Secretory IgA (sIgA)
Secretory IgA is found in saliva in the mouth, throughout the gastrointestinal tract and in mucous secretions throughout the body. SIgA provides our first line of defence against bacteria, food residue, fungus, parasites and viruses. Low levels of SIgA make us more susceptible to infection and may be a fundamental cause of asthma, autoimmune conditions, coeliac, chronic infections, crohns, candidiasis, food intolerances and allergies, autism and other behavioural problems. Very high levels are found in people who have chronic infections and whose immune system is overloaded. Lifestyle and nutritional factors can also influence sIgA levels.
Chronic intestinal infections (due to bacterial, yeast or parasites), food sensitivities, aging, antibiotics, medication and stress all decrease sIgA levels.
sIgA is an important indicator of digestive immune function.Low levels can lead to recurrent infections and food intolerances. Very low levels of this important antibody class have also been observed in autistic spectrum disorders.
People with low SigA are susceptible to
- Pathogens in the GI tract
- There is a particularly high prevalence of low sIgA in coeliacs (5%)
- SigA imbalances may be associated with asthma, autoimmune disease, candidiasis, coeliac disease and food allergies
- Ulcerative colitis and Crohn’s all tend to have low sIgA. There is some evidence, that increasing the levels may help disease.
- Upper respiratory tract infections are common symptoms of low
- sIgA status
- High stress levels can suppress sIgA levels
- Periodontal disease is associated with imbalanced sIgA levels
- Chronic dermatological conditions
- High levels are found in patients with chronic and present infections
What can lead to Imbalanced Secretory IgA levels?
- Anti-inflammatory drugs
- Antibiotics
- Intestinal infections
- Intestinal bacteria and fungus
- Aging
- High alcohol intake
- Maldigestion and malabsorption
- Gastroenteritis
- Chemotherapy
- Food poisoning
- Poor diet
- High stress levels
SpecimenRequirements
1 x 2ml saliva
Before taking the test
Avoid immuno-suppressive medications for at least one week
Chemotherapy may interfere with test results
Do not stop taking prescriptive medication without the supervision of your doctor
See instructions inside test kit for details
Turnaround time
14 days
Buy SIgA Test UK & Europe
The Secretory IgA test is also available as part of our Comprehensive Adrenal Stress Index, this is because chronic stress can have a dramatic effect on Secretory IgA production.

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