The Root Cause Medicine Podcast

Dr. Oscar Coetzee joins Dr Lara Zakaria on the Root Cause Medicine Podcast to discuss emerging research on keystone commensal organisms and how microbial communities interact within the gut ecosystem.The conversation focuses on organisms including Akkermansia muciniphila, Faecalibacterium prausnitzii, Roseburia, Bifidobacterium longum, and Bifidobacterium adolescentis. Rather than viewing individual microbes in isolation, Dr. Coetzee describes an ecosystem model centered on cross-feeding, short-chain fatty acid production, and the intestinal environment.The episode also notes an important context: research on next-generation commensals is still developing, meaning findings from mechanistic studies, case reports, and early clinical research offer initial insights that complement rather than replace evidence from larger randomized controlled trials. (Jan 2024) (Kern 2026)Clinical takeawaysKeystone organisms are discussed as members of an interconnected ecosystem. The episode explores how organisms can produce metabolites or modify environmental conditions that may influence other members of the microbial community. (Belzer 2017) (Fusco 2023)Short-chain fatty acids are a major theme. Akkermansia, Faecalibacterium, and Roseburia are discussed in relation to acetate, propionate, and butyrate production and their potential roles within the intestinal environment. (Martin-Gallausiaux 2021) (Tingler 2025)Clinical evidence remains emerging. Dr. Coetzee describes early clinical observations and studies in progress, while the conversation acknowledges the need for additional published research, including controlled trials, before broader clinical conclusions can be drawn. (Jan 2024) (Kern 2026)Guest: Oscar Coetzee, PhD, DCNDr. Oscar Coetzee is Vice President of Clinical Education and Practitioner Support at Designs for Health. In the episode, he discusses his work in nutrition and microbiome research and his interest in next-generation commensal organisms.His discussion centers on moving beyond a single-organism view of probiotics toward understanding microbial communities, cross-feeding, and the environment in which commensal organisms coexist.Clinician FAQ1. What are keystone commensal organisms?They are microbes discussed for their potentially important roles within the broader gut ecosystem. (Rios Garza 2026)The episode focuses on how selected commensals interact with other organisms and their environment rather than evaluating them solely by abundance. (Banerjee 2018)2. Which organisms are discussed?The main organisms include Akkermansia muciniphila, Faecalibacterium prausnitzii, Roseburia, Bifidobacterium longum, and Bifidobacterium adolescentis.The conversation also discusses Anaerostipes caccae separately in the context of butyrate production and microbial cross-feeding. (Belzer 2017)3. What is microbial cross-feeding?Cross-feeding describes how metabolites produced by one organism can serve as substrates or influence conditions for another. (Culp 2023) (Louis 2017)The episode uses this concept to explain why microbial communities may be more informative than considering individual organisms in isolation. (Culp 2023)4. Why are short-chain fatty acids discussed?They are microbial metabolites that form part of the communication between gut microbes and their environment. (Martin-Gallausiaux 2021)The conversation highlights acetate, propionate, and butyrate while exploring how different commensal organisms contribute to their production. (Martin-Gallausiaux 2021)5. How established is the clinical evidence?Research on these next-generation commensals is still evolving. (Jan 2024) (Kern 2026)The guest describes case observations, prospective studies, and additional research underway. These early findings can generate hypotheses, but they do not establish that a specific probiotic combination prevents or treats disease.Timestamps / key moments00:00:00 Introducing keystone commensal organisms00:05:35 Why newer technology matters for anaerobic microbes00:08:09 Moving beyond probiotic quantity and individual strains00:13:32 Microbial compensation and ecosystem dynamics00:18:00 Keystone organisms and emerging clinical observations00:21:28 Akkermansia and microbial metabolites00:24:08 Faecalibacterium prausnitzii and butyrate00:30:49 Roseburia and the anaerobic environment00:32:24 Bifidobacterium species in the microbial community00:35:52 Anaerostipes caccae and cross-feeding00:39:58 Supporting the microbial ecosystem00:44:18 Current research and evidence limitations00:48:02 Clinical considerations and unanswered questions01:02:15 Future research and closing discussionWant to learn more about microbiome science?This episode highlights an evolving way of thinking about the microbiome: not simply as a collection of individual organisms, but as an ecosystem shaped by microbial interactions, metabolites, available substrates, and environmental conditions.For additional practitioner education on supplement quality and clinical decision-making, visit Fullscript Academy.DisclaimerThe views expressed on this podcast are those of the host and guest and do not necessarily reflect those of Fullscript or affiliated organizations.This episode is for informational and educational purposes only and is not medical advice. Research on next-generation commensal organisms and related probiotic formulations is evolving, and emerging findings should be interpreted in the context of the strength and