38TERA was founded by Dr. Will Bulsiewicz, a renowned gastroenterologist and expert in gut health, with one clear mission: to create the absolute best gut health supplements on the planet.
At 38TERA, we believe that a healthy gut is the foundation for a healthy life, and our products are designed to support and optimize your well-being from the inside out. This is the right way to your health.
Drawing on the latest in gut health science, we offer products that are not only effective but also safe and transparent. Every ingredient we use has been carefully selected to promote gut health and is backed by rigorous research. Manufactured in FDA- and GMP-accredited facilities, our products undergo comprehensive third-party testing to ensure they meet the highest standards of safety and efficacy.
We’re committed to transparency, sharing every detail about what goes into our products and why. Our supplements are free from harmful additives, preservatives, and artificial ingredients—because we believe in clean, natural nutrition for your gut.
At 38TERA, we’re not just improving gut health; we’re revolutionizing it. Join us in nurturing your microbiome and discovering how great you can feel when your gut is working for you, not against you.
Meet Dr. B
Dr. Will Bulsiewicz (or "Dr. B") is an award winning gastroenterologist, internationally recognized gut health expert, the New York Times-bestselling author of Fiber FueledandThe Fiber Fueled Cookbook, and the Founder of 38TERA. His research has been published in Nature Medicine, Gastroenterology and more. He has given more than forty presentations at scientific meetings, spoken to Congress and the USDA, and through social media, podcasts, his books and courses he has educated millions on the importance of gut health.
Dr. Will Bulsiewicz, MD, MSCI
Education, training, and awards
Education
Vanderbilt University
Bachelor of Science, Chemistry
Georgetown University
Doctor of Medicine
Northwestern University
Master of Science, Clinical Investigation
Training
Northwestern University (McGaw Medical Center)
Intern, Resident, & Chief Medical Resident
University of North Carolina Hospitals
Gastroenterology Fellow, GI Epidemiology Fellow & Chief GI Fellow
UNC-Gillings School of Global Public Health
Fellow in Translational and Clinical Research Curriculum
Awards
Rambach Award
Northwestern “Intern of the Year”
Alpha Omega Alpha Medical Honor Society
National Institutes of Health LRP Grant Recipient
AGA/ASGE President Plenary
Digestive Disease Week 2013
UNC Award for Excellence in Clinical Gastroenterology
During 20 years of studying medicine, Dr. B developed a unique approach to healing patients by addressing the root cause of their issues: gut health. By focusing on restoring the microbiome through targeted nutrition, lifestyle changes, and supplements, he achieved remarkable results. Inspired to share his methods with a wider audience, he authored two New York Times bestselling books, built a large online community, and created popular digital courses on gut health.
However, he encountered a significant problem: the available gut health supplements didn't meet his high standards. The market was flooded with outdated products lacking scientific backing, transparency, and third-party testing—more hype than help. Frustrated by this gap, he decided to do something radical and build the brand that he always wished existed.
During 20 years of studying medicine, Dr. B developed a unique approach to healing patients by addressing the root cause of their issues: gut health. By focusing on restoring the microbiome through targeted nutrition, lifestyle changes, and supplements, he achieved remarkable results. Inspired to share his methods with a wider audience, he authored two New York Times bestselling books, built a large online community, and created popular digital courses on gut health.
However, he encountered a significant problem: the available gut health supplements didn't meet his high standards. The market was flooded with outdated products lacking scientific backing, transparency, and third-party testing—more hype than help. Frustrated by this gap, he decided to do something radical and build the brand that he always wished existed.
Our Vision
Premium quality
Crafted from the finest ingredients based on the latest gut health science.
Certified Manufacturing
Produced in an FDA- and GMP-certified facility ensuring top-notch quality.
Rigorous testing
Every lot is third-party tested for 100+ substances to ensure purity and safety.
Continuous improvement
Committed to further testing, research, and certifications to enhance product quality.
Educational support
Offer valuable resources for maximizing benefits from our supplements AND improving diet and lifestyle.
Community building
Foster a supportive network of gut health enthusiasts for mutual encouragement and growth.
Exceptional service
Provide friendly and supportive customer care.
Customer satisfaction
Dedicated to consistently going above and beyond customer expectations.
