Can probiotics and fermented foods help us fight cancer?


We behind this blog own and operate a kombucha microbrewery, and we want to begin this post by saying that kombucha is not a cure for cancer, and neither is sauerkraut, yogurt, applecidervinegar or other probiotics. For those afflicted with cancer, there don’t appear to be any miracle cures or easy solutions, and clinical “western” medicine, with the standards of controlled human trials to develop drugs and treatments, appears to be the best route to go for treatment. Having said that, we believe, based on careful reading of many peer-reviewed studies, that there is convincing evidence that kombucha and other probiotics may play a role in preventing and treating cancers.

A rapidly growing area of research in probiotics has been the role of our microbiomes in our susceptibility to cancers, and interest in the potential for probiotics to help stave off cancer. Most of this research has focused on colorectal cancers, but a lot of research has also been conducted into stomach cancers caused by a bacteria Helicobacter pylori. The research is promising, and hopefully, with more research, and emerging technologies to study our microbiomes, we will soon know much more about how large a role probiotics can play in the prevention and treatment of cancers.

Europeans have a lifetime risk of developing colo-rectal cancers of about 2% (1), and a 5-year survival rate of 65% (2) . It is the third most common type of cancer worldwide (1). In a meta-analysis of animal studies investigating the effect of probiotics on colo-rectal cancers, 80% of the studies found a reduction in cancers with probiotics and that reduction was generally amplified when prebiotics were added. In addition to inhibition of cancer formation, studies have also found that probiotics, when administered after cancerous lesions have formed slowed or stopped their growth (3). It was suggested that the mechanisms for the cancer fighting actions of probiotics was a combination of the following factors:

  • Competing with and displacing other components of the gut microflora.
  • Producing antibacterial agents, including bacteriocins (and bacteriocin-like components), to control the growth of other members of the microflora.
  • Producing lactic and other organic acids, thereby lowering the luminal pH and thus modulating enzyme activity.
  • Improved immune system function- upregulating immune system activities which target and destroy or inhibit cancer growths

Research indicates with increasing certainty that diets high in red meats, fats, and especially processed meats increase our risk for colon-cancer, and the mechanisms for this, while not established, appear to arise from increased concentrations of N-nitroso compounds and heterocyclic amines and studies have shown that some micro-organisms are more adept at taking up and detoxifying such compounds (4). In animal studies bacteria from the groups Bacteroides and Clostridium appear to increase formation and severity of colonic tumors while bacteria from the most common probiotic groups Lactobacillus and Bifidobacteria have been shown to prevent or slow tumorigenesis (5, 6, 7, 8, 9)

In addition to colorectal cancers, probiotics have been increasingly studies as potential therapeutic agents to combat stomach cancer. There is a great deal of research on the potential for probiotics to treat or prevent infections with Helicobacter pylori. H. pylori, as it is commonly called, is a bacteria that colonizes our stomach and, among other effects, causes stomach ulcers. It affects an amazingly large portion of the global population, with nearly 50% of the world’s population, mostly in the developing world, infected. Australian researchers Drs. Barry Marshall and Robin Warren received the Nobel prize in 2005 for their work “discovering” it in 1982. It was an amazing discovery, in part because it was amazing that we only discovered its prevalence so recently. It is estimated that 60% of stomach cancers are due to H. pylori (10, 11, 12,). Stomach cancer is the fifth leading cause of cancer and the third leading cause of death from cancer. In 2012 it occurred in 950,000 people and caused 723,000 deaths (1). Research on probiotics in treating or preventing H. pylori has been very promising. A number of studies have found that ingestion of Lactobacillus and Bifidobacterium containing yogurt helped control or prevent H. pylori infections (13, 14, 15,)

The specific mechanism of cancer inhibition of probiotics remains to be elucidated, and, due to the multi-faceted protective effects of probiotics this is a major challenge. In addition, most of the research discussed here occurred in animal models not in humans. Much research remains to be done before a specific probiotic, prebiotic, or synbiotic can be therapeutically administered for cancer treatment. However the evidence is compelling that probiotics derived from common dairy fermentations as well as their co-occurring symbionts have a role to play in the treatment and prevention of colo-rectal and stomach cancers.

