Is IgG food testing endorsed by allergy and gastroenterology societies?

No. Major allergy organisations, including the American Academy of Allergy, Asthma & Immunology and the European Academy of Allergy and Clinical Immunology, state that IgG food testing is not a validated diagnostic for food allergy or intolerance, because IgG responses occur with normal dietary exposure.

How should practitioners use the 184 IgG panel results?

Results are exploratory data to guide a structured elimination trial. High-titre foods may be removed for 4–6 weeks, then systematically reintroduced while tracking symptoms. The antibody titre alone does not confirm intolerance; clinical validation comes from symptom response during elimination and rechallenge.

Can this test diagnose coeliac disease or lactose intolerance?

No. Coeliac disease requires tissue transglutaminase IgA and total IgA, confirmed by duodenal biopsy. Lactose intolerance is diagnosed by hydrogen breath testing or a lactose challenge. IgG to gluten or dairy reflects exposure, not these specific conditions.

Should patients follow an elimination diet before testing?

No. Patients should maintain their usual diet so that IgG titres reflect habitual exposure. Starting an elimination diet before the draw can lower antibody levels and reduce the interpretability of the results.

What does a high IgG titre to a specific food mean?

A high IgG titre indicates immune exposure and antibody production, often reflecting frequent consumption. It does not by itself prove clinical reactivity. Practitioners use elevated titres to select candidates for elimination, with symptom change as the ultimate measure of relevance.

Are IgG food panels standardised across laboratories?

No. IgG food testing is not standardised; antigens tested, cut-points, and reporting formats vary between laboratories. Serial results should be compared only within the same platform, and inter-laboratory agreement is poor.

How long does it take to receive results?

Results are typically available within 7–10 business days from specimen receipt at Alletess Medical Laboratory, though turnaround may be longer if batching or repeat analysis is required.

Is fasting required for the IgG food panel?

No. Fasting is not required, and patients should continue their usual diet to ensure that IgG titres reflect normal dietary exposure.

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184 IgG Gastrointestinal Portfolio

The 184 IgG Gastrointestinal Portfolio measures serum IgG antibodies to 184 food antigens via ELISA. Used in functional medicine to guide elimination diets, it reflects dietary exposure and is contested as a diagnostic for food intolerance; major allergy societies do not endorse IgG testing. Clinical utility depends on symptom response during elimination and reintroduction.

Biomarkers

Blood (serum)

Sample

7–10 business days

Turnaround

Fasting

What is the 184 IgG GI Portfolio test?

The 184 IgG Gastrointestinal Portfolio measures serum IgG antibodies to a broad array of foods, including dairy, gluten-containing grains, other cereals, legumes, nuts, seeds, meats, fish, shellfish, fruits, vegetables, spices, and additives. It is ordered by practitioners working within functional, integrative, or naturopathic frameworks who use the results to guide targeted elimination diets in patients with chronic gastrointestinal symptoms—bloating, altered bowel habit, pain—or with extra-intestinal manifestations such as fatigue, headache, or joint discomfort that have not responded to conventional investigation. Because food-specific IgG is present in healthy populations and reflects dietary exposure as much as pathology, this test occupies a contested position in clinical practice. It is not a diagnostic for IgE-mediated food allergy, coeliac disease, or lactose intolerance, each of which has validated laboratory and clinical criteria. Instead, the panel serves as hypothesis-generating data: elevated IgG titres suggest candidates for elimination, and the clinical utility is determined by whether symptoms improve when implicated foods are removed and recur upon reintroduction.

What does the 184 IgG GI Portfolio test measure?

IgG Food Panel(IgG Antibodies to 184 Food Antigens)

Range: Method-specific thresholds classify reactions as negative, borderline, moderate, or high; cut-points are laboratory-defined and not standardised across platforms.Optimal: No evidence-based optimal IgG titre exists. Laboratories report relative classifications (e.g. 'Class 0' through 'Class 4'), but these are method-specific and non-standardised.U/mL / relative units

IgG antibodies to dietary proteins are part of the normal adaptive immune response to food antigens crossing the gastrointestinal mucosa. Following repeated exposure, B cells produce IgG subclasses—particularly IgG4—that can reflect tolerance rather than pathology. The presence of food-specific IgG does not by itself confirm allergy or intolerance; IgE mediates acute allergic reactions, whereas the clinical significance of IgG responses remains contested. Elevated IgG titres may indicate increased gut permeability, chronic low-grade immune activation, or simply dietary exposure without symptomatology.

Food-specific IgG testing is used in functional and integrative medicine to guide empirical elimination diets in patients with chronic gastrointestinal complaints, fatigue, or systemic symptoms not explained by IgE-mediated allergy. Mainstream allergy and gastroenterology societies do not endorse IgG testing as a diagnostic for food allergy or intolerance, because IgG production occurs in healthy individuals and correlates with dietary exposure. When practitioners use this panel, results are interpreted as exploratory data to personalise an elimination trial, not as definitive evidence of pathology. Clinical validation comes from symptom response during elimination and reintroduction, rather than from the antibody titre alone.

Why is the 184 IgG GI Portfolio test ordered?

