Meet Our Team

Meet Our Team

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WHAT SETS US APART

Advanced Gastroenterology Solutions in Katy, TX

At Houston Gastro Institute, we take a multidisciplinary approach to our patients’ gastrointestinal conditions. Through the integration of conventional and alternative medicine, we are better able to take a patient-centric approach to effectively address gastrointestinal issues.

This scientific method combines functional medicine and wellness modalities, education, nutritional changes, as well as a personal consultation to find the root cause of illness and disease.


Through innovative testing and integrative treatment plans, we work hand-in-hand with our patients to give them the long-lasting and sustainable health improvements they need. We do so all while building an ongoing optimal health partnership that helps patients regain control of their health, guiding them into a new, and multi-dimensional journey filled with optimal health and happiness.

meet your doctor

Vivian Asamoah, MD

Maintaining optimal health in our demanding lives can be hard; that’s why we deliver innovative solutions that make healthy living easy for you. Dr. Vivian Asamoah, a Board-Certified Gastroenterologist, emphasizes evidence-based integrative and functional medicine, combining Conventional and Integrative Medicine. Dr. Asamoah and her multilingual team support a diverse range of patients, ensuring effective communication and care.


By taking a patient-centric approach, Dr. Asamoah assesses unique genomic, biochemical, and environmental factors to understand the complexities of disease. This multidisciplinary method allows her to efficiently treat gastroenterological conditions, achieving superior health outcomes. Embrace a holistic approach to wellness with Dr. Asamoah’s expert care.

Education:

University of Geneva, Geneva, Switzerland, Medical Degree

Johns Hopkins Bayview Medical Center, Internal Medicine Residency

Johns Hopkins Hospital, Gastroenterology, Hepatology, and Nutrition Fellowship

  • Ranked No. 1 in U.S. and World Report Rankings
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meet your doctor

Ting-Hui Hsieh, MD

Dr. Ting-Hui Hsieh, MD, is a Board Certified gastroenterologist renowned for his expertise in Liver Disease and Esophageal Disorders. With a profound commitment to patient care, Dr. Hsieh is dedicated to providing high-quality, compassionate treatment that is tailored to each patient’s unique needs. At Houston Gastro Institute, he brings cutting-edge diagnostic and therapeutic skills to ensure optimal outcomes for those seeking advanced gastroenterological care.


Dr. Hsieh's educational journey began at Taipei Medical University, where he earned his medical degree. He then furthered his training at the prestigious Maimonides Medical Center, completing both his residency and internship. His pursuit of excellence continued at the Mayo Clinic, where he completed an advanced fellowship in gastroenterology, sharpening his skills in the latest techniques and treatments in the field.


In addition to English, Dr. Hsieh is fluent in Mandarin, allowing him to provide care to a diverse patient population. Staying at the forefront of his specialty, Dr. Hsieh is committed to helping his patients achieve better digestive health and overall wellness through innovative, evidence-based care.

Education:

Taipei Medical University, Medical School

Maimonides Medical Center, Residency

Maimonides Medical Center, Internship

Mayo Clinic, Fellowship

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meet your pa team

Shirley Fung Wu, MPAS, PA-C

Shirley is a Certified Physician Assistant with a Master’s degree from The University of Texas Medical Branch, backed by a solid foundation in biology from The University of Texas. Her certification by the NCCPA reflects her commitment to high standards in patient care. Shirley is also actively involved in community initiatives, demonstrating her dedication to both medical excellence and service.

Education:

The University of Texas Medical Branch, Master's Degree, Physician Assistant

The University of Texas at Austin, Bachelor of Science and Arts, Biology

The University of Texas at San Antonio, Biology, General

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meet your pa team

Jessica Zheng, MPAS, PA-C

Jessica is a Certified Physician Assistant with a Master’s Degree from The University of Texas Medical Branch, where she developed a strong foundation in medical care. Certified by the National Commission on Certification of Physician Assistants (NCCPA), Jessica is dedicated to providing compassionate and high-quality care to her patients, focusing on gastrointestinal health.

Education:

The University of Texas Medical Branch, Master's Degree, Physician Assistant

The University of Texas at Austin, Bachelor of Sciences and Arts, Human Development and Family Sciences

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meet your Registered Dietitian

Lucia Kaufer, MS, RD

Lucia Kaufer is an Integrative and Functional Registered Dietitian at Houston Gastro Institute, specializing in treating chronic gastrointestinal (GI) issues through nutrition and food as medicine. Passionate about uncovering the root causes of health concerns, Lucia provides holistic, personalized care that addresses the whole person.


Lucia is dedicated to helping patients rediscover the joy in food and eating, improving their relationship with food along the way. At Houston Gastro Institute, she empowers patients with the knowledge and tools for lasting wellness.

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meet your Functional Nutrition Expert 

Gayatri Saldivar, MS, RDN, CLT, IFNCP

Gayatri is an expert in lab-based protocol design, specializing in addressing the root causes of chronic fatigue, brain fog, anxiety, gut issues, weight gain, and autoimmune conditions. Her approach, rooted in the functional biochemistry lineage of Dr. Richard Lord, utilizes the Kalish method and nutritional genomics to address imbalances at the cellular level. 


Practicing as a registered dietitian nutritionist in Berkeley, California since 2017, Gayatri’s training includes a BS from the University of California, Berkeley, and an MS in Dietetics with 1200 hours of supervised practice through Eastern Michigan University. She holds additional certifications as a LEAP dietitian and an advanced practice functional nutrition practitioner through the Integrative and Functional Nutrition Academy. Gayatri has trained under the guidance of Dr. Dan Kalish since 2020 at the Kalish Institute and focuses on balancing the gut-hormone-detox axis utilizing diet, lifestyle factors, and science-based labs to facilitate true healing.


Gayatri became interested in functional nutrition to gain tools and science-backed data that transcend beyond the “calories in, calories out” approach for energy balance and her metabolic health. Though undiagnosed, she had struggled with a connective tissue disorder since the age of 9. Functional nutrition offered solutions and helped put the focus back on health as the currency for longevity. Gayatri founded The Functional Clinic Immersion Mentorship in 2023 and trains dietitians and up-and-coming dietetic interns in functional nutrition. She is currently working on an eBook and is pursuing an additional credential as a Physician’s Assistant. 


By recognizing triggers, managing stressors, and providing personalized support, Gayatri empowers young adults and busy professionals to feel their best and be symptom-free so they can pursue their true journey in life! She has helped hundreds of clients optimize their health and regain their life back.

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meet your nutritionist & wellness educator

Kira Whitham

Kira Whitham is a functional nutritionist and wellness educator whose teachings emanate from her extensive education in holistic nutrition, functional medicine, and culinary genomics. She's a firm believer in the healing power of food, and the body's ability to heal when given the right tools.

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Your Patient Care Team

patient-centered care. always.

Why Choose Houston

Gastro Institute?

When you want to live a vibrant and healthy life free from pain and discomfort, we are the functional medicine practice that can get you to that better quality of life you’ve been hoping for. Patient care is out top-priority.

Taking the time to delve into your unique gastrointestinal issues allows us to understand the complexities of your condition. By gaining this insight, we can better choose the treatments and techniques that will deliver sustainable and long-term health results.


As seasoned professionals in the world of functional medicine, we can help you reach the optimal health you need and deserve. With our commitment to patient-centric care and functional health and wellness, we can effectively identify and treat your GI condition, while simultaneously helping to heal your body, mind, and soul.

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