limitations of the available evidence.ReferencesBanerjee, S., Schlaeppi, K., & van der Heijden, M. G. A. (2018). Keystone taxa as drivers of microbiome structure and functioning. Nature Reviews Microbiology, 16(9), 567–576. https://doi.org/10.1038/s41579-018-0024-1Belzer, C., Chia, L. W., Aalvink, S., Chamlagain, B., Piironen, V., Knol, J., & de Vos, W. M. (2017). Microbial metabolic networks at the mucus layer lead to diet-independent butyrate and vitamin B12 production by intestinal symbionts. mBio, 8(5), e00770-17. https://doi.org/10.1128/mBio.00770-17Culp, E. J., & Goodman, A. L. (2023). Cross-feeding in the gut microbiome: Ecology and mechanisms. Cell Host & Microbe, 31(4), 485–499. https://doi.org/10.1016/j.chom.2023.03.016Fusco, W., Lorenzo, M. B., Cintoni, M., Porcari, S., Rinninella, E., Kaitsas, F., Lener, E., Mele, M. C., Gasbarrini, A., Collado, M. C., Cammarota, G., & Ianiro, G. (2023). Short-chain fatty-acid-producing bacteria: Key components of the human gut microbiota. Nutrients, 15(9), 2211. https://doi.org/10.3390/nu15092211Jan, T., Negi, R., Sharma, B., Kumar, S., Singh, S., Rai, A. K., Shreaz, S., Rustagi, S., Chaudhary, N., Kaur, T., Kour, D., Sheikh, M. A., Kumar, K., Yadav, A. N., & Ahmed, N. (2024). Next generation probiotics for human health: An emerging perspective. Heliyon, 10(16), e35980. https://doi.org/10.1016/j.heliyon.2024.e35980Kern, L., Tofield, A., Frame, J., & Elinav, E. (2026). Next-generation probiotics: An outlook into current applications and future developments. Nature Reviews Microbiology, 24(8), 539–558. https://doi.org/10.1038/s41579-026-01311-0Louis, P., & Flint, H. J. (2017). Formation of propionate and butyrate by the human colonic microbiota. Environmental Microbiology, 19(1), 29–41. https://doi.org/10.1111/1462-2920.13589Martin-Gallausiaux, C., Marinelli, L., Blottière, H. M., Larraufie, P., & Lapaque, N. (2021). SCFA: Mechanisms and functional importance in the gut. Proceedings of the Nutrition Society, 80(1), 37–49. https://doi.org/10.1017/S0029665120006916Rios Garza, D., Gonze, D., & Faust, K. (2026). Keystone concept revisited: Insights into microbial community dynamics and control. Nature Reviews Microbiology, 24(5), 359–371. https://doi.org/10.1038/s41579-025-01266-8Tingler, A. M., & Engevik, M. A. (2025). Breaking down barriers: Is intestinal mucus degradation by Akkermansia muciniphila beneficial or harmful? Infection and Immunity, 93(9), e0050324. https://doi.org/10.1128/iai.00503-24

Dr. Eric Viegas joins the Root Cause Medicine Podcast to discuss an often-overlooked part of evaluating botanical supplements for menopause: whether the product being used actually matches the ingredient that was studied.The conversation focuses on five botanicals and botanical categories—black cohosh, Vitex (chasteberry), rhapontic rhubarb, maca, and soy isoflavones. Rather than framing individual herbs as simply effective or ineffective, Dr. Viegas emphasizes three considerations: identity, standardization, and patience.Identity refers to confirming the correct plant species and plant part. Standardization addresses whether relevant constituents or studied extracts are consistently represented in a product. Patience refers to allowing an appropriate evaluation period rather than judging a botanical after only a few days of use.Clinical takeawaysBotanical evidence is closely tied to the ingredient that was actually studied. Dr. Viegas emphasizes that results from research on a particular species, plant part, extract, or standardized preparation cannot automatically be generalized to every product carrying the same botanical name.Black cohosh has a substantial research history, but product characteristics matter. The episode discusses Actaea racemosa and the importance of confirming botanical identity, the appropriate plant part, and the characteristics of the extract being used. Standardized preparations feature prominently in the research discussed. (Castelo-Branco 2021) (NIDDK 2025) Vitex is discussed primarily in the context of cyclical symptoms and perimenopause. Also known as chasteberry (Vitex agnus-castus), Vitex is presented as having a stronger research history for premenstrual and cyclical symptoms than for classic postmenopausal symptoms. The episode also highlights variation in extracts and marker compounds. (Csupor 2019) Rhapontic rhubarb illustrates the importance of extract-specific evidence. The discussion focuses on the studied rhapontic rhubarb extract ERr 731 rather than treating all rhubarb preparations as interchangeable. This provides an example of why practitioners should identify the exact preparation evaluated in clinical research. (Dubey 2024) Maca presents additional standardization challenges. The episode discusses differences among maca varieties and processing methods and notes that there is not one universally dominant marker used across all products. Maca is discussed in relation to menopausal symptoms, mood, and sexual function without positioning it as a direct hormone replacement. (Lee 2011)Soy isoflavone response may vary between individuals and formulations. The conversation highlights differences among individual isoflavones and discusses equol production as one possible contributor to variability in response. (Mayo 2019)Time is part of interpreting a botanical trial. A recurring theme throughout the episode is that botanical interventions studied over weeks or months should not necessarily be judged after a very short