Reseach on Prebiotics and Cancer & Polyps
Roles of Probiotics and Prebiotics in Colon Cancer Prevention: Postulated Mechanisms and In-vivo Evidence.
Int J Mol Sci. 2008 May;9(5):854-63. Epub 2008 May 20. Liong MT. Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia;
- Probiotics are live bacteria that could exert health beneficial effects upon consumption. In additional to their conventional use as gut modulators, probiotics are investigated for their role to prevent cancer.
- In-vivo and molecular studies have demonstrated encouraging outcomes, mainly attributed to its antimicrobial effects against carcinogen-producing microorganisms, antimutagenic properties, and alteration of the tumor differentiation processes.
- Prebiotics are indigestible food components that could promote the growth of beneficial bacteria including probiotics.
- Present studies have suggested that prebiotics also possess protective effect against colon carcinogenesis, mainly attributed to the production of short chain fatty acids upon its fermentation by gut microflora, and alteration of gene-expressions in tumor cells.
- Synbiotic (combination of probiotic and prebiotic) has been found to exert a synergistic effect in improving colon carcinogenesis compared to when both were used individually.
Probiotics, prebiotics and synbiotics: a role in chemoprevention for colorectal cancer?
Geier MS et al; Cancer Biol Ther. 2006; 5(10): P-1265-9
- Colorectal cancer (CRC) is the third most common form of cancer.
- Current treatments including chemotherapy, radiotherapy and surgery are all associated with a high risk of complications and are not always successful, highlighting the need to develop new treatment strategies.
- The ingestion of probiotics, prebiotics or combinations of both (synbiotics) represents a novel new therapeutic option. Probiotics and prebiotics act to alter the intestinal microflora by increasing concentrations of beneficial bacteria such as lactobacillus and bifidobacteria, and reducing the levels of pathogenic micro-organisms.
- This strategy has the potential to inhibit the development and progression of neoplasia via mechanisms including; decreased intestinal inflammation, enhanced immune function and anti-tumorigenic activity, binding to potential food carcinogens including toxins found in meat products, and a reduction in bacterial enzymes which hydrolyse precarcinogenic compounds, such as beta-glucuronidase.
- There is substantial experimental evidence to suggest that probiotics and prebiotics may be beneficial in the prevention and treatment of colon cancer, however to date there have been few conclusive human trials.
- Probiotics and prebiotics have the potential to impact significantly on the development, progression and treatment of colorectal cancer and may have a valuable role in cancer prevention.
Dietary synbiotics reduce cancer risk factors in polypectomized and colon cancer patients.
Am J Clin Nutr. 2007 Feb;85(2):488-96. Rafter J, Bennett M, Caderni G, Clune Y, Hughes R, Karlsson PC,Klinder A, O'Riordan M, O'Sullivan GC, Pool-Zobel B, Rechkemmer G,Roller M, Rowland I, Salvadori M, Thijs H, Van Loo J, Watzl B, Collins JK. Department of Medical Nutrition, Karolinska Institutet, Huddinge, Sweden, University College Cork, Cork, Ireland.
- Synbiotic intervention resulted in significant changes in fecal flora: Bifidobacterium and Lactobacillus increased and Clostridium perfringens decreased.
- The intervention significantly reduced colorectal proliferation and the capacity of fecal water to induce necrosis in colonic cells and improve epithelial barrier function in polypectomized patients.
- Genotoxicity assays of colonic biopsy samples indicated a decreased exposure to genotoxins in polypectomized patients at the end of the intervention period.
- Synbiotic consumption prevented an increased secretion of interleukin 2 by peripheral blood mononuclear cells in the polypectomized patients and increased the production of interferon gamma in the cancer patients.
- CONCLUSIONS: Several colorectal cancer biomarkers can be altered favorably by synbiotic intervention.
Consumption of prebiotic inulin enriched with oligofructose in combination with the probiotics Lactobacillus rhamnosus and Bifidobacterium lactis has minor effects on selected immune parameters in polypectomised and colon cancer patients.
Br J Nutr. 2007 Apr;97(4):676-84. Roller M, Clune Y, Collins K, Rechkemmer G, Watzl B. Institute of Nutritional Physiology, Federal Research Centre for Nutrition and Food, Haid-und-Neu-Str. 9, D-76131 Karlsruhe, Germany.
- The objective of this study was to investigate whether daily intake of probiotics and prebiotics (SYN) modulates immune functions. In a randomised double-blind, placebo-controlled trial, thirty-four colon cancer patients who had undergone 'curative resection' and forty polypectomised patients participated.
- Subjects of the SYN group daily received encapsulated bacteria (1 x 10(10) colony-forming units of Lactobacillus rhamnosus GG (LGG) and 1 x 10(10) colony-forming units of Bifidobacterium lactis Bb12 (Bb12)) and 10 g of inulin enriched with oligofructose. Controls received encapsulated maltodextrin and 10 g of maltodextrin.
- In the cancer group, SYN treatment resulted in an increased capacity of PBMC to produce IFN-gamma at T3 (P < 0.05).
- In conclusion, supplementation with this SYN has minor stimulatory effects on the systemic immune system of the two study groups. Further studies in humans should aim to focus on the gut-associated immune system.