Giardia is a neglected parasite that produces diarrhea and different degrees of malabsorption. The drugs used for treatment (such as 5-nitroimidazoles, benzimidazoles, nitrofuranes, acridine and nitrotiazoles) produce undesirable secondary effects including genetic damage and the selection of resistant strains(1). A fraction of oregano was tested against two strains of Giardia. In-vitro testing demonstrated it to be effective against both strains (G. duodenalis, G lamblia). Another study using a patented, emulsified oil of oregano in a sustained release formula was shown to be effective for intestinal parasites including Blastocystis hominis, Entamoeba hartmanni and Endolimax nana(2). Of the 14 participants who tested positive at the beginning of the trial, 10 tested negative, and 3 showed significant reduction following 6 weeks of oral supplementation. In a separate trial of patients testing positive for H. pylori, 39 participants completed a full 2-week course of treatment of a combination of supplements which included oil of oregano (same patented product as previously mentioned), mastic gum and bismuth(3). Follow-up testing demonstrated eradication of H. pylori in 29 (73.4%) of participants. All successfully treated patients also showed improvement in their presenting symptoms of dyspepsia or irritable-bowel type symptoms.
1. Rufino-Gonzalez Y, et al. In vitro activity of the F-6 fraction of oregano against Giardia intestinalis. Parasitjology. 2012 Apr; 139(4):434 40.
2. Mark Force, William Sparks and Robert Ronzio. Inhibition of Enteric Parasites by Emulsified Oil of Oregano in vivo. Phytotherapy Research 14, 213-214 (2000).
3. Liponis M, Geyer C, and Hubkova T. Successful Eradication of Helicobacter pylori with over-the-counter Products; An observational study of 39 patients treated with 3 nonprescription remedies. Natural Medicine Journal May 2015 Vol. 7 Issue 5