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What is the vaginal microbiome?

A microbiome consists of microbes that are both helpful and potentially harmful. In a healthy body, pathogenic and beneficial bacteria coexist without problems. In the human body we have microbiomes everywhere – in our gut, on our skin, in our mouths, in our bladder and if you have a vagina, in the vagina.

We hear a lot about the gut microbiome these days - that it’s good to have lots of different types of bacteria, we are encouraged to eat foods that contain and feed bacteria i.e., probiotics and prebiotics.

Unlike the gut and the bladder which have diverse microbiomes, the vagina doesn’t, which makes it unique.

The vagina is heavily lactobacillus dominant, including L.crispatus, L.gasseri, L.jenseneii, and L.iners. Around the world there are varied vaginal bacterial communities with 5 community state types (CSTs) identified.CST1 has L.crispatus dominating and is the ideal one to have.

Like other topics we have been discussing, estrogen plays starring roles – both one of protection or vulnerability.

Eubiosis of the vagina refers to the healthy state of the vagina, versus dysbiosis having bacterial imbalance. The vagina will house both beneficial bacteria, and pathobionts which are bacteria that will only cause harm if circumstance change, whereby they proliferate, and lactobacillus lose dominance. Examples of pathobionts are gardnerella vaginalis, atopobium vaginalis, proteus, streptococcus, ureaplasma, staphylococcus, E. coli, shigella, and candida albicans.

In a healthy vagina in a woman of reproductive age, there is as a pH of 3.5-4.5 which is acidic thanks to lactic acid produced by 70% dominance of Lactobacillus, and the presence of estrogen is associated with high glycogen in vaginal walls which is an energy source for lactobacillus. Low pH is protective of m any bacterial infections, but not for candida overgrowth due to its acid tolerance.

50% of reproductive age women worldwide have vaginal dysbiosis which increases risk of HIV, HSV, HPV and other STIs, Pelvic inflammatory Disease (PID), preterm birth, maternal and neonatal infections, UTIs, cervical cell changes and cancer.

Bacterial vaginosis (BV) is the key player with vaginal dysbiosis – lactobacillus lose dominance allowing BV bacteria to proliferate and what can ensue is a viscous cycle of dysbiosis:

  • Low estrogen means less glycogen = less food for lactobacilli

  • Higher pH than 4.5 encourages the growth of BV bacteria

  • If low lactobacillus then low lactic acid, which encourages growth of BV bacteria

  • Some BV bacteria encourage growth of other bacteria

  • BV bacteria consume glycogen and starve the lactobacillus

BV can be asymptomatic and not inflammatory hence the -osis, not -itis in the name. BV typically presents with excess grey/white watery discharge that is unchanging over a cycle (unlike normal vaginal mucous changes), as fishy odour and pH greater than 4.5. It can be mistaken for candida (thrush) and won’t respond to antifungal treatments.

Candida, often referred to as thrush, is another common infection that is fungal in nature. There are various species of candida, but candida albicans ins the most common. For women with chronic or recurrent candida, the consequences are significant when it comes to psychological stress, low productivity in life, pain, inflammation, pelvic floor sensitisation, and long term or cyclic medications. Symptoms are typically all of some of pain, itch, swelling, redness, dryness, and a thick white discharge.

Estrogen and the menstrual cycle are essential to understand when it comes to the vaginal microbiome and vulnerability to infections

  • With the onset of puberty in girls, estrogen levels rise, and lactobacillus becomes dominant in the vagina

  • BV is more likely in higher pH/low estrogen states and candida the opposite

  • Estrogen levels vary over the course of the menstrual cycle, with pH being lowest mid cycle as estrogen rises prior to ovulation and mid luteal phase, and highest during menstruation due to lower estrogen and the presence of blood (pH of blood is 7.4)

  • The higher estrogen states of the cycle can encourage candida outbreaks, with relief during the menstrual cycle vs BV flares more prone post menses with the rise in pH and the iron rich environment of menstruation, or in some, post ovulation as estrogen drops dramatically before rising again

  • While pregnant, estrogen levels are very high with vaginal pH usually 3.5-4 which is usually BV protective, but not protective against candida or Group B step (GBS) which is tested for during pregnancy

  • During perimenopause there is variable and fluctuating levels of estrogen, often much higher than normal at times, increasing risk of candida outbreaks

  • During menopause, estrogen is consistently reduced which consistently reduces glycogen in the vagina, reduces lactobacillus and acid production, pH may rise as high as 7.5 which increases the risk of vaginal infections and UTIs

  • Unlike the vagina, the bladder has a diverse microbiome - vaginal bacteria can cause UTIs, and bladder bacteria can cause vaginal infections - 50% of patients with recurrent UTIs will have BV especially gardnerella

  • Some antibiotics kill off some lactobacillus and some don’t, so this needs to be considered with UTIs - UTI treatment could make a vaginal infection better or worse or create one that wasn’t there before!

