A recent post (Mechanisms of Postinfectious IBS & Functional Pain) reviewed a study which described how food antigens during an infectious process can result in meal-induced pain.

• Aguilera-Lizarraga, J., Florens, M.V., Viola, M.F. et al. Local immune response to food antigens drives meal-induced abdominal pain.  Nature (2021). https://doi.org/10.1038/s41586-020-03118-2 

A recent review of this study (M Rothenberg. NEJM 2021; 384:2156-2158. An Allergic Basis for Abdominal Pain) provides more insight.

Key points:

• “A peripheral immune mechanism involving local mast cells stimulated by food-induced local IgE may underlie the symptoms associated with IBS and functional abdominal pain; these findings prompt consideration of new therapeutic strategies to target mast cells and allergies.”
• The article reviews the experimental methods/results used in both mice and humans. Mice that were treated with agents that interfered with allergy “including anti-IgE, mast-cell stabilizers, and histamine H1 receptor antagonists, attenuated the pathologic and symptomatic responses…mice [that were] deficient in mast cells or in histamine H1 receptor were protected” as well.
• The study shows that a “bacterial infection can break oral tolerance to a dietary antigen…which in turn can lead to increased gut permeability.”
• The findings in human “showed no evidence of systemic IgE against common foods” but localized reactions were identified in every IBS patient after allergen injection into rectal mucosa.

My take: This study adds to the evidence that specific foods can lead to localized tissue-specific allergic responses. Nevetheless, it is still a futile effort to look for systemic allergic food reactions in patients with IBS and functional GI disorders.

Related blog posts:

• Mechanisms of Postinfectious IBS & Functional Pain
• Is There a Way to Prove Which Dietary Factors Trigger IBS?
• “The Truth About Allergies and Food Sensitivity Testing”
• How Allergy Testing Can Lead to More Allergies
• What’s Wrong with “I Want My Kid Tested for Food Allergies”
• Clinically Useful Biomarkers for Irritable Bowel Syndrome? | gutsandgrowth
• IBS Subtypes in Pediatrics | gutsandgrowth
• Mechanisms of irritable bowel syndrome
• Ondansetron for Irritable Bowel with Diarrhea? | gutsandgrowth