# Ingestible active capsule for gastrointestinal microbiome sampling

## TL;DR

A new ingestible capsule can collect gut microbiome samples from specific parts of the gastrointestinal tract, improving the accuracy of microbiome studies.

## Contribution

The development of a modular, wireless sampling capsule that enables segment-specific microbiome collection in variable gastrointestinal conditions.

## Key findings

- The capsule's actuator module successfully collected and preserved liquid samples in vitro using a stool simulant and porcine intestine.
- The opening valve activated within 3.6 ± 0.5 seconds, and the closing valve sealed the inlet completely within 10 minutes.
- The design functions effectively in liquids with varying pH, chemical composition, viscosity, and particle size.

## Abstract

Various gastrointestinal disorders have been linked to gut microbiome dysbiosis, as it plays a critical role in immune regulation, metabolism, nutrient digestion, and pathogen suppression. However, the microbiome’s spatial variability across gastrointestinal segments and its intra- and interindividual differences complicate its study and clinical interpretation. While fecal DNA analysis is commonly used, stool samples only capture an accumulated signal and miss the spatial dynamics of microbial populations. To address this, we propose a modular sampling capsule capable of wirelessly collecting liquid. The capsule consists of two main modules: (i) an actuator module integrating a polymer-based microfluidic system with meltable wax-based opening valve, screen-printed microheater, cellulose membrane-based closing valve, evacuated sampling chamber with dried sample preservative material, filter membrane (size exclusion 150 μm), and sample extraction channel; and (ii) a control electronic module with communication, localization, and power supply units. The actuator module was validated in vitro using a diluted stool simulant (330 mg/mL) and an uncleaned porcine intestine. The opening valve activated within 3.6 ± 0.5 s at 120 ± 10 mA and 0.8 V. The sample was then filtered and aspirated into the sampling chamber within 1–2 s, and the closing valve sealed the inlet completely within 10 min. We overcame design, material, and fabrication challenges to construct an actuator module that functions effectively in liquids with variable physicochemical conditions (pH, chemical composition, viscosity, and particle size). These results demonstrate the feasibility of a controlled, segment-specific intestinal sampling capsule, representing a step towards precise and accurate microbiome profiling.

The online version contains supplementary material available at 10.1007/s10544-026-00802-4.