Necrotizing enterocolitis (NEC) destroys the intestines of premature babies, and survivors often face lasting brain damage. National Institute of Health’s Eunice Kennedy Shriver National Institute of Child Health and Human Development director Diana Bianchi has stated, “It is estimated that one infant in the United States dies almost every day from NEC.”

On October 28, 2026, the NLM indexed a report that describes the condition as “the most devastating gastrointestinal emergency in preterm infants, frequently causing mortality and long-term neurodevelopmental impairment.” First published by Nature, the study connected to the report finally names the culprit for that condition that has puzzled doctors for decades: Delta toxin, made by certain strains of the common gut bacterium Clostridium perfringens.

In this study, stool from infants with severe or fatal NEC was loaded with Delta-toxin-carrying strains. In mice, the toxin alone reproduced the disease, with no other stressors required. Delta toxin hunts macrophages, the immune system’s cleanup cells, and makes them rupture within an hour. The resulting inflammatory flood pries open the blood-brain barrier. While the toxin never reaches the brain itself, brain injury “is probably driven by systemic inflammation rather than direct brain toxin accumulation,” the authors write. Furthermore, the NLM-report concludes that, “these findings suggest that a subset of NEC is a specific-toxin-mediated disorder and validates the Delta toxin-CD9 axis as a therapeutic target for this subset.”