Probiotics and cancer treatments
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Probiotics and cancer treatments
By Professor Thomas |April 27, 2025|
Why a healthy gut can reduce side effects and improve outcomes
Enhancing and protecting the gut microbiome is one of the most important self-help strategies people can do during cancer treatments to reduce side effects and enhance effectiveness. Despite the overwhelming body of evidence to support this, many patients are sadly still told by their oncology team to actually avoid fermented foods and probiotics – the opposite advice!
The trillions of commensal bacteria in and on our bodies have a significant influence, not only, on our overall well-being, response to cancer treatments, chance of getting cancer in the first place or relapsing after surgery. This is thought to be via its influence on inflammation, oxidative stress, immune surveillance. One study showed that women with poor gut health have a higher percentage of cells which encourage cancer cells to metastasize. The trouble is, even if a person's good health is good before treatment, it takes a battering from drugs such as antibiotics, anti-indigestion remedies and steroids. Chemotherapy agents can damage to the gut lining directly and gut microbiome, contributing to symptoms such as indigestion, fatigue, “brain fog”, joint aches, nausea and diarrhea, which if severe, this can lead to dehydration, concentration of the chemotherapy in the bloodstream leading to neutropenic infection and a high risk of peripheral neuropathy. The gut microbiome is also implicated in cancer incidence
How to help your gut?
Many cancer centers such as Memorial Sloane Kettering recommend a range of safe lifestyle and nutritional strategies to improve gut health during chemotherapy, radiotherapy, hormone therapies and immunotherapies. These include
- increasing the intake of fermented foods such as kimchi and kefir
- stop smoking and exercise more
- eating more fibers in beans, vegetables, mushrooms,
- eating more prebiotic phytochemicals,
- trying to get a good night's sleep
- reducing processed sugar intake.
The role for probiotic supplements
Chemotherapy: On top of these practical measures, a number of placebo-controlled randomized trials have also shown that certain lactobacillus probiotics capsules can further reduce chemotherapy induced diarrhea particularly from fluorouracil and irinotecan agents although they are likely to help with others. A recent summary (systemic review ) of 20 studies showed that lactobacillus probiotics are very safe during chemotherapy. In this review, 17 of the studies revealed that probiotics reduced the incidence of treatment-related side effects in oncology patients, whilst only 3 reported no impact in their findings – N0 study reported any harm… read more. In particular lactobacillus during chemotherapy:
- Reduced chemo brain
- lowered the risk of neutropenia
- prevented diarrhea and gut issues
Not all probiotics are safe during cancer treatments. The safest varieties are lactobacillus, which also have the most evidence of benefit. Try to pick a blend which has been evaluated in medical studies so has a high level of quality assurance – For example yourgutplus .
Hormonal therapies such as tamoxifen, aromatase inhibitors in women and ADT in men can adversely affect gut health which in the longer term contributes to menopausal symptoms, metabolic syndrome, arthralgia, cognitive impairment and osteoporosis. Dietary measure to maintain or restore gut health would be very sensitive and some studies are showing that probiotic supplements may have an additional role. ..more
Immunotherapies: People with poor gut health receive immunotherapies increased chances of toxicity including diarrhea and pulmonary inflammation. Clinical trials show that people with poor gut health have up to 40% lower chance of these treatments working including for tumors such as glioblastoma, melanoma, lung, breast, bowel cancers and sarcomas… read more
Radiotherapy: Several well-conducted trials have demonstrated that probiotics can help prevent radiation bowel injury, oral mucosities, secondary candida infection and aid recovery after radiotherapy.. . more.
Prostate Cancer: Laboratory models have shown that aging the gut microbiome can slow prostate cancer (CaP) progression [ Pernigoni ]. In men with CaP, lower levels of gut lactobacillus strains have been associated with a higher rate of prostate cancer and biochemical recurrence [ Kim ]. Most importantly, a recent double blind RCT found that an intervention with the lactobacillus, inulin and vitamin D capsule called Yourgutplus significantly slowed CaP progression in men compared to placebo especially it combined with the supplement YourPhyto which contained 6 phytochemical rich foods [ Thomas ].
References:
Li et al `systemic review of probiotics and chemotherapy Journal of Advanced Research Volume 64 , 2024, 223-235
Masaaki et RCT neo-adjuvant chemotherapy oesophageal cancer Clinical Nutrition 36, 1 , 2017, 93-99
Juan Z, et al. Probiotics reduce chemo-related cognitive impairment in women with breast cancer: a randomized, double-blind, placebo-controlled trial. Your J Cancer. 2022 ;161:10-22.
Rodriguez-Arrastia M, et al Probiotic Supplements on Oncology Patients' Treatment-Related Side Effects: A Systematic Review of Randomized Controlled Trials. Int J Environ Res Public Health. 2021 17;18(8):4265. doi: 10.3390/ijerph18084265. PMID: 33920572; PMCID: PMC8074215.
Feng TY, et al. Reciprocal Interactions Between the Gut Microbiome and Mammary Tissue Mast Cells Promote Metastatic Dissemination of HR+ Breast Tumors. Cancer Immunol Res. 2022 Nov 2;10(11):1309-1325. doi: 10.1158/2326-6066.CIR-21-1120. PMID: 36040846; PMCID: PMC9633553.
Pernigoni N et al. Commensal bacteria promote endocrine resistance in prostate cancer through androgen biosynthesis. Science. 2021 Oct 8; 374(6564):216-224. doi: 10.1126/science.abf8403. Epub 2021 Oct 7. PMID: 34618582.
Thomas R, Kenfiled S, Newton R et al. Gut health and prostate cancer: The influence of a specific phytochemical-rich food capsule plus or minus a probiotic/prebiotic blend on symptoms and progression—A randomized, double-blind placebo-controlled trial. 2025. https://ascopubs.org/doi/10.1200/JCO.2025.43.5_suppl.311
Kim JH, et al. Biochemical Recurrence in Prostate Cancer Is Associated with the Composition of Lactobacillus: Microbiome Analysis of Prostatic Tissue. Int J Mol Sci. 2023 Jun 21;24(13):10423. doi: 10.3390/ijms241310423.
López-Gómez L, et al. Probiotics and Probiotic-like Agents against Chemotherapy-Induced Intestinal Mucositis: A Narrative Review. J Pers Med. 2023 Oct 12;13(10):1487. doi: 10.3390/jpm13101487.
Mego et al. Probiotic bacteria in cancer patients undergoing chemotherapy and radiation therapy, Complementary Therapies in Medicine,. Volume 21, Issue 6,
2013, https://doi.org/10.1016/j.ctim.2013.08.018.