Microbiome Effects on Systemic Estrogen

There is undeniable proof that our diet can have an impact on our overall health. The questions here is can it really help control the symptoms and spread of endometriosis? Unfortunately nutrients and endometriosis are two under researched fields of medicine. Even so, we can look at the data that does exist and conclude diet can have a positive impact on quality of life of those who suffer. That being said there are a lot of unsubstantiated claims and fab diets that claim to cure this or help that. My hope is, with this blog, I will be able to delve into current scientific findings and hopefully create some kind of clarity as to what dietary changes will have the greatest overall impact on the life of those struggling with endometriosis.

As I have jumped head first into the world nutrition and its relation the endometriosis I have found one must consider many different physiological aspects. Diet can decrease systemic estrogen, decrease inflammation, increase energy levels, and much more. So where do we start? Well I think the most talked about effect diet can have in the endometriosis community is its effect on systemic estrogen. Most who have researched endometriosis at all know it is a disease process negatively influenced by high estrogen levels. So how can diet changes help keep estrogen levels as low as reasonably possible?

Often the first thought is that, if we avoid phytoestrogens (dietary estrogens found in some plants) and animal products that may contain estrogen systemic estrogen levels would decrease. This is something I believed to be very cut and dry when I started making my diet changes. Yet, after having looked more to the scientific literature I found it’s not actually that simple.

To understand how to balance estrogen through diet you must understand a basic level of gastrointestinal physiology. Our GI tract is home to an entire microscopic ecosystem (microbiome). One gram on lumin contains an average of one hundred BILLION microorganisms. That is a lot of little critters. These little critters do their own “digesting” and processing of the food we ingest.The balance of all these little critters can affect how much, and what we actually absorb into our systemic blood stream. let’s get a little more specific. Our estrobolome is the collection of GI microbes (primarily bacteria) that are capable of secreting β-glucuronidase. β-glucuronidase aids in the deconjucating estrogen. What does that mean? Well, without getting too sciency estrogen gets conjugated in our liver. Conjugated estrogen can then be excreted through our urinary or GI tract. But, if conjugated estrogen is passed to the intestinal tract via liver bile and is deconjugated by the estrobolome it will be reabsorbed into the blood stream instead of being excreted from the body. There for, an overpopulated estrobolome will increase systemic estrogen level1 (anyone with estrogen mediated disease processes like endometriosis do not want increased systemic estrogen levels).

So what does this mean for our diet? What changes can we make to keep our estrobolome from over populating our GI tract and increasing estrogen? Well i’m gonna have to get into some potty talk to explain this so if you’re squeamish proceed with caution. Gastrointestinal re-absorption level can be monitored via comparing fecal estrogen levels to blood estrogen levels. When less estrogen is being reabsorbed in the GI tract more is excreted in the feces. So low blood estrogen & high fecal estrogen = a well balanced estrobiome. High blood levels and low fecal estrogen indicates your estrobiome is too high. A few studies have been done comparing fecal and blood estrogen levels between women consuming high fat, and low fiber diets to women consuming low fat high fiber diets. One study showed a group of women living in asia eating low fat high fiber diets had 30% lower blood estrogen levels and 30% higher fecal estrogen levels when compared to a group of women consuming a traditional “western” high fat low fiber diet. Another study compared women on a tradition “western” diet whos caloric intake consisted of 40% fat to a group of vegetarians who caloric intake was composed of 30% fat and more fiber. The vegetarians had 3 times the amount of estrogen in their feces and 20% less blood estrogen.2

Now, you meat lovers don’t panic, I am not necessarily suggesting you become a vegetarian (although some have found this very helpful). But looking at this data in can be concluded that by simply lowering your fat intake by 10% and increasing your fiber intake you can greatly reduce your systemic estrogen levels by balancing out your gut estrobiome. This is one of the easier changes I am going to suggest and a good place to start for women who are just beginning to explore diet changes. Next time you go to the store reach for the leaner meat option, the lower fat breakfast options etc. and consider adding some high fiber foods to your list. (oatmeal, raspberries, artichokes, black beans etc).

1Baker, James M., et al. “Estrogen–Gut Microbiome Axis: Physiological and Clinical Implications.” Maturitas, vol. 103, 2017, pp. 45–53., doi:10.1016/j.maturitas.2017.06.025.
2Kwa, Maryann. “The Intestinal Microbiome and Estrogen Receptor–Positive Female Breast Cancer.” JNCI: Journal of the National Cancer Institute, 2016, doi:10.1093/jnci/djw029.

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