Intero Biosystems Sells Lab-Grown Mini Intestines for Drug Testing as FDA Weighs Animal Alternatives

The startup’s flagship product, GastroScreen, is a human intestinal organoid model sold to pharmaceutical, biotech, food and chemical companies for testing drugs and other compounds, according to TechCrunch. Each organoid is about one millimeter across, and the company ships roughly 100 at a time in a tube, co-founder and CEO Charlie Childs said. Customers can use them as healthy intestinal models or induce disease-like conditions to test how the tissue responds to different compounds. “We’re literally shipping mini living organs in the mail to people,” Childs said.

Intero says its organoids differ from simpler models that replicate only part of the gut. They contain multiple cell and tissue types found in the human intestine, co-founder and CTO Madeline Eiken told TechCrunch. “Most drugs fail clinical trials, and I think it’s pretty easy to appreciate that we are neither mice nor flat layers of cells,” Eiken said. Beyond the organoids themselves, Intero sells supplies needed to grow and work with them, such as nutrient mixes that feed the cells and chemicals used in experiments. It also runs studies for customers, including designing custom experiments, performing lab tests and delivering the resulting data. Much of this work focuses on drug safety and disease research.

Founded in 2024, Intero has seven employees and just under 10 customers after raising a $2.3 million pre-seed round last year, Childs said. It generated more than $400,000 in revenue from the fourth quarter of last year through the third quarter of this year, he noted.

Regulatory changes have helped drive interest in alternatives to animal testing. In April 2025, the U.S. Food and Drug Administration laid out plans to reduce its reliance on animal testing in drug development, promoting organoids, organs-on-chips and AI-based computational models as potential alternatives. In March 2026, the FDA issued draft guidance outlining how drug developers should validate new approach methodologies, or NAMs, when using them to support regulatory submissions. The guidance provides a framework for validation but does not endorse any specific method, and whether a NAM can support a submission depends on factors including the method, how it is used and the data provided. Eiken told TechCrunch that changes in U.S. law allowing drug developers to use non-animal testing methods in some cases have made pharmaceutical companies more willing to explore technologies such as organoids, with companies once hesitant now looking to bring the technology in-house.

Intero is not alone in trying to build more human-relevant models of the gut. Altis Biosystems develops stem cell-derived intestinal models, while InSphero offers patient-derived intestinal organoids for gastrointestinal toxicity testing. MIMETAS takes a different approach with organ-on-chip technology, using microfluidic systems to recreate aspects of the environment inside human tissues.

Intero says it sets itself apart through the complexity and scalability of its model. Unlike intestinal models grown from tissue collected through procedures such as colonoscopies, GastroScreen is derived from induced pluripotent stem cells, which are adult cells reprogrammed to become almost any cell type and can be generated from a blood sample, Eiken explained. That approach gives the startup the potential to personalize its models to different patients and scale production more easily, she added.

When asked what evidence shows GastroScreen can predict human drug responses more accurately than existing animal or cell-based models, Childs said the company is still building that evidence and is now in the second stage of a three-stage validation process. Having first shown that GastroScreen contains the key tissues of the human gut, Intero is now testing well-known drugs with documented effects in humans.

Editor's Summary Intero Biosystems is commercializing human intestinal organoids for drug and chemical testing as regulators and drugmakers seek alternatives to animal models. The Denver startup has raised $2.3 million, reported more than $400,000 in revenue, and says its GastroScreen model is in the second stage of validation. FDA draft guidance and U.S. legal changes have encouraged broader industry interest in non-animal methods.