THE vagina and its exterior, the vulva, are the most intimate part of a woman’s body. Measuring about seven centimetres, the vagina is a muscular organ that connects the uterus to the outside. It is the path to procreation. Its inner lining, referred to as the mucosa, is a multi-layered cell structure. This lining needs to be kept moist.
What is little realised however is that the vagina possesses an ecosystem of its own. It is a dynamic environment and the vaginal mucosa in particular, undergoes changes with differing stages of a woman’s life.
What is seldom understood too is that the consequences of any change in this eco-system can have a profound effect not only on the vagina itself, but also to the vulva.
Evolution of the vaginal ecosystem
Before birth, the vaginal lining is only single layered. That does not pose a problem, because at that stage there is no need for protection against any ascending infection.
But at birth the vagina becomes exposed. The cells of the lining become flattened and multi-layered so as to form an effective barrier against trauma or infection.
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How the Doderleins bacillus keeps the vaginal environment healthy. |
There is an important purpose for this because, over time, the origins of which are still unclear, the vagina becomes colonised by an acid producing bacteria named Doderleins bacillus. Its scientific name is Lactobacillus acidophilus.
Living up to its name, these bacilli are capable of using the glycogen stored in the cells as a substrate to render the pH of the vagina acidic by producing lactic acid.
By convention, a pH of 7 is neutral. Anything above that is alkaline and anything below is acidic. The lower it is, the more acidic the environment and the more protection it affords.
The lactic acid produced renders and maintains the pH of the vaginal secretions to be between 3.8 to 4.2. This has a bonus effect – it promotes further growth of the bacillus and a favourable cycle is set in motion.
However as the child grows, the maternal oestrogens begin to deplete. Furthermore, the ovaries have not begun to secrete oestrogens. This results in reducing the amount of lactic acid being produced. The child may therefore be prone to infection.
Fortunately the main culprit for vaginal infections – sexual intercourse – does not occur and most children sail through without any untoward incident, unless of course there are poor toilet habits.
Changes during puberty
But with puberty, the scenario changes drastically. The out-pouring of oestrogen from the ovaries stimulates the cells to store glycogen and reactivate the Doderleins bacillus. The vaginal pH becomes acidic and protects it from infection; it is nature’s way of protection because puberty come the child-bearing years.
During each menstrual cycle too, the hormones undergo cyclical changes. In the first half, oestrogens dominate, but during the second half, another hormone, progesterone dominates. Progesterone renders the cells less likely to store glycogen and indirectly, affects the acidity of the environment. Infection is more likely. Thankfully, the period is short.
Changes during pregnancy
The next change comes with pregnancy. The vagina becomes very vascular and the secretions are more copious. However in pregnancy the dominant hormone is not oestrogen but progesterone. This hormone counteracts the effect of oestrogen.
Together with the increased sugar levels in the vaginal secretions that occur in pregnancy, it creates a milieu that promotes yeast infection, in particular the Candida species. Not surprisingly therefore, it is an infection commonly seen in pregnancy.
Changes during menopause
The last significant change in the vaginal ecosystem comes with the menopause. The oestrogen level drastically falls. The vaginal mucosa thins out and the cells become devoid of glycogen. The acidic protection is lost.
The vagina now becomes vulnerable to infections. Fortunately, sexual intercourse at this stage is less frequent and the change in lifestyle acts as a check and balance.
Why is feminine hygiene important?
This is because developmentally, the vagina and the anal canal have a common origin and it was inevitable therefore that the two would be closely related.
Therein lay the problem. The surrounding exterior is very likely to be contaminated with bacteria or other organisms and the vagina provides a perpetual “open-house” to this exterior.
Whether from poor feminine hygiene or from repeated sexual intercourse, ascending infection is always a risk.
The vagina is able to keep these ascending infections at bay because of its acidic environment. But if this defence is lost, the opportunistic infections, either bacteria or fungi, are capable of taking over. There is a compounding effect to this.
These infections tend to raise the pH of the vaginal milieu and this further inhibits the growth of the acidophilus bacteria. A vicious cycle is set in motion.
The answer to the problem therefore is to always be on top of it – be proactive. A knee-jerk response would be to use antiseptics. But this would remove all, the good and the bad bacteria.
A more sensible and longer lasting way would be to maintain a consistent and favourable vaginal and vulval ecosystem, the central role being to provide for an acidic environment.
Common sense dictates that if lactic acid plays a central role in doing so, enhancing the vaginal milieu with washings of lactic acid is the logical choice.
Furthermore, it promotes an appropriate environment both for maintaining and promoting the growth of the Doderleins bacillus.
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