Insights from 100 Years of Research with Probiotic E. Coli

Summary

Abstract A century ago, Alfred Nissle discovered that intentional intake of particular strains of Escherichia coli could treat patients suffering from infectious diseases. Since then, one of these strains became the most frequently used probiotic E. coli in research and was applied to a variety of human conditions. Here, properties of that E. coli Nissle 1917 strain are compared with other commercially available E. coli probiotic strains, with emphasis on their human applications. A literature search formed the basis of a summary of research findings reported for the probiotics Mutaflor, Symbioflor 2, and Colinfant. The closest relatives of the strains in these products are presented, and their genetic content, including the presence of virulence, genes is discussed. A similarity to pathogenic strains causing urinary tract infections is noticeable. Historic trends in research of probiotics treatment for particular human conditions are identified. The future of probiotic E. coli may lay in what Alfred Nissle originally discovered: to treat gastrointestinal infections, which nowadays are often caused by antibiotic-resistant pathogens. Keywords: probiotics, Escherichia coli, Nissle, Symbioflor, human studies, applicationsIntroduction Many probiotic products are based on particular strains of lactic acid bacteria, such as Lactobaccillus and Lactococcus species (both Firmicutes) or Bifidobacterium species (belonging to the Actinobacteria). Other genera of bacteria (and even yeast species) are also used for probiotic applications, including Escherichia coli, a member of the Gammaproteobacteria. This working horse of bacteriology is not only the most frequently studied bacterial species on the planet but also a rather complicated one, since it includes both commensal and pathogenic strains whose genomes can widely vary in size and gene content [1]. That E. coli is chosen as a probiotic would be in line with its presumed ubiquitous presence in the gut. But how often is E. c...