Overview
Microbiome medicine has moved from wellness pitch to regulated drug class. These companies are developing therapies for infections, allergic disease, and cancer, and each has shown real clinical, regulatory, or platform progress.
The first microbiome-based live biotherapeutic products ever FDA approved in the United States were Ferring’s Rebyota in late 2022 and Seres/Nestlé's Vowst in spring 2023. Both are used to treat recurrent Clostridioides difficile (C. diff) infection.
“Before those approvals, the microbiome was a hypothesis with a venture slide deck. After them, it was a regulated drug class with a label, a price, and a reimbursement fight,” says David H. Crean, PhD, Founder and Managing Partner at Cardiff Advisory.
Since then, Crean says the microbiome stopped being a story about wellness and became a story about mechanisms such as colonization resistance, gut-immune signaling, and the growing evidence that gut bacteria shape how patients respond to cancer immunotherapy. “Mechanism is what regulators approve and what acquirers pay for. That is the driver,” Crean says.
While demand will continue and deepen, he says this will be the case where the biology is tight and the endpoint is measurable including recurrent C. diff, graft-versus-host disease, bloodstream-infection prevention in stem-cell transplant patients, and oncology adjuvancy.
“The lesson is simple,” Crean says. “This is not a field with unlimited demand. It is a field with concentrated demand in the settings where a disordered microbiome is close to the mechanism of the disease. Bet there.”
Biotech companies that will be most successful in this space share four traits, according to Crean.
They make a defined, reproducible product with cloned, standardized consortia they can manufacture to specifications, not a donor-dependent process they can’t control.
They anchor to one tight indication with clinical urgency and a hard endpoint, rather than a platform chasing ten diseases at once.
They have a strategic partner supplying capital and commercial muscle. Seres had Nestlé, the Akkermansia Company had Danone, and Vedanta pulled in non-dilutive BARDA funding for its C. diff program.
They match their cash runway to a real catalyst, so they reach a data readout before they reach zero.
“The pattern is not subtle. Focus survives. Platforms without focus die,” he says. “The successful microbiome company today looks less like a discovery engine and more like a disciplined single-asset developer with an adult on the balance sheet.”
The defined consortium is the modality that has actually reached patients, and precision tools such as phages, engineered strains, metabolites are the ones to watch, not yet the ones to bank on, Crean notes.
He says the field is quietly repositioning itself. “It is no longer selling ‘the microbiome cures everything.’ It is selling the microbiome as a precision instrument in defined settings: preventing infection in immunocompromised patients, improving survival in graft-versus-host disease, and the one to watch tuning how cancer patients respond to immunotherapy,” Crean says.
We gathered nine U.S.-headquartered biotechnology companies developing microbiome-based medicines that have demonstrated meaningful clinical, regulatory, or platform progress.
Vedanta Biosciences
Sector: Live biotherapeutic products for gastroenterology, infectious diseases, and immunology
HQ: Cambridge, Massachusetts
Year Founded: 2010
Origin Story: Founded as a spinout incubated by PureTech Health, Vedanta was built around rationally designing medicines from defined consortia of human commensal bacteria, drawing on insights from microbial ecology and mucosal immunology pioneered by academic co-founders.
Key Leaders: Bernat Olle, PhD, Founder & CEO; Dan Couto, Chief Operating Officer; Steven Shiff, MD, SVP of Clinical Research; Anna Yuan, Senior Clinical Research Scientist
Number of Employees: ~84
Stage: Late clinical stage
Financial Snapshot: The company has raised between $355.7 million – $366 million to date.
Notable Investors: Atika Capital Management; Atlantic Neptune; AXA Investment Managers; and Fiscus Ventures; AMR Action Fund and BNP Paribas Asset Management Alts
Key Products: VE303, an 8-strain defined bacterial consortium for prevention of recurrent C. difficile infection
Recent Highlights: In August 2026, the company secured $60 million in funding. And in April 2026, the independent Data Monitoring Committee overseeing RESTORATiVE303, the pivotal Phase 3 trial of VE303, completed its first prespecified interim analysis and recommended the study continue without modification after determining efficacy exceeded the prespecified futility threshold with no new safety signals. Enrollment is expected to complete in the second half of 2026.
