Cheryl Sew Hoy's daughter developed eczema and food sensitivities shortly after birth, a contrast to her younger son born without such issues. The difference prompted Sew Hoy to investigate the infant gut microbiome, a field her doctors were not familiar with. That experience led her to found Tiny Health in 2020, a company now raising $33 million in Series B funding to expand its at-home microbiome testing platform.

What You Need to Know

Tiny Health's at-home tests use shotgun metagenomic sequencing to analyze microbial DNA from stool samples, offering a broader view than traditional methods. The funding underscores growing investor interest in personalized gut health, with the company's revenue more than doubling each year. Its B2B arm, Powered by Tiny, saw fourfold growth last year, signaling demand from healthcare providers. The round, led by B Capital, brings total funding to $46 million and highlights the shift from infant-focused testing to a larger adult segment.

A Startup Born From a Mother's Question

After her daughter's birth via C-section, Sew Hoy read research linking early microbial exposure to health outcomes. She incorporated Tiny Health in Austin in 2020, a week after her son's birth. Today, the company announced a $33 million Series B round led by B Capital, with participation from Spero Ventures, The Venture City, Overwater Ventures, Black Opal Ventures and Alumni Ventures. B Capital's Nick Whitehead will join the board. Sew Hoy declined to disclose the valuation but said it was much higher than the $8.5 million Series A raised in late 2023.

The financing brings Tiny Health's total to $46 million, including a $4.5 million seed round in 2021. Sew Hoy invested $50,000 of her own money into an initial study before raising outside capital. The company spent two years developing its platform before launching a baby gut test in 2022.

From Infant Gut to Adult Markets

Tiny Health initially focused on infant testing, targeting parents of children with conditions such as eczema. The tests provide reports on detected microbes along with explanations and next steps. Adults, however, have since become the larger testing segment, according to Sew Hoy. The company also offers pregnancy, vaginal microbiome and adult tests. Its B2B arm, Powered by Tiny, sells tests through healthcare providers and other businesses, growing fourfold last year.

Sew Hoy believes a key differentiator is the use of shotgun metagenomic sequencing, which analyzes microbial DNA comprehensively rather than targeting a limited set of organisms. Chief science officer Kimberley Sukhum leads the scientific work, while co-founder Donald Koo handles technology and Dr. Elisa Song serves as chief medical officer.

  • Shotgun metagenomic sequencing: Provides a broad view of all microbes in a sample.
  • At-home collection: Customers use a swab to collect a small stool sample and mail it in.
  • Personalized reports: Includes explanations of detected microbes and suggested follow-up actions.
  • Subscription option: Tiny Plus offers a baseline test and a retest for ongoing monitoring.

Why This Matters

The funding validates the market for direct-to-consumer microbiome testing, a space that has seen both hype and skepticism. Tiny Health's focus on early-life intervention and its transition to adult testing suggest the company sees broader applications for gut health data. For parents, the tests could offer insights into conditions like eczema before symptoms worsen. For the healthcare system, companies like Tiny Health push clinicians to adopt microbiome analysis as a practical tool. The round also signals that investors see long-term potential in personalized, data-driven wellness outside traditional pharmaceutical models. As the company scales, the challenge will be translating microbial data into actionable advice that leads to measurable health outcomes.

Cheryl Sew Hoy's journey from concerned mother to CEO of a venture-backed startup illustrates the convergence of personal experience and scientific innovation. With $46 million in total funding and a growing customer base, Tiny Health is positioned to explore what gut data can reveal about future health, starting with the earliest stages of life.