Iron-peptide complexes from spent yeast: Evaluation of iron absorption using a Caco-2 monolayer

Anaemia is one of the most prevalent nutritional diseases worldwide with Fe deficiency being its major cause. In fact, the limited bioavailability of dietary iron and its interaction with food compounds contribute to its poor absorption in the human body and dietary Fe supplementation has been widely used to address this issue. By incorporating a circular economy framework, this study takes a novel approach of production of iron-peptide complexes from spent yeast peptide-rich extracts as a more effective substitute to conventional salt-based iron supplements, which are related with adverse consequences. Considering the regulation of iron absorption on duodenal enterocytes, iron-peptides complexes absorption was assessed using a Caco-2 monolayer, evaluating both iron uptake and the capacity to stimulate ferritin synthesis, after their in vitro simulated gastrointestinal digestion following INFOGEST protocol. An iron salt and a commercially available benchmark (iron bisglycinate) were also included in this study to compare the absorption performance. Results showed that iron-peptide complexes exhibited a similar behaviour (no statistically significant alterations (p > 0.05)) concerning the other tested samples, thus being a promising alternative for iron dietary supplementation. The remaining digested peptides from the complexes also showed potential antioxidant activity, suggesting protection of iron from oxidation within human body.