Kari Natwick, RDN, LD, IFNCP, CGN

Kari Natwick, RDN, LD, IFNCP, CGN, is an integrative and functional dietitian, clinical educator, and mentor with more than 20 years of experience. She is the founder of Kari Natwick Nutrition and is known for helping practitioners make sense of cases that do not fit neatly into one diagnosis, body system, or protocol.

Kari’s clinical work focuses on complex gastrointestinal conditions, including IBS, SIBO, GERD, IBD, along with many other persistent digestive conditions. Known professionally as the GutBrain RD, she has particular expertise in the gut-brain connection and the ways gastrointestinal health can intersect with brain fog, cognitive changes, anxiety, depression, and other mental health concerns. Her expertise also includes autoimmune and thyroid disorders and mold and mycotoxin-related illness. She has a special interest in supporting women during perimenopause and midlife, when hormonal changes can affect digestion, metabolism, thyroid function, mood, and cognitive health.

Kari integrates health histories, symptoms, conventional biomarkers, and functional testing to identify meaningful patterns and establish clinical priorities. Her laboratory experience includes comprehensive stool testing, including GI-MAP, SIBO breath testing, organic acids testing, DUTCH hormone testing, mycotoxin testing, micronutrient assessment, hair tissue mineral analysis, and conventional blood chemistry.

Her approach is also informed by advanced training with Aviva Romm, MD, and years of studying the evidence-informed use of herbs and botanicals. Her perspective is shaped by both clinical practice and her personal experience navigating Hashimoto’s, mold and mycotoxin-related illness, and perimenopause.

Kari earned her IFNCP credential in 2019. Her background includes coordinating dietetic internship rotations, supervising staff dietitians and multidisciplinary teams, providing rural telehealth care in Alaska, and teaching nursing students and other health professionals.

During mentoring sessions, Kari helps mentees examine case histories, laboratory reports, disease mechanisms, root-cause patterns, and intervention strategies. She guides mentees in applying IFNA tools such as the Nutrition Care Process, STAIN Root Cause Analysis, HANDS-on Tool, and IFNA assessment forms. Together, they identify priorities, sequence nutrition, lifestyle, supplement, and botanical recommendations, decide what to monitor, and recognize when referral or collaboration is needed. Kari can also provide guidance on client communication, telehealth care, and building a sustainable private practice.

Kari is especially well-suited for mentees who understand the individual concepts but feel uncertain when several systems overlap or a case becomes complicated. Her mentoring style is warm, direct, collaborative, and practical. She will help you identify gaps in your thinking without making you feel inadequate for having them. Her goal is not to give you a protocol to copy. It is to help you become a more thoughtful, capable, and confident functional nutrition practitioner.