Larch gum is a rich source of arabinogalactans, a type of fiber made of highly branched and high molecular weight non-starch polysaccharides. Arabinogalactans from larch are bound to galactose and arabinose sugar units. Arabinogalactan molecules are fermented in the gut by the microbiome, allowing the gut bacteria to cleave off the sugar side chains and create short-chain fatty acids (SCFAs). SCFAs are utilized as an energy source for the epithelial cells that line the lower gastrointestinal tract, as well as the liver. Preclinical studies have found that dietary larch arabinogalactans may also be incorporated into cell walls of neurons to protect sensitive brain tissue. In a study done on 199 healthy people over 6 months, Larch arabinogalactan (LAG) supplementation was shown to support wintertime wellness. In a study done on 49 healthy women, combination LAG and Echinacea supplementation was shown to increase complement properdin, an immune system regulator, by 18%. Study participants also noted improvements in overall physical health, emotional health and vitality. Supplementation of LAGs in 45 healthy adults before and after vaccination was shown to improve specific antibody count without influencing white blood cell counts in a pilot study, suggesting a supportive action of LAGs on the adaptive immune system. LAGs also act as a prebiotic for the microbiome, particularly the beneficial microbial species Bifidobacteria and Lactobacillus. Interestingly arabinogalactans have been showed to decrease the Clostridia class of bacteria which are associated with pathologies.