trial. Appropriate duration depends on the ingredient, formulation, patient, and clinical context.Guest: Eric Viegas, NDDr. Eric Viegas is a naturopathic doctor based in Ottawa, Canada, and works with Fullscript’s quality program.In the episode, he describes Fullscript’s approach to supplement quality, including supplier qualification and review of product documentation. He also discusses Fullscript Tested, a program in which products are selected from Fullscript distribution centers and submitted to third-party laboratories for testing related to factors such as identity, potency, and contaminants.His discussion of menopause botanicals centers on connecting published research with the practical question practitioners face when evaluating supplements: Does the ingredient in the product correspond to the ingredient evaluated in the research?Clinician FAQ1. What do identity and standardization mean for botanical supplements?Identity refers to confirming what botanical material is actually present, while standardization addresses consistency in relevant constituents or preparations.Depending on the botanical, identity can include species, plant part, variety, and other characteristics. Standardization may involve a marker compound, defined extract, or another specification associated with the preparation used in research.2. Why does the episode focus on patience?Because botanical research generally evaluates outcomes over a defined period rather than after only a few doses.Dr. Viegas argues that stopping a botanical substantially earlier than the period evaluated in research can make it difficult to determine whether the preparation received a meaningful trial. The appropriate evaluation period varies by ingredient and clinical context.3. What does the episode say about black cohosh?Black cohosh is presented as a botanical for which product identity and extract characteristics can affect how research is interpreted.The discussion focuses on Actaea racemosa, particularly root and rhizome preparations, and distinguishes studied standardized extracts from unspecified black cohosh products. (Castelo-Branco 2021) (NIDDK 2025)4. Is Vitex primarily a menopause botanical?The episode describes its strongest evidence base as being related to premenstrual and cyclical symptoms rather than classic menopause symptoms. (Csupor 2019)Dr. Viegas discusses why Vitex may nevertheless appear in conversations about perimenopause and also notes that some research evaluates it as part of multi-ingredient botanical combinations.5. What is different about rhapontic rhubarb?The discussion centers on a specific studied extract rather than rhapontic rhubarb as a broad ingredient category.Dr. Viegas identifies ERr 731 as the preparation featured in the research discussed during the episode. This serves as an example of why botanical extract identity can matter when translating research findings to commercial products. (Dubey 2024) 6. What quality considerations are discussed for maca?The episode highlights botanical variety, processing, and the absence of a single universally dominant standardization marker. (Lee 2011)Different maca varieties and processing approaches can make product-to-product comparisons more complicated than simply confirming that “maca” appears on the label.7. Why might people respond differently to soy isoflavones?Both formulation and individual biology may contribute to variation.The episode discusses differences among isoflavones and describes the conversion of daidzein to equol by certain gut microorganisms as one potential source of individual variation. (Mayo 2019)8. Does a botanical's presence on the label mean it matches the clinical research?Not necessarily.The episode emphasizes checking the species, plant part, preparation or extract, relevant standardization information, and other product specifications before assuming that findings from a particular study apply to another formulation.Timestamps / key moments00:00:00 Introducing menopause botanicals, identity, standardization, and patience00:02:59 The three themes: identity, standardization, and patience00:04:15 Black cohosh and its research history00:07:41 Standardized black cohosh extracts and product testing00:10:13 Vitex (chasteberry) and where it fits clinically00:14:14 Introducing rhapontic rhubarb00:16:28 Maca, menopause, libido, and mood00:20:04 Soy isoflavones and the evidence discussion00:21:15 Daidzein, equol, and individual response00:22:54 Soy isoflavones and evaluation over time00:25:08 Fullscript Academy and closing remarksWant to learn more about supplement quality?This episode highlights how botanical identity, standardization, formulation, and research design can affect the way practitioners interpret supplement evidence.For additional practitioner education on supplement quality and clinical decision-making, visit Fullscript Academy.The goal is not to reduce botanical selection to a single marker or label claim, but to help practitioners evaluate whether a product meaningfully corresponds to the ingredient and preparation described in the available evidence.DisclaimerThe views expressed on this podcast are those of the host and guest and do not necessarily reflect those of Fullscript or affiliated organizations.This episode is for informational and educational purposes only and is not medical advice. Botanical supplements may have contraindications, adverse effects, and medication interactions, and suitability can vary by patient. Patients should consult a qualified healthcare professional before making changes to their healthcare routine.ReferencesCastelo-Branco, C., Gambacciani, M., Cano, A., Minkin, M. J., Rachoń, D., Ruan, X., Beer, A.