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

Prebiotics may inf luence the risk of hormone-related female cancers by modulating the gut microbiota involved in estrogen 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 (n = 2588 control participants), 454 of the endometrium (n = 908 control participants), and 1031 of the ovary (n = 2411 control participants). Inulin-type fructans and selected fructo-oligosaccharides (namely, nystose, kestose, and 1F-β-fructofuranosylnystose) and galacto-oligosaccharides (namely, raffinose and stachyose) were quantified in food products via laboratory analyses. Prebiotic intake was estimated by multiplying intake according to food frequency questionnaire responses by the foods’ prebiotic content. Odds ratios (ORs) and the corresponding 95% CIs were derived by multiple logistic regression models. Nystose intake was marginally directly associated with breast (for quartile 4 vs quartile 1: OR = 1.20; 95% CI, 1.00-1.45), ovarian (OR = 1.39; 95% CI, 1.04-1.84), and endometrial (OR = 1.32; 95% CI, 0.85-2.03) cancer risk. High amounts of 1F-β-fructofuranosylnystose intake were inversely associated with ovarian cancer (OR = 0.67; 95% CI, 0.52-0.85). Inulin-type fructans, kestose, raffinose, and stachyose were not associated with the 3 cancers. The intake of most fiber-type prebiotics was not appreciably and consistently associated with breast, endometrial, and ovarian cancer risks.