H-D-Trp-OH

H-D-Trp-OH (D-Tryptophan) is the D-isomer of tryptophan, which is occasionally found in natural peptides, such as marine toxin peptides. H-D-Trp-OH can increase intestinal microbial diversity and counteract the inhibitory effect of allergic airway inflammation on intestinal microbial diversity^[1]. In Vitro: H-D-Trp-OH (D-Tryptophan) in probiotics affects the gut microbiota and allergic airway disease. Allergic airway inflammation reduces gut microbial diversity, while D-Tryptophan increases gut microbial diversity^[1]. In Vivo: H-D-Trp-OH (D-Tryptophan) (~0.09 or ~0.9 mg/day/mouse; p.o. in drinking water; 3 d) can prevent experimental asthma models in mice, increase the number of regulatory T cells in the lung and intestine, reduce lung TH2 responses, and improve allergic airway inflammation and hyperresponsiveness^[1].