The gut microbiome and cancer treatment outcomes: emerging studies
You may have heard me discuss the importance of gut health as a crucial factor in supporting our overall well-being. This is largely due to the trillions of bacteria that reside in our gastrointestinal tract, collectively known as our microbiome.
In this post, I want to talk about some exciting findings from recent studies and review the literature around the connection between our gut microbiome and breast cancer, in both treatment and recovery.
Research shows that our microbes play a significant role in shaping our immune response. This effect can be both positive and negative. While a balanced microbiome can support our health, an overgrowth of harmful or pathogenic bacteria can lead to potential health issues, including cancer, as some of the bacteria found in our gut may have direct carcinogenic effects.
The term ‘polymorphic microbes’ has been added to the accepted list of cancer hallmarks, and most recently, in a promising new step that this gut-immune communication network is being taken seriously within the medical field, a review of the literature published in the Journal Of The American Medical Association cautiously acknowledged that microbes may:
Affect carcinogenesis and metastasis
Moderate cancer treatment, outcomes and responses
Change the incidence and experience of treatment-related adverse effects- our response and recovery from surgery, chemotherapy, radiotherapy and immunotherapy.
It is essential to recognise that tumours have their own microbiome, which influences treatment responses; thus, this factor should be considered in future treatment plans.
As a nutritional therapist, I utilise a wide range of in-depth functional testing within my practice, and upon reading this latest research, I felt a sense of reassurance that I can look into the health of not only my microbiome, but that of my clients as another supportive tool in our quest for optimal health after a breast cancer diagnosis and a tough treatment regime.
It’s also easy to believe that certain symptoms stem from our almost overnight transition into medical or surgical menopause, but I have observed in my clinic that it’s not always the reason you feel the way you do.
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I had a client who was post-breast cancer and came to me with severe fatigue, joint pain, and brain fog. She believed that these issues were solely due to her being postmenopausal, which is understandable, as hormonal changes can indeed cause similar symptoms for some women. However, during her consultation, I began to suspect that there might be another underlying cause for her health struggles.
I shared my thoughts, we agreed to order some testing, and the results confirmed my suspicions: Candida fungal yeast overgrowth. As well as the symptoms above, it was the sudden, worsening cravings for sugary foods and occasional bloating and reflux that led me to believe this commensal but opportunistic microorganism had overgrown and was causing problems.
Now, as stated above, candida is a commensal microorganism found in around 70% of the population’s gut, commensal meaning it usually lives there quite happily without issue. But when the terrain of the gut is less favourable, it thrives, and we end up with a fungal yeast overgrowth, and if left untreated, can cause both digestive and systemic inflammation and damage to tissues and other organs.
And what can affect the health of the gut?
Sadly, the collateral damage from Chemotherapy and radiotherapy :(
These treatments target rapidly dividing cells, which also line the digestive tract and, once damaged, lead to gut permeability, chronic inflammation and dysbiosis, a decrease in ‘good’ bacteria and an increase in harmful, pathogenic bacteria, thus killing off the very beneficial bacteria that we need for efficient immune function and the anti-cancer benefits of a healthy and robust terrain that I have discussed.
A healthy microbiome consists of a wide DIVERSITY of beneficial bacteria, and for these to flourish, we need to include lots of fibre and polyphenols from fruits and veggies within our diet. These prebiotic fibres feed and promote the growth and survival of the bacteria, and also produce Short-chain fatty acids (SCFAs) that strengthen the gut wall that cancer treatments can damage.
This highlights the evidence of combining nutrition, conventional treatment and the further functional testing available to us in supporting our body and the potential for better outcomes.
When I was going through treatment, and at the time feeling very lost and scared, I read a sentence written by the brilliant Dawn Waldron that reminded me of the very thing I preach daily, that good nutrition heals! she wrote ‘terms like prognosis are outdated and we have more leverage on our health than we are led to believe’ and I think these studies support just that!
I thought I would share a lunchtime favourite of mine: full of gut-loving goodness! Enjoy :)
Veggie & feta Fritters
serves 2
Feel free to swap any veg for whatever you have, sweetcorn also goes well with courgette
1 large carrot, grated and squeezed in a muslin to remove excess water
2 medium/ 1 large courgette, grated and squeezed in a muslin to remove excess water
1 cooked beetroot, grated and water removed
4 Tbsp. of ground almonds
100g feta, crumbled
pinch of salt
1 level tsp Invivo Prebio PHGG powder*
A low-FODMAP prebiotic fibre made from partially hydrolysed guar gum
Mix all of the ingredients well in a large bowl
Using your hands, shape into 8 fritters (not too thick or they will not cook through) and fry gently for a few minutes on each side or until golden. Serve with a side salad and a drizzle of extra-virgin olive oil.
REFS:
Chen, F., Zhuang, X., Lin, L., Yu, P., Wang, Y., Shi, Y., Hu, G., & Sun, Y. (2015). New horizons in tumor microenvironment biology: Challenges and opportunities. BMC Medicine, 13(1), 45. https://doi.org/10.1186/s12916-015-0278-7
Dzutsev, A., Goldszmid, R. S., Viaud, S., Zitvogel, L., & Trinchieri, G. (2015). The role of the microbiota in inflammation, carcinogenesis, and cancer therapy. European Journal of Immunology, 45(1), 17–31. https://doi.org/https://dio.org/10.1002/eji.20144497
Jaye K, Li CG, Bhuyan DJ. The complex interplay of gut microbiota with the five most common cancer types: From carcinogenesis to therapeutics to prognoses. Crit Rev Oncol Hematol. 2021 Sep;165:103429. doi: 10.1016/j.critrevonc.2021.103429. Epub 2021 Jul 19. PMID: 34293459.
