Holobiome and Radicle Science Launch U.S. History’s Largest Mental Wellness Trial Targeting the Gut-Brain Axis

The GUT-FEELINGS program, funded by ARPA-H, will identify readily deployable non-prescription solutions for mental wellness while also creating an unprecedented interventional dataset from over 6,000 Americans to support mapping the gut-brain axis

BOSTON and SAN DIEGO, Oct. 08, 2026 (GLOBE NEWSWIRE) -- Holobiome and Radicle Science today announced the launch of GUT-FEELINGS, a landmark two-year research initiative backed by an award from the Advanced Research Projects Agency for Health (ARPA-H), an agency within the U.S. Department of Health and Human Services. The study will enroll over 6,000 diverse Americans in two waves and test 19 readily deployable proprietary food-derived prebiotic formulas against placebo to determine which can improve feelings of anxiety and related mental wellness outcomes—and in which populations—with initial results expected in the second half of 2027.

The scale and design of GUT-FEELINGS set a new standard for interventional research – combining a tech-enabled, randomized, placebo-controlled decentralized design with 19 prebiotic interventions, more than 6,000 diverse citizen scientists, and the collection and analysis of over 24,000 fecal samples and 12,000 blood samples.

The 16-week, 20-arm study will randomize participants experiencing feelings of anxiety to receive one of 19 distinct prebiotic formulations or placebo. The teams will assess validated measures of feelings of anxiety alongside stress, mood, sleep, quality of life, flourishing, weight and waist measurements, and diet quality. These participant-reported outcomes will be paired with deep biological and digital data, spanning ultra-deep fecal microbiome sequencing and metabolomics, blood proteomics, wearable data, facial scans, and continuous glucose monitoring.

Combined, these rich data streams will broadly support Holobiome’s effort to build a foundation model of the human gut microbiome – Mercator – which will be used to understand how the gut microbiome interfaces with biology relevant for mental wellness and beyond, as well as inform probiotic and prebiotic development.

GUT-FEELINGS will conduct rigorous human research prior to product launch and apply a high-throughput, parallel approach to evidence generation. Instead of advancing one intervention at a time through a linear process, the study evaluates 19 interventions in parallel across two waves to uncover which ones work, and for whom. This approach is enabled by Radicle Science’s patented Reflexive Trials™ platform, which orchestrates and automates complex, multi-arm, multi-omic trials at national scale and feeds resulting human evidence directly back into R&D, formulation, regulatory, and marketing efforts. This can dramatically compress and de-risk the innovation cycle: a single trial can identify the strongest candidates to advance, substantiate compliant health claims, reveal responder subpopulations, surface nonobvious insights that may support patent filings, and generate data to inform next-generation formulations.

A vast majority of food and wellness brands reach the market without clinical trials on their formulas, and when trials are conducted, they are often treated as a final checkpoint at the end of the innovation cycle. Here, human research becomes the engine for innovation, accelerating and de-risking the path from hypothesis to human evidence to proven, precision health interventions in the market.

The implications extend well beyond this study. GUT-FEELINGS will also demonstrate how it is now possible to combine large-scale citizen science, convenient decentralized participation, AI agents, gold standard interventional trial design, and at-home biological sampling and digital measurement. The result is a novel, rapid, repeatable model for generating rigorous evidence on non-pharmaceutical health interventions across large, diverse populations—without the business model constraints or budgets of pharmaceutical drug development.

The collaboration is only possible through the combination of two cutting edge, complementary platforms and datasets. Holobiome’s microbiome discovery platform is built around its Microbiome Vault (the world’s most diverse collection of human gut bacteria), its high-throughput human gut-simulator, and a proprietary database mapping more than 120,000 human metagenomes to specific health states. Radicle Science brings its patented reflexive trials platform, nationwide community of citizen-scientists, vertically integrated research operations, and proprietary clinical dataset from Radicle’s food and wellness trials on nearly 100,000 Americans (world’s largest such dataset).

