Larch Arabinogalactan

A soluble fiber and prebiotic polysaccharide from larch tree bark (Larix). One pediatric RCT (Grube 2006, ~200 children, 1.5 g/day) showed modest reductions in cold episodes over 12 weeks. Prebiotic effects (SCFA production) demonstrated primarily in vitro and animal models — human prebiotic data is weak. ImmunEnhancer (Lonza) is a branded larch arabinogalactan extract. FDA GRAS status as a dietary fiber. Evidence is limited — immune claims rest on a small number of trials.