Swallowable capsule technology: current perspectives and future directions

Introduction

The mammalian gut is a complex ecosystem, which is colonized by a diverse collection of microbes [1]. For many years this ecosystem has been treated as a black box. Firstly, it is very difficult to obtain accurate data on what is happening throughout the intestinal tract, and secondly, many of the bacteria in the gut cannot be cultured in vitro. Whereas the latter issue is a technical matter for microbiologists, the former is an issue due to current approaches by gastroenterologists to obtain data on the physiology of the gut. The ideal solution to this problem would be a system that would either collect or measure in situ, without the need to change or perturb the gut ecosystem. This approach would provide information for the clinician on the “state of the gut,” and whether it differs from what would be considered a normal gut. The swallowable capsule has the potential to provide this capability. These tiny devices can noninvasively access the gut. The devices can visualize the gut in the form of capsule endoscopes. Recent advances in the area are resulting in capsules with controlled movement, from either magnetic or electrical stimulation. Capsules with useful features, such as chemical sensors and dissolved gas sensors, are being developed to obtain more specific information on the gut. These capabilities can be used in addition to, or eventually instead of, the traditional markers of urine, blood, and feces.

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