Probiotics are living microorganisms that provide a health benefit, and prebiotics are fibers that feed these friendly bacteria, mostly in your gut. These therapies, found in certain foods or as supplements, can manage gastrointestinal symptoms and some body terrainthe internal conditions of your body, including nutritional status, fitness, blood sugar balance, hormone balance, inflammation and more factors common in cancer, and they may lead to better recovery from surgery.

Safety and precautions

If you are immunosuppressed, consult an oncology dietician to see if you have any restrictions on eating unpasteurized, fermented, or cultured foods.

Expert consensus

A systematic approach to assessing consensus found 100% agreement among experts that “probiotics have a favorable safety profile in patients with a range of lower GI [gastrointestinal] symptoms typically managed in primary care or general practice” after reviewing evidence from 50 studies.1Hungin APS, Mitchell CR et al; European Society for Primary Care Gastroenterology. Systematic review: probiotics in the management of lower gastrointestinal symptoms—an updated evidence-based international consensus. Alimentary Pharmacology and Therapeutics. 2018 Apr;47(8):1054-1070.

Side effects

Few adverse events are reported with probiotics use for bowel symptoms.2Sun JR, Kong CF et al. Efficacy and safety of probiotics in irritable bowel syndrome: a systematic review and meta-analysis. Saudi Journal of Gastroenterology. 2020 Mar-Apr;26(2):66-77; Li B, Liang L et al. Efficacy and safety of probiotics in irritable bowel syndrome: a systematic review and meta-analysis. Frontiers in Pharmacology. 2020 Apr 3;11:332; Asha MZ, Khalil SFH. Efficacy and safety of probiotics, prebiotics and synbiotics in the treatment of irritable bowel syndrome: a systematic review and meta-analysis. Sultan Qaboos University Medical Journal. 2020 Feb;20(1):e13-e24.

Use of probiotics, prebiotics, or both, can cause gas and cramping for three or four days. Symptoms often resolve after that.3Winters N. The Metabolic Approach to Cancer. White River Junction, Vermont: Chelsea Green Publishing. 2017.

Case reports of probiotics from the genera Lactobacillus, Leuconostoc, Pediococcus, Enterococcus, and Bifidobacterium isolated from infection sites have led researchers to postulate that these probiotics can move within the body (translocate). Probiotic translocation is difficult to induce in healthy humans, and even if it does occur, detrimental effects are rare. Despite this, various reports have documented health-damaging effects of probiotic translocation in immunocompromised patients.4Liong MT. Safety of probiotics: translocation and infection. Nutrition Reviews. 2008 Apr;66(4):192-202. Five case reports showed probiotic-related bacteraemia/fungaemia/positive blood cultures in an analysis of 25 studies including 2242 people.5Hassan H, Rompola M, Glaser AW, Kinsey SE, Phillips RS. Systematic review and meta-analysis investigating the efficacy and safety of probiotics in people with cancer. Supportive Care in Cancer. 2018 Aug;26(8):2503-2509.

Use during pregnancy or lactation

“Probiotics do not appear to pose any safety concerns for pregnant and lactating women. Systemic absorption is rare when probiotics are used by healthy individuals, and the current literature does not indicate an increase in adverse pregnancy outcomes.”6Sheyholislami H, Connor KL. Are probiotics and prebiotics safe for use during pregnancy and lactation? a systematic review and meta-analysis. Nutrients. 2021 Jul 13;13(7):2382.

Use after antibiotic treatment

Use of probiotics may not be the quickest way to return to a pre-antibiotic treatment fecal microbiome in some situations.

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of slower and less complete return to baseline stool microbiome configuration after antibiotic treatment among people treated with probiotics

Keep reading about probiotics and prebiotics


Nancy Hepp, MS

Lead Researcher
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Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher and writer for CancerChoices and also served as the first program manager. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.

Nancy Hepp, MS Lead Researcher

Andrew Jackson, ND

Research Associate
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Andrew Jackson, ND, serves as a CancerChoices research associate. As a naturopathic physician practicing in Kirkland, Washington, he teaches critical evaluation of the medical literture at Bastyr University in Kenmore, Washington. His great appreciation of scientific inquiry and the scientific process has led him to view research with a critical eye.

Andrew Jackson, ND Research Associate


Laura Pole, RN, MSN, OCNS

Senior Clinical Consultant
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Laura Pole is senior clinical consultant for CancerChoices. Laura is an oncology clinical nurse specialist who has been providing integrative oncology clinical care, navigation, consultation, and education services for over 40 years. She is the co-creator and co-coordinator of the Integrative Oncology Navigation Training at Smith Center for Healing and the Arts in Washington, DC. Laura also manages the “Media Watch Cancer News That You Can Use” listserv for Smith Center/Commonweal. In her role as a palliative care educator and consultant, Laura has served as statewide Respecting Choices Faculty for the Virginia POST (Physician Orders for Scope of Treatment) Collaborative as well as provided statewide professional education on palliative and end-of-life care for the Virginia Association for Hospices and Palliative Care.

For CancerChoices, Laura curates content and research, networks with clinical and organizational partners, brings awareness and education of integrative oncology at professional and patient conferences and programs, and translates research into information relevant to the patient experience as well as clinical practice.

Laura sees her work with CancerChoices as a perfect alignment of all her passions, knowledge and skills in integrative oncology care. She is honored to serve you.

Laura Pole, RN, MSN, OCNS Senior Clinical Consultant

Last update: January 31, 2024

Last full literature review: November 2022

CancerChoices provides information about integrativein cancer care, a patient-centered approach combining the best of conventional care, self care, and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocialtherapy, and acupuncture therapies and self carelifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.

Our staff have no financial conflicts of interest to declare. We receive no funds from any manufacturers or retailers gaining financial profit by promoting or discouraging therapies mentioned on this site.

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