Specific Immunoglobulin E and G to Common Food Antigens and Increased Serum Zonulin in IBS Patients: A Single-Center Bulgarian Study

Abstract

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder whose pathogenesis is considered multifactorial, including abnormal gut motility, visceral hyperreactivity, psychological factors, disturbances in the brain-gut axis, leaky gut, oxidative stress, etc. We aimed to investigate serum levels of specific immunoglobulin E and G to common food antigens and zonulin and to assess their use in clinical practice for patients with IBS. Material and methods. We included 23 participants, 15 with IBS (diagnosed according to the Rome IV criteria) and 8 healthy controls. We investigated serum levels of specific IgG antibodies to 24 food antigens, specific IgE antibodies to 20 food antigens, anti-celiac antibodies, fecal calprotectin and serum zonulin by ELISA. Results. Food-specific positive IgG antibodies were significantly higher in patients with IBS than in controls (p = 0.007). IgE-mediated allergic reactions were found in five patients with IBS; no one had anti-TG antibodies. One-third of IBS patients demonstrated a low degree of chronic inflammation (positive fecal calprotectin test > 50 ng/mL) without specific bacterial infection. Serum levels of zonulin in IBS patients were higher than in healthy controls (0.378 ± 0.13 vs. 0.250 ± 0.14 ng/mL, p = 0.0315). However, no correlations between clinical symptoms and zonulin levels were found. Conclusion. The mechanisms of IgG hypersensitivity and low degree inflammation in IBS and elevated zonulin may contribute to multifactor pathogenesis in IBS.

Associations between food-specific IgG antibodies and intestinal permeability biomarkers

“…The relationship between egg consumption and intestinal permeability is less clear than that of dairy, yet similarly appears to be independent of zonulin. A recent study looking at the relationship between food-specific IgG titers and serum zonulin levels in patients with irritable bowel syndrome did not find any significant correlations between egg-specific antibodies and zonulin (20). As such, the contributions of egg and dairy consumption to intestinal permeability, specifically in the context of IgG-mediate food sensitivities, remain unclear.…”

“…Previous studies have revealed associations between food-specific IgG titers and certain gastrointestinal pathologies, such as irritable bowel syndrome (IBS) ( 20 , 21 ) and inflammatory bowel disease ( 22 ), highlighting a connection between IgG-mediated food sensitivities and gastrointestinal inflammation. Pro-inflammatory cytokines produced during these events may act directly on the intestinal barrier to increase permeability ( 23 , 24 ).…”