Computational analysis of the relationship between allergenicity and digestibility of allergenic proteins in simulated gastric fluid

Bingjun Jiang,Zhongping Lin,Yuanlei Hu,Hong Qu,Ting Ni

doi:10.1186/1471-2105-8-375

Abstract

BackgroundSafety assessment of genetically modified (GM) food, with regard to allergenic potential of transgene-encoded xenoproteins, typically involves several different methods, evaluation by digestibility being one thereof. However, there are still debates about whether the allergenicity of food allergens is related to their resistance to digestion by the gastric fluid. The disagreements may in part stem from classification of allergens only by their sources, which we believe is inadequate, and the difficulties in achieving identical experimental conditions for studying digestion by simulated gastric fluid (SGF) so that results can be compared. Here, we reclassify allergenic food allergens into alimentary canal-sensitized (ACS) and non-alimentary canal-sensitized (NACS) allergens and use a computational model that simulates gastric fluid digestion to analyze the digestibilities of these two types.ResultsThe model presented in this paper is as effective as SGF digestion experiments, but more stable and reproducible. On the basis of this model, food allergens are satisfactorily classified as ACS and NACS types by their pathways for sensitization; the former are relatively resistant to gastric fluid digestion while the later are relatively labile.ConclusionThe results suggest that it is better to classify allergens into ACS and NACS types when understanding the relationship between their digestibility and allergenicity and the digestibility of a target foreign protein is a parameter for evaluating its allergenicity during safety assessments of GM food.

Highlights

Safety assessment of genetically modified (GM) food, with regard to allergenic potential of transgene-encoded xenoproteins, typically involves several different methods, evaluation by digestibility being one thereof
Astwood et al found that the main allergens of peanut and soybean were more stable in simulated gastric fluid (SGF) than nonallergenic proteins such as spinach ribulose bis-phosphate carboxylase/oxygenase, and proposed that the resistance of a protein to digestion is an important factor in its allergenicity [4]
Assessment of the digestibility of a foreign protein in GM foods as a means of evaluating allergenicity was included in a decision tree approach proposed by Food and Agriculture Organization (FAO) and World Health Organization (WHO) in January 2001 [3], and in a weight-of-evidence approach proposed by The Codex Alimentarius Commission (Codex) in 2003 [5]

Summary

Introduction

Safety assessment of genetically modified (GM) food, with regard to allergenic potential of transgene-encoded xenoproteins, typically involves several different methods, evaluation by digestibility being one thereof. The Food and Agriculture Organization (FAO) and the World Health Organization (WHO) proposed that milk, seashell, egg, fish, peanut, soybean, nut and wheat are eight major sources of food allergens and the causes of most food allergies [3]. These allergens have attracted much attention, and efforts have been made to determine the reasons for their allergenicity and what we can do to reduce it or to remove them. We have considered computer simulation of gastric fluid digestion to elucidate the relationship between the allergenicity and digestibility of proteins

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Discussion

Conclusion