A new study from Ben-Gurion University of the Negev (BGU) has revealed that damage to blood stem cells caused by long-term Salmonella infections is completely reversible with a course of antibiotics.
The research, published in Cell Reports, shows that giving an effective course of antibiotics fully restores the stem cells, allowing them to recover their health and rebuilding power. The study was led by Professor Roi Gazit and Dr Ofir Cohen from BGU’s Shraga Segal Department of Microbiology, Immunology, and Genetics in the Faculty of Health Sciences.
While short-term infections are known to temporarily disrupt blood production, the impact of a permanent, chronic bacterial illness on adult stem cells has been difficult to study. Using a long-term model of Salmonella, the BGU research team found that a persistent infection causes severe full-body stress, including weight loss and a heavily enlarged spleen as the body fights the bacteria. Shown above is a colour-enhanced scanning electron micrograph showing Salmonella Typhimurium (red) invading cultured human cells.
Most importantly, the researchers discovered that just 14 days after infection, the blood stem cells lost almost all of their biological potency. When transplanted, these ‘sick’ stem cells were completely unable to rebuild a healthy blood system or take root in a new host.
To understand exactly what went wrong inside the bone marrow, the team used advanced single-cell genetic mapping to look at the stem cells one by one. In a healthy body, over 90% of blood stem cells stay dormant, protecting them from genetic wear and tear.
The genetic mapping revealed that chronic Salmonella forces these cells into a dangerous spiral:
- Forced into overdrive: the infection aggressively wakes up the sleeping stem cells, forcing them into a constant, exhausted cycle of dividing and duplicating
- Imbalanced output: the stressed stem cells become heavily biased, pumping out specific inflammatory white blood cells at the expense of a balanced, healthy blood supply
- Inflammatory distress: the cells' internal genes become flooded with signals linked to severe stress, inflammation, and cellular distress.
The most promising part of the discovery is how quickly and completely the bone marrow can heal once the bacteria is cleared. When the chronic infection was treated with a curative course of antibiotics, the body recovered rapidly: weight returned to normal and enlarged spleens shrank back to their proper size.
Deep inside the bone marrow, the genetic mapping confirmed that the antibiotics successfully wiped away the damage signals. The hyperactive, exhausted stem cells calmed down at once and retreated back into their safe, dormant state. Laboratory tests verified that these cured stem cells completely regained their health, rebuilding blood and immune systems just as effectively as cells that had never been sick.
"Our findings introduce an important new rule for bone marrow transplants: cure the donor's infection and let the stem cells rest before trying to transplant them," the authors note. "By proving that adult stem cells can fully bounce back even after a severe, long-term bacterial challenge, this research highlights how critical it is to check a donor's immune health to guarantee a successful transplant".
- Elfassy E, Koren O, Likhterov P, Thapa R, Cohen O, Gazit R. Reversible loss of hematopoietic stem cells transplant potency by chronic Salmonella infection. Cell Rep. 2026;45(6):117474. 10.1016/j.celrep.2026.117474)