Immune reconstitution after hematopoietic cell transplantation promotes intestinal microbiome recovery in chronic granulomatous disease[
People born with Chronic Granulomatous Disease (CGD) lack critical immune defenses, frequently causing severe bacterial/fungal infections and painful chronic bowel inflammation. A stem cell transplant (HCT) replaces the faulty immune system with healthy donor cells, but little was known about how the gut's trillions of beneficial microbes recover after such an intensive treatment. By analyzing stool samples from 78 patients with CGD before and up to several years after transplantation, this study demonstrates that while transplant treatments initially disrupt gut bacteria, immune system recovery enables the gut microbiome to rebuild itself. Within 1 to 2 years post-transplant, patients regained healthy microbial diversity and key beneficial gut bacteria, coinciding with a reduction in gut inflammatory signals. This research highlights how restoring a healthy immune system helps re-establish a balanced gut microbiome and relieve chronic gut disease.