Probiotic products typically take the form of oral supplements or food-based products containing microorganisms, typically bacteria. The number of bacteria present in a dose of probiotic can be several orders of magnitude lower than the label claims, and in some cases, undetectable. The objective of this study was to assess probiotic products containing Escherichia coli to verify manufacturer claims, which have not yet been independently assessed, regarding the number of viable E. coli per suggested dose. It was found that the products tested contained E. coli in numbers several orders of magnitude less than claimed, and when subjected to simulated stomach conditions, the number of viable E. coli was significantly reduced.
Keywords: Escherichia coli; live biotherapeutics; probiotics; viable cell counts.