Gastrointestinal dysfunction and loss of gut microbiome diversity have been associated with an increased risk of IgE allergy, leaky gut syndrome and sensitivities. Sensitivities are inappropriate immune responses to common environmental antigens such as foods or inhalants. As research into gut-mediated immune responses has progressed, non-IgE-mediated food reactions, or sensitivities, are now acknowledged. These food sensitivity reactions are all mediated, directly or indirectly, by IgA, IgG or IgG-immune complexes and complement activation. The management of IgE allergy is different than for food/inhalant sensitivities and both require a basic understanding of the hypersensitivity responses involved. The symptom profiles for IgE and IgG hypersensitivity are usually easy to distinguish, although some symptoms may overlap.
IgE symptoms may present as anaphylaxis (sudden sneezing, coughing or wheezing reaction, difficulty breathing, hives, swelling of lips, tongue, throat, sudden hypotension, sudden GI symptoms) or a less aggressive response; the keynote IgE symptom is consistency. The reaction happens consistently, within minutes to hours, every time food exposure occurs. IgE responses in children may be different, and include symptoms such as rectal bleeding, constipation, colic, dermatitis, chronic nasal congestion, or failure to thrive. IgE allergic responses may be moderated by dose or the presence of IgG4antibodies. IgG4 “competes” with IgE antibodies to block their enzyme activity or protein-protein interactions that cause allergic reactions. IgG4 levels can increase when there is prolonged, chronic exposure to high levels of protein antigens, providing some protection against IgE hypersensitivity. It is important to evaluate both IgE and IgG4 in allergic patients, and it is essential that patients strictly avoid foods that induce allergic reactions.
IgG symptoms are different. Symptoms develop over time and may not become apparent until 1-3 days after a food is eaten, or symptoms may be chronic if a food is eaten frequently. IgG sensitivity to foods may contribute to chronic inflammation, either locally or via systemic symptoms such as autoimmune conditions, migraine, skin rashes, asthma, or fatigue, irritability, nervousness, or gastrointestinal symptoms (indigestion, gas, abdominal cramps or bloating). The keynote symptoms here are delayed response and chronicity of symptoms. Food intolerance (sensitivity) may be a symptom of digestive disorders, genetic enzyme deficiencies, gut microbiome imbalances, as well as the result of IgG or other non-IgE mediated immune responses.
Allergy or sensitivity reactions in the gastrointestinal system can result in local inflammation and loss of gut barrier functions. The gut mucosa and the immune system may be further influenced by diet and nutrition, and the gut-associated lymphoid tissue (GALT) system uses essential dietary components (such as lipids and vitamins) as modulatory molecules to maintain the gut mucosa and maintain immune tolerance. Some essential vitamins and compounds, such as B-vitamins and short-chain fatty acids, are produced in the gut by bacteria in the gut microbiome. A loss of diversity in the gut microbiome may result in a shortage of essential nutrients and anti-inflammatory signaling molecules.
Knowledgeable clinicians can employ a series of steps to manage both food sensitivity and inhalant allergies, improve tolerance, and provide patient relief:
US BioTek’s stool testing may be used to evaluate digestion, absorption, and microbiome diversity. Based upon the results of a GI profile, a clinician may choose to improve diet quality and/or provide nutritional support. Action steps may include:
Gastrointestinal dysfunction and loss of gut microbiome diversity induce proinflammatory changes in the gut mucosal lining and immune reactivity. These changes increase the risk of IgE allergy, IgG or IgA food sensitivity, and compromise gut barrier functions. IgE allergy, IgA and IgG sensitivity and stool testing can provide guidance for therapeutic interventions to restore gut homeostasis and immune tolerance required for health and wellness.
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