The human intestines play host to an enormous variety of bacteria and fungi. Most of these are harmless or even helpful. However, other microscopic organisms can also take up residence in the intestines. Such organisms are called intestinal parasites.
Common parasites include amoebas (especially Entamoeba histolytica), cryptosporidium, giardia ( Giardia lamblia), hookworm ( Ancylostoma duodenale and Necator americanus), pinworm ( Enterobius vermicularis), roundworm ( Ascaris lumbricoides), and tapeworm ( Taenia species).
Intestinal parasites can cause a wide variety of symptoms, including gas, bloating, diarrhea, abdominal cramping, bloody stools, itching in the anus, weight loss, and many others. Some parasites are no more than a nuisance, while others can cause serious disease and even death.
Conventional treatment for parasites begins with careful identification of the particular parasite involved, followed by the use of medications capable of destroying the infestation. Careful attention to hygiene while camping or traveling in developing countries can help prevent future infections with parasites.
Intestinal parasites are hardy organisms not easily killed. Traditional remedies used for parasites are generally fairly toxic. Until recently, conventional treatments for parasites were also quite toxic. However, now that safe drugs have been developed, it can be said as a general rule that conventional therapies for parasites are less toxic and almost certainly more effective than natural remedies.
Despite this, many natural products are marketed for the treatment of parasites. The profusion of such offerings is due primarily to a particular current of thought among some alternative practitioners that states that parasites are the underlying cause of many illnesses. Most such natural products are made of herbs that kill parasites in the test tube. However, it is a long way from a test tube study to meaningful effects in humans, and there is no reliable meaningful evidence that any of these natural therapies are useful in a practical sense. Some herbs commonly mentioned for the treatment of parasitic infections include anise, black walnut fruit, cloves, curled mint, essential oils, garlic, gentian, grapefruit seed extract, lapacho, neem, olive leaf, oregano, propolis, pumpkin seed, sweet Annie, tansy, Terminalia arjuna, thyme, wormseed, and wormwood.
The substance berberine has shown some promise for the treatment of parasites, and it was, for a time, evaluated as a potential new anti-parasitic drug.1-4 Berberine is found in barberry, goldenseal, goldenthread, Oregon grape, and other herbs, and for this reason these herbs are commonly mentioned as useful for the treatment of parasitic infections. However, the only studies relevant to these herbs used purified chemical berberine. To obtain the same amount of berberine in the form of an herb, you would have to consume massive (and possibly toxic) quantities.
One placebo-controlled study conducted in Africa concluded that use of dried papaya seeds could reduce levels of intestinal parasites generally.5 However, this study suffered from significant problems in design and reporting. Note: The form of papaya used in this trial was not equivalent to the digestive enzyme papain.
1. Kaneda Y. In vitro effects of berberine sulphate on the growth and structure of Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis. Ann Trop Med Parasitol. 1991;85:417-425.
2. Soffar SA, Metwali DM, Abdel-Aziz SS, et al. Evaluation of the effect of a plant alkaloid (berberine derived from Berberis aristata) on Trichomonas vaginalis in vitro. J Egypt Soc Parasitol. 2001;31:893-904.
3. Gupte S. Use of berberine in treatment of giardiasis. Am J Dis Child. 1975;129:866.
4. Choudhry VP, Sabir M, Bhide VN. Berberine in giardiasis. Indian Pediatr. 1972;9:143-146.
5. Okeniyi JA, Ogunlesi TA, Oyelami OA, et al. Effectiveness of dried carica papaya seeds against human intestinal parasitosis: a pilot study. J Med Food. 2007;10:194-196.
Last reviewed December 2015 by EBSCO CAM Review Board
Last Updated: 12/15/2015