Equol is produced exclusively by gut bacteria from daidzein, one of the principal isoflavones in soy. Unlike its precursor, equol is a selective estrogen receptor-beta agonist with greater antioxidant activity and bioavailability, and it can cross the blood–brain barrier, where laboratory studies suggest it exerts neuroprotective effects against toxin-induced cytotoxicity. The capacity to produce equol, however, is strikingly uneven across the globe: up to 70 percent of East Asians, whose habitual diets are rich in soy, are producers, compared with only 20 to 30 percent of Western populations. This disparity may help explain why randomized trials of soy isoflavones in Europe and the United States have yielded inconsistent results while observational studies in East Asia keep linking equol—not soy isoflavones themselves—to favorable outcomes.

The observational evidence is compelling. Equol producers in East Asian cohorts show lower aortic calcification, reduced risk of coronary heart disease and stroke, lower serum triglycerides, improved endothelial function, and reduced carotid intima-media thickness. Cross-sectional studies have also associated equol production with fewer postmenopausal symptoms and lower risk of mild cognitive impairment. A prospective cohort study in Chinese adults found that producers harbor richer gut microbiota, with enrichment of short-chain fatty acid–producing genera and depletion of inflammation-associated taxa. Taken together, these findings suggest that equol production may be a marker of a broader, functionally favorable gut ecosystem rather than a simple pharmacological trait.

To assess whether that trait can be instilled, the researchers followed PRISMA guidelines and registered their protocol with PROSPERO, searching PubMed, Embase, and Web of Science from the mid-1990s through January 2026. From 503 initial records, screening and full-text review winnowed the field to twelve eligible randomized trials. Eight studies enrolled only women, and six focused exclusively on postmenopausal women. Interventions fell into three broad categories: soy isoflavones alone, soy combined with probiotics or prebiotics, and fermented soy products or other dietary additions such as wheat bran and seaweed. Durations ranged from a single dose over 48 hours to 2.5 years, and eight trials used crossover designs.

The results were uniformly null with respect to conversion. In the isoflavone-only trials, neither ten weeks of high-dose soy nor six months to 2.5 years of supplementation changed producer status. The probiotic and prebiotic trials—most using Lactobacillus acidophilus and Bifidobacterium longum strains, sometimes with fructo-oligosaccharides—likewise failed to convert nonproducers, though two studies hinted that probiotics might enhance equol excretion among women who were already producers. Fermented soymilk converted two of eight participants in one small trial, a trend that did not reach significance, while seaweed combined with isoflavones increased equol secretion in existing producers without changing anyone’s status. Quality assessment using the National Heart, Lung, and Blood Institute tool rated seven trials as fair and five as poor; not one met the criteria for good quality, largely due to missing power calculations and dropout rates exceeding 20 percent in five studies.

The review’s authors argue that these failures reflect the ecological complexity of the gut microbiome rather than biological impossibility. Equol conversion depends on a limited consortium of anaerobic bacteria, notably Slackia isoflavoniconvertens and Adlercreutzia equolifaciens. Crucially, the probiotic strains deployed in the reviewed trials are not equol converters themselves; their beta-glucosidase activity can hydrolyze isoflavone glucosides into aglycones, but they cannot perform the subsequent reductive steps from daidzein to equol. Increasing substrate availability, in other words, accomplishes little when the specialized microbial machinery is absent. Japanese population studies have detected equol-converting bacteria in both producers and nonproducers at comparable levels, indicating that the broader community context—abundance, metabolic activity, and the surrounding microbial network—determines whether conversion actually occurs.

Adding a further complication, equol-producing status may not be a fixed trait. In the Women’s Isoflavone Soy Health trial, 14 percent of postmenopausal and 11 percent of premenopausal participants changed producer status at some point during follow-up, and status crossover occurred even among placebo recipients. A four-year prospective cohort of 498 Japanese adults reported that 26.1 percent of participants had unstable producer status across annual assessments despite comparable daidzein intake. Notably, stable producers exhibited significantly higher gut microbiota diversity and distinct microbial composition compared with both unstable producers and nonproducers, suggesting that only sustained equol production supported by a favorable ecosystem confers the full health benefits. Unstable producers, whose intermediate microbial profiles suggest they may be more amenable to intervention, could represent a key target population for future trials.

