What Is Well Established?	What Should be Further Investigated?
Amylase action influences the resulting remnants of ingested starch and thereby the microbiome	Whether different amylase action and concentration, e.g., in stress situations, also leads to different outcome regarding allergenicity of the food
Food processing changes protein structure and digestibility	Whether food processing might impact on gastrointestinal pH levels
Heating can lead to glycation and Maillard products, and thereby influences digestibility of involved proteins	Whether proteins become more able to sensitize, or to elicit reactions in allergic patients
Anti-ulcer medication and antacids elevate gastric pH levels and consequently influence food protein digestion	Whether gastric acid suppression influences also intestinal pH levels and small intestinal protein digestion
Loading of lipid transfer proteins (LTP) with ligands changes their digestibility	Whether loading of LTP changes their immunogenicity and allergenicity in vivo
Blocking of gastric digestion increases the risk for allergic sensitization	Whether the subsequent intestinal digestion is also influenced by the changed gastric pH. Whether a functional intestinal digestion could equalize the detrimental sensitizing effect of a blocked gastric digestion