The effects of food components on the digestion of DNA by pepsin

AbstractRecently, our study found that naked nucleic acids (NAs) can be digested by pepsin. To better understand the fate of dietary DNA in the digestive tract, in this study we investigated the effects of several food compositions on its digestion. The results showed that protein inhibited the digestion of DNA when the protein:DNA ratio was higher than 80:1 (m/m). DNA found in nucleoprotein (NA), which more closely resembles the state of DNA in food, was as efficiently digested as naked DNA. When the carbohydrate:DNA ratio was 50:1–140:1 (m/m), mono-, di- and polysaccharides did not inhibit DNA digestion. NaCl exhibited an inhibitory effect at 300 mM, whereas divalent cations (Ca2+ and Mg2+) exerted a much stronger inhibitory effect even at 50 mM. The polycation compounds (e.g. chitosan and spermine) showed a significant inhibitory effect at N/P (NH3+/PO4−) = 10:1. The close relationship between food composition and DNA digestion suggests that dietary habits and food complexes are important for understan...