Phage Therapy in Gastrointestinal Diseases

Gastrointestinal tract microbiota plays a key role in the regulation of the pathogenesis of several gastrointestinal diseases. In particular, the viral fraction, composed essentially of bacteriophages, influences homeostasis by exerting a selective pressure on the bacterial communities living in the tract. Gastrointestinal inflammatory diseases are mainly induced by bacteria, and have risen due to the emergence of antibiotic resistant strains. In the lack of effective treatments, phage therapy has been proposed as a clinical alternative to restore intestinal eubiosis, thanks to its immunomodulatory and bactericidal effect against bacterial pathogens, such as Clostridioides difficile in ulcerative colitis and invasive adherent Escherichia coli in Crohn's disease. In addition, genetically modified temperate phages could be used to suppress the transcription of bacterial virulence factors. In this review, we will highlight the latest advances in research in the field, as well as the clinical trials based on phage therapy in the area of gastroenterology.