Methodological weaknesses compound the problem. Only four of the twelve trials used the standardized three-day soy challenge to establish baseline producer status, and just one applied the reference-standard cutoff of a log-transformed urinary equol/daidzein ratio greater than −1.75. Measurement approaches varied widely, from 24-hour urine collections to overnight urine or serum samples. Ten of the twelve trials were conducted in Western countries, and none included sufficient pre- and post-treatment fecal microbiome analyses—a critical gap that leaves open the question of whether interventions altered microbial community structure even when they failed to induce equol production. The heterogeneity of isoflavone formulations, doses, and delivery routes further obscures whether null results reflect true biological inertness, insufficient bioavailability, or simply inadequate duration.

There are glimmers of promise outside the randomized evidence. Nonrandomized studies suggest that longer-term, higher-dose soy exposure can convert nonproducers: one trial providing one liter of soymilk daily for 16 weeks converted 8 of 20 nonproducers, and vegetarian populations in Western countries produce equol at roughly four times the rate of nonvegetarians, approaching Asian levels—likely because fiber-rich plant-based diets cultivate the fermentative microbial environment the daidzein-to-equol pathway requires. Preclinical work has shown that Slackia isoflavoniconvertens can stably colonize the intestine and convert daidzein to equol in gnotobiotic rat models, providing direct support for prioritizing true equol-converting organisms, potentially paired with prebiotic substrates that selectively sustain them, in future human trials.

The review concludes with a roadmap for the field. Future randomized trials should enroll both sexes across a wide age range, extend intervention durations, employ shotgun metagenomics and targeted quantitative PCR to track equol-converting bacteria, and adopt the standardized urinary equol/daidzein ratio with repeated measurements to avoid misclassification. Trials should also distinguish explicitly among three outcomes—de novo conversion, enhancement of production in existing producers, and stabilization of status in unstable producers. With an ongoing US clinical trial currently testing equol supplementation for cardiovascular and brain health in aging populations, the stakes of getting this right are rising. The authors caution that the negative findings should not be read as proof that conversion is impossible; rather, they reflect the limits of short-term, one-size-fits-all interventions applied to a complex microbial ecosystem. Unlocking equol’s benefits for the majority of Western adults who lack it may require reshaping the gut community itself—a far more ambitious project than simply adding soy to the menu.

Subject of Research: Randomized clinical trials of dietary interventions aimed at converting equol nonproducers to producers through gut microbiome modulation

Article Title: Converting Equol Nonproducers to Producers: A Systematic Review of Randomized Clinical Trials

Article References: Li, J., Li, M., Aboushanab, S., Ebeid, M., Hatanaka, R., Iida, M., Takase, M., Jacobs, I., Gusmanov, A., Hirata, A., Miyagawa, N., Nakaya, N., Sugiyama, D., Tilves, C., Hozawa, A., Li, X., Mueller, N. T., Benos, P. V., & Sekikawa, A. (2026). Converting Equol Nonproducers to Producers: A Systematic Review of Randomized Clinical Trials. Food Science & Nutrition, 14(10), Article e72394. https://doi.org/10.1002/fsn3.72394

Image Credits: AI Generated

DOI: 10.1002/fsn3.72394

Keywords: equol, soy isoflavones, daidzein, gut microbiome, systematic review, randomized clinical trials, probiotics, prebiotics, menopause, cardiovascular health, phytoestrogens, nutrition

The two dominant technologies at the heart of this debate are intravascular ultrasonography (IVUS) and optical coherence tomography (OCT). IVUS uses a miniaturized ultrasound transducer mounted on a catheter to generate cross-sectional images of the vessel wall, penetrating deeply enough to visualize the full plaque burden and the external elastic lamina. OCT, by contrast, employs near-infrared light to achieve resolution roughly ten times finer than ultrasound — on the order of 10 to 20 micrometers — allowing clinicians to identify thin-cap fibroatheromas, macrophage infiltration, microchannels, calcium thickness, and dissection planes with unprecedented detail. The trade-off is penetration depth: OCT light struggles to see beyond roughly 1 to 2 millimeters of tissue, whereas ultrasound reaches the adventitia. Together they offer complementary windows onto the pathology that angiography misses.

The cumulative randomized evidence now indicates that imaging-guided percutaneous coronary intervention (PCI) delivers measurable prognostic benefit over angiography guidance alone, but with important heterogeneity. The Korean IVUS-XPL and ULTIMATE trials showed reduced major adverse cardiac events with IVUS guidance in long lesions and in mixed populations. RENOVATE-COMPLEX-PCI and IVUS-ACS extended this signal to complex lesions and acute coronary syndromes. On the OCT side, OCCUPI demonstrated fewer device-oriented composite endpoints in complex lesions, and OCTOBER showed that OCT guidance dramatically improved outcomes in true bifurcation stenting, reducing target-vessel failure by roughly a third compared with angiography. Notably, ILUMIEN IV in North America and IVUS-CHIP in Europe failed to reach their primary endpoints, underscoring that trial design, protocol intensity, operator expertise and patient mix all shape whether imaging’s theoretical advantages translate into clinical gains.