-M., Schnitker, J., Henneicke-von Zepelin, H.-H., & Pickartz, S. (2021). Review & meta-analysis: Isopropanolic black cohosh extract iCR for menopausal symptoms – an update on the evidence. Climacteric, 24(2), 109–119. https://pubmed.ncbi.nlm.nih.gov/33021111/Csupor, D., Lantos, T., Hegyi, P., Benkő, R., Viola, R., Gyöngyi, Z., Csécsei, P., Tóth, B., Vasas, A., Márta, K., Rostás, I., Szentesi, A., & Matuz, M. (2019). Vitex agnus-castus in premenstrual syndrome: A meta-analysis of double-blind randomised controlled trials. Complementary Therapies in Medicine, 47, 102190. https://pubmed.ncbi.nlm.nih.gov/31780016/Dubey, V. P., Sureja, V. P., & Kheni, D. B. (2024). Efficacy evaluation of standardized Rheum rhaponticum root extract (ERr 731) on symptoms of menopause: A systematic review and meta-analysis study. Journal of Biomedical Research, 38(3), 278–286. https://pubmed.ncbi.nlm.nih.gov/38646867/Lee, M. S., Shin, B.-C., Yang, E. J., Lim, H.-J., & Ernst, E. (2011). Maca (Lepidium meyenii) for treatment of menopausal symptoms: A systematic review. Maturitas, 70(3), 227–233. https://pubmed.ncbi.nlm.nih.gov/21840656/LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. (2025). Black cohosh. National Institute of Diabetes and Digestive and

You've been hearing new voices in the host chair lately — so this week we're pulling back the curtain to introduce them properly. Dr. Kate Kresge sits down with Dr. Holly Lucille, Dr. Lara Zakaria, and Dr. Jessica Christie for a roundtable on the winding, deeply personal paths that led each of them into root-cause medicine.A pharmacist nearly buried under her own stack of nutrition books who came out dual-licensed. A psychology student who couldn't find a medical school that took food and sleep seriously, so she built her own path. A holistic nurse turned naturopathic doctor who fought for her profession on the statehouse floor. And a host whose decade-long "mystery illness" resolved in three days once the right test was finally run. What ties them together is a stubborn refusal to stop at the easy answer — the instinct to say, let's think this through, because so often the protocol failed the patient, not the other way around.Consider this your proper introduction to the team learning and sharing what works, right alongside you.What you'll hearWhy every one of these clinicians came to functional medicine as a "detective" — and often as a patient first.Dr. Lara Zakaria's path from community pharmacist to dual-licensed nutritionist, and a clear-eyed explainer on what the CNS credential actually requires.Dr. Jessica Christie's move from developmental psychology into naturopathic medicine, becoming her own first patient, and finding her way into fertility and women's health.Dr. Holly Lucille's journey through holistic nursing and naturopathic medicine — and helping pass California's ND licensing bill (SB 907) in 2004.Dr. Kate Kresge's decade of misdiagnosed illness that resolved in days once the root cause was identified — and why it reshaped how she thinks about mental-health symptoms with a physiological root cause.How Rupa and Fullscript coming together puts labs, education, boot camps, webinars and AI-assisted evidence in one free place for clinicians.The team's reframe of "the patient failed treatment" into "the treatment failed the patient" — and what patient-centered care really means.Key themesLet's think things through — clinical reasoning over the 15-minute prescribe-and-go visit.The empowered, informed patient is a good thing; clinicians add the nuance.Whole-person care means mind and body are never truly separate.Personalization: the protocol fits the patient, not the other way around.Timestamps02:21 — Welcoming the hosts03:13 — Naming the listeners05:35 — "Let's think things through"06:40 — Nuance and the empowered patient09:02 — Dr. Lara Zakaria's story12:16 — Dr. Jessica Christie's story16:00 — Rupa magazine + free education17:03 — What a CNS is20:10 — Dr. Holly Lucille's story28:17 — Whiskey Flower + Wipeout30:16 — Rupa + Fullscript coming together32:20 — AI Assist for whole-person care34:00 — Dr. Kate Kresge's story44:11 — The protocol failed the patient46:05 — What excites the team next53:21 — Wrap-up + listener name revealWant to elevate your practice? This episode is sponsored by Fullscript, a comprehensive care delivery platform designed to support whole-person, integrative healthcare. Fullscript allows clinicians to streamline supplement dispensing, lab ordering, and patient education in one free, centralized system—helping reduce administrative burden while supporting clinical decision-making. For practitioners, Fullscript offers access to professional-grade supplements, evidence-informed protocols, and lab integrations that can support more efficient planning and follow-up. For patients, it provides a clear, organized way to receive recommendations, manage refills, and stay engaged in their care. The goal is not to replace clinical judgment, but to make it easier for clinicians to focus on what matters most: thoughtful, individualized patient care.Disclaimer: Views expressed are those of the hosts and guests and do not necessarily reflect Fullscript or affiliated organizations. For informational and educational purposes only; not medical advice.

