Diet supplements do not affect colorectal cancer markers

NEW YORK (Reuters Health) - Use of prebiotic, probiotic, and synbiotic dietary supplementation leads to changes in fecal microflora but not to variables associated with colorectal cancer, according to Australian and US researchers.

"Gut microorganisms are a critical aspect of health," lead investigator Dr. Daniel L. Worthley told Reuters Health.

"This study," he added, "showed how gut microorganisms could be changed by taking a probiotic with a fiber supplement. But, we still have much to learn about the relationship between gut microorganisms and important digestive diseases, such as bowel cancer and inflammatory bowel disease."

In the September issue of the American Journal of Clinical Nutrition, Dr. Worthley of the Queensland Institute of Medical Research, Herston, and colleagues report on their randomized crossover trial of supplementation with resistant starch and Bifidobacterium lactis.

This was given alone or as a combined synbiotic preparation to 20 volunteers. The aim was to determine the effects on luminal, inflammatory, epigenetic, and epithelial biomarkers of colorectal cancer.

In the 17 subjects who completed the study, the team found that the synbiotic intervention fostered a significantly different fecal stream bacterial community than did either the prebiotic or the probiotic intervention alone.

However, there was no significant alteration in any other fecal, serum, or epithelial variables.

Nevertheless, the researchers conclude that even in the absence of other significant luminal events, "the mechanisms underlying the microbial consequences of synbiotic interventions are worth exploring, particularly with regard to their implications for early colorectal carcinogenesis."

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