Can Probiotics Help Cancer Patients?

Check out this answer from Consensus:

The current evidence suggests that probiotics can offer several benefits to cancer patients, including improved gut health, reduced treatment side effects, and enhanced immune responses. However, the variability in probiotic strains, dosages, and patient characteristics necessitates further research to confirm these findings and establish standardized guidelines for probiotic use in cancer care.

Cancer treatments, including chemotherapy and radiotherapy, often come with a host of side effects that can significantly impact the quality of life of patients. Recently, there has been growing interest in the potential role of probiotics in alleviating some of these side effects and improving overall outcomes for cancer patients. This article explores the current evidence on the benefits and limitations of probiotic use in cancer care.

Probiotics and Colorectal Cancer

Probiotics have shown promise in improving the quality of life for patients with colorectal cancer (CRC). A systematic review of randomized controlled trials (RCTs) found that probiotics supplementation in CRC patients improved gut microbiota diversity, reduced postoperative infection complications, and inhibited pro-inflammatory cytokine production. Additionally, probiotics helped reduce the side effects of chemotherapy, improved surgical outcomes, shortened hospital stays, and decreased the risk of death1.

Probiotics During Chemotherapy and Radiation Therapy

Cancer treatments like chemotherapy and radiation therapy can cause severe gastrointestinal issues, including diarrhea and oral mucositis (OM). Probiotics have been studied for their potential to mitigate these side effects. For instance, a study on nasopharyngeal carcinoma patients undergoing concurrent chemoradiotherapy (CCRT) found that a probiotic cocktail significantly reduced the severity of OM and enhanced the immune response3. Another systematic review and meta-analysis confirmed that probiotics could reduce the incidence and severity of cancer therapy-induced OM6.

Probiotics in Breast Cancer

The role of probiotics in breast cancer has also been explored. A systematic review and meta-analysis of randomized clinical trials indicated that probiotics might protect against breast cancer by modulating the immune system and impacting intestinal microbiota. Probiotic combinations, particularly those including Lactobacillus and Bifidobacterium, showed potential benefits in countering obesity and dyslipidemia, reducing pro-inflammatory markers, and improving quality of life in breast cancer patients and survivors4.

Gastrointestinal and Psychosocial Health

Cancer treatments can lead to significant gastrointestinal (GI) and psychosocial health issues. A systematic review found that probiotics were associated with improvements in abdominal pain, gas/bloating, and diarrhea. Additionally, probiotics showed potential in improving anxiety, depression, fatigue, and overall quality of life in cancer patients and survivors5.

Safety and Efficacy Concerns

While probiotics are generally considered safe, their use in immunocompromised cancer patients requires careful consideration. A systematic review highlighted that probiotics might reduce the severity and frequency of diarrhea in cancer patients but also noted rare cases of probiotic-related infections7. Therefore, more well-designed clinical trials are needed to establish the safety and efficacy of probiotics in oncology2 8.

Probiotics and Immune Checkpoint Inhibitors

Recent studies have also investigated the impact of probiotics on the outcomes of cancer patients treated with immune checkpoint inhibitors (ICIs). A meta-analysis revealed that probiotics could improve overall survival and objective response rates in ICI-treated cancer patients, particularly those with non-small cell lung cancer (NSCLC)9.

Can probiotics help cancer patients?

Hannah Wardill has answered Uncertain

An expert from University of Adelaide in Gastroenterology, Microbiome

This is a very interesting, but difficult to answer question. As discussed by many other experts, there are a variety of ways in which the microbiome may be implicated in cancer development and treatment. The biggest piece of evidence suggesting we should think about the microbiome in cancer therapy is the simple fact that, people that take antibiotics often have worse treatment outcomes. This has largely been focused on the efficacy outcomes, that is how well someone’s tumour responds to therapy, and it has been best described in the setting of immunotherapies (which are different to traditional chemotherapy and radiotherapy). NB: this is not a public service announcement to stop all antibiotics!

