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Alexa Johnson headshot
Fellowship Start Year



First Year

Research Topic

Early-life interventions on modulating the microbiome to improve health and reduce methane emissions in dairy cattle, and understanding the role of the gut microbiome in equine health and welfare.


Alexa Johnson

School of Veterinary Medicine


Alexa Johnson is a Postdoctoral Fellow in the Agricultural Systems and Microbial Genomics Laboratory at the University of Pennsylvania Veterinary School of Medicine. She holds a PhD in Animal and Food Science from University of Delaware and received other degrees from the University of California, Davis. Her research has focused on utilizing dairy cattle and equine phenotypes to identify unique gastrointestinal microbial populations and microbial activities by combining anerobic culture methods with next generation sequencing technologies.

Postdoc Appointment

Center, Lab, or Institute
  • Center for Stewardship Agricultural and Food Security
Penn Faculty Mentor
  • Dipti Pitta, Ph.D.


  • 2023, Ph.D., Equine Microbiology, University of Delaware
  • 2018, M.S., Animal Biology, The University of California, Davis
  • 2016, B.S., Animal Science with Equine Emphasis, The University of California, Davis
Disertation Title

A Comparative Evaluation of the Microbiome Effects of Easy and Hard Keeper Horses

Research Advisors
  • Amy Biddle, Ph.D.