title: Antacids and dietary supplements with an influence on the gastric pH increase the risk for food sensitization.
abstract: BACKGROUND
  Elevation of the gastric pH increases the risk for sensitization against food allergens by hindering protein breakdown. This can be caused by acid-suppressing medication like sucralphate, H2-receptor blockers and proton pump inhibitors, as shown in recent murine experimental and human observational studies.
  
  
  OBJECTIVE
  The aim of the present study was to assess the sensitization capacity of the dietary supplement base powder and of over-the-counter antacids.
  
  
  METHODS
  Changes of the pH as well as of protein digestion due to base powder or antacids were measured in vitro. To examine the in vivo influence, BALB/c mice were fed codfish extract with one of the acid-suppressing substances. Read-out of antibody levels in the sera, of cytokine levels of stimulated splenocytes and of intradermal skin tests was performed.
  
  
  RESULTS
  The pH of hydrochloric acid was substantially increased in vitro by base powder as well as antacids in a time- and dose-dependent manner. This elevation hindered the digestion of codfish proteins in vitro. A significant increase in codfish-specific IgE antibodies was found in the groups fed codfish combined with Rennie Antacidum or with base powder; the latter also showed significantly elevated IgG1 and IgG2a levels. The induction of an anaphylactic immune response was proven by positive results in intradermal skin tests.
  
  
  CONCLUSIONS
  Antacids and dietary supplements influencing the gastric pH increase the risk for sensitization against allergenic food proteins. As these substances are commonly used in the general population without consulting a physician, our data may have a major practical and clinical impact.
authors.affiliation: IPP-Department of Pathophysiology, Centre of Physiology, Pathophysiology and Immunology, Medical University of Vienna, Vienna, Austria. isabella.pali@meduniwien.ac.at
authors.forename: I
authors.initials: I
authors.lastname: Pali-Schöll
authors.forename: R
authors.initials: R
authors.lastname: Herzog
authors.forename: J
authors.initials: J
authors.lastname: Wallmann
authors.forename: K
authors.initials: K
authors.lastname: Szalai
authors.forename: R
authors.initials: R
authors.lastname: Brunner
authors.forename: A
authors.initials: A
authors.lastname: Lukschal
authors.forename: P
authors.initials: P
authors.lastname: Karagiannis
authors.forename: S C
authors.initials: SC
authors.lastname: Diesner
authors.forename: E
authors.initials: E
authors.lastname: Jensen-Jarolim
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D000863:Antacids / Q000009:adverse effects*; D019587:Dietary Supplements / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D029941:Fish Proteins / Q000276:immunology; D005512:Food Hypersensitivity / Q000150:complications* / Q000276:immunology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D051379:Mice; D004366:Nonprescription Drugs / Q000009:adverse effects; D013276:Stomach Ulcer / Q000150:complications
chemical_list: D000485:Allergens; D000863:Antacids; D029941:Fish Proteins; D004366:Nonprescription Drugs