Tiny Health has secured $33 million in an oversubscribed Series B funding round as the health technology company expands its gut and vaginal microbiome testing platform across different stages of life.
The Austin, Texas-based company was founded by Cheryl Sew Hoy in 2020 and launched commercially in 2022. The round was led by B Capital, with participation from existing investors Spero Ventures, The Venture City and Overwater Ventures, alongside new investors including Black Opal Ventures, Denver Ventures, Pave Health Ventures, Alumni Ventures, Gaingels and Pari Passu Ventures. The funding brings Tiny Health’s total funding to $46 million.
Tiny Health develops at-home microbiome tests covering the gut and vaginal microbiome. Its testing uses shotgun metagenomic sequencing to analyse microbial DNA in samples and provide information about the microorganisms detected and their potential functions.
The company initially focused on babies and mothers, building its platform around research into the first 1,000 days of life. Its offering has since expanded to include gut microbiome testing for babies, children and adults, alongside vaginal microbiome testing. Adult testing has now surpassed paediatric testing in volume as Tiny Health expands its platform across the lifespan.
Tiny Health says its platform now serves nearly 200,000 customers and more than 6,000 healthcare practitioners across independent practices, hospital systems, longevity clinics, consumer health companies and precision medicine organisations. Its B2B platform, Powered by Tiny, grew fourfold over the past year.
From Personal Experience to Health Technology
Sew Hoy’s experience as a mother was central to the creation of Tiny Health.
Her first child was born by caesarean section and later developed eczema, food sensitivities and a sesame allergy. Sew Hoy began researching the infant gut microbiome and became interested in whether differences in early microbial exposure could be connected to health outcomes.
After reading scientific research and discussing the subject with doctors, Sew Hoy began developing a way to make microbiome testing more accessible to parents. She invested $50,000 of her own money into an initial study before raising external funding.
Sew Hoy previously founded Reclip.It, a digital coupon company that was acquired by Walmart Labs in 2013. She incorporated Tiny Health in 2020 and spent two years developing its platform before launching its first at-home baby gut microbiome test in 2022.
The company subsequently expanded into pregnancy, vaginal microbiome testing and adult gut testing. According to Sew Hoy, adults have now become Tiny Health’s larger testing segment by volume.
$5M Microbiome Research Programme
Alongside the funding round, Tiny Health has announced a $5 million Microbiome Research Programme.
The programme will give researchers, clinicians and scientific partners access to Tiny Health’s microbiome testing, data and research capabilities. The aim is to support studies investigating microbiome interventions and generate further evidence around the role of the microbiome in human health.
Tiny Health says it has four published scientific papers and a second randomised controlled trial underway. The company’s research is moving beyond early-life health into areas including inflammatory bowel disease, menopause, GLP-1 therapies and responses to oncology treatments.
One 2025 study involving infants born by caesarean section reported that targeted microbiome interventions reduced the infants’ odds of developing eczema by 83%. The finding comes from that specific study and should not be interpreted as evidence that microbiome interventions generally prevent eczema.
Expanding Into Women’s Health
While Tiny Health began with a strong focus on babies and mothers, the company is now positioning its technology across the entire lifespan.
Its platform includes gut microbiome tests for babies, children and adults, as well as vaginal microbiome testing. Its research programme is also examining the microbiome in relation to menopause and other areas of women’s health.
The company’s focus on vaginal microbiome testing places it within the growing women’s health technology sector, while its wider platform is designed to address preventive health, chronic conditions and longevity.
Tiny Health describes its testing as a wellness service rather than a diagnostic. The company’s tests identify microorganisms and microbial functions in samples but cannot establish the cause of a person’s symptoms or replace medical diagnosis and professional medical care.
Building a Microbiome Data Platform
The new funding will support clinical research, interventional studies, healthcare practitioner education and the expansion of Powered by Tiny.
Tiny Health is also developing TinyAI, an artificial intelligence tool designed to help users understand their microbiome results. The system draws on the company’s proprietary dataset of nearly 200,000 microbiome profiles and scientific research reviewed by its team.
The company is also developing tools focused on areas such as Gut Microbiome Age, Gut Resilience and Gut Body Connections as it expands its research into longevity and healthy ageing.
Powered by Tiny is meanwhile expanding the company’s reach beyond direct-to-consumer testing. The platform provides microbiome testing and related capabilities to healthcare and consumer health organisations. Tiny Health says its enterprise partnerships include Fullscript, Mayo Clinic’s Executive Health and Longevity Programmes, Atria Institute and Superpower.
Tiny Health’s revenue has more than doubled each year, according to Sew Hoy, while its B2B business grew fourfold over the past year. The company has not disclosed its current valuation.
With its latest $33 million investment, Tiny Health is moving beyond its original focus on infant microbiome testing and building a broader health technology platform focused on gut health, vaginal health, clinical research and personalised health insights across the lifespan.