Dr. Lara Zakaria is joined by Stephanie Venn-Watson, DVM, MPH, to explore emerging research on pentadecanoic acid (C15:0), an odd-chain saturated fatty acid initially studied through research involving bottlenose dolphins.The conversation connects C15:0 with cell-membrane composition, lipid peroxidation, ferroptosis, iron metabolism, metabolic health, and steatotic liver disease. It also examines research on circulating C15:0 as a biomarker associated with cardiometabolic outcomes and early human trials of C15:0 supplementation. (Imamura 2018) (Sawh 2021) C15:0 has been proposed as a candidate essential fatty acid, however, that classification and a specific human “C15:0 deficiency syndrome” remain emerging hypotheses rather than established clinical diagnoses.Clinical TakeawaysFerroptosis is an iron-dependent form of regulated cell death. First characterized in 2012, ferroptosis involves iron-dependent lipid peroxidation and differs mechanistically from apoptosis and other forms of cell death. (Dixon 2012) Polyunsaturated fatty acids in phospholipids are particularly relevant substrates for ferroptotic lipid peroxidation. (Yang 2016)C15:0 is an odd-chain saturated fatty acid being studied for metabolic effects. Pentadecanoic acid, or C15:0, is found in dairy fat and smaller amounts in other foods. Higher circulating C15:0 has been associated with lower incidence of type 2 diabetes in prospective observational research, but these associations do not establish that C15:0 itself prevents diabetes. (Imamura 2018)Calling C15:0 an “essential fatty acid” remains an emerging scientific proposal. Experimental work has proposed C15:0 as a candidate essential fatty acid based on dietary exposure, biological activity, and associations between circulating levels and health outcomes. More research is needed before C15:0 can be treated as equivalent to the established essential fatty acids linoleic acid and alpha-linolenic acid. (Venn-Watson 2020) (Venn-Watson 2022) Metabolic hyperferritinemia is a recognized clinical framework, but it is not synonymous with ferroptosis or C15:0 deficiency. Metabolic hyperferritinemia describes elevated ferritin occurring with metabolic dysfunction. Ferritin is also an acute-phase reactant, so elevated values require evaluation in clinical context rather than being interpreted as tissue iron overload by themselves. (Valenti 2023)Human C15:0 supplementation evidence is early. Within this broader metabolic context, circulating C15:0 is an emerging biomarker of interest. In a small 12-week randomized, placebo-controlled trial in young adults with overweight or obesity, 200 mg/day oral C15:0 significantly increased circulating C15:0 concentrations. Exploratory analyses suggested that participants who achieved post-treatment circulating C15:0 concentrations above 5 µg/mL had greater reductions in ALT and AST and a greater increase in hemoglobin; these achieved-level findings were not definitive treatment effects and require replication in larger trials designed for liver and hematologic outcomes. (Robinson 2024)Diet and lifestyle remain the better-established foundation for metabolic and liver health. Dairy fat is the principal dietary source of C15:0, although circulating odd-chain fatty acids may also be influenced by endogenous production. (Weitkunat 2017) For people who avoid or tolerate little dairy, C15:0 supplementation is an emerging option that may be useful alongside high-fiber, Mediterranean-style minimally processed dietary patterns, regular exercise, metabolic-risk reduction, and appropriate evaluation and treatment of fatty liver disease or abnormal iron markers. (Chooi 2024)Guest: Stephanie Venn-Watson, DVM, MPHStephanie Venn-Watson is a veterinary epidemiologist whose research has included comparative medicine and the health of bottlenose dolphins cared for through the U.S. Navy Marine Mammal Program.Research involving dolphins identified similarities in metabolic and age-associated physiology that led investigators to study odd-chain saturated fatty acids, including C15:0 and C17:0. Her subsequent research has focused on the biological activity of C15:0 and the hypothesis that inadequate C15:0 may contribute to cellular vulnerability.Some of this research is connected with patents and commercial C15:0 products, making independent replication and larger human clinical trials particularly important when interpreting the findings.Clinician FAQ1. What is C15:0?C15:0, or pentadecanoic acid, is a 15-carbon odd-chain saturated fatty acid.It occurs in foods including dairy fat and has historically been studied as a biomarker related to dairy-fat intake. (Imamura 2018) More recent research is examining whether C15:0 itself has biologically relevant metabolic effects. (Venn-Watson 2020)2. Is C15:0 an essential fatty acid?Not yet by established nutritional consensus.C15:0 has been proposed as a candidate essential fatty acid, but this remains an emerging area of research. (Venn-Watson 