Abstract
Lactobacillus reuteri resides in the gastrointestinal ecosystem of humans and other animals. In an earlier report we showed that this enteric species converts glycerol into reuterin—a substance with broad-spectrum antibacterial activity. In this report we show that reuterin also has antimycotic and antiprotozoal activity. A minimum inhibitory concentration (MIC) assay was developed and used to study the conditions under which reuterin is synthesised. The results show reuterin to be synthesised in vitro under pH, temperature and relative anaerobic conditions similar to those believed to exist in the regions of the gastrointestinal ecosystem inhabited by L.reuteri. It was also demonstrated that L.reuteri cells are stimulated to produce reuterin when permitted to interact directly with a variety of other microorganisms. A symbiotic relationship between L.reuteri and its host is postulated and discussed.