Estrogen on Candida spp. of the vagina: Is there any effect?

A variety of Candida spp. as the most common fungi in the human body can normally be found in the vagina competing with other microbotes. Their presence is influenced by a variety of conditions in the vaginal environment. The proliferation of Candida spp. in the vagina under specific conditions can result in a fungal disease known as vaginal candidiasis. More than 17 species of Candida out of 200 members of this genus are capable of causing diseases within the human body. Estrogen, along with other steroidal hormones, has been shown to have direct multifunctional effects on various pathogenic microorganisms by numerous activities. Its production as well as other factors such as disturbance of microbial balance and immune activity may alter the vaginal physical environment and promote the development of vaginal fungal infection. The vaginal functions can be affected by the level of circulation of estrogens in the blood according to the stage of the menstrual cycle in women. It also has many other functional actions on the vaginal structure. Estrogen and several other factors play an important role in determining the vaginal content of Candida species. Its effect could be a direct action on the cells of Candida or through an indirect effect on the immunity defenses of the vagina.