One of the most consistent findings across the pooled datasets is that the benefit of imaging scales with lesion complexity. Simple, short, non-calcified lesions in large vessels rarely benefit measurably — the angiogram usually suffices. But in left main coronary interventions, true bifurcations, long diffuse disease, chronic total occlusions, and heavily calcified plaques, imaging changes management decisions in a substantial fraction of cases: stents are sized larger, placed longer, and dilated more aggressively. In the OCTOBER bifurcation population, for example, OCT uncovered extensive unintended stent deformation after side-branch techniques, deformities invisible on the angiogram that imaging-guided optimization could correct. Meta-analyses, including network meta-analyses by Stone and colleagues and by Giacoppo and colleagues, converge on the conclusion that both OCT and IVUS guidance reduce cardiac mortality, stent thrombosis and repeat revascularization relative to angiography alone, without meaningful differences between the two modalities in head-to-head comparisons such as OCTIVUS and OPINION.

The mechanistic explanation for the survival benefit is procedural. Imaging-guided PCI consistently results in larger post-dilatation balloons, larger and longer stents, greater minimal stent area, and more complete coverage of the diseased segment. Registry data going back to the HORIZONS-AMI substudies and the seminal work of Fujii have linked stent underexpansion and residual reference stenosis to acute and late stent thrombosis — the most feared complication of PCI, carrying high mortality. Imaging makes these failure modes visible before the patient leaves the catheterization laboratory. Achieving prespecified optimization criteria — typically a minimal stent area of 5.0 square millimeters by OCT or 5.5 square millimeters by IVUS in distal references, plus full lesion coverage — has been repeatedly associated with improved long-term outcomes, although the review’s authors stress that pursuing these numeric thresholds must never come at the cost of procedural safety, for instance by forcing oversized balloons into vessels at risk of rupture.

Patient subgroups add further nuance. In acute coronary syndromes, imaging characterizes the culprit plaque, identifies plaque rupture and erosion, detects residual thrombus, and helps distinguish which lesions truly warrant stenting — particularly valuable when multiple lesions compete for attention. Patients with diabetes mellitus, whose plaques tend to be diffuse and negatively remodeled, and those with chronic kidney disease, who face elevated event rates after PCI, appear to derive particular prognostic benefit from imaging-guided optimization in complex anatomy, as shown in analyses from ULTIMATE and from the JAMA Network Open cohort of Kwon and colleagues. Conversely, in straightforward lesions, the added contrast injections, catheter exchanges, cost, and procedural time may not be justified. Current guidelines reflect this gradient: the 2024 European Society of Cardiology chronic coronary syndrome guidelines give imaging a class IIa recommendation for stent sizing and optimization, while the 2025 American ACC/AHA acute coronary syndrome guideline similarly endorses imaging use in selected settings.

The barriers to wider adoption are less scientific than economic and cultural. Surveys by the European Association of Percutaneous Cardiovascular Interventions and the Japanese association CVIT documented persistent underuse outside East Asia, where imaging guidance in complex PCI has become routine. A white paper by Escané and colleagues catalogued the reasons: reimbursement gaps, longer procedure times, unfamiliarity with image interpretation, and organizational inertia. Health-economic analyses complicate the picture in imaging’s favor — the RENOVATE-COMPLEX-PCI cost-effectiveness analysis suggested that, despite upfront device costs, avoided repeat revascularizations and reduced infarctions can offset expenditures, particularly in complex anatomy where the event-rate reduction is largest.

The review also charts where the field is heading. Hybrid catheters combining IVUS and near-infrared spectroscopy can map lipid-rich, potentially vulnerable plaques, and the PROSPECT II natural-history study showed that such non-culprit lipid-rich plaques predict future events, opening the door to preventive local therapy. Computational advances promise to shrink the learning curve: artificial-intelligence algorithms now perform automated lumen and external elastic membrane contouring, stent-apposition analysis, calcium scoring, and even OCT-derived fractional flow reserve, validated in trials such as FLASH and FUSION. Combining optical flow ratio with post-stent physiology assessment may eventually let one imaging pull-through yield both anatomical and functional verdicts on the result, reducing contrast load and procedure time simultaneously.

