Fiber-type prebiotics and gynecological and breast cancers risk: the PrebiotiCa study.

ABSTRACT

Prebiotics may influence the risk of hormone-related female cancers by modulating the gut microbiota involved in estrogens metabolism. We evaluated the association of fiber-type prebiotic intake with breast, endometrial, and ovarian cancers. Data derived from a network of Italian hospital-based case-control studies (1991-2006), including 2560 cases of cancer of the breast (2588 controls), 454 of the endometrium (908 controls) and 1031 of the ovary (2411 controls). Inulin-type fructans (ITFs), and selected fructo-oligosaccharides (FOSs, nystose, kestose and 1F-ß-fructofuranosylnystose) and galacto-oligosaccharides (GOSs, raffinose and stachyose) were quantified in food products. Prebiotic intake was estimated by multiplying food frequency questionnaire intake by the foods' prebiotic content. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) were derived by multiple logistic regression models. Nystose intake was marginally directly associated with breast (OR for the 4th versus the 1st quartile 1.20, 95% CI 1.00-1.45), ovarian (OR 1.39, 95% CI 1.04-1.84) and endometrial cancer risk (OR 1.32, 95% CI 0.85-2.03). High 1F-ß-fructofuranosylnystose intake was inversely associated with ovarian cancer (OR 0.67, 95% CI 0.52-0.85). ITFs, kestose, raffinose and stachyose were not associated with the three cancers. The intake of most fiber-type prebiotics was not appreciably and consistently associated with breast, endometrial and ovarian cancer risks.