Metabolic tracking of isoflavones in soybean products and biosamples from healthy adults after fermented soybean consumption

•Fermentation changed soybean isoflavones, enhancing absorption and bioavailability.•Total isoflavone levels were similar in 24 h urine samples after FS or NFS diet.•Urinary genistein 7-O-sulfate level may discriminate between FS and NFS diets.•Isoflavone conjugate profiles might be a potential marker for FS diet.