
Dr. Mariela Fierro is a licensed dietitian and functional nutrition expert with a specialized focus on gut health and chronic conditions. She earned her Ph.D. in Integrative and Functional Nutrition from Saybrook University in April 2025, where her research explored the role of the gut microbiome and systemic inflammation in chronic disease.
With over 15 years of experience spanning clinical nutrition, education, and counseling, Dr. Fierro blends science, compassion, and personalized care to help individuals address the root causes of illness. Her work is grounded in evidence-based, whole-body healing, using functional lab interpretation—such as GI-MAP, DUTCH, and advanced metabolic panels—to create customized nutrition and lifestyle protocols.
Fluent in Spanish, she is passionate about health equity and has worked extensively with diverse populations to make integrative care more accessible. Prior to her transition into clinical nutrition, she spent over a decade as a school counselor and educator, where she designed wellness-based programming and earned statewide recognition for excellence in student support.
Dr. Fierro is committed to transforming lives through education, empowerment, and sustainable healing—helping individuals reconnect with their bodies and restore vitality from the inside out.
Personal Journey
I became passionate about gut health after spending decades battling digestive issues myself. Constant bloating, discomfort, and pain after nearly every meal were a daily reality—one I knew far too well. Despite trying countless conventional treatments and being repeatedly prescribed antacids, nothing truly helped. At my lowest point, I turned to my husband and said, “I hate eating.”
It wasn’t a lifestyle choice—it was a fight for comfort and peace in my own body. Even the healthiest meals left me in pain.
I’ll never forget the moment a patient said those exact same words to me during a consultation—through tears “I hate eating.”
Her words hit me like a wave. I knew exactly how she felt, because I had lived it too.
That moment changed everything. It reminded me why I dug deeper into the root causes of gut dysfunction and committed myself to functional nutrition. I discovered what conventional approaches often overlook: the gut requires a precise balance of nutrients and beneficial bacteria in order to heal. Without it, imbalances like dysbiosis can wreak havoc on the entire body.
Once dysbiosis was corrected, her symptoms disappeared. The bloating, the pain, the discomfort… gone. Her transformation was profound. She couldn’t believe that after so many years of suffering, relief had finally come.