Both ”probiotic” and ”cancer fighting” are among the many health benefits people attribute to kombucha, and there is evidence to support both. However, the anti-cancer effects of kombucha are primarily attributed to the presence of compounds that inhibit cancer and promote the body’s ability to fight cancer, and not to the probiotic properties of kombucha. Nor have there been any studies of how the probiotic effects of kombucha may help fight cancer in humans, and thus, there is limited evidence to support a probiotic role of kombucha in fighting cancer. There have, however, been some studies in vitro (in petri dishes) showing that kombucha inhibits the growth of H. Pylori (16), which may lower the risk for stomach cancer. In addition, many of the characteristics of probiotics that are thought to play a role in the ability of probiotics to help prevent and fight colon cancer (see the bulleted list above) are characteristic of kombucha, so there are certainly grounds to believe that there may be a probiotic mechanism by which kombucha may help prevent and fight cancers. Unquestionably, more research is needed establish a clear link though, and, as with many functional foods,t he cost and effort that would be required to establish such a link (human studies, following cohorts for many years and controlling their diets) may make such studies prohibitively expensive, especially considering the lack of a profit motive for a product which is freely and cheaply available. In future blog posts, we’ll delve into the evidence for the non-probiotic mechanisms by which kombucha may help prevent and fight cancers, for which there is considerably more evidence.


1: World Cancer Report 2014. World Health Organization. 2014. pp. Chapter 1.1. ISBN 9283204298

2: “SEER Stat Fact Sheets: Colon and Rectum Cancer”. NCI. Retrieved 18 June 2014.

3: Commane D, Hughes R, Shortt C, Rowland I. 2005. The potential mechanisms involved in the anti-carcinogenic action of probiotics. Mutation Research 591: 276–289.

4: Wollowski I, Rechkemmer G, Pool-Zobel BL. Protective role of probiotics and prebiotics in colon cancer. Am J Clin Nutr 2001; 73 (suppl): S451–45.

5: Onoue M, Kado S, Sakaitani Y, Uchida K, Morotomi M. Specific species of intestinal bacteria influence the induction of aberrant crypt foci by 1,2-dimethylhydrazine in rats. Cancer Lett 1997; 113: 179–86.

6: Horie H, Kanazawa K, Okada M, Narushima S, Itoh K, Terada A. Effects of intestinal bacteria on the development of colonic neoplasm: an experimental study. Eur J Cancer Prev 1999; 8: 237–45.

7: Singh J, Rivenson A, Tomita M, Shimamura S, Ishibashi N, Reddy BS. Bifidobacterium longum, a lactic acid-producing intestinal bacterium inhibits colon cancer and modulates the intermediate biomarkers of colon carcinogenesis. Carcinogenesis 1997; 18: 833–41.

8: Pool-Zobel BL, Neudecker C, Domizlaff I, et al. Lactobacillus- and bifidobacterium-mediated antigenotoxicity in the colon of rats. Nutr Cancer 1996; 26: 365–80.

9: O’Mahony L, Feeney M, O’Halloran S, et al. Probiotic impact on microbial flora, inflammation and tumour development in IL-10 knockout mice. Aliment Pharmacol Ther 2001; 15: 1219–25.

10: Sim, edited by Fiona; McKee, Martin (2011). Issues in public health (2nd ed.). Maidenhead: Open University Press. p. 74. ISBN 9780335244225.

11: World Cancer Report 2014. World Health Organization. 2014. pp. Chapter 5.4. ISBN 9283204298.

12: Chang, A. H.; Parsonnet, J. (2010). ”Role of Bacteria in Oncogenesis”. Clinical Microbiology Reviews 23 (4): 837–857. doi:10.1128/CMR.00012-10. ISSN 0893-8512. PMC 2952975.PMID 20930075.

13: Wang KY, Li SN, Liu CS, Perng DS, Su YC, Wu DC, Jan CM, Lai CH, Wang TN, Wang WM (September 2004). ”Effects of ingesting Lactobacillus- and Bifidobacterium-containing yogurt in subjects with colonized Helicobacter pylori” (PDF). The American Journal of Clinical Nutrition 80 (3): 737–41. PMID 15321816.

14: Michetti, P., Dorta, G., Wiesel, P.H., Brassart, D., Verdu, E., Herranz, M., Felley, C., Porta, N., Rouvet, M., Blum, A.L., Corthesy-Theulaz, I., 1999. Effect of whey-based culture supernatant of Lactobacillus acidophilus ( johnsonii ) La1 on Helicobacter pylori infection in hu- mans. Digestion 60, 203–209.

15: Zhang MM, Qian W, Qin YY, et al. (2015) Probiotics in Helicobacter pylori eradication therapy: a systematic review and meta-analysis. World J Gastroenterol 21, 4345–4357.

16: Sreeramulu G, Zhu Y, Knol W. 2000. Kombucha fermentation and its antimicrobial activity. Journal of Agricultural and Food Chemistry 48 (6): 2589–2594.




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