Male Tract Microbiota and Male Infertility.

In recent years, several studies have analyzed the composition of the male genital tract microbiota and its changes in infertility or in different situations associated with infertility. The aim of this narrative review is to obtain more insight on this topic; in particular, to describe actual evidence about changes in the semen microbiota in patients with infertility, male tract infections, or HPV infections. In semen, an increase in semen spp. is associated with oligozoospermia and with obesity-associated asthenozoospermia; an increase in is more frequently associated with asthenozoospermia and oligozoospermia; a reduction in spp. (namely in ) may represent a marker of low semen quality. However, an increase in is considered a risk factor for a reduced sperm concentration. In patients with prostatitis, there is a reduction in spp. and an increase in spp., opening important perspectives about the role of probiotic treatments in these patients. Finally, an increase in spp. was observed in patients with an HPV infection. In the conclusion, we underline the interactions between the seminal and vaginal microbiota, so that further studies should focus on the "couple genital microbiota".