For clinicians, the practical message distilled by Biccirè and colleagues can be organized around four questions: why, when, how and which. Why: because imaging converts an educated guess into measurement, and the randomized evidence shows this conversion lowers cardiac death, stent thrombosis and repeat procedures in the right patients. When: preferentially in left main, bifurcation, long, calcified and chronic total occlusion lesions, in acute coronary syndromes with ambiguous culprits, and in patients with diabetes or chronic kidney disease undergoing complex PCI. How: with disciplined pre-implantation sizing, deliberate post-dilatation, and verification against validated optimization thresholds, without compromising safety. Which: either OCT or IVUS produces comparable outcomes in most settings, so the choice can follow availability, operator expertise and specific needs — OCT’s superior resolution for bifurcation morphology and plaque characterization, IVUS’s deeper penetration for sizing large vessels such as the left main. What began as a technology searching for proof now stands, for complex interventions, on one of the firmer evidentiary foundations in interventional cardiology.

Subject of Research: Use of intracoronary imaging to guide percutaneous coronary intervention in randomized clinical trials

Article Title: Intracoronary imaging in percutaneous coronary intervention: why, when, how and which from large, randomized trials

Article References: Biccirè, F. G., Gonzalo, N., Hahn, J.-Y., Jang, I.-K., & Räber, L. (2026). Intracoronary imaging in percutaneous coronary intervention: why, when, how and which from large, randomized trials. Nature Reviews Cardiology. https://doi.org/10.1038/s41569-026-01342-3

Image Credits: AI Generated

DOI: 10.1038/s41569-026-01342-3

Keywords: intracoronary imaging, percutaneous coronary intervention, optical coherence tomography, intravascular ultrasound, stent optimization, randomized trials, bifurcation lesions, acute coronary syndrome, stent thrombosis, left main PCI, coronary artery disease, interventional cardiology

INSIGHT CRN, recognized as one of the largest urban clinical networks nationwide, operates through a consortium of eight prominent academic health centers located in New York City and the Houston metropolitan area. Spearheaded by a leading team from Weill Cornell Medicine, the network’s collaborators span esteemed institutions such as Columbia University Irving Medical Center, Montefiore Health System, Mount Sinai Health System, NewYork-Presbyterian, NYU Langone Health, Houston Methodist, and the recent inclusion of Stony Brook Medicine, which contributes an additional 1.3 million patient records. This collective trove of electronic health records (EHRs) encompasses comprehensive medical histories, laboratory results, and diagnostic data, creating an unparalleled reservoir for research.

At the core of INSIGHT’s data architecture is the integration of rich, longitudinal patient information. Beyond standard clinical variables, the network ingeniously links electronic health records with claims data from commercial payers and government agencies, as well as non-medical determinants of health, such as socioeconomic status, housing instability, educational attainment, and food insecurity. This multidimensional data fusion profoundly expands the potential for patient-centered outcomes research, particularly in addressing health disparities and fostering health equity.

Leading this ambitious enterprise, Dr. Rainu Kaushal, the principal investigator, senior associate dean of clinical research, and chair of the Department of Population Health Sciences at Weill Cornell Medicine, underscores the transformative power of this database. According to Dr. Kaushal, INSIGHT’s robust and accessible data infrastructure is uniquely positioned to support research that improves health outcomes across diverse populations, particularly those historically underrepresented in clinical research. The capability to analyze real-world evidence at such scale is essential for bridging gaps in patient care and optimizing therapeutic strategies.

INSIGHT’s leadership team also includes Dr. Mark G. Weiner, professor of clinical population health sciences and medicine, and Dr. Thomas R. Campion, Jr., chief research informatics officer and professor of research in population health sciences. Together, they advance the network’s mission through innovative informatics solutions and by fostering collaborations that amplify scientific discovery. Their expertise ensures that the data is not only voluminous but also meticulously standardized and curated to meet the stringent criteria for clinical research validity.

Originally established in 2013 with a foundational $7 million grant, INSIGHT is integrated within PCORnet®, the National Patient-Centered Clinical Research Network. PCORnet itself is a pioneering initiative designed to accelerate patient-centered research by leveraging electronic data resources nationwide. During its initial phase, Weill Cornell Medicine and its collaborators developed a secure, cloud-based infrastructure to govern and facilitate data sharing with robust patient protections in place. The governance model notably incorporates patient representatives who play active roles in shaping research priorities, study designs, and dissemination strategies, thereby embedding the patient voice at every stage.