Siolta Therapeutics
Sector: Live biotherapeutic products / Immunology & allergic disease
HQ: San Carlos, California
Year Founded: 2016
Origin Story: Founded by Susan Lynch, PhD (UCSF) and Nikole Kimes, PhD, in partnership with Samir Kaul of Khosla Ventures. Nikole Kimes’s research in Dr. Susan Lynch’s lab at UCSF provided the foundation for the company’s translational research program.
Key Leaders: Susan Lynch PhD, Founder & Board of Directors; Nikole Kimes, PhD, Co-founder & CEO; Richard Shames, MD, Chief Medical Officer, Ricardo Valladares, PhD, Chief Scientific Officer
Number of Employees: ~15
Stage: Series C
Financial Snapshot: The company has raised approximately $42 million to date.
Notable Investors: Khosla Ventures; SymBiosis; TIME Ventures; Seventure; and Global Brain
Key Products: STMC-103H, an oral live biotherapeutic designed to prevent atopic dermatitis, food allergy, and allergic asthma in at-risk infants
Recent Highlights: In November 2025, Siolta reported positive top-line results from its Phase 2 ADORED study, with STMC-103H showing a 64% reduction in the risk of atopic dermatitis in infants completing one year of treatment, with strong and consistent effects across multiple efficacy endpoints and a favorable safety profile.
Osel Inc.
Sector: Live biotherapeutic products for women’s health, oncology/immunotherapy, and GI disease
HQ: Mountain View, California
Year Founded: 1996
Origin Story: The company filed its first IND with the FDA in 2003 for the clinical testing of a live biotherapeutic, well before the term Live Biotherapeutic Product (LBP) was introduced by the FDA in 2012.
Key Leaders: Peter Lee, MD, Founder & Executive Chairman; Tom Parks, PhD, Director of Product Development; Laurel A. Lagenaur, PhD, Director of Research and Board Member
Number of Employees: ~7
Stage: Clinical stage
Financial Snapshot: Osel is privately held and has received substantial government/non-dilutive funding over its history, but a concrete number isn’t readily available.
Notable Investors: U.S. Department of Health and Human Services (HHS) and Suma Ventures
Key Products: LACTIN-V, for recurrent bacterial vaginosis and preterm birth prevention; CBM588, for prevention of antibiotic-associated diarrhea/C. diff. Osel also announced a pivotal Phase 3 oncology trial in January 2026 for MO-03.
Recent Highlights: In May 2026, Osel launched FLIP-2, a Phase 2b trial in partnership with Imperial College London and March of Dimes, evaluating LACTIN-V in pregnant women at high risk of preterm birth, building on encouraging FLIP-1 pilot results showing LACTIN-V was safe, well-tolerated, and associated with a lower rate of preterm birth versus historical controls. The trial will enroll 360 high-risk pregnant patients across four UK maternity units.
Concerto Biosciences
Sector: Microbial discovery platform / dermatology & consumer health
HQ: Cambridge, Massachusetts
Year Founded: 2020
Origin Story: The company was founded on founder Jared Kehe’s MIT-developed “kChip” technology, which is a microfluidic device with 43,000 micro-wells enabling high-throughput screening of microbial community combinations.
Key Leaders: Cheri Ackerman, PhD, Co-founder & CEO; Jared Kehe, PhD, Co-founder & CSO; Bernardo Cervantes, PhD, Co-founder & COO
Number of Employees: ~24
Stage: Series A
Financial Snapshot: The company has raised approximately $24.5 million over two funding rounds.
