Most smart pills deliver medication, track medication compliance, or contain a microscopic camera for internal diagnostic imaging. Now, innovative smart pills can also take a sample of gut bacteria to help understand and diagnose illness. Researchers at Purdue University have designed a new smart pill that can extract a sample from a targeted gut area for precision analysis.

The intestinal microbiome involves many biochemical processes that benefit both the host and the microorganisms that dwell in the gut. In the last decade, science has illuminated the connection between gut bacteria and various health conditions, such as diabetes, Alzheimer’s disease, and depression.

The large and small intestines each have sections that house a unique microbiome. A thriving biome supports the immune system and has a positive impact on neurological function. When the wrong bacteria invades the biome, or not enough good bacteria is present, it compromises immunity as well as brain and nervous system health.

Clinicians have continued to rely on fecal samples to evaluate gastrointestinal flora. Yet, it’s impossible to determine which part of the digestive system the bacteria contained in such samples represent. To address this issue, the Purdue University research team designed a 3D printed outer capsule that houses an absorbent hydrogel. There are no electronics involved in this passive device. The capsule has a top that dissolves when it encounters a target pH level in the intestine.

When a patient swallows the pill, the top dissolves as it enters the target biome, exposing the hydrogel. The hydrogel absorbs a bacterial sample; as it swells, it presses on the remaining lower capsule, triggering it to close in to protect the contents. The pill then continues through the colon, eventually exiting the body.

The team first tested their prototype in a lab setting; currently, studies are underway in pigs, which have a digestive system similar to humans. This smart pill could potentially target any part of the digestive tract and provide a diagnostic tool that complements camera imaging systems.