A new industry analysis maps 30-plus microbiome startups against longevity, and finds a field still torn between wellness and medicine.
For a long time, the gut microbiome sat in the “probably relevant, hard to prove” bucket of aging science. That changed, officially at least, in 2023, when the widely cited framework describing the hallmarks of aging, the biological processes researchers broadly agree drive us toward decline, expanded from nine categories to twelve. Gut dysbiosis, the breakdown of a healthy microbial balance in the digestive tract, made the cut. It’s now considered a driver of aging in its own right, not just a symptom of it.
A new landscape analysis from Plug and Play Ventures, a firm that scouts startups across health and biotech, takes stock of what’s actually being built in response. The team mapped more than 30 companies working at the intersection of microbiome science and longevity [1]. What comes back is a field with real scientific momentum and, frankly, a still-unresolved identity crisis.
Some of the underlying biology explains why investors keep circling back here. About 70% of the human immune system lives in the gut. Roughly 90% of the body’s serotonin, the neurotransmitter tied to mood, gets produced there too, not in the brain as most people assume. And unlike a person’s genome, the microbiome is something people can actually change through diet, lifestyle and now, increasingly, through targeted intervention.
The market has followed the science, more or less. According to the Microbiome Global Market Report 2026, the global microbiome market grew from $295 million in 2020 to more than $800 million in 2025, and it’s projected to top $3 billion by 2035. Diagnostics, the tests that tell you what’s going on in your gut, still make up more than 80% of that market today. But therapeutics and active microbiome modulation, the products that try to actually change what’s happening rather than just report on it, are the fastest-growing slice. The field, in other words, is moving from measuring the problem to treating it.
The report organizes the startup landscape around four biological “levers,” though the lines between them blur more than any tidy framework suggests. Inflammaging, the chronic low-grade inflammation that builds quietly over decades, is the best understood of the four, tied to a weakened gut barrier that lets bacterial fragments leak into the bloodstream and trigger a slow-burning immune response linked to heart disease and type 2 diabetes. Metabolic health is the best-funded corner by a wide margin. Companies like Viome and Pendulum have raised hundreds of millions of dollars around the idea that gut bacteria shape how the body handles blood sugar and energy, a story that’s picked up extra relevance now that GLP-1 drugs dominate the metabolic conversation.
The gut-brain axis might be the most surprising piece of all this. Research published in Nature in 2024 found distinct microbiome signatures showing up years before the clinical symptoms of cognitive decline appeared, which raises the odd possibility that the gut functions as an early warning system for conditions like Parkinson’s and Alzheimer’s. Then there’s the gut-skin axis, probably the least expected connection on the list, linking intestinal inflammation to visible aging: everything from eczema to accelerated collagen breakdown. It’s part of why L’Oréal, Unilever, and Estée Lauder have all quietly built out microbiome research programs of their own.
Worth remembering here: this isn’t the field’s first attempt. Kaleido Biosciences shut down in 2022. Evelo Biosciences closed in 2023. Seres Therapeutics, despite winning FDA approval for its therapy Vowst, ended up selling it to Nestlé Health Science in 2024 rather than commercialize it alone. The common thread, according to the report, is that these companies treated the microbiome as a single, isolated drug target, when it actually behaves as an interconnected system touching inflammation, metabolism, brain function and skin, more or less all at once. Newer entrants, armed with better sequencing and AI-driven modeling, are betting they can finally treat it that way instead.
One company the report singles out is Jona, a New York-based platform founded by Leo Grady, who previously led the AI pathology company Paige.ai to its first-ever FDA approval for an AI diagnostic product. Jona’s real difference isn’t the testing itself, but what happens after. Its AI cross-references a person’s results, which can flag more than 21,000 different microorganisms, against roughly 220,000 peer-reviewed studies, then simulates how different diets or supplements might shift that person’s biology before recommending anything.
“We’re seeing a real inflection point in consumer interest around the microbiome,” Grady said, noting that nearly half of Americans now report taking probiotics daily or almost daily [2].
Still, the report is candid that most startups in this space haven’t fully committed to a longevity positioning yet, leaning instead on general wellness claims or narrow disease indications. That’s starting to shift. Whether it shifts fast enough, and whether these companies end up getting judged by clinical trial data instead of gut-health marketing copy, is probably the question that decides which ones are still around in five years.
[1] https://www.plugandplaytechcenter.com/insights/microbiome-and-longevity-startups
[2] https://www.forbes.com/sites/margauxlushing/2026/03/27/digital-health-platform-everlywell-announces-new-microbiome-test-and-partnership-with-jona/