Over the past decade, INSIGHT has undergone three competitive renewals and attracted more than $100 million in research funding. This success speaks to the network’s rigorous data quality, governance, and ability to support cutting-edge clinical research studies. Patient and community engagement remain central pillars of INSIGHT’s operation, underscoring its commitment to co-creation and transparency. Employing the Accelerator Model, a multi-stakeholder engagement framework, the network fosters dynamic interaction among investigators, patients, regulatory bodies, and community advocates, ensuring that diverse perspectives inform every research initiative.

In its recent Phase 3 activities, the INSIGHT network played a crucial role in the RECOVER PCORnet Adult Initiative, a large-scale consortium dedicated to studying Post-Acute SARS CoV-2 Syndrome (PASC), commonly known as Long COVID. This initiative harnessed the power of real-world and EHR data spanning more than 40 healthcare institutions nationwide to better understand the heterogeneous manifestations of Long COVID. The groundbreaking work identified four primary clinical subtypes of the syndrome and delineated how long COVID risk varies across different demographic and clinical populations, providing invaluable insights for tailored treatment approaches.

Dissemination of these Phase 3 findings has been comprehensive, reaching academic platforms through nearly 100 peer-reviewed publications and numerous presentations at national conferences. Moreover, the wide media coverage—including prominent outlets such as NBC News, Today, and PBS—has ensured public awareness and facilitated the translation of research into actionable health policies. The network’s commitment to transparent and timely dissemination reinforces its goal of accelerating beneficial outcomes for patients and communities at large.

Looking ahead, the newly funded Phase 4 of INSIGHT aims to enhance four strategic pillars: engagement, data infrastructure, dissemination, and governance with research readiness. Critical advancements will include the development of real-time dashboards to monitor study progress and results transparently, repositories for sharing analytic code to promote reproducibility, and expanded presentations that showcase the full spectrum of INSIGHT and PCORnet’s research capabilities. Moreover, the network will continue refining the PCORnet® Common Data Model, a standardized framework that harmonizes data variables and definitions across contributing sites to maximize interoperability and analytic precision.

The network’s vision also encompasses the integration of innovative data streams, such as claims data, patient-reported outcomes, and nuanced social determinants of health. Such comprehensive data amalgamation will dramatically increase the dimension and depth of research inquiries possible, enabling studies with unprecedented scale and granularity. INSIGHT’s enhanced capacity positions it to lead investigations shaping novel therapies, emerging care models, and health policies that address social determinants and promote systemic social change.

Collaborative synergy lies at the heart of INSIGHT’s continued success. By actively working with other Clinical Research Networks across the country, INSIGHT shares best practices, harmonizes methodologies, and optimizes collective data assets. This inter-network collaboration within the PCORnet umbrella ensures that patient-centered research benefits from nationwide integration, promoting powerful discoveries that transcend geographic boundaries.

In addition to expanding traditional clinical research frameworks, the INSIGHT dataset increasingly supports the development and validation of advanced artificial intelligence (AI) and machine learning models. These models are applied to complex clinical challenges such as predictive risk stratification, early intervention strategies, and personalized treatment plans across myriad chronic and acute conditions. Techniques ranging from target trial emulation to natural language processing of unstructured clinical notes enable the extraction of critical clinical insights not readily accessible through conventional analyses, thus empowering clinicians and public health experts with actionable intelligence.

As Dr. Kaushal eloquently summarized, the forthcoming four years of INSIGHT work will harness this expanding and richly detailed real-world database to address the most pressing health questions of our time. By fostering convergence between clinical research, informatics, and patient engagement, INSIGHT is poised to redefine how health outcomes are improved on both local and national scales. Its growing data infrastructure stands as a beacon of innovation and equity in modern clinical research.

Subject of Research: Patient-centered clinical research using large-scale electronic health record data to improve health equity and outcomes, with applications in chronic diseases and Long COVID.

Article Title: (Not provided)

News Publication Date: (Not provided)

Web References:

• https://vivo.weill.cornell.edu/display/cwid-rak2007
• https://vivo.weill.cornell.edu/display/cwid-mgw4001
• https://vivo.weill.cornell.edu/display/cwid-thc2015
• https://news.weill.cornell.edu/news/2022/02/98-million-nih-grant-drives-clinical-research-into-long-covid
• https://news.weill.cornell.edu/news/2022/12/study-identifies-four-major-subtypes-of-long-covid
• https://news.weill.cornell.edu/news/2023/05/study-discovers-long-covid-risk-and-symptoms-vary-in-different-populations

References: (Detailed academic references not provided in source content)

Image Credits: (Not provided)

Keywords: Health equity; Health care policy