Please note BV bacteria and candida species are opportunistic – meaning there needs to be a vulnerability in the system for them to take hold. This may be due the state of the vaginal mucous membranes, loss of normal levels of beneficial bacteria, poor immunity, poor hygiene, sexual factors, nutritional deficiencies, tendency to high blood sugar, stress, or hormone imbalance. The normal fluctuations of estrogen and pH in a woman’s vagina are not a problem themselves – otherwise all women would have issues!

Vaginal microbiome issues can also extend to STIs, mollicutes and aerobic bacteria, and considering BV and candida, there can be mixed infections which can get very complex. If you are wondering if this could be you or someone you know, vaginal infections should be considered with any of the following conditions.

  • Incontinence, urinary urgency, overactive bladder, pelvic pain, vaginismus, vulvodynia, Interstitial cystis, recurrent UTIs

  • Symptoms associated with urinating or with the urethra - itch, irritation, urge, discharge, pain during/after, low level symptoms with flares

  • Pain/irritation during/after intercourse and/or examinations

  • History or STIs

  • History or UTIs especially recurrent or poor/incomplete response to antibiotics

  • Cervical cell changes/treatment

  • Unexplained infertility, recurrent miscarriage, unsuccessful IVF, premature rupture of membranes, labour before 36 weeks, salpingitis, baby low birth weight (less than 2.5kg), neonatal infections, PID, endometriosis

  • Recurrent candida, vulva cysts or skin conditions/infections, lumps and bumps that come and go

  • Recent, extensive, concentrated, or IV use of antibiotics, specifically - ampicillin, cefazolin, cefotaxime, clindamycin, tetracycline, vancomycin, erythromycin which all negatively impact vaginal lactobacillus

  • Use of the The Pill or vaginal estrogen may promote candida

  • Copper IUD, Mirena IUD, and Depo-Provera can increase BV risk

  • Vaginal or urethral device use without appropriate hygiene increase infection risk such as catheters, pessaries, menstrual cups, sex toys, dilators

Diet and lifestyle can also impact the vaginal microbiome with consideration to sexual practices, stress, low Vit D, low iron, high intake of poor-quality fats, low variety of antioxidants/colourful fruit and vegetables, wearing of tight/synthetic clothing, use of soaps/sprays/douches/washes/some lubricants – pH is higher than vagina and can throw pH out

What can you do?

  • Only wash your vulva and vagina with water

  • Work on Vit D and iron stores if deficient

  • Don’t ignore urinary, vulva, or vaginal symptoms

  • Seeing you GP is a good start for an examination and vaginal swab/culture, and if needed a urine culture. Getting up to date iron studies and Vit D levels in blood test also a good idea.

  • A vaginal swab result will not show up everything as not all bacteria can be cultured, some need a PCR test – an alternative is a vaginal microbiome test which uses a variety of test processes to test for BV and aerobic bacteria, mollicutes such as ureaplasma, STIs, candida species, and lactobacilli species. This sort of test needs a referral from a practitioner and is typically from a naturopath, clinical nutritionist, or pelvic health physiotherapist (such as Kristine Miles at Balance health who is trained in the vaginal microbiome)

  • See a naturopath or clinical nutritionist for assessment and management of any gut, hormonal, or nervous system imbalances that may be contributing

  • See a pelvic health physiotherapist for an examination of your vulva and vagina to look at skin integrity, pelvic floor function and assessment of pH. Not all pelvic floor issues are ones of weakness – many pelvic floors are over-active and tight which can give the illusion of weakness and prolapse and can co-exist with prolapse. Furthermore, vaginal dysbiosis may make vaginal tissues sore and sensitive contributing to an overactive pelvic floor.

At Balance Health, Casey Cleeland, Kristine Miles, and Kara Cassells are trained in pelvic floor examinations. Kristine is also trained in management of the vaginal microbiome.

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