Examination of the Bioavailability and Bioconversion of Wheat Bran-Bound Ferulic Acid: Insights into Gastrointestinal Processing and Colonic Metabolites.

The postingestion journey and bioconversion of wheat bran-bound ferulic acid, a known beneficial phytochemical, remain insufficiently understood. This study aims to systematically investigate its bioaccessibility, bioavailability, excretion, and colonic metabolism, both and . Initial analysis confirmed the abundance and bioactivity of ferulic acid in wheat bran. Using a simulated gastrointestinal model, 1.7% of the ferulic acid was found to be bioaccessible, in contrast to 43.4% for total phenolics. In vivo bioavailability was assessed in rats via oral gavage of cooked wheat bran, with a plasma ferulic acid level peaking at 32.5 ± 4.9 ng/mL, corresponding to an absorption rate of 0.3%, while 1% was excreted in urine. Fecal metabolomic analysis revealed extensive colonic bioconversion, with elevated levels of ferulic acid and its metabolites, including 3-phenylpropionic acid, dihydroferulic acid, 5-hydroxyferulic acid, and hippuric acid. Novel metabolites, such as 3-(2,5-dimethoxyphenyl)propionic acid and -(2-furoyl)glycine, were detected for the first time. These findings shed light on the complex biotransformation of wheat bran-bound ferulic acid and its potential health implications.