GUT-FEELINGS is part of ARPA-H’s Evidence-Based Validation & Innovation for Rapid Therapeutics in Behavioral Health initiative (EVIDENT), which is focused on finding objective measures of mental health and well-being.

PERSPECTIVES ON WHY GUT-FEELINGS MATTERS

Philip Strandwitz, PhD
CEO and Co-founder, Holobiome
“The human microbiome matters for so many aspects of our health, including mental wellness, but we do not yet have the data or the tools to bring its promise to the world. The missing link is large-scale multimodal data from interventional studies, the kind this trial is designed to generate. We are so excited to launch this initiative, which provides a scalable framework we can apply time and time again.”

Pelin Thorogood and Jeff Chen, MD, MBA
Co-founders, Radicle Science
“Clinical research has traditionally been used to validate products after they are developed. We built Radicle to invert that model—using rigorous human evidence earlier to catalyze discovery, optimize formulations and accelerate the path to proven, precision interventions. GUT-FEELINGS brings that vision to life at a scale never before possible. It is not simply a landmark study; it is a blueprint for evidence-first health innovation.”

Jonathan E. Fielding, MD, MPH, MBA
Distinguished Professor, UCLA; former Director and Health Officer, Los Angeles County Department of Public Health
“One of the great challenges in public health is identifying interventions that are not only effective, but practical and broadly accessible. GUT-FEELINGS can help establish whether food-based approaches can meaningfully improve mental wellness across a diverse population.”

Jonathan D. Ketcham, PhD
Professor, Arizona State University; Health Economist; Radicle Science Advisory Board
“Health innovation creates the greatest value when meaningful outcomes and broad accessibility coexist. GUT-FEELINGS can help establish where food-based interventions can have the greatest impact—and build the evidence needed to understand how improved health outcomes can translate into economic value for individuals, employers and health systems.”

This research was, in part, funded by the Advanced Research Projects Agency for Health (ARPA-H). The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the United States Government.

ABOUT HOLOBIOME

Holobiome is a biotechnology company harnessing the potential of the human gut microbiome to generate products for consumer, food, and pharmaceutical markets. The Holobiome platform is a lab-in-the-loop system that combines large-scale human data with wet-lab experiments. It is powered by its Microbiome Vault (the world’s most diverse collection of human gut bacteria), its high-throughput human gut-simulator, and a proprietary database mapping more than 120,000 human metagenomes to specific health states. Mercator, its developing foundation model of the human gut microbiome, learns from this data, guides experiments in the lab, and informs product development. Interventional experiments, from the gut simulator to large-scale human trials such as GUT-FEELINGS, are designed to feed results back into the model.

Holobiome’s initial focus is on the gut-brain axis, with programs in mood, anxiety, stress, and pain. Through its partnership model, Holobiome is advancing microbiome programs with consumer, food, and pharmaceutical partners. Holobiome has been supported by a world-class investor base and non-dilutive funding from ARPA-H, the NIH, and the Translational Research Institute for Space Health (TRISH). It is headquartered in Boston, Massachusetts.
www.holobiome.org

ABOUT RADICLE SCIENCE

Radicle Science is a healthtech company building the evidence and innovation infrastructure for proven, precision wellness. Its patented Reflexive Trials™ platform powers Radicle’s Proof-as-a-Service™ model, combining AI, citizen science and large-scale decentralized clinical trials to generate rigorous evidence with unprecedented speed, scale and precision.

Since 2021, Radicle has conducted placebo-controlled research involving nearly 100,000 diverse Americans across all 50 states. By moving human evidence earlier in the innovation cycle, Radicle helps catalyze discovery and accelerate the development of proven, precision interventions.

Radicle Science has been recognized as a Fast Company World Changing Idea and named to the Inc. 5000 for two consecutive years.
www.radiclescience.com

Media Contacts:

Holobiome: Jonathan Krive, jonathan@holobiome.org, 857-244-1633
Radicle Science: Heather Granato, heather.granato@radiclescience.com, 480-390-4327