Dietary synbiotics reduce colon cancer risk factors

Several colorectal cancer biomarkers can be altered favorably by synbiotic intervention, finds this month's American Journal of Clinical Nutrition.

Animal studies suggest that prebiotics and probiotics exert protective effects against tumor development in the colon.

However, human data supporting this suggestion are weak.

Dr Joseph Rafter and colleagues from Sweden verified whether the prebiotic concept as induced by a synbiotic preparation is able to reduce the risk of colon cancer in humans.

The prebiotic concept includes a selective interaction with colonic flora of nondigested carbohydrates.

Synbiotic consumption prevented an increase of interleukin 2

American Journal of Clinical Nutrition

The symbiotic preparations involved oligofructose-enriched inulin with Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb12.

The research team conducted a 12-week randomized, double-blind, placebo-controlled trial.

The team assessed 37 colon cancer patients and 43 polypectomized patients.

Fecal and blood samples were collected before, during, and after the intervention.

The researchers obtained colorectal biopsy samples before and after the intervention.

The effect of synbiotic consumption on a battery of intermediate bio-markers for colon cancer was examined.

The team found that synbiotic intervention resulted in changes in fecal flora.

Bifidobacterium and Lactobacillus increased, and Clostridium perfringens decreased.

The intervention reduced colorectal proliferation in polypectomized patients.

The team found that the intervention reduced the capacity of fecal water to induce necrosis in colonic cells.

It also improved epithelial barrier function in these 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.

The researchers noted that symbiotic consumption increased the production of interferon in the cancer patients.

Dr Rafter's team concludes, “Several colorectal cancer biomarkers can be altered favorably by synbiotic intervention.”