In a recent review published within the journal Gut, researchers discussed using smart and robotic capsules for sampling and sensing the gut. They described the advantages and limitations of those miniaturized devices while identifying their potential applications in personalized medicine, food plan, and the early diagnosis of several chronic gut ailments, including cancer.

Study: Smart capsules for sensing and sampling the gut: status, challenges and prospects. Image Credit: SewCreamStudio/Shutterstock.com

Background

The human gastrointestinal (GI) tract is as much as nine meters long, with 4 structurally and functionally distinct segments, namely the esophagus, the stomach, the small intestine, and the big intestine. The tract is colonized by diverse bacteria, fungi, and archaea, a set of about 1013 microorganisms. The gut microbiota ferment fiber, provide essential nutrients and are actually known to be markers of health.

Dysbiosis of those organisms is reported to be related to inflammation, aging, in addition to diseases equivalent to diabetes, obesity, metabolic diseases, arterial dysfunction, and cancer. Fecal sample collection is probably the most common noninvasive method employed to check gut microbiota.

Nevertheless, the sample collected from feces may not accurately describe the microflora of the disease site, thus missing major spatiotemporal information. Biopsies is probably not reliable methods for sampling microorganisms and are limited by procedural risks.

For the reason that advent of tiny, ingestible capsule endoscopes within the early 2000s, our understanding of the gut, the associated microflora, and their links to overall health has greatly improved. This review focuses on the newest advances in gut sensing and sampling and their potential role in diagnosing and treating diseases and monitoring health.

Smart capsules for gut sensing

While the diagnosis of gut-related diseases in the sooner era widely relied upon the usage of X-rays, endoscopy, and surgery, the sphere regularly progressed to the usage of swallowable capsules about 3 cm x 1 cm in size, that might transmit information on the pH, temperature, and pressure of the gut. These devices have evolved greatly since then, overcoming the challenges related to their movement contained in the gut in addition to their adversarial effects.

Today’s commercially available smart capsule endoscopes can transmit images of the gut lining, finding clinical applications in sensing, drug delivery, and monitoring gut diseases. Smart capsules, including the Bravo reflex capsule, the alphaOne capsule, and the Heidelberg pH capsule, have been used to measure the pH of varied sections of the GI tract. Smart capsules equivalent to eCelsius and myTemp could be used to repeatedly measure the core temperature of the gut, especially in athletes during exercise, which shouldn’t be possible conventionally.

The measurement of peristaltic forces (which also govern the in vivo movement of the capsules) is well possible using these devices. SmartPill and Bravo capsules have been used to measure pressure and the transit time of food contained in the gut to sense conditions equivalent to constipation, achalasia, and dysmotility. The Atmo Gas Capsule was tested in humans for its ability to measure gases and discover the origin of gas generation contained in the gut.

Robotic capsules for gut-sampling

Despite these advantages, smart capsule-based imaging doesn’t capture the wealth of knowledge available contained in the human gut. Robotic capsules address this gap by enabling sample collection in the shape of tissues and/or fluids and allowing their detailed examination post-retrieval.

Robotic capsules, equipped with blades and razors in cylindrical, barb-based, scissor-based, and magnet-based designs, have been used to gather small tissue samples via biopsy of the intestinal wall, providing an edge over traditional tethered devices.

Moreover, robotic capsules could also be designed to extract content samples from the gut in the shape of fluids, mucus, microflora, and exfoliates. Several of those designs have been patented since 1957.

Laboratory and business prototypes

Three sorts of laboratory prototypes are described within the literature: passive, energetic, and dynamic. Passive capsules could also be osmotic or gelatin-based; their coating dissolves when contacting the goal fluid within the gut lumen. Nevertheless, they’re limited by an extended sampling time and lack of control inside the gut.

Lively sampling capsules use microelectromechanical systems (MEMS) that trigger the sampling process on the goal site. They could be motor-based, vacuum suction-based, or magnetic actuation-based of their mechanism of motion. While energetic and passive capsules sample content from the gut lumen, dynamic capsules may sample the intestinal wall.

Although dynamic capsules can scrape and extract microbial samples from the mucosal layer, a site previously unexplored, in vivo trials are yet to be conducted to gauge their effectiveness.

Future perspectives

Smart and robotic capsules have allowed minimally invasive, rapid, and accurate measurement of varied gut parameters. Nevertheless, multitasking capsules that may sense and sample various sites and measure several gut parameters in a single run are yet to be developed and tested. Further, auto-location of the goal site and functioning in a stand-alone manner are desirable features that may very well be introduced in these capsules. Developing low-cost options and easing their operation via computers and the web could lower the healthcare burden related to using these devices in medical facilities and at-home settings.

In conclusion, the event of advanced ingestible capsules in the longer term for sensing and sampling the gut could aid the early diagnosis of diseases while allowing easy monitoring of health amongst patients, thereby improving clinical outcomes.