Comparative resistance of food proteins to adult and infant in vitro digestion models

Abstract

IgE-mediated allergy to milk and egg is widespread in industrialised countries and mainly affects infants and young children. It may be connected to an incomplete digestion of dietary proteins causing an inappropriate immune response in the gut. In order to study this, a biochemical model of infant gastroduodenal digestion has been developed, which has reduced levels of protease (eightfold for pepsin and tenfold for trypsin and chymotrypsin), phosphatidylcholine and bile salts, compared with the adult model. This model has been used to study the behaviour of three characterised food-relevant proteins (bovine beta-lactoglobulin (beta-Lg), beta-casein (beta-CN) and hen's egg ovalbumin), all of which are relevant cows' milk and hens' egg allergens. Digestion products were characterised using electrophoresis, immunochemical techniques and MS. These showed that ovalbumin and beta-CN were digested more slowly using the infant model compared with the adult conditions. Resistant fragments of beta-CN were found in the infant model, which correspond to previously identified IgE epitopes. Surprisingly, beta-Lg was more extensively degraded in the infant model compared with the adult one. This difference was attributed to the tenfold reduction in phosphatidylcholine concentration in the infant model limiting the protective effect of this phospholipid on beta-Lg digestion.

Broad and efficient control of major foodborne pathogenic strains of Escherichia coli by mixtures of plant-produced colicins

“…Subsequent SIF incubation results in further peptide degradation to fragments of about 2-3 kDa (Fig. S6A), which is below the size threshold for development of allergic reactions (22). Similar results were obtained for colicins E7, K, and U.…”

β-Lactoglobulin-linoleate complexes: In vitro digestion and the role of protein in fatty acid uptake

“…In vitro adult digestion model was adapted from Dupont et al (2009). Briefly, βlg samples were dissolved in simulated gastric fluid (0.15 M NaCl, pH 2.5) and the pH was adjusted to 2.5 with 0.5 M HCl solution.…”

Extending in vitro digestion models to specific human populations: Perspectives, practical tools and bio-relevant information

“…Infant fasting gastric pH is less acidic than of an adult (respectively 4e5 vs. 2 in the fasted state) which may change gastric proteolysis, as optimal activity of pepsin is 1.5e2.2 (Henderson, Hamosh, Armand, Mehta, & Hamosh, 1998;LiChan & Nakai, 1989;Schlamowitz & Peterson, 1959). Reduced pepsin secretion in newborns, 10e20% from adult levels, is another physiological reason explaining the limited gastric proteolysis (15%) reported for infants Dupont et al, 2010a;Romano, Giosafatto, Masi, & Mariniello, 2015). Pepsin secretion increases with postnatal age and is more immature in preterm infants (Guyton, 1991).…”

“…Based on the current physiological knowledge of the infant GI, various static and dynamic IVD models have been applied by researchers (Blanquet et al, 2004;de Oliveira et al, 2015;Dupont et al, 2010a;Roussel et al, 2016;Shani-Levi et al, 2013). Yet, the development of a harmonized static infant IVD is needed.…”