Wheat germ agglutinin (WGA) is a lectin found in wheat that binds to N-acetylglucosamine and sialic acid residues on cell surfaces. It is a component of wheat's natural defense system against predators and can affect gut barrier function and immune responses in humans.
WGA binds to glycoproteins on intestinal epithelial cells, particularly targeting sialic acid residues (Neu5Ac). This binding can disrupt tight junctions, increase intestinal permeability, and trigger inflammatory responses. WGA also binds to immune cell receptors and can cross the gut barrier to reach systemic circulation, potentially affecting distant tissues. Unlike gliadin, WGA is heat-stable and resistant to digestive enzymes.
WGA represents one mechanism by which wheat consumption may increase gut permeability and contribute to systemic inflammation, even in individuals without celiac disease. As part of the lectins and antinutrients in grains, WGA contributes to non-celiac gluten sensitivity and may trigger immune responses. Understanding WGA helps explain why grain elimination benefits many patients with autoimmune conditions and chronic inflammation.
- Lectin found in wheat germ
- Binds to N-acetylglucosamine and sialic acid (Neu5Ac) on cell surfaces
- Heat-stable and resistant to digestive enzymes unlike many proteins
- Can increase intestinal permeability by disrupting tight junctions
- Crosses gut barrier and reaches systemic circulation
- May bind to immune cell receptors and trigger inflammatory responses
- Part of wheat's natural defense system against predators
- Contributes to non-celiac gluten sensitivity mechanisms
- Lectins — WGA is a specific type of lectin found in wheat
- Neu5Ac — WGA binds to sialic acid (Neu5Ac) residues on cell surfaces
- Zonulin — WGA can increase zonulin release, opening tight junctions
- gut permeability — WGA binding to epithelial cells increases intestinal permeability
- Gliadin — both are wheat components that affect gut barrier; WGA is more resistant to digestion
- Gluten sensitivity — WGA contributes to non-celiac gluten sensitivity mechanisms
- Non-celiac gluten sensitivity — WGA is one mechanism explaining symptoms in NCGS patients
- Tight junctions — WGA disrupts tight junction proteins to increase permeability
- gut barrier — WGA crosses and damages the intestinal barrier
- immune system — WGA can bind immune cell receptors and trigger inflammatory responses
- inflammation — systemic WGA may contribute to low-grade inflammation
- Autoimmunity — barrier disruption from WGA may facilitate autoimmune responses
- Coeliac disease — WGA effects are distinct from but may compound gluten-mediated damage in celiac
- Haptoglobin polymorphism — related concept in module 1 involving protein binding and immune effects
- CXCR3 — chemokine receptor potentially affected by WGA-induced inflammation
- sialic acid — WGA specifically binds sialic acid residues on glycoproteins
- Antinutrients in Grains and Legumes — WGA is one of several antinutrients in grains affecting human health
- gut dysbiosis — WGA-induced barrier damage may contribute to dysbiosis
- systemic inflammation — circulating WGA may trigger distant tissue inflammatory responses
- Food sensitivities — WGA is a mechanism underlying wheat sensitivity beyond celiac disease