One bacterial toxin can push preterm gut injury toward brain injury

A Nature study found Delta-toxin-positive Clostridium perfringens in the gut microbiome of severe and fatal necrotizing enterocolitis cases. Experiments show that Delta toxin uses the host CD9 receptor to preferentially attack macrophages, activate inflammasomes and pyroptosis, amplify systemic inflammation, disrupt the blood–brain barrier and drive neuroinflammation. The toxin itself was not detected in the brain, suggesting remote injury through the immune response. In mice, removing CD9 from myeloid cells or giving a neutralizing antibody improved survival and reduced intestinal, brain and lung damage. The result suggests that a subset of preterm-infant NEC may be driven by one specific toxin and identifies the Delta-toxin–CD9 axis as a treatment target. Evidence still comes mainly from associated clinical samples, cells and mouse models; prevalence, diagnostic testing, human safety and antibody efficacy require multicentre clinical research.