Swallowing this colonoscopy-like bacteria grabber could reveal secrets
about your health

Date:
August 12, 2020
Source:
Purdue University
Summary:
Your gut bacteria could say a lot about you, such as why you're
diabetic or how you respond to certain drugs. But scientists can see
only so much of the gastrointestinal tract to study the role of gut
bacteria in your health. Researchers built a way to swallow a tool
that acts like a colonoscopy, except that instead of looking at
the colon with a camera, the technology takes samples of bacteria.



FULL STORY ==========================================================================
Your gut bacteria could say a lot about you, such as why you're diabetic
or how you respond to certain drugs.


==========================================================================
But scientists can see only so much of the gastrointestinal tract to
study the role of gut bacteria in your health. What comes out of you
is just a small sample of these bacteria, without indicating where they
came from in the digestive system.

Purdue University researchers built a way to swallow a tool that acts
like a colonoscopy, except that instead of looking at the colon with a
camera, the technology takes samples of bacteria.

The technology could also move throughout the whole GI tract, not just
the colon. This tract, in addition to the colon, includes the mouth,
esophagus, stomach, pancreas, liver, gallbladder, small intestine
and rectum.

Essentially, this tool would make it possible to conduct a "gut-oscopy."
"It's all about being able to take samples of bacteria anywhere in
the gut.

That was impossible before," said Rahim Rahimi, a Purdue assistant
professor of materials engineering.



==========================================================================
The tool is a drug-like capsule that passively weasels through the gut
without needing a battery. A pill version of a colonoscopy is already commercially available to view areas of the colon that a traditional colonoscopy can't see, but neither tool can sample bacteria.

"If a colonoscopy or camera pill sees blood, it can't sample that area
to investigate further. You could just sample bacteria from a person's
fecal matter, but bacteria can vary a lot throughout the GI tract. Our
approach could be complementary," Rahimi said.

The bacteria-sampling capsule also would be a lot cheaper, each costing
only about a dollar, he estimates.

Rahimi's team is working on testing this capsule in pigs, which have a
similar GI tract to humans. An initial demonstration of the prototype
is published in RSC Advances, a journal by the Royal Society of Chemistry.

The researchers 3D-printed the capsule out of resin, the same material
used in dental molds and implants. This material would need to be slightly modified for humans to ingest, but is otherwise nontoxic, Rahimi said.



==========================================================================
When exposed to the pH of a certain gut location, the capsule's
biodegradable cap dissolves. Inside the capsule, a hydrogel similar to
those used in diapers expands and collects intestinal fluid containing bacteria. Pressure closes shut the capsule's aperture when the sampling
is complete, kind of like a plunger.

The researchers have tested the prototype capsule in a culture solution designed to simulate the gut bacterial flora of a GI tract. They also
tested the capsule's ability to protect the sampled bacteria in different extreme environments. Their experiments so far show that the capsule
could successfully sample bacteria common in the gut, such as E. coli,
within an hour.

In a human, the capsule would continue to move throughout the GI tract
with other fecal matter. A scientist could then recover the capsule from
a study participant's fecal matter, unscrew the capsule, and study the collected bacteria.

"This approach is providing new opportunities to study what type of
bacteria are present in the gut. It would help us figure out how to
manipulate these bacteria to combat disease," Rahimi said.

A patent has been filed for this technology through the Purdue
Research Foundation Office of Technology Commercialization. The work
is funded by Eli Lilly and Company and Purdue's School of Materials Engineering. Rahimi's team is conducting this research at the Birck Nanotechnology Center in Purdue's Discovery Park.

Background Gut microbiota plays an important role in host physiology
such as obesity, diabetes, and various neurological diseases. Thus,
microbiome sampling is a fundamental approach towards better understanding
of possible diseases.

However, conventional sampling methods, such as endoscopies or
colonoscopies, are invasive and cannot reach the entire small
intestine. To address this need, a battery-less 3D-printed sampling
capsule, which can collect microbiome samples throughout the entirety of
the GI tract was designed. The capsule (9 mm x 15 mm) consists of a 3D
printed acrylic housing, a fast-absorbing hydrogel, and a flexible PDMS membrane. Fluids containing samples of the microbial flora within the
GI tract enter the device through a sampling aperture on the cap of the
device. Once the microbiome enters the housing, the hydrogel absorbs the
fluid and swells, effectively protecting the samples within its polymeric matrix, while also pushing on the flexible PDMS membrane to block the
sampling aperture from further fluid exchange. The retrieved capsule can
be readily disassembled due to the screw-cap design of the capsule and the hydrogel can be removed for further bacterial culture and analysis. As
a proof of concept, the capsule's bacterial sampling efficiency and
the ability to host microbial samples within the hydrogel in a sealed
capsule were validated using a liquid culture containing Escherichia
coli. The demonstrated technology provides a promising inexpensive
tool for direct sampling and assessment of microbes throughout the GI
tract and can enable new insights into the role of diet in mediating host-microbe interactions and metabolism.


========================================================================== Story Source: Materials provided by Purdue_University. Original written
by Kayla Wiles. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Jose Fernando Waimin, Sina Nejati, Hongjie Jiang, Jake Qiu,
Jianghsan
Wang, Mohit S. Verma, Rahim Rahimi. Smart capsule for non-invasive
sampling and studying of the gastrointestinal microbiome. RSC
Advances, 2020; 10 (28): 16313 DOI: 10.1039/c9ra10986b ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200812161333.htm

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