Irritable bowel syndrome (IBS) can result from alteration of the gastrointestinal microbiota as well as from small intestinal bacterial overgrowth. An in vitro study investigated the potential of different medicinal herbs as treatments for IBS. The antibacterial activity of the essential oils of culinary and medicinal herbs were measured by testing their ability to inhibit E. coli growth. Peppermint, lemon balm and coriander seed oils proved to be the most potent. Peppermint and coriander seed oils also proved to be more potent than the antibiotic rifaximin.
Thompson et al. Comparison of the antibacterial activity of essential oils and extracts of medicinal and culinary herbs to investigate potential new treatments for irritable bowel syndrome. BMC Complement Altern Med Nov 2013.