Notable Investors: MassRobotics; Golden Seeds Ventures; 8VC; Allston Venture Fund; Alumni Ventures Safar Partners, Horizons Ventures, M Ventures, Golden Seeds, Humboldt, MassVentures, The Yard Ventures, Excelestar Ventures, Impact Science Ventures
Key Products: ENS-002, a three-strain topical live biotherapeutic targeting Staphylococcus aureus for atopic dermatitis, discovered via Concerto’s platform. Dermatologics; ENS-003, live microbial product designed to inhibit the virulence of Candida albicans and prevent recurrent vaginal yeast infections
Recent Highlights: In October 2025, Concerto announced positive topline results from the Phase 1b trial of ENS-002, which included eight adults. The study was designed to establish safety/tolerability and explore early efficacy signals.
Persephone Biosciences
Sector: Microbiome infant health and precision microbiome medicines for the identification of clinically actionable cancer-specific biomarkers
HQ: San Diego, California
Year Founded: 2017
Origin Story: When founder Stephanie Culler, PhD, was researching colon cancer, she became a mom. This pushed her to research the microbiome of babies. She launched the My Baby study on infant gut health and showed that nine in 10 U.S. babies were missing one or more keystone strains of Bifidobacterium.
Key Leaders: Stephanie Culler, PhD, CEO and Co-founder; Steve Van Dien, CTO and C-Founder
Number of Employees: ~19
Stage: Clinical stage
Financial Snapshot: The company has raised approximately $15.2 million since being founded.
Notable Investors: Capita3, Gaingels, Mesa Verde Venture Partners, Ocampo Capital, First Bight Ventures, Propel Bio Partners, Y Combinator, Fifty Years, Susa Ventures, BrightEdge, Pioneer Fund and ZhenFund
Key Products: Daily Synergistic Synbiotic, probiotic and prebiotic combination designed for infants and toddlers, which has been commercially launched.
Recent Highlights: In November 2025, Persephone announced positive topline results from the ARTEMIS study, a randomized, double-blind, placebo-controlled trial of its infant/toddler synbiotic, demonstrating rapid microbial colonization within 30 days of treatment and a statistically significant improvement in treated toddlers’ sleep quality. Persephone’s ARGONAUT study, the largest U.S. gut-microbiome study in cancer patients, is designed to analyze stool and blood samples across multiple cancer types with roughly half of participants from racial and ethnic minority backgrounds. In early 2025, the company’s AMBROSIA food-as-medicine trial for colorectal cancer risk reached full enrollment.
Kanvas Biosciences
Sector: Live biotherapeutic products / spatial biology & immuno-oncology
HQ: Princeton, New Jersey
Year Founded: 2020
Origin Story: Founded by Cornell PhD student Hao Shi, his advisor Iwijn De Vlaminck, and medical microbiologist Matthew Cheng, after the team developed HiPR-FISH, a breakthrough imaging platform.
Key Leaders: Matthew Cheng, Co-founder & CEO; Hao Shi, PhD, Co-founder & CTO, Iwijn De Vlaminck, PhD, Co-founder and Chair of the Scientific Advisory Board
Number of Employees: ~42
Stage: Series A
Financial Snapshot: The company aised a $48 million Series A in May 2026 to bring total funding to $78 million.
Notable Investors: DCVC; Lions Capital LLC; Gates Foundation; ATHOS KG; Germin8; Ki Tua Fund; Pangaea Ventures
Key Products: KAN-001, live biotherapeutic product designed to designed to improve response to immune checkpoint inhibitor therapy in solid tumors; KAN-004, a metabolically complete live biotherapeutic product for the treatment of immune-related colitis
Recent Highlights: In May 2026, Kanvas Biosciences received new funding to develop first-in-category microbiome therapeutic for improving maternal, newborn and child health. The money will fund initiation of clinical trials for KAN-001 and scale commercial partnerships built on Kanvas’s spatial imaging and manufacturing platform. The company is also preparing a Phase 1 trial for KAN-004.
Fzata, Inc.
