John Haran

John Haran, MD, PhD, is an Associate Professor of Emergency Medicine at UMass Chan Medical School's T.H. Chan School of Medicine, with cross-appointments in Microbiology and Biomedical Sciences. His research focuses on the microbiota-gut-brain axis and drug-resistant pathogens, particularly in relation to Alzheimer's disease, long-COVID, and post-traumatic neurological disorders. He leads NIH-funded studies on gut microbiome-immune-cognition interactions in aging populations and directs the Center for Microbiome Research's antimicrobial stewardship initiatives to reduce hospital-acquired infections.

• Education: BS in Biochemistry & Biophysics (Rensselaer Polytechnic Institute), MD and PhD in Biomedical Sciences (University of Massachusetts Medical School)
• Appointments: Associate Professor of Emergency Medicine, Associate Professor in Microbiology & Physiological Systems, Associate Clinical Director of the Center for Microbiome Research

His research spans three core domains:
1. Microbiota-gut-brain axis - linking dysbiosis to Alzheimer's progression, long-COVID, and post-trauma cognition
2. Antimicrobial stewardship - reducing C. difficile and MDR transmission in hospitals and nursing homes
3. Neuroimmune trauma - mapping neural circuits associated with PTSD and depression via AURORA study's multimodal data

Key trends in his publications include:
- 2023-2025: machine learning applications for PTSD prediction
- 2021-2025: gut-brain axis studies connecting microbial metabolites to brain function
- 2018-2025: antibiotic misuse analyses in emergency settings

Through the Antimicrobial Stewardship Taskforce, he implemented protocols reducing vancomycin overuse for skin infections. His research clinic enrolls longitudinal cohorts of elders with cognitive issues to develop microbiome-targeted therapies, and he collaborates with CDC on healthcare worker infection risks during pandemics.