2020) (Venn-Watson 2022) Linoleic acid and alpha-linolenic acid remain the conventionally recognized essential fatty acids in human nutrition.3. What is ferroptosis?Ferroptosis is a regulated, iron-dependent form of cell death characterized by damaging lipid peroxidation. (Dixon 2012)The process involves interactions among cellular iron, oxidizable membrane phospholipids, and antioxidant defense systems. Ferroptosis is being investigated across metabolic, neurologic, cardiovascular, liver, and cancer biology.4. Is high ferritin evidence that a patient is undergoing ferroptosis?No.Ferritin reflects iron storage but is also an acute-phase reactant. Elevated ferritin can occur with inflammation, liver disease, metabolic dysfunction, infection, malignancy, iron overload, and other conditions. (Valenti 2023) Ferroptosis cannot be diagnosed from serum ferritin alone.5. What is metabolic hyperferritinemia?Metabolic hyperferritinemia describes elevated serum ferritin occurring in the context of metabolic dysfunction.A published consensus framework proposes ferritin above 300 ng/mL in men or 200 ng/mL in women together with specified metabolic criteria, while excluding or reassessing alternative explanations for hyperferritinemia. (Valenti 2023) The framework also distinguishes hyperferritinemia from confirmed tissue iron accumulation. (Liu 2024)6. Does elevated ferritin mean a patient needs phlebotomy?Not necessarily.The metabolic hyperferritinemia consensus states that evidence supporting routine iron-depletion therapy is insufficient. (Valenti 2023) Phlebotomy should not be inferred from ferritin alone; evaluation of the cause of hyperferritinemia and, when appropriate, tissue iron burden is important.7. What foods contain C15:0?Dairy fat is one dietary source of C15:0, and C15:0 is also present in smaller amounts in some meats, fish, and other foods.Circulating odd-chain fatty acids are not exclusively determined by dairy intake. Research also suggests that endogenous pathways involving gut-derived propionate can contribute to odd-chain fatty acid production. (Weitkunat 2017)8. Does eating more full-fat dairy increase C15:0?Dietary dairy fat can contribute to circulating C15:0, but the health implications of increasing full-fat dairy cannot be reduced to C15:0 alone.Dairy foods contain multiple fatty acids, proteins, carbohydrates, minerals, and other components, and observational evidence differs by dairy-food type. (Imamura 2018) (Sawh 2021) Dietary recommendations should therefore consider the patient's overall diet and clinical context.9. What has human supplementation research shown?Human evidence remains limited.One randomized trial studied 200 mg/day of C15:0 for 12 weeks in 30 young adults with overweight or obesity and found increased circulating C15:0. (Robinson 2024) A separate randomized trial evaluated 300 mg/day as an addition to an Asian-adapted Mediterranean-style diet in women with fatty liver and reported an additional reduction in LDL cholesterol and an increase in Bifidobacterium adolescentis abundance. (Chooi 2024)Neither study establishes C15:0 supplementation as treatment for metabolic disease, ferroptosis, or metabolic hyperferritinemia.10. Can C15:0 levels be used as a clinical treatment target?A standardized clinical target has not been established.Thresholds such as 5 μg/mL or 0.2% of total fatty acids have been proposed and explored in C15:0 research, but they should not currently be treated as universally validated diagnostic thresholds for deficiency or treatment targets. (Robinson 2024) (Venn-Watson 2024) Timestamps / Key Moments00:00:18 Introducing C15:0, cellular aging, and ferroptosis00:02:19 Stephanie Venn-Watson’s background and dolphin research00:05:29 How C15:0 emerged from metabolomics research00:10:20 Alzheimer’s disease-like pathology in dolphins00:11:33 What C15:0 is and how fatty acids are classified00:18:18 C15:0, membrane stability, and lipid peroxidation00:19:25 Understanding ferroptosis00:24:34 Metabolic hyperferritinemia and clinical patterns00:27:37 Proposed C15:0 thresholds and metabolic research00:30:43 Dietary sources of C15:000:40:19 Measuring circulating C15:000:45:49 Human clinical research on C15:0Fatty acids and biological processes discussedPentadecanoic acid (C15:0)Heptadecanoic acid (C17:0)Odd-chain saturated fatty acidsSaturated fatty acidsPolyunsaturated fatty acidsLinoleic acidAlpha-linolenic acidEPADHACell-membrane lipidsLipid peroxidationFerroptosisReactive oxygen speciesMitochondrial functionIron metabolismFerritinClinical markers and conditions discussedFerritinTransferrin saturationHemoglobinRed blood cell distribution width (RDW)ALTASTGGTLipid peroxidationLDL cholesterolGlucoseInsulinMetabolic hyperferritinemiaInsulin resistanceType 2 diabetesMetabolic syndromeMASLDMASHIron overloadCognitive declineWant to elevate your practice?This episode is sponsored by Fullscript, a comprehensive care delivery platform designed to support whole-person, integ

