Soyasaponin I and sapongenol B have limited absorption by Caco-2 intestinal cells and limited bioavailability in women.

@article{Hu2004SoyasaponinIA,
  title={Soyasaponin I and sapongenol B have limited absorption by Caco-2 intestinal cells and limited bioavailability in women.},
  author={Jiang Hu and Manju B Reddy and Suzanne Hendrich and Patricia A. Murphy},
  journal={The Journal of nutrition},
  year={2004},
  volume={134 8},
  pages={1867-73}
}
A human study was conducted to evaluate soyasaponin bioavailability in humans. Eight healthy women ingested a single dose of concentrated soy extract containing 434 micromol of group B soyasaponins, the predominant form of soyasaponins in soybeans. Neither soyasaponins nor their metabolites were detected in a 24-h urine collection. Soyasapogenol B, a major metabolite of group B soyasaponins, was found (36.3 +/- 10.2 micromol) in a 5-d fecal collection but no group B soyasaponins were detected… CONTINUE READING