Sex-based differences in in vitro digestibility of milk and oat drink, and powder counterparts

This study examines differences in the digestibility of bovine milk and oat-based milk alternative using a sex-based in vitro digestion model, focusing on protein breakdown, and consumer sex as an underexplored variable that generates variability in digestive functions. For this, a semi-dynamic in vitro digestion model was used to examine how males or females degrade two protein sources and their concomitant protein powder products. This research aims to optimize nutrition, create gender-specific dietary recommendations and functional foods, improve health outcomes, and promote sustainable food choices by enhancing protein utilization efficiency. Results indicate that physiological differences between males and females delineate differences in gastric and intestinal protein clotting and breakdown into peptides and amino acids. Interestingly, in vitro digestion conditions relevant for females exhibit a different proteolytic trajectory leading to higher efficiency in breakdown of oat proteins, while males' gastro-intestinal conditions show a tendency for improved breakdown of bovine milk proteins. Liquid chromatography-mass spectrometry proteomic analyses also stress that males and females' gastric conditions were able to generate different bioaccessible peptides. In the case of milk, male gut conditions liberated various known bioactive peptides with antimicrobial, Dipeptidyl peptidase-4 inhibitor and cholesterol regulating activities. Contrary, female gastric conditions led to the liberation of an osteoanabolic peptide. Moreover, female gut conditions were able to liberate more free amino acids from oats rather than from milk while male conditions yielded an inverse trend. Thus, the findings suggest consumer biological sex could have significant ramifications to the rational design of future foods and food reformulation efforts.