Dr. Geeta Maker-Clark joins the Root Cause Medicine Podcast to discuss ideas from her book, Medicine for All People: Science and Ancient Wisdom for Revolutionary Healing. Drawing from family medicine, integrative medicine, culinary medicine, community health and her own upbringing, she explores a broader view of medicine that includes food, plants, nature, community, service, trust, dance, gratitude, and play.The conversation centers on a simple idea: health is shaped not only by what happens in the clinic, but also by the environments, relationships, resources, cultural traditions, and daily practices that surround a person. Dr. Maker-Clark organizes these ideas into three areas—medicines of the earth, medicines of connection, and medicines of spirit—and discusses how practitioners can think about them alongside conventional medical care.Clinical TakeawaysFood and nutrition are part of whole-person care. Dr. Maker-Clark describes food as a central part of her clinical philosophy and discusses culinary medicine as a way to combine nutrition education with practical cooking skills. Her University of Chicago culinary medicine work includes medical students, community members, and middle school students, with an emphasis on nutrition literacy, accessibility, and culturally relevant food education. (Maker-Clark 2023)Nature exposure may support stress regulation and mental well-being. The episode frames time outdoors and connection with the natural environment as accessible ways to support well-being. Research has associated nature exposure with lower perceived and physiologic stress, although study designs, settings, and outcomes vary. (Shuda 2020)Social connection deserves attention in clinical assessment. Dr. Maker-Clark emphasizes community, belonging, and service as dimensions of health. Research supports associations between loneliness and social isolation and adverse cardiovascular, brain, mental health, and inflammatory outcomes, although mechanisms and the effectiveness of specific interventions continue to be studied. (Cené 2022) (Smith 2020)Trust includes both healthcare relationships and self-trust. The conversation explores how previous negative healthcare experiences, chronic illness, and unexplained symptoms can affect trust. Dr. Maker-Clark describes rebuilding trust through relationships and small, achievable commitments rather than treating trust as something patients should simply provide.Dance combines movement, cognition, emotion, and often social interaction. Dance is presented as an accessible form of joyful movement rather than a replacement for clinical care. Research suggests dance can influence cognitive and neuroplasticity-related outcomes, particularly in older adults, although effects vary by population and intervention. (Teixeira-Machado 2019) (Hewston 2021)Gratitude and play can be viewed as practices that support well-being. Gratitude interventions have shown generally modest benefits for well-being and some psychological outcomes. (Diniz 2023) (Kerry 2023) Adult play can take many forms, including creativity, competition, collecting, storytelling, exploration, and restorative activities. (Blanche 2024)Guest: Geeta Maker-Clark, MDDr. Geeta Maker-Clark is a family and integrative medicine physician whose work spans patient care, nutrition education, culinary medicine, and community health. In the episode, she describes early clinical work in high-risk obstetrics and underserved communities as formative in expanding her understanding of health beyond the clinic.She co-developed culinary medicine programming connected with the University of Chicago, including medical student education and community-based nutrition programs. Her book, Medicine for All People: Science and Ancient Wisdom for Revolutionary Healing, brings together themes of ancestral knowledge, scientific research, social justice, connection, and accessible approaches to well-being.Clinician FAQ1. What does Dr. Maker-Clark mean by “medicine for all people”?She uses the phrase to describe a broader framework for health that includes conventional medicine alongside food, nature, relationships, community, cultural knowledge, and everyday practices. Accessibility and social justice are central themes in the framework.2. What is culinary medicine?Culinary medicine combines nutrition education with practical food preparation and cooking skills. In the program discussed in the episode, medical students learn nutrition counseling and cooking skills while community and middle school programs focus on nutrition literacy, food preparation, food justice, and culturally relevant education. (Maker-Clark 2023)3. What does research say about nature exposure and stress?Research generally supports an association between exposure to natural environments and improvements in some measures of perceived and physiological stress. Results vary across studies, and the effects depend on factors such as the population, type of nature exposure, comparison