A cocktail containing three bacteriophages successfully dealt with almost all tested strains of Escherichia coli without affecting beneficial intestinal microflora.

Scientists from the University of Copenhagen (Denmark) claim it will soon be possible to eliminate intestinal infections without harming the symbiotic human intestinal microflora (microbiota). They have tested a drug based on bacteriophages—viruses that specifically target bacteria.

To create conditions as close to physiological as possible, the authors developed a model that replicates the conditions of the small intestine. While such models typically simulate only the biochemistry of the process (pH, the effects of bile acids, and enzymes), this model includes an important factor: the intestinal microbiota. As is known, microorganisms living in the intestine play a significant role not only in digestion but also in other aspects of human life. An imbalance in intestinal microflora, particularly due to antibiotic use, can cause metabolic, immune, and other disorders.

In the experiment, pathogenic strains of E. coli were introduced into a small intestine model populated with intestinal microflora, and then a phage preparation specific against them (developed by Intralytix) was introduced.

Bacteriophages, under conditions simulating physiological ones, destroyed multiple strains of E. coli without affecting beneficial intestinal microflora. The next steps include animal testing of the phage preparation, followed by clinical trials.

Three bacteriophages (pink dots) were tested against a large collection of Escherichia coli strains of various serotypes. The combination of phages destroyed virtually all strains (infographic by Intralytix, Inc.)

* Cieplak T, Soffer N, Sulakvelidze A, and Nielsen DS. A bacteriophage cocktail targeting Escherichia coli reduces E. coli in simulated gut conditions, while preserving a non-targeted representative commensal normal microbiota // Gut Microbes, 2018. DOI: 10.1080/19490976.2018.1447291