Mathematical Modeling and Analysis of Probiotic Bacteria
by
Hedia Fgaier
Department of Mathematics and Statistics, University of Guelph
Coauthors: H.J. Eberl

Microorganisms inhabit the gastrointestinal tract (GIT) and have adapted by having individual growth niches so that the concentration of each species is fairly consistent. In order for the intestine to function properly, this balance of microbial flora must be maintained. However, a number of factors in modern life, such as increased stress and the consumption of pharmaceutical compounds (e.g. antibiotics), have contributed to shifting this microbial balance away from its optimal levels and towards an increase in harmful pathogenic microorganisms. The introduction of probiotics has been recommended as a preventive approach to maintaining a normal balance and thereby enhance 'well-being'. Probiotics are living microorganisms which have beneficial effects and which can promote good health. These beneficial effects include the protection against pathogenic microorganisms, viruses and carcinogens, stimulation of the immune system, enhanced disease resistance, correction of some bowel diseases, and reduced allergic diseases.

Probiotics have been consumed as functional foods and nutraceuticals for several decades, most notably together with dairy products. There has been recently a resurgence of interest in the potential of probiotics for medical and clinical purposes. Several factors prompted this development, but the most significant is the surging level of multi-drug resistance among pathogens in hospitals. This has been accompanied by an increasing emergence of scientific and clinical evidence for the efficacy and effectiveness of some probiotic strains

In this presentation, several models that can describe the population dynamics of microbial systems and which also take into account the mechanism of probiotic activity are presented. The models are based on qualitative and phenomenological descriptions of microbial actions and interactions. The use of the models as tools for screening and for optimal dosing strategies of probiotic bacteria will be illustrated on a number of case studies.

Date received: June 29, 2008