Arabinogalactan (from Larix spp. wood)

Arabinogalactans are a class of long, densely branched high-molecular weight polysaccharides extracted for commercial uses from the bark of the Eastern and Western Larch trees, Larix larcinia and Larix occidentalis. Their monosaccharide constituents include galactose, arabinose, glucose and mannose 1. Larch arabinogalactans are considered a good source of prebiotic soluble dietary fiber 2,3. Small amounts of arabinogalactans can be found in some food plants, including corn, carrots, tomatoes, pears, wheat and red wine 4.

A human double-blind, placebo-controlled trial indicates that intake of 1.5 grams of a larch arabinogalactan can enhance the antigenic response to a bacterial (tetanus) and viral (flu) challenges in healthy subjects 5. Both Ambrotose powders provide > 1.5 grams of this larch arabinogalactan/day.  Two human double-blind, placebo-controlled trials indicated that higher doses of  this arabinogalactan (4.5 grams) can enhance the response to a bacterial (pneumococcal) challenge 6,7.

Larch arabinogalactans are approved by the U.S. Food and Drug Administration (FDA) as generally recognized as safe (GRAS) (21CFR172.610).

This ingredient can be found in the following products in United States:


  1. Luta G, Duncan C, Sinnott R. Chemical characterization of polysaccharide-rich ingredients from Aloe vera, Larix laricina and Larix occidentalis, and Undaria pinnatifida. Presented at the Scripps Center for Integrative Medicine's 6th Annual Natural Supplements Conference, San Diego, California.January 22-25, 2009. 2009.
  2. Crociani F, Alessandrini A, Mucci MM, Biavati B. Degradation of complex carbohydrates by Bifidobacterium spp. Int J Food Microbiol 1994;24:199-210.
  3. Kelly GS. 'Larch arabinogalactan: clinical relevance of a novel immune-enhancing polysaccharide. Altern.Med Rev 1999;4:96-103.
  4. Cui SW. Polysaccharide Gums from Agricultural Products: Processing, Structures & Functionality. Lancaster, Pa.: Technomic Publishing Co., Inc., 2001.
  5. Udani JK. Immunomodulatory effects of ResistAid: A randomized, double-blind, placebo-controlled, multidose study. J Am Coll Nutr 2013;32:331-8.
  6. Udani JK, Singh BB, Barrett ML, Singh VJ. Proprietary arabinogalactan extract increases antibody response to the pneumonia vaccine: a randomized, double-blind, placebo-controlled, pilot study in healthy volunteers. Nutr J 2010;9:1-7.
  7. Riede L, Grube B, Gruenwald J. Larch arabinogalactan effects on reducing incidence of upper respiratory infections. Curr Med Res Opin 2013;29:251-8.