Reseach on Prebiotics and Cancer & Polyps

Fermentation products of inulin-type fructans reduce proliferation and induce apoptosis in human colon tumour cells of different stages of carcinogenesis Umang Munjala1, Michael Gleia1, Beatrice Louise Pool-Zobela1 and Daniel Scharlau; Br Journ Nutr. 2009; 102: 663-671 Cambridge University Press

• Epidemiological evidence suggests that the intake of prebiotic dietary fibres, for example, inulin, protects against colorectal cancer.
• Inulin enriched with oligofructose (Synergy 1) was incubated under anaerobic conditions with faecal inocula and the supernatant fraction was characterised for content of SCFA and secondary bile acid deoxycholic acid (DCA).
• Compared with the faecal blank, produced without the addition of oligofructose inulin, the SFS resulted in an almost 2·5-fold increase of SCFA and 3·4-fold decrease of DCA.
• The present results indicate growth-inhibiting and apoptosis-inducing effects of fermentation supernatant fractions of inulin. Moreover, since early adenoma cells were found to be more sensitive, this may have important implications for chemoprevention when translated to the in vivo situation, because survival of early transformed cells could be reduced.

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.