The link between breast cancer and gut health.
Do you know that ER+ breast cancer is one of the most common breast cancers
diagnosed (about 70-80%)? ER+ breast cancer means the cancer cells respond
to and get growth signals from estrogen. Some very interesting research
has looked at all the microorganisms in our gut and their relationship
to the estrogen in our body. One of the key indicators of having a healthy
gut is to have diverse and abundant microbiome (DNA of gut flora).
Recent studies suggest that gut microbes play a crucial role in regulating
circulating estrogen levels. The estrobolome, a subset of microbiome,
controls estrogen through two mechanisms: (1) increasing gut permeability
(aka. leaky gut) for estrogen to slip out into the blood stream and (2)
secreting an enzyme, called β-glucuronidase, that breaks down estrogen
into their active forms to bring estrogen back to the body instead of
being eliminating in the feces. As a result, your body becomes more estrogen
dominant and therefore, the hormone sensitive tissue like the breasts
can be affected.
This is still a new concept in research but has an exciting application
for us. Taking care of our microbiome is one of the ways that may have
a major impact on reducing the risk of breast cancer and recurrence, and
overall wellbeing may be improved by reducing inflammation and obesity.
Having a diverse and balanced microbiome is critical in gut health and
the immune system. Simply speaking, promoting a healthy balanced microbiome
may help you regulate estrogen naturally. Here are a few tips you can try:
1. Eat plenty of vegetables, composed of ALL colors, plus introduce fermented
vegetables to boost your gut flora.
2. Avoid trans-fat and corn syrup, which will increase inflammation in
the gut and also liver, which are the major detox systems in your body.
3. Reduce sugar consumption — bad bugs tend to like “sweet
4. Reduce stress which can significantly compromise a diversity of gut microbes.
5. Walking in nature: did you know spending time in nature can actually
diversify a healthy microbiome without taking probiotics?
6. Go green: try to minimize plastics, which can contain a lot of toxic
chemicals, such as bisphenol-A(BPA). Good bacteria can’t thrive
in the chemical environment.
7. Be aware of some medications which can disturb a healthy microbiome
such as antibiotics, acid reducers and steroids.
8. Try to have a good bowel movement daily to make sure you are excreting
an excess of estrogen.
9. Lastly, get adequate sleep at night. Research shows that the disrupted
or shifted circadian rhythm can compromise your gut flora.
Reference: Maturitas 103 (2017) 45–53; JNCI J Natl Cancer Inst (2016) 108(8)