Gastric administration of garlic powder containing the trpa1‐ agonist allicin induces specific epigastric symptoms and gastric relaxation in healthy subjects

Background TRPA1 is an excitatory ion channel and is involved in sensory processes including thermal nociception and inflammatory pain. The allicin in garlic is a strong activator of the TRPA1 channel. Aim To evaluate the effect of intragastric garlic powder containing allicin on perception, gastric tone, and mechanosensitivity. Methods An infusion‐barostat balloon assembly was used for infusion of test solutions, for distension, and to measure proximal gastric compliance and tone. After an initial open label dose finding with 1 g, 2 g, 3.75 g, and 7.5 g commercially available garlic powder, a bolus of 2 g garlic powder (11 mg allicin)/60 mL H2O was considered to induce moderate but constant sensation and was used hereafter in a placebo‐controlled, single‐dose, double‐blind, randomized study in 7 volunteers to evaluate gastric sensation, tone, and mechanosensitivity. Key Results Bolus injection of garlic caused immediate epigastric symptoms, mean aggregate symptom scores (AUC in 15 minutes) were 106 ± 49 vs. 35 ± 30 after placebo (P = 0.01). Garlic induced significant epigastric pressure, stinging, and warmth (P 0.05). Garlic induced an immediate, short lived fundic relaxation (balloon volume 627 ± 349 mL vs. −145 ± 120 mL; P