression of the strain GDN1 atcA, a marker gene for anaerobic androgen catabolism. The ELISA and metabolite profile analysis indicated a significant reduction of serum androgen level in GDN1-gavaged male but not in female mice. Noticeably, we did not detect the oxygenolytic ring-cleavage product of androgen in mouse fecal extracts, although the androgen-degrading oxygenase gene kshA was expressed in mouse cecum. Our data thus indicate the important role of anaerobic androgen catabolism and the corresponding gut microbes in the regulation of host circulating androgen.