Tiny Health raises $33M for microbiome testing and outcomes research

Tiny Health sells at-home microbiome tests to consumers and supplies testing through clinicians and wellness companies. Customers collect a small stool sample with a swab, mail it in and receive a report describing detected microbes, possible functions and suggested next steps. The Austin startup announced a $33 million Series B led by B Capital on September 29.

The company entered through baby gut tests in 2022, then broadened into pregnancy, vaginal and adult testing; adults are now its largest testing segment, according to co-founder and CEO Cheryl Sew Hoy. That evolution matters because the product is a wellness tool, not a diagnostic test. Insurance doesn’t cover it, and while it can identify microbes in a sample, it can’t establish what caused a person’s symptoms.

Tiny Health says it uses shotgun metagenomic sequencing to analyze microbial DNA, providing a broader view than tests limited to selected microbes. Reports pair the findings with explanations, dietary suggestions and links to research. A subscription called Tiny Plus bundles a baseline test with a retest.

The faster-growing side of the business is Powered by Tiny, which distributes testing through healthcare providers and companies that incorporate it into their own services or research. Tiny Health says more than 6,000 practitioners use its tests, and names Superpower, Fullscript and Mayo Clinic’s Executive Health and Longevity Programs as partners. Overall revenue has more than doubled annually, while this business-to-business arm grew fourfold last year, Sew Hoy said; the company did not disclose revenue.

The startup also says it has collected nearly 200,000 microbiome samples. Its planned TinyAI tool will combine that data, health information stripped of identifying details and research reviewed by company scientists to help users interpret results. The larger ambition is finding patterns associated with future health risks, but whether microbiome-guided interventions actually improve outcomes remains unresolved.

New capital will expand work with providers and other companies, train clinicians and support outcomes research. Tiny Health plans to dedicate $5 million to giving researchers and clinical partners access to its tests and data, and to add 30 employees to a workforce of about 40. The round brings total funding to $46 million after a $4.5 million seed round in 2021 and an $8.5 million Series A in late 2023.