Direct-to-consumer gut microbiome tests are everywhere. But how reliable are they? A newly published study in Communications Biology rigorously evaluated seven at-home microbiome testing companies using a standardized NIST-developed stool reference material. The findings are striking. Led by my husband and colleague @thescottjackson and an exceptional interdisciplinary team, this work demonstrates that: 🔬 Variability between companies was on the same scale as biological variability between different donors 🧪 Methodological differences, not biology, were often driving discrepancies 📊 Only 1 of 18 common genera showed less methodological variability than biological variability ⚠️ Health classifications and recommendations could differ substantially for the exact same sample In other words: the same stool sample, sent to different companies, can yield meaningfully different results. Why does this matter? ⛈ Because consumers are using these reports to guide dietary changes, supplement purchases, and even medical decisions. ⚕️ Analytical validity must precede clinical interpretation. This study does not argue against microbiome science. It argues for standards, transparency, and rigor —especially as commercial testing outpaces regulatory oversight. If you are a company working in the microbiome space and want to strengthen analytical performance, validation, and methodological transparency, this is exactly the kind of gap that can be addressed proactively. Scott’s firm, The NEST (zurl.co/glCrZ), works with organizations to improve measurement rigor and reproducibility. Proud of this team for asking the hard questions and advancing the field responsibly. Full paper: zurl.co/vbclB #Microbiome #PrecisionMedicine #IntegrativeMedicine #TranslationalScience #Reproducibility #ConsumerHealth #PublicHealth