Citation

Ishikawa H, Akedo I, Otani T, Suzuki T, Nakamura T, Takeyama I, Ishiguro S, Miyaoke E, Sobue T,  Kakizoe T (2005) Randomized trial of dietary fiber and Lactobacillus casei administration for prevention of colorectal tumours. International Journal of Cancer 116: 762-767

Objective

To determine whether consumption of dietary fibre from wheat bran +/- Lactobacillus casei Shirota (LcS) prevented the occurrence of colorectal tumours.

Methods

In this randomised clinical trial 398 subjects, who had previously had at least two colorectal tumours surgically removed, were assigned to one of the following dietary interventions for four years: (i) dietary advice with consumption of wheat bran (7.5g three times a day), (ii) LcS (10¹⁰ viable cells/g three times a day), (iii) both or (iv) neither. During this period, consultations occurred every three months. The primary endpoint was the presence or absence of new tumours after two and four years’ intervention (detected by colonoscopy).

Results

Multivariate adjusted OR (95% CI) for occurrence of tumours was 0.76 (0.50-1.15) for the LcS group and 1.31 (0.87-1.98) in the wheat bran group after two years.

There was a statistically significant decrease in occurrence of colorectal tumours with moderate to severe atypia after four years associated with the probiotic consumption (OR 0.65, 95% CI 0.43-0.98).

Wheat bran consumption resulted in a significantly higher incidence of tumours > 3mm. Groups consuming the combination of wheat bran and LcS had a higher tumour occurrence than those on single dietary interventions but a lower incidence than those without any dietary intervention.

Conclusions

Intake of the probiotic L. casei Shirota appeared to suppress the development of colorectal tumours. There was a statistically significant association between consumption and prevention of development of tumours with moderate to severe atypia.