The balance between the vagina and oestrogen begins at birth when the newborn baby produces glycogen in her vagina due to the influence of high maternal oestrogen. Vaginal glycogen provides fuel for “good” bacteria which then begin to colonise the vagina. Lactobacillus is the predominant type of bacteria in the female vagina, responsible for maintaining balance and preventing pathogenic micro-organisms thriving and causing infection.
Lactobacilli species in the vagina are believed to work in the following manner:
- They produce lactic acid, which helps keep the vaginal environment acidic.
- They produces hydrogen peroxide which creates a harsh environment for nasty micro-organisms.
- They can block other organisms from attaching to the vaginal walls and taking hold. They can also compete with, and displace bad micro-organisms that have already adhered to the vaginal wall.
- Probiotics are also thought to stimulate the host’s immune system to kill off bad micro-organisms.
Although the newborn begins life with a little help from her mother, it is during the reproductive years, when oestrogen is released again, that vaginal colonies begin to play a greater role. At puberty when oestrogen surges, glycogen also increases encouraging the healthy growth of Lactobacillus in the vagina. During these years, the risk of infection is highest, and it is also the time when good vaginal bacteria are at their highest levels, helping to maintain balance.
Not only does oestrogen have an effect on good vaginal bacteria during the reproductive years, it also plays a role at difference stages of the menstrual cycle. For example, many women complain of irritation, or are more prone to infection when oestrogen levels are at their lowest, around menstruation. After menstruation, oestrogen levels increase which increases Lactobacillus species. and also lactic acid production by good bacteria. These changes protect and help maintain balance in the vagina.
Vaginal acidity, or pH, is another factor that influences the vaginal microflora and is also affected by oestrogen levels. The slightly acidic pH of the vaginal which is around 4.2 supports good bacterial growth and deters bad bacteria and yeast from. Researches have found a less acidic pH, which is related to lower oestrogen levels often around menstruation and after menopause, is more likely to favour pathogenic micro-organisms.
This complex interplay between hormones, bacteria and lifestyle provides protection and helps maintain a healthy vaginal ecosystem. Maintaining balance, especially when prone to repeated infection, is vital. This is achieved through:
- Supplementing with healthy Lactobacillus probiotics which may help maintain the balance of good bacteria in the vagina
- Maintaining healthy oestrogen levels. Smoking for example diminishes oestrogen levels, and increases the risk of pathogenic micro-organisms thriving
- Avoiding vulval contact with irritants such as alkaline soaps and shampoos and douching as this can disrupt the pH of the vagina
- Drinking plenty of water
- Maintain healthy hygiene practises and wiping from front to back can help
For more information on BV or vaginal candida please see the article Is it fungus or bacteria?
References available upon request