Christian John Lillis is a nationally recognized patient advocate, policy strategist, and expert on C. diff (Clostridioides difficile) infection. He is the co-founder and CEO of the Peggy Lillis Foundation for C. Diff Education and Advocacy, which he and his brother, Liam, established in 2010 following the death of their mother, Peggy Lillis, from a C. diff infection. Over 16 years, he has built PLF into the country's only national CDI patient advocacy organization: a community of patients, caregivers, clinicians, and policy leaders working to prevent C. diff deaths and transform care for those affected.

Christian is the primary driver of named CDI federal legislation introduced in the last Congress. He has testified before Congress and presented to the Presidential Advisory Council on Combating Antibiotic-Resistant Bacteria. His work has been recognized with the CDC Excellence in Partnership Award. He has co-authored peer-reviewed publications in the American Journal of Gastroenterology and Advances in Therapy, and has been covered in Consumer Reports, USA Today, and Reuters, and featured in two published books on CDI and antimicrobial resistance.

As a consultant and speaker, Christian helps pharmaceutical, diagnostic, and infection control companies, corporate teams, and healthcare organizations understand the C. diff patient and caregiver experience, navigate the CDI federal policy environment, and build relationships with the advocacy community grounded in genuine partnership. He maintains active working relationships with companies across the CDI space, including Nestle, Pfizer, Merck, AstraZeneca, Ferring, and Acurx.

Christian speaks regularly at infectious disease, patient advocacy, and healthcare leadership conferences, as well as sales meetings. He has presented at Merck’s Chief Patient Officer Rounds, Cepheid’s 2026 sales meeting, Making A Difference in Infectious Diseases conference, among others. His perspective combines the authority of 16 years in advocacy leadership with the directness of someone who has lived the experience he speaks about.

A native of Brooklyn, New York, he lives in its Kensington neighborhood with his husband and their beagle. When he’s not working to make healthcare safer and better for CDI patients, Christian enjoys reading, writing poetry, travel, live music, and being the best “guncle” to Peggy’s only grandchild.