The surprising link between gut microbiome and preconception

Did you know that your gut, mouth, and vaginal microbiomes call all influence your ability to fall pregnant?

Optimising fertility isn’t just about hormones, ovulation tests, or frequency of intimate moments – your microbiome may be a missing piece of the preconception puzzle. From your gut to your mouth to your intimate parts, the trillions of microbes that call your body home play a surprisingly powerful role in shaping your reproductive health.

Let’s break down how three key microbiomes can influence your journey to conception – and what you can do to support them.

1. Vaginal microbiome

Your vaginal microbiota may be one of the most underrated players in conception success. A healthy vaginal microbiome is typically Lactobacillus-dominant, especially L. crispatus, which protects the reproductive tract, maintains optimal pH, and reduces inflammation.

Did you know?

• A “Lactobacillus-impaired” microbiome can increase infertility risk ninefold.
• Vaginal dysbiosis is linked to higher miscarriage rates and less success with IVF treatment.
• Common pathobionts like Gardnerella and Ureaplasma are tied to preterm birth.

Below are a few tips that can to support vaginal microbiome health:

• Ditch soap and body wash – just water on external areas (vulva/anus) only.
• Avoid douching and vaginal deodorants.
• Consider vaginal pH testing (ideal: under 4.5).
• Eat more plants: being overweight and eating a high animal protein diet is linked to reductions in vaginal Lactobacilli populations.

2. Oral microbiome

Periodontal disease doesn’t just affect your smile – it may also affect your baby. Poor oral hygiene is linked to preterm birth, growth restriction, and pre-eclampsia. In fact, some scientists think that inflammatory oral bacteria may even trigger systemic inflammation and reach the placenta.

So, what does the science say?

• Alterations in oral bacteria may enter the bloodstream and contribute to intrauterine infections.
• They may also affect nitric oxide production, which impacts blood pressure and could impact blood pressure regulation during pregnancy.

A few tips for a healthy oral microbiome:

• Prioritise dental checkups and regular flossing.
• Only use a mouthwash if your dentist says you need one.
• Brush twice daily (or as often as your hygienist recommends).
• Stay hydrated to support saliva production, a key oral microbiome regulator.

3. Gut microbiome

Your gastrointestinal (GI) microbiome helps regulate inflammation, hormone metabolism, immune balance, and even mood – all critical for conception. An imbalance here can silently sabotage fertility and pregnancy outcomes.

A thriving gut microbiome features:

• healthy levels of butyrate-producers (anti-inflammatory)
• good populations of Bifidobacterium and Faecalibacterium
• lower levels of gram-negative bacteria and endotoxins like LPS

Gut dysfunction has been shown in animal studies to disrupt:

• ovarian function and normal female hormone levels
• implantation of the fertilised egg in the womb
• increased pregnancy complications like gestational diabetes and preeclampsia

A few tips to nurture your gut microbiome include:

• Eating a high-fibre, plant-rich diet (fruits, veg, legumes, whole grains).
• Minimising processed food and added sugars.
• Working on stress management – it impacts gut bacteria too.

The microbiome is just one piece of a complex preconception health puzzle, alongside nutrition, emotional well-being, social support, and environmental exposures.

If you are ready to find out how to best support your whole-body health, including your oral, gut and vaginal microbiome, on your path to pregnancy, get in touch with a nutrition professional. 

Together, you can uncover what your body may be trying to tell you – and make a personalised plan that supports a healthy conception