The only region of the male reproductive system that is colonised by microbes is the urethra, and its indigenous microbiota has already been described in Chapter 5. This chapter, therefore, is devoted to a discussion of the indigenous microbiota of the reproductive system in females.

Anatomy and physiology of the female reproductive system

The female organs of reproduction include the ovaries, Fallopian tubes, uterus, cervix, vagina, and vulva (Figure 6.1). Of these, only the vagina, vulva, and cervix of the uterus are normally colonised by microbes. While a large number of studies have been devoted to elucidating the indigenous microbiota of the vagina and, to a lesser extent, the cervix, relatively little is known with regard to which microbes inhabit the various regions of the vulva.

The vulva is a term used to denote the external female genitalia, which include the mons pubis, labia majora and minora, clitoris, and vestibule (Figure 6.2). The vestibule is lined with a stratified squamous epithelium and located within it are the vaginal orifice, the external urethral orifice, and the openings of the mucus–secreting paraurethral and Bartholins glands. The mons pubis consists of a layer of adipose tissue covered by skin and pubic hair (Table 6.1). The labia majora are longitudinal folds of skin which contain adipose tissue, have sebaceous and sudoriferous glands, and are covered in pubic hair on their outer surfaces.