Do probiotics reduce diarrhoea from cancer treatment?

by | Cancer Care, Gastrointestinal Health


Bowel problems are a common side-effect from cancer chemotherapy and radiotherapy. Probiotic supplements appear to have a favourable benefit in reducing these problems.

Chemotherapy and radiotherapy are effective treatments for certain types of cancers but, like any cancer treatment, they are not without their side effects.

Gastrointestinal problems such as diarrhoea are a common side-effect from therapies targeted to cancers of the abdominal and pelvic region. Severe diarrhoea can worsen a person’s quality of life, which can lead to interruptions or even discontinuation of treatment.

Chemotherapy is effective in destroying cancer cells of the abdominal region, but healthy cells lining the bowel can succumb to ‘friendly fire’. Gut microbes can also be affected by chemotherapy.

A healthy gut microbiota is important in maintaining an intestinal defence barrier and a well-functioning immune system. If chemotherapy upsets the function of gut microbes, then this could explain in some part the link with diarrhoea.

Probiotics are a potential way to reduce diarrhoea risk from chemotherapy and radiotherapy. Keeping the gut microbe population happy may keep the person receiving treatment happy too from having fewer bowel problems to deal with.

Fortunately, clinical trials with probiotics in people receiving chemo- and radiotherapy for cancers in the pelvic region have been published. The downside is the trials have been very mixed in the bacterial strains used, at what stage the probiotic was given, and for how long it was taken.

Combining the nine clinical trials of probiotics use in chemotherapy or radiotherapy in people with abdominal or pelvic cancer gives a clearer picture.

Diarrhoea incidence was much lower in people taking a probiotic compared to a placebo. The strongest benefit was seen in reducing the risk of more severe diarrhoea by over half. Less of a benefit was seen in reducing the risk of less severe diarrhoea. Safety was also assessed with the majority of studies reporting no adverse events.


With further studies likely to add to the evidence base in the future, the use of probiotics could become a standard part of some radiotherapy and chemotherapy treatments.