Provider Spotlight: Sarah J. Zielsdorf, MD, MS, ABIM, IFMCP


Dr. Sarah Zielsdorf is an Institute for Functional Medicine Certified Practitioner, American Board of Internal Medicine certified physician, a microbiologist, musician, and unashamed nerd. She values the transformative power of the patient-physician relationship. Dr. Zielsdorf understands that every individual is biochemically and genetically unique so there’s never a one-size-fits-all solution, and rarely is anything black and white. Above all, she knows health is not simply the absence of disease but living a life of passionate vitality.

Dr. Z humbly refines her craft on a daily basis, learns from her patients, and is never satisfied with her knowledge base. She truly believes in the art of medicine which keeps her relentlessly searching for the best answers to difficult questions. And, often before seeing Dr. Zielsdorf a patient may have asked those questions of the top medical institutions without receiving an answer.   


DUTCH: What inspired you to become a healthcare practitioner?

Dr. Zielsdorf: I have wanted to be a doctor since I could remember – certainly by age 4. I was born 6 weeks premature with a TEF (Tracheoesophageal Fistula), which required major surgical correction at birth. I then required several procedures as a child, which was frankly traumatic. One of my earliest memories was being held down and force-fed barium to assess the narrowing of my esophagus, and distinctly thinking, “I can do this better.” Obviously I was a precocious child, but my family encouraged my love of science. I spent many hours watching documentaries on the human body and visiting museums. I shadowed my deeply compassionate father who was a nursing home administrator and social worker, and I watched science fiction shows with my mom. Juno, the Transparent Woman (a self-narrating anatomic model) at the Cleveland Health Museum absolutely fascinated me. My grandfather gave me Paul De Kruif’s The Microbe Hunters when I was only ten years old, and it cemented my passion for microbiology and infectious disease. I horrified my parents when I declared that I wanted to hunt Ebola and other deadly viruses after reading Richard Preston’s The Hot Zone in middle school.

DUTCH: What is your medical training?

Dr. Zielsdorf: received a BA in Microbiology, minors in molecular biology and religious studies, and a concentration in oboe performance from Miami University in Oxford, Ohio. I then earned an MS in Public Health, Microbiology, and Emerging Infectious Diseases from The George Washington University in Washington, DC and my MD from Loyola University Chicago Stritch School of Medicine in Maywood, Illinois. I completed my Internal Medicine internship and residency at Loyola University Medical Center and the Edward Hines Jr. VA Hospital.  I am also an Institute for Functional Medicine Certified Practitioner and am board-certified in Internal Medicine by the American Board of Internal Medicine.

DUTCH: Describe your medical background/practice

Dr. Zielsdorf: I am an Internist with twenty years of experience as a microbiologist and grant-funded research scientist. I have advanced clinical training in autoimmunity, neuroimmunology, functional endocrinology, public health, medical microbiology, infectious disease, and translational researchAs a skilled diagnostician, my passion is to find the root causes of chronic illness. served thousands of patients prior to establishing my practice, Motivated Medicine, in 2019. Motivated Medicine is an innovative, consultative medical practice in the western suburbs of Chicago. I am proud to say I have treated patients all over the United States and even internationally. I am also a medical and research advisor to the Low Dose Naltrexone Research Trust. My team wrote the 2020 LDN Guides, and I am a featured author in the LDN Book, Volume 2. 

DUTCH: What other functional testing do you use in your practice?

Dr. Zielsdorf: I believe the first step is taking the time to listen to the patient’s story. This skill is rarely done in modern allopathic medicine due to time constraints, but there cannot be any substitution when personalizing according to patient needs. We draw an impressively comprehensive panel of serum labs to correlate many patient symptoms with their clinical imbalances. In addition to using DUTCH hormone metabolite testing (and certain saliva and serum blood hormone assessments), we use advanced genomic, nutrition, metabolic, mitochondrial, immunologic, environmental/toxicological, and microbiome analyses. 

DUTCH: How have you incorporated DUTCH Testing into your practice?

Dr. Zielsdorf: I have been using the DUTCH Test® since 2016. It is a profoundly important test. While many critics state we cannot make judgments about a person’s true hormone levels with urine metabolites, I believe (after analyzing thousands of DUTCH tests) being able to interpret patterns of hormone metabolites enables me to understand fine nuances of how a patient’s symphony of hormones and enzymes (including their microbiome’s enzymes) work together. These are very intricate relationships which cannot be measured by serum and salivary hormone values alone. It takes many tools to gain an understanding about what may be driving the symptoms causing great suffering.

DUTCH: What are the changes you have seen in your patients and practice since incorporating the DUTCH Test®?

Dr. Zielsdorf: The results have been no less than lifesaving. Concerning results from a DUTCH Test® and a patient’s symptoms pushed me to sending the patient for an ultrasound leading to diagnosis of stage 1 endometrial cancer. These are often silent cancers, which are rarely found so early. The patient was able to have surgery without more invasive treatments, and we were able to utilize her DUTCH Test® results to help guide other recommendations for treatment and future cancer prevention. Many women with lifelong menstrual cycle abnormalities have seen great improvement or even complete resolution of symptoms after a DUTCH analysis. DUTCH testing has impacted nearly every one of my patients who have used it, giving great insight for management of adrenal, metabolic, and hormonal concerns.

DUTCH: Where do you see functional/integrative medicine twenty years from now?

Dr. Zielsdorf: Integrative Medicine can be thought of as all “alternative” modalities and healing traditions, which complement traditional allopathic medicine. Functional Medicine is a roadmap; a patient-centered practice of medicine which works to find the root causes of illness and focuses on modifiable lifestyle changes, and utilizes 21st century testing and research. The practice of medicine is notoriously slow to change; we are decades behind when it comes to the translation of research “from bench to bedside.” Functional Medicine clinicians tend to be savvy readers of current medical literature and eager to transcend “the standard of care.” Patients are consumers and are demanding better care. Right now there is a great deal of backlash against this new model, because it threatens assembly-line medicine. There is no way to do this work in 15-minute appointments. I believe in twenty years many of these testing and treatment strategies will be embraced as the standard of care, such as advanced microbiome analysis. 

DUTCH: What do you like to do outside of work?

Dr. Zielsdorf: Right now I have less than zero free time as we just opened our beautiful new office. I am a full-time clinician, teacher, business owner, wife, and mother. When not doctoring, I spend time with my amazing husband, young daughter and son, playing music, cooking, reading, and getting outside.