What is Immunoglobulin G Food-Specific Antibodies?
Immunoglobulin G is the most abundant circulating antibody, mediating delayed immune responses through Fc-receptor binding and complement activation. Food-specific IgG antibodies form when dietary proteins cross the intestinal barrier and trigger an adaptive immune response. Their presence indicates prior antigen exposure and immune recognition but does not, in isolation, prove food intolerance or allergy; healthy individuals eating diverse diets routinely develop IgG to commonly consumed foods without clinical symptoms. The clinical relevance of elevated IgG to individual foods remains contested, with mechanistic debate over whether such antibodies reflect tolerance, normal exposure, increased gut permeability, or a pathogenic driver of inflammation.