At Biograph, our mission is to deliver the world’s most advanced, evidence-based preventive health and longevity program. By collecting comprehensive data through 30+ sophisticated evaluations, ranging from whole-body MRIs to AI-driven coronary plaque characterization, we build a clear, uncompromised risk profile designed to maximize your healthspan.
Because our members are deeply engaged in optimizing their long-term health, we are frequently asked an excellent question: “Why doesn't Biograph include gut microbiome testing in its protocols?”
It is a fair question. The scientific evidence supporting the role of the gut microbiota in human health is accumulating and exciting, and its long-term clinical potential is immense. However, as an evidence-based longevity clinic, our foundational focus is tests that provide clinically validated, highly reproducible, and actionable insights.
A rigorous study published in Communications Biology [1] illustrates exactly why consumer gut microbiome testing does not yet meet that standard.
The promise vs. the reality of the microbiome
The human gut microbiome is associated with critical facets of wellness and pathology, including metabolic dysfunction [2], mental health [3], and oncology [4]. We have even begun to see the frontier of therapeutics advance with recent regulatory approvals for microbiome-targeted treatments [5].
Yet, there is a profound difference between identifying a biological system's importance and using a commercial kit to guide your personal medical care. Currently, direct-to-consumer (DTC) microbiome tests straddle a gray area between tightly regulated diagnostic devices and minimally regulated wellness products, a distinction that is rarely apparent to the consumer. In fact, there are currently no FDA cleared or approved clinical microbiome diagnostic tests in the United States.
To systematically investigate the reliability of the current marketplace, researchers at the National Institute of Standards and Technology (NIST) evaluated seven leading direct-to-consumer gut microbiome testing services.
The NIST study: Standardized samples, conflicting results
To evaluate these services without the confounding variable of individual biological differences, NIST developed a novel, completely homogeneous human fecal reference standard. Because the test samples sent to every lab were identical, any variation in the reported data would point directly to flaws and biases in the testing methodologies themselves.
The findings revealed systemic issues regarding data reliability across the industry:
Methodology Eclipses Biology: The technical variability between the different testing companies was on the same scale as the biological variability between completely different human donors. In short, your results may tell you more about which company ran your sample than what is actually living in your gut.
Discrepancies in Pathogen Detection: When analyzing the same standardized material for Clostridioides difficile (a clinically relevant pathogen), three companies reported that the microbe was present, while four reported it was entirely absent.
Conflicting Health Recommendations: In one particularly telling example, distinct replicates of the same sample were processed by the same provider. One replicate scored above average for gut health metrics and was labeled "healthy," while another replicate scored below average across multiple functional categories and was labeled "unhealthy," triggering entirely contradictory lifestyle and dietary recommendations.
"The company reported the microbiome as healthy for replicate 1 and 2, but unhealthy for replicate 3, which could lead to unnecessary interventions if such a report was received by a consumer."
Why actionability dictates our protocol
For the high-performing individuals and executives we serve, clinical data must translate into precise, safe, and effective action. When a diagnostic tool suffers from poor comparability and a lack of analytical validation, it introduces noise rather than clarity.
Receiving an artificial "unhealthy" score can prompt members to make unwarranted, costly, or potentially unsafe lifestyle and dietary supplement changes. Conversely, relying on highly variable wellness metrics to manage gut health could inadvertently cause an individual to delay appropriate, evidence-based medical care for chronic conditions.
Our commitment to true precision
We remain highly optimistic about the future of microbiome science. As the medical and scientific community continues to establish standardized guidelines, refine analytical frameworks, and uncover causative links, microbiome analyses will undoubtedly mature into a cornerstone of precision medicine.
Until then, Biograph remains fiercely committed to the clinical frontier that is fully realized today. We will continue to focus your time and investment on high-fidelity, validated diagnostics, such as advanced CT angiography and multi-modal brain health assessments, that deliver the uncompromised accuracy your longevity strategy deserves.
Commonly asked questions about gut microbiome testing
Is gut microbiome testing accurate?
Current direct-to-consumer gut microbiome tests can produce different results depending on the testing company and methodology used. Research suggests that analytical variability remains a major limitation across the industry.
Why doesn’t Biograph offer gut microbiome testing?
Biograph prioritizes diagnostics that are clinically validated, highly reproducible, and actionable. While microbiome science is promising, current consumer testing does not yet meet the standards we require for inclusion in our preventive health program.
What did the NIST microbiome study find?
Researchers at the National Institute of Standards and Technology (NIST) found that identical stool samples processed by different microbiome testing companies often produced substantially different results and recommendations, highlighting ongoing challenges with standardization and reproducibility.
Can two microbiome testing companies produce different results?
Yes. The NIST study found that methodological differences between testing providers can significantly influence results, even when analyzing identical samples.
Are gut microbiome tests clinically validated?
Currently, there are no FDA cleared or approved clinical microbiome diagnostic tests for routine use in the United States. Researchers continue to work toward establishing standardized methods and clinically validated applications.
What makes a health test clinically actionable?
A clinically actionable test provides reliable information that can be used to guide evidence-based medical decisions, interventions, or follow-up care. Biograph prioritizes diagnostics with strong evidence for accuracy, reproducibility, and clinical utility.
Will microbiome testing become more useful in the future?
Potentially. The gut microbiome remains an active area of scientific research, and future advances in standardization, analytics, and clinical validation may expand its role in precision medicine and preventive healthcare.
Dr. Michael Doney is Biograph’s Executive Medical Director, with over 20 years of experience leading clinical care and advancing a more proactive, data-driven approach to medicine.
Clinical references
Servetas SL, Gierz KS, Hoffmann D, et al. Evaluating the analytical performance of direct-to-consumer gut microbiome testing services. Commun Biol. 2026;9:269. doi:10.1038/s42003-025-09301-3
Van Hul M, Cani PD. The gut microbiota in obesity and weight management: microbes as friends or foe? Nat Rev Endocrinol. 2023;19(5):258-271. doi:10.1038/s41574-022-00794-0
Shoubridge AP, Choo JM, Martin AM, Keating DJ, Wong ML, Licinio J, et al. The gut microbiome and mental health: advances in research and emerging priorities. Mol Psychiatry. 2022;27(4):1908-1919. doi:10.1038/s41380-022-01479-w
Gopalakrishnan V, Helmink BA, Spencer CN, Reuben A, Wargo JA. The influence of the gut microbiome on cancer, immunity, and cancer immunotherapy. Cancer Cell. 2018;33(4):570-580. doi:10.1016/j.ccell.2018.03.015
Monday L, Tillotson G, Chopra T. Microbiota-based live biotherapeutic products for Clostridioides difficile infection: the devil is in the details. Infect Drug Resist. 2024;17:623-639. doi:10.2147/IDR.S419243
