Salmonella, a member of the Enterobacteriaceae family, is one of the leading causes of foodborne illness worldwide. Although the human body can usually fight off salmonella infections on its own, sometimes this is not the case, requiring treatment with antimicrobials. Due to the global spread of antibiotic-resistant salmonella strains, the search for new, effective treatments for salmonellosis is urgent.

There is currently insufficient data on how a normally balanced human intestinal microflora (microbiota) responds to Salmonella infection. Swedish scientists investigated* this question and also compared two treatment regimens for Salmonella infection: one using bacteriophages and the other using antibiotics.

They cultivated human intestinal microflora (ACHIM) under anaerobic conditions and used it as a model for in vitro experiments. When simulating a Salmonella infection, the authors observed that ACHIM alone could significantly reduce the number of pathogenic bacteria. The addition of bacteriophages or antibiotics further inhibited the growth of pathogenic Salmonella. However, non-target bacteria—normal components of the intestinal microbiota—were significantly less affected by the use of bacteriophages than by antibiotics.

An antibiotic to which the bacterium causing intestinal disease is resistant can destroy a significant portion of a person's normal microbiota without affecting the pathogen. This "treatment" significantly worsens the situation, as normal intestinal microflora itself is a defense against infections, and its disruption affects not only the digestive system but also other body systems.

Thus, according to the authors, treatment of salmonella infection with bacteriophages is highly specific and, unlike antibiotic therapy, does not disturb the balance of intestinal microbiota.

* Hu YOO, Hugerth LW, Bengtsson C, Alisjahbana A, Seifert M, Kamal A, Sjöling Å, Midtvedt T, Norin E, Du J, Engstrand L. 2018. Bacteriophages synergize with the gut microbial community to combat Salmonella. mSystems 3: e00119-18. https://doi.org/10.1128/mSystems.00119-18 .