P0165 A highly miniaturized ingestible sensor for measuring gut health along the GI tract
Authors: Even A , Minderhoud R , Torfs T , Leonardi F , van Heusden A , Sijabat R , Firfilionis D , Dario Castro Miller I , Rammouz R , Teichmann T , van Bergen R , Vermeeren G , Capuano E , Armstrong R , Mathwig K , de Vries S , Goris A , Van Helleputte N , Hooiveld G , Van Hoof C 
Published: January 2025

Abstract

Background
The human gastrointestinal (GI) tract is challenging to examine due to its intricate structure and inaccessibility. Current diagnostic methods are either invasive, like endoscopy, or offer a limited view, such as faecal tests. Endoscopy capsules allow for a visual inspection of the whole GI tract but still require uncomfortable bowel preparation, including laxatives and dietary restrictions, and cannot provide biochemical analysis of the gut environment.

Methods
To enable non-invasive assessment of in vivo gut health, we developed a highly miniaturized, ultra-low-power ingestible sensor (the Gastrointestinal Smart Module, or GISMO) capable of measuring pH, temperature, and redox balance throughout the GI tract. Redox balance is crucial for maintaining intestinal barrier function and regulating interactions among the host, immune system, and gut microbiota. Imbalances in redox levels can lead to oxidative stress, characterized by an imbalance between oxidants and antioxidants, and are associated with adverse gut processes, such as inflammation1. Redox balance plays as such an important role in inflammatory bowel disease (IBD)2. The GISMO sensor was validated in both in vitro and in vivo pre-clinical models and subsequently tested in a first-in-human trial.

Results
In the first-in-human trial, the GISMO system demonstrated feasibility, safety, and ease of use, with 66 ingestible sensors administered to 15 healthy participants. Participants reported ease in swallowing the sensors and expressed willingness to ingest multiple capsules. No device-related adverse events occurred throughout the study. GISMO is the first device capable of measuring in vivo redox balance, providing high-resolution data every 20 seconds. The data revealed consistent profiles from an oxidative environment in the stomach to a strongly reducing environment in the colon.

Conclusion
We successfully developed, validated, and clinically tested miniaturized technology for assessing GI health in a simple, non-invasive manner. Our ingestible sensors are the first to measure in vivo redox balance along the human gut, requiring no uncomfortable bowel preparation, and enabling real-time monitoring. This innovative technology has the potential to enable easy localization and objective quantification of inflammation, revolutionizing the diagnosis and monitoring of IBD and other gastrointestinal diseases.

References
1.Campbell EL, Colgan SP. Control and dysregulation of redox signalling in the gastrointestinal tract. Nat Rev Gastroenterol Hepatol. 2019;16(2):106-120. doi:10.1038/s41575-018-0079-5
2.Bourgonje AR, Feelisch M, Faber KN, Pasch A, Dijkstra G, van Goor H. Oxidative Stress and Redox-Modulating Therapeutics in Inflammatory Bowel Disease. