14/10/2026
Secretory IgA (sIgA) is an antibody that helps protect the intestinal lining, supports immune tolerance and prevents unwanted microbes from attaching to the gut wall.
3 POSSIBLE CONTRIBUTING FACTORS
Chronic stress: Prolonged stress may alter gut immune signalling and mucosal immunity.
Nutritional deficiencies: Inadequate protein, zinc and vitamin A can compromise normal immune function.
Dysbiosis: Changes in gut bacteria, infections and intestinal inflammation may influence sIgA levels.
🚩 POSSIBLE ASSOCIATED SYMPTOMS
Low stool sIgA doesn’t cause a specific set of symptoms, but some people may experience:
• Bloating and abdominal discomfort
• Constipation or diarrhoea
• Food-related digestive discomfort
• Recurrent gastrointestinal infections
HOW CAN WE CAN IMPROVE sIgA WITH DIET?
Vitamin A (700–900 µg/day): Supports intestinal IgA production. Found in sweet potato, carrots and eggs.
Zinc (8–14 mg/day): Essential for immune function. Found in oysters, beef and pumpkin seeds.
Protein (at least 0.8 g/kg/day): Provides amino acids required for antibody production. Include eggs, fish, tofu and legumes.
Prebiotic fibre: Nourishes beneficial gut bacteria. Include oats, garlic, onions, legumes and green bananas.
Polyphenols: Berries, pomegranate, cocoa and green tea provide plant compounds that interact with gut microbes.
SUPPLEMENTS WORTH CONSIDERING
• Probiotics: Certain strains, including B. lactis Bb-12, have shown promising effects on faecal IgA.
• PHGG: A prebiotic fibre that supports beneficial gut bacteria.
• Zinc & vitamin A: May be beneficial when intake or status is inadequate.
• Saccharomyces boulardii: Research suggests that this beneficial yeast may stimulate mucosal immune responses and intestinal sIgA production.