Written by Dr Helen O’Neill
We get asked about this a lot so we’ve asked expert Dr Helen O’Neill founder of Hertilty Health, to give us to lowdown on how our gut health and fertility are connected…
We tend to separate out our bodies “systems” because anatomy lessons do too. Our abdomen is filled with both the digestive system and reproductive system but they are connected to each other through more than proximity. You may not ever link your guts with your “bits” but there are many ways in which they affect each other’s function through both genetics and diet. While genomics (the study of genomes) is considered a relatively new field, the study of the microbiome is still in its infancy (excuse the pun!).
The ‘microbiome’ is the official term used to describe the genetic material of all the microorganisms such as bacteria, yeast and fungi that live inside our bodies, including your gut microbiome. There are trillions of these microorganisms living inside us, mostly in our gut but also on our skin, up our nose, in our lungs, vagina and throughout our reproductive tract. Despite playing a critical role in our overall wellbeing, it was not been until relatively recently that scientists began to characterise and better understand the human microbiome.
Research suggests that there are almost 1,000 species of bacteria in our gut microbiome. There are a lot of them, so it’s not surprising that these microscopic organisms play such an important role in our health. The role of these tiny but mighty microorganisms affects our body from birth and throughout our lifetime, managing our immune system, our central nervous system (which is responsible for our brain function) and, most importantly, controlling the digestion of food.
Although most of the bacteria are beneficial to our health, sometimes microbes disrupt the balance of the gut microbiome leading to ‘dysbiosis’. This imbalance of bacteria can be caused by many different things, including diet, stress and poor sleep. Around 70% of your immune system resides in your gut. There is strong evidence to suggest that this microbial imbalance activates immune cells leading to inflammation. Inflammation is our bodies way of fighting foreign invaders, toxins or cell injury but over a long period of time, it can start to negatively affect our health.
Gut Microbiome Imbalance
This imbalance of the gut microbiome can also affect our reproductive system. In particular, there is evidence to suggest that gut dysbiosis is associated with a common reproductive condition called endometriosis. Endometriosis is caused by cells from the lining of the womb (uterus) migrating elsewhere in the body. As many as 1 in 10 women suffer from endometriosis – we call them #EndoWarriors! Studies have shown that the imbalance in the gut microbiome can cause increased estrogen levels. Increased estrogen stimulates these misplaced cells causing them to react in the same way to those in the womb, building up and then breaking down and bleeding. Unlike the cells in the womb that leave the body as a period, this blood has no way to escape and subsequently causes an abnormal inflammatory response and a lot of discomfort and pain to our warriors.
It may actually be possible that the gut microbiome with its role in the regulation of the estrogen cycle, can also be associated with endometriosis. Women who are estrogen dominant should be careful with foods containing biogenic amines, these are found in fermented foods such as red wine and beer, pickles and mature cheeses. These foods are known to increase your susceptibility to the actions of adrenaline and noradrenaline, which in turn affects your other hormones.
This is just one example of the role of diet and your gut microbiome being synced with your reproductive system. It can be hard to tell where one problem starts and the other begins, but it is great evidence to show that keeping in touch with your hormones is a really important step in acknowledging your overall wellbeing.
About the authors
Dr. Natalie Getreu & Dr. Helen O’Neill
Find out more from Helen on her instagram @dr.helenoneill
- Flores, R., Shi, J., Fuhrman, B., Xu, X., Veenstra, T. D., Gail, M. H., Gajer, P., Ravel, J., & Goedert, J. J. (2012). Fecal microbial determinants of fecal and systemic estrogens and estrogen metabolites: a cross-sectional study. Journal of translational medicine, 10, 253. https://doi.org/10.1186/1479-5876-10-253
- Ata, B., Yildiz, S., Turkgeldi, E., Brocal, V. P., Dinleyici, E. C., Moya, A., & Urman, B. (2019). The Endobiota Study: Comparison of Vaginal, Cervical and Gut Microbiota Between Women with Stage 3/4 Endometriosis and Healthy Controls. Scientific reports, 9(1), 2204. https://doi.org/10.1038/s41598-019-39700-6
- Sender, R., Fuchs, S., & Milo, R. (2016). Revised Estimates for the Number of Human and Bacteria Cells in the Body. PLoS biology, 14(8), e1002533. https://doi.org/10.1371/journal.pbio.1002533
- Sonnenburg, E. D., Smits, S. A., Tikhonov, M., Higginbottom, S. K., Wingreen, N. S., & Sonnenburg, J. L. (2016). Diet-induced extinctions in the gut microbiota compound over generations. Nature, 529(7585), 212–215. https://doi.org/10.1038/nature16504
- Levy, M., Kolodziejczyk, A., Thaiss, C. et al. Dysbiosis and the immune system. Nat Rev Immunol 17, 219–232 (2017). https://doi.org/10.1038/nri.2017.7