Self-polymerizing pill developed to sample gut microbes

10 Sep 2020 --- Researchers have developed an ingestible pill that is released in the intestine to collect gut microbes, which are known to be difficult to capture.

Colonoscopy, endoscopy and collecting stool samples are the three main ways that researchers currently obtain gut microbes, but the pill tested in a new rat study presents a “strong foundation” for researching more effective, non-invasive treatment for patients.

Moreover, the findings advance the understanding of host–gut microbiome interactions, leading to a “better understanding” of their commensal behavior and associated gastrointestinal (GI) disease progression in the near future.

“Personally, I believe this is a great opportunity for the supplement industry, especially the probiotics sector,” Sarvesh Kumar Srivastava, study co-author from the IDUN Center of Excellence, Danish Technological Institute (DTU) Health tech, DTU Denmark, tells NutritionInsight.

Although “considerable scientific progress” in high throughput sequencing has been made, isolating the microbes in the upper GI tract is “of considerable importance” but has remained a “considerable challenge.”

There are gaps in our scientific understanding of gut microbes given they are difficult to collect.“We have created a platform technology that can validate probiotics consumption in a completely new light, which is simply not possible with other methods,” he details.

Self-polymerizing reaction system
The researchers developed a self-polymerizing reaction system of poly(ethylene glycol) diacrylate monomer, iron chloride and ascorbic acid that was loaded into tiny hollow cylinders. 

The cylindrical microdevices were packaged in miniature gelatin capsules, which were coated with a protective layer to prevent digestion in the stomach’s acidic environment. 

The capsules remained protected in the rats’ stomach but disintegrated in the small intestine’s more-neutral pH, releasing the microdevices. 

Exposure to intestinal fluid caused the cylinders’ chemical cocktail to polymerize, forming a hydrogel that trapped microbes and protein biomarkers in its surroundings. The bacterial composition recovered from the microdevices “closely resemble” the bacterial composition of the gut microenvironment to which the microdevice is exposed. 

The devices were then surgically removed, which remains a step that the researchers intend on replacing by natural elimination in the future. 

The researchers also demonstrated that these tiny cylinders could be triggered over a range of pH to deliver biologics, like insulin, to cells in a petri dish in the presence of intestinal mucus. 

“We have demonstrated that our ‘targeted radical polymerization (TRAP) technology can overcome existing challenges with a high degree of precision and patient compliance in the near future. This technology is safe, efficacious and highly biocompatible – with FDA/GRAS approved ingredients,” Srivastava adds.

Circumventing microbiome research obstacles
Researching the gut microbiome presents many practical barriers. Colonoscopy and endoscopy are invasive procedures that may deter some patients. Meanwhile, stool samples cannot capture all the microorganisms in the upper GI tract or keep microbes from different parts of the tract separate. 

Such obstacles have motivated researchers to find novel ways to circumvent these issues. In previous research strides, ingestible gas-sensing capsule technology was found to monitor key gases produced within the gut in real-time. 

Scientists from the Massachusetts Institute of Technology (MIT) have also developed a tool for modeling the human gut microbiome. With this device, the team can research bacteria associated with Crohn’s disease outside the human gut for up to four days.

By Anni Schleicher