According to NCCAM, there are nine known species of echinacea, all of which are native to the United States and southern Canada. The most commonly used, Echinacea purpurea, is believed to offer the most health benefits. The common names include echinacea, purple coneflower, coneflower, American coneflower.
Echinacea has traditionally been used to treat or prevent colds, flu and other
infections. Echinacea is believed to stimulate the immune system to help fight infections. Echinacea is thought to benefit people suffered from skin issues, such as acene or boils, and wounds. [NCCAM]
Bacteroides fragilis, an opportunistic pathogen, is a commensal organism in the large intestine, where it utilizes both dietary and host-derived polysaccharides as a source of carbon and energy. [x2]
Recently Jerald C. Foote, assistant professor at University of Arkansas claimed an increase in bacteria in the gastrointestinal tract linked to intake of echinacea supplement. The increase in amount of certain bacteria such as Bacteroides fragilis may contribute to inflammatory bowel disease and diarrhea. [X1]
References
[NCCAM] NCCAM Publication No D271 July 2005. [x1] Study connects echinacea, tract bacteria AP December 20, 2006. [x2]Spence C et al, Characterization of the primary starch utilization operon in the obligate anaerobe Bacteroides fragilis: Regulation by carbon source and oxygen. J Bacteriol. 2006 Jul;188(13):4663-72