Sector: Engineered oral biologics / gastrointestinal disease
HQ: Halethorpe, Maryland
Year Founded: 2015
Origin Story: Co-founders Hanping Feng, PhD, and Zhiyong Yang, PhD, spun out the company from University of Maryland antibody research on neutralizing C. diff toxins. The company was built to commercialize a first-in-class oral platform (BioPYM) that turns live yeast into a “micro-factory” for producing therapeutic biologics on-site in the gastrointestinal tract, avoiding needle-based delivery.
Key Leaders: Zhiyong Yang, PhD, Co-founder and CEO; Hanping Feng PhD, Co-Founder and Chief Scientific Officer
Number of Employees: ~10
Stage: Preparing for Series A
Financial Snapshot: The company has received NIH non-dilutive funding totaling more than $24 million.
Notable Investors: National Institutes of Health (NIAID, NINDS); Sage-Angel BioIncubator; Shenzhen Sangel Venture Capital
Key Products: FZ002, oral live yeast engineered to express a tetraspecific anti-toxin for prevention and treatment of C. difficile infection; FZ006, oral anti-TNFα therapy for IBD
Recent Highlights: In March 2026, Fzata was named a finalist for the Maryland ICON Award in the category of Emerging Life Sciences Company of the Year. The company is also targeting IND submission and Phase 1 initiation, pending FDA clearance.
Lumen Bioscience
Sector: Engineered oral biologics / infectious & gastrointestinal diseases
HQ: Seattle, Washington
Year Founded: 2017
Origin Story: Co-founders Brian Finrow, JD, a former senior executive at Adaptive Biotechnologies, and Jim Roberts, MD, PhD, a former head of basic sciences at the Fred Hutchinson Cancer Research Center, founded the company on the premise that spirulina, a cyanobacterium with a long history as a food, could be genetically engineered as a low-cost biomanufacturing host, making oral biologics economically viable for diseases previously considered uncommercial to treat.
Key Leaders: Brian Finrow, JD, Co-founder and CEO; Jim Roberts, MD, PhD, Co-founder and Chief Scientific Officer; John Morrow, COO
Number of Employees: ~101
Stage: Series C
Financial Snapshot: The company has raised $186.8 million cumulatively, including a $30 million Series C extension.
Notable Investors: WestRiver Group; Gates Foundation; Biomechanical Capital
Key Products: LMN-201, an oral biologic cocktail of four therapeutic proteins for treatment and prevention of recurrent C. difficile infection
Recent Highlights: In October 2025, Lumen closed a $30M financing round. In April 2025, top-line results from the RePreve Phase 2 trial showed LMN-201 achieved a 100% initial clinical cure rate in the sentinel cohort for C. difficile infection, with significant reduction in recurrence and a favorable safety profile.
Bloom Science
Sector: Live biotherapeutic products / neurology & metabolic disease
HQ: San Diego, California
Year Founded: 2018
Origin Story: Founded by Christopher Reyes, PhD, and Tony Colasin, building on UCLA research into how the ketogenic diet reduces seizures via changes to the gut microbiome. Bloom set out to “reverse-translate” that clinical observation, using its IrisRx platform to identify the specific microbial strains and metabolic pathways responsible, in order to replicate the diet’s therapeutic effects in a live biotherapeutic without requiring patients to maintain the diet itself.
Key Leaders: Christopher Reyes, PhD, Co-founder & CEO; Paolo Baroldi, PhD, MD, Chief Medical Officer; Louis Licamele, PhD, Chief Development Officer/EVP of Clinical and Data Science
Number of Employees: ~17
Stage: Series B
Financial Snapshot: The company has raised about $23 million to date.
Notable Investors: Leaps by Bayer; ALS Investment Fund; Apollo Health Ventures; Joyance Partners
Key Products: BL-001, orally-delivered live biotherapeutic in development for Dravet syndrome, obesity
Recent Highlights: In February 2026, the company initiated a Phase 1b obesity trial of BL-001, positioning it as a differentiated, non-GLP-1 approach to metabolic disease, and its leadership presented at the January 2026 J.P. Morgan Healthcare Conference and Sachs Neuroscience Innovation Forum.