We also know that the microbiome becomes injured after cancer treatment, with fewer bacteria and a disproportionate number of pathogenic or bad bacteria compared to good bacteria. Research has shown that this can exacerbate some of the side effects of cancer treatment, including sepsis (infection) and a condition called graft versus host disease, a chronic complication seen in stem cell transplant recipients.

So all of this suggests that probiotics should help cancer patients, but unfortunately we do not have the evidence to support that widely at this stage. I suspect that probiotics are unlikely to have the microbial load or complexity to overcome the intensity of the damaged caused by cancer therapy, and perhaps we need something like faecal transplantation. We must also be careful how we approach the use of microbial interventions in people with cancer as they can have a weakened immune system, which might make them more susceptible to infection.

So, in simple terms… some type of probiotic intervention is likely to help people with cancer either by enhancing the efficacy of their treatment, or controlling the severity of the side effects. We just aren’t quite sure of exactly how to maximise their impact.

Can probiotics help cancer patients?

Kate Secombe has answered Uncertain

An expert from University of Adelaide in Microbiome, Cancer

This is a big question, and it probably depends on what reason we were using probiotics to help people with cancer.

Diarrhoea is a common side effects of a range of cancer treatments. Two recently published studies have looked at evidence for probiotics reducing diarrhea from cancer treatments. One was a systematic review looking at chemotherapy and radiotherapy (https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD008831.pub3/full), which found that there was insufficient evidence to suggest probiotics were useful. Another was a meta-analysis, published by my colleagues here at the University of Adelaide (https://www.ncbi.nlm.nih.gov/pubmed/29547491). They also found, in chemotherapy, and a targeted therapy called dacomitinib, there was no evidence to support use of probiotics for diarrhoea prevention. However, the Multinational Association for Supportive Care in Cancer, which produces guidelines for treating side-effects of cancer treatment such as diarrhoea, suggests that probiotics containing Lactobacillus species be used to prevent diarrhea in patients receiving chemotherapy and/or radiation therapy for a pelvic malignancy (https://www.ncbi.nlm.nih.gov/pubmed/24615748).

A new type of cancer treatment is immunotherapy, which uses our own immune system to help fight off cancer. One study has shown people using probiotics had a poorer response to this immunotherapy treatment (https://www.parkerici.org/2019/04/02/probiotics-linked-to-poorer-response-to-cancer-immunotherapy-in-skin-cancer-patients/). We also know that immunotherapy response is really intricately linked to your gut microbiome profile (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5827966/), so artificially altering this with probiotics may cause unwanted effects.

There are many other reasons you may use probiotics too, however I think the research is inconclusive at this stage. It is very possible that specific probiotics or specific gut microbiome compositions are best in people with cancer to have the best response to treatment and the least risk of side effects. However, ‘probiotics’ is too big an umbrella to be sure of that right now!

Can probiotics help cancer patients?

Tingtao Chen has answered Near Certain

An expert from Nanchang University in Food Safety, Microbiome, Cancer

In my opinions, probiotics can not directly treat cancer, but they can play an adjuvant therapy effect.

  Recently, a series studies has indicated that intestinal microbiota play key role in cancer development and treatments (Gut microbiome influences efficacy of PD-1–based immunotherapy against epithelial tumors; Gut microbiome modulates response to anti–PD-1 immunotherapy in melanoma patients), and our work also proven that probiotics can significantly reduce the side effect caused by chemoradiotherapy (A randomized, double-blind, placebo-controlled trial of probiotics to reduce the severity of oral mucositis induced by chemoradiotherapy for patients with nasopharyngeal carcinoma) and partial gastrectomy (A randomised trial of probiotics to reduce severity of physiological and microbial disorders induced by partial gastrectomy for patients with gastric cancer).

As we know, the clearest effect of probiotics is to treat gastrointestinal microbiota imbalance, and nearly all treatments for cancer will harm patients’ normal foundations, which have a strong connection with the intestinal disorder. Therefore the measures to reduce side effects of cancer have a certain positive effect.

In addition, the reasonable diet, moderate exercise and a good mood are crucial for cancer patients, especially for the patients after treatments.