Mechanistic hypotheses support a role for dietary fiber in the prevention of breast cancer through a reduction of IGFs bioactivity, notably by increasing insulin-like growth factor binding protein 3 (IGFBP3) concentration [14], [15]; an influence on steroid hormone concentrations by decreasing circulating estrogens [16] and upregulating SHBG concentrations [17] and a reduction of inflammation, thanks to the production of short-chain fatty acid (SCFA) by colonic fermentation [18]–[21]. Here, IGFBP3 is linked to breast carcinoma.