Will Bulsiewicz, MD

Dr. Will Bulsiewicz, MD, also known as Dr. B, is a double board-certified gastroenterologist, gut health expert, and New York Times bestselling author of Fiber Fueled and The Fiber Fueled Cookbook. With over two decades of clinical experience, he combines microbiome science, nutrition, and lifestyle medicine to promote whole-person health. A graduate of Georgetown University School of Medicine, he completed his residency at Northwestern Memorial Hospital and gastroenterology fellowship at UNC Hospitals. He is also the founder of 38TERA and has served as US Medical Director of ZOE, a personalized nutrition company. His approach emphasizes understanding each patient’s individual experiences, recognizing that gut health extends beyond diet to include emotional well-being, stress, and meaningful human connection. Through his books, research, and educational work, Dr. Bulsiewicz encourages a more personalized and compassionate approach to lasting health.