Larch arabinogalactan (LA) is a branched polysaccharide from Western larch tree wood (Larix occidentalis). Our research shows it functions as both a prebiotic fiber (increases Bifidobacterium and Lactobacillus) and an immune stimulant (enhances NK cell cytotoxicity). A 2013 study found 4.5g/day LA increased IgG antibody response to pneumococcal vaccine by 53% — a meaningful immune enhancement. It's FDA GRAS, dissolves completely in water with no taste, and has excellent GI tolerance (less bloating than inulin). The dual prebiotic + immune mechanism makes it unique among fibers.
Larch arabinogalactan: (1) Prebiotic fermentation — gut bacteria (particularly Bifidobacterium) ferment arabinogalactan to SCFAs (butyrate, propionate, acetate), promoting beneficial microbiome composition; (2) Complement activation — LA activates the complement system via the alternative pathway, enhancing opsonization and pathogen clearance; (3) Macrophage activation — LA binds to macrophage surface receptors, stimulating phagocytosis and cytokine production (IL-1, IL-6, TNF-α); (4) NK cell enhancement — increases NK cell cytotoxicity (mechanism not fully elucidated — may involve macrophage-derived cytokines that activate NK cells); (5) IgG enhancement — improves antibody response to vaccination.
No significant drug interactions identified. LA is a dietary fiber with low systemic absorption.
Reviewed by the Scan Dose Research Team and Clinical Advisory Board | Last updated:
Not medical advice. Based on published clinical research and systematic reviews.