Patients with chronic, unexplained gastrointestinal symptoms—bloating, flatulence, abdominal discomfort, or irregular bowel habit—who have had negative coeliac serology, normal endoscopy, and no other identifiable cause
Individuals with suspected non-IgE-mediated food sensitivities or intolerances for whom a structured elimination diet guided by laboratory data may improve adherence and outcomes
Assessment of possible food-related contributions to systemic complaints such as chronic fatigue, migraines, or joint pain in the context of a functional-medicine evaluation
Patients with inflammatory bowel disease in remission or irritable bowel syndrome in whom adjunctive dietary modification is being explored, interpreted cautiously and not as a substitute for standard care
Individuals seeking a structured, data-informed elimination protocol rather than empirical broad restriction, particularly when dietary compliance and motivation benefit from objective findings
Practitioners working in integrative or naturopathic settings where IgG-guided elimination is part of the therapeutic model, with clear communication that the test is exploratory and that symptom response is the ultimate arbiter

Sample collection and turnaround

Sample type

Blood (serum)

Fasting required

Collection method

Venipuncture at patient service centre

Turnaround

7–10 business days

Collection notes

Phlebotomy required; specimen is sent to Alletess Medical Laboratory for analysis. Patients should maintain their usual diet before testing so that IgG titres reflect habitual exposure. An elimination diet started before the draw may lower antibody levels and reduce the interpretability of results.

Specimen requirements

Minimum serum volume per Alletess protocol (typically 3–5 mL); separator tube acceptable. Avoid haemolysis. Specimen stability and shipping instructions must follow the specialty laboratory's kit guidelines.

What can affect 184 IgG GI Portfolio results?

elevatesRecent dietary intake and exposure history

IgG titres rise in response to dietary exposure, so foods eaten frequently or recently may show higher antibody levels independent of clinical reactivity. An elimination diet begun before testing can lower titres and obscure patterns.

elevatesIntestinal permeability and mucosal inflammation

Increased gut permeability allows greater antigen translocation and IgG production, so conditions such as inflammatory bowel disease, coeliac disease, or dysbiosis may elevate multiple IgG responses non-specifically.

reducesImmunodeficiency or immunosuppression

Patients with hypogammaglobulinaemia or those on immunosuppressive therapy may produce blunted IgG responses, reducing the sensitivity of the panel.

variableCross-reactivity between antigens

Structural similarity between food proteins can yield cross-reactive IgG binding, so an elevated titre to one food may reflect antibodies raised against a related allergen rather than independent sensitisation.

variableAssay methodology and reference intervals

IgG food panels are not standardised; cut-points, antigens tested, and reporting formats differ between laboratories, making inter-laboratory comparisons unreliable and serial monitoring valid only within the same platform.

elevatesCoexisting gastrointestinal or systemic disease

Chronic inflammation, infection, or autoimmune conditions can generate polyclonal IgG elevations that include food-specific antibodies, potentially leading to false attribution of symptoms to dietary antigens.

What do 184 IgG GI Portfolio results mean?

Elevated

An elevated IgG titre to a specific food antigen indicates immune exposure and antibody production but does not confirm clinical reactivity. In the context of chronic symptoms, practitioners may trial elimination of high-titre foods for 4–6 weeks, followed by systematic reintroduction to assess symptom change. Response to elimination is the clinical validation; the antibody titre alone is not diagnostic of intolerance or pathology.

Normal

A 'normal' or Class 0–1 result across the panel suggests no substantial IgG response to the foods tested. This does not rule out food-related symptoms; elimination trials guided by symptom diaries, FODMAP protocols, or other non-IgG approaches remain valid. Negative IgG results may reassure patients that immunological sensitisation is unlikely, narrowing the differential.

Reduced

Low or negative IgG titres suggest minimal recent exposure or no significant antibody response to the tested antigens. They do not exclude food intolerance mediated by non-immunological mechanisms (enzyme deficiency, malabsorption, chemical sensitivity) or IgE-mediated allergy, which requires separate testing.

Note: IgG food testing is not endorsed by major allergy or gastroenterology societies for diagnosing food allergy or intolerance, because IgG responses occur in healthy individuals and correlate with dietary exposure. Use results as exploratory data within a structured elimination protocol, not as definitive proof of pathology. Reintroduction and symptom tracking are essential. Do not restrict diets unnecessarily based on laboratory findings alone, particularly in children or patients at risk of nutritional deficiency.

Frequently asked questions

IgE mediates acute allergic reactions—hives, anaphylaxis—and is the validated marker for food allergy. IgG reflects immune exposure and dietary intake; it is present in healthy individuals and its role in food intolerance is contested. IgG testing does not diagnose IgE-mediated allergy.

How to access the 184 IgG GI Portfolio test

The 184 IgG GI Portfolio reference page is free and open to all practitioners. Create a free practitioner account to see pricing, save tests to your list, and generate requisition forms. Verification takes 1–2 business days.

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About this page

Published: October 7, 2026

Last reviewed: October 7, 2026

References:

Stapel SO, et al. EAACI Task Force report: testing for IgG4 against foods is not recommended as a diagnostic tool. Allergy. (2008)
American Academy of Allergy, Asthma & Immunology position statement on IgG testing for food allergy. (2020)
Gocki J, Bartuzi Z. Role of immunoglobulin G antibodies in diagnosis of food allergy. Postepy Dermatol Alergol. (2016)
Brostoff J, Gamlin L. Food Allergies and Food Intolerance: The Complete Guide to Their Identification and Treatment. (2000)

This content is for licensed healthcare practitioners only and does not constitute medical advice. Clinical decisions should be based on the full clinical picture and not on any single test result.