Food Intolerance

"One man’s food may be another man’s poison." – Lucretius

Food hypersensitivity is defined as an adverse reaction to a food, and can be grouped into two basic categories (1) non-immunological food sensitivities, such as lactose intolerance, fructose intolerance and histamine intolerance, and (2) adverse food reactions mediated by the immune system. The latter category can be subdivided into “real” food allergies (food allergy type I) characterized by the presence of IgE with severe immediate reactions, and/or non-IgE-mediated immunological reactions with delayed on set and less severity, such as IgG or IgG4 mediated food intolerance.

Food intolerance

Food intolerance comprises the major part of the adverse reactions which individuals have to food and affect our health in many different ways. As we pay more and more attention to nutrition and health, food intolerances have come to the forefront of public interest in recent years.


Immediate onset (IgE-mediated)

  • Trace amounts of food are enough to trigger reactions
  • Reactions occur within 2 hours of eating trigger food
  • Severe symptoms
  • Primarily affects: skin, airway and digestive system
  • IgE and skin test positive
  • Treatment: avoidence/exclustion from diet; Emergency: epinephrin in emergencies

Delayed Onset (IgG-mediated)

  • Large amount of food needed to provoke symptoms
  • Reactions occur 2-72 hours after eating trigger food
  • Less severe symptoms
  • Any organ system can be involved
  • IgE RAST negative; IgG positive
  • Treatment: avoidence/exclusion from diet

The clinical manifestations of food intolerance are multiple and include not only gastro-intestinal disorders, but also diseases of many organ systems:

  • Digestive tract: vomiting, seizures, constipation, diarrhea, IBS, Crohn’s disease
  • Migraine, headache
  • Atopic disease: atopic dermatitis, allergic conjunctivitis, allergic rhinitis and asthma
  • Adiposity/Type II diabetes
  • Cardiovascular system: hypertension, arteriosclerosis
  • Fatigue, depression


The most important function of the gastro-intestinal (GI) tract is to digest the food intake and adsorb nutrients. It is however also one of the most active organs in terms of the immune system. Chronic stimulation of the GI tract with certain food ingredients (food antigens) can impair basic functions and potentially lead to chronic inflammation and greater permeability of the gut mucosa – also known as “leaky gut syndrome”. If the gut permeability is increased, undigested food ingredients leak through the intestines into the bloodstream. The body then recognizes these particles as foreign “invaders,” and the immune system attempts to fight them off, causing various autoimmune disorders.


Signs of IgG involvement in food intolerances have been described in several studies. Increased levels of IgG have been found in food-sensitive individuals, and the level returned to normal when the offending food was removed from the diet. Moreover, specific serum IgG has been reported in cases of celiac disease, dermatitis or atopic eczema, as well as in disease with increased intestinal permeability and inflammatory bowel disease (IBD).


According to recent studies, the assessment of allergen specific IgG and/or IgG4 antibodies can be helpful in identifying the cause of food intolerance.

FinTest™ concept

Fin Test

Assessment of food intolerance using the FinTest™ concept is based on the combination of three essential factors: (1) the diagnostic tool, (2) a laboratory which analyzes patient samples and (3) the nutritionist who gives individual diet advices according to the test result.


It is often difficult to identify the food that triggers the intolerance. Our FinTest™ intolerance tests help to overcome this difficulty: it is an excellent tool for assessing food intolerance by quantifying the body’s immune response. FinTest™ is a state-of-the-art blood test offering a rapid, sensitive and reliable method for detecting food-related IgG and IgG4 antibodies.


To establish the FinTest™ concept cycle worldwide, we are in search for laboratory partners and nutritionists who work with us to implement and maintain this concept. IBL International will provide our partners with comprehensive information and excellent support in the establishment of the FinTest™ concept.


To meet user requirements we are offering two product formats (1) FinTest™ Basic and (2) FinTest™ Flex in ELISA.


All assays are available for the quantitative determination of either whole IgG- or IgG4- antibodies in serum, plasma or capillary blood.


FinTest™ Basic

The basic tests are designed as introductory tests, and contain fixed allergen panels, allowing the screening of most common foods.


FinTest™ IgG Screen 24 ELISA – Screening of 3 patients against 24 allergens
FinTest™ IgG4 Screen 20 ELISA – Screening of 4 patients against 20 allergens
FinTest™ IgG Screen 88 ELISA – Screening of 1 patient against 88 allergens
FinTest™ IgG4 Screen 88 ELISA – Screening of 1 patient against 88 allergens
FinTest™ IgG4 Screen 7 ELISA – Screening of 12 patients against 7 allergens
FinTest™ IgG4 Screen 14 ELISA – Screening of 6 patients against 14 allergens
FinTest™ IgG4 Screen 90 ELISA – Screening of 1 patient against 90 allergens
FinTest™ IgG4 Screen 284 ELISA – Screening of 1 patient against 284 allergens


FinTest™ Flex

The flexible system features FinTest products which are available upon request and meets customer specific requirements such as region-specific food panel and the allergen number. FinTest™ Flex covers a range of more than 700 available food allergens, allowing the screening of up to 360 allergens (four plates). Depending on the number of allergens, the configuration of calibrators and controls can be flexible.


Food Groups

Technical specifications

Graphical evaluation of results

  • Quantitative (arbitary units) or "Classes"
  • "Classes" provide relative ranking of the IgG or IgG4 response (based on the IgE RAST classes)
  • Antibody titer is associated with complexity of symptoms
  • Graphical evaluation of results using a user friendly software


Graphical evauation of the result


Automated processing

  • IBL FinTests are adaptable on open systems (DSX, BEP 2000 and ETI-MAX 3000)
  • manuell vs. automated processing is well correlated


ELISA technology with ready-to-use reagents

Kit size
Test principle
Incubation time
Standard range
Sample Volume
Regulatory Status

12 x 8 (96) tests
Sandwich ELISA
2 x 1 h, 1 x 30 min.
0.35 - 100 U/mL
Serum, plasma and capillary blood
100 µL (pre-diluted)
PNPP 405 nm
CE marked

ELISA Principle