environment, and outcome measured. (Shuda 2020)4. Why are loneliness and social connection clinically relevant?Social isolation and loneliness have been associated with poorer cardiovascular and brain health and with some inflammatory markers. However, loneliness and objective social isolation are distinct concepts, and evidence does not establish that every health effect attributed to social disconnection operates through inflammation. (Cené 2022) (Smith 2020)5. Can dance support brain health?Dance combines physical movement with rhythm, learning, coordination, and sometimes social interaction. Systematic reviews have reported changes in cognitive and neuroplasticity-related outcomes, particularly among middle-aged and older adults. The magnitude of benefit and the cognitive domains affected vary across studies. (Teixeira-Machado 2019) (Hewston 2021) (Fong Yan 2024)6. Does practicing gratitude improve mental health?Gratitude interventions have been associated with small improvements in well-being and, in some studies, psychological symptoms. Results are heterogeneous, and gratitude should be viewed as a supportive practice rather than a substitute for appropriate mental healthcare. (Diniz 2023) (Kerry 2023)Timestamps / Key Moments00:01:41 Fullscript and whole-person care00:02:39 Introducing Medicine for All People00:03:09 How the book’s title and philosophy developed00:06:07 Family medicine, obstetrics, and community health00:07:18 How living conditions shaped Dr. Maker-Clark’s view of medicine00:10:00 Food as a central part of whole-person care00:11:02 Growing up with food and traditional practices00:13:19 Bringing nutrition back into clinical practice00:15:14 Culinary medicine and medical student education00:16:03 Bringing food education into Chicago public schools00:17:23 Plants, ancestral knowledge, and connection with the natural world00:20:29 Developing relationships with plants in everyday environments00:22:49 Plants and the history of medicines00:24:52 Nature, stress regulation, and belonging00:27:19 Access to nature as a health-equity issue00:31:26 Community as a medicine of connection00:35:16 Service, or seva, and connection with others00:41:31 Trust in healthcare relationships00:45:22 Rebuilding trust in the body during chronic illness00:46:39 Small practices for rebuilding self-trust00:49:21 Why dance, gratitude, and play are “medicines of spirit”00:50:36 Dance, movement, and neuroplasticity00:53:28 Dance as culture, ancestry, and expression00:54:27 Gratitude without toxic positivity00:58:22 Why adults still need play01:00:44 Different adult play personalities01:03:20 Play and social development01:05:56 Where to find Dr. Maker-Clark and her bookWant to elevate your practice? This episode is sponsored by Fullscript, a comprehensive care delivery platform designed to support whole-person, integrative healthcare. Fullscript allows clinicians to streamline supplement dispensing, lab ordering, and patient education in one free, centralized system—helping reduce administrative burden while supporting clinical decision-making. For practitioners, Fullscript offers access to professional-grade supplements, evidence-informed protocols, and lab integrations that can support more efficient planning and follow-up. For patients, it provides a clear, organized way to receive recommendations, manage refills, and stay engaged in their care. The goal is not to replace clinical judgment, but to make it easier for clinicians to focus on what matters most: thoughtful, individualized patient care.DisclaimerThe views expressed on this podcast are those of the host and guest and do not necessarily reflect those of Fullscript or affiliated organizations. This episode is for informational and educational purposes only and is not medical advice. Practices discussed in the episode should not replace individualized medical assessment or treatment. Patients should consult a qualified healthcare professional before making changes to their healthcare routine.ReferencesMaker-Clark G, McHugh A, Shireman H, et al. Empowering Future Physicians and Communities on Chicago’s South Side through a 3-Arm Culinary Medicine Program. Nutrients. 2023;15(19):4212.Shuda Q, Bougoulias ME, Kass R. Effect of nature exposure on perceived and physiologic stress: A systematic review. Complement Ther Med. 2020;53:102514.Smith KJ, Gavey S, Riddell NE, Kontari P, Victor C. The association between loneliness, social isolation and inflammation: A systematic review and meta-analysis. Neurosci Biobehav Rev. 2020;112:519–541.Cené CW, Beckie TM, Sims M, et al. Effects of Objective and Perceived Social Isolation on Cardiovascular and Brain Health: A Scientific Statement From the American Heart Association. J Am Heart Assoc. 2022.Teixeira-Machado L, Arida RM, de Jesus Mari J. Dance for neuroplasticity: A descriptive systematic review. Neurosci Biobehav Rev. 2019;96:232–240.Hewston P, Kennedy CC, Borhan S, et al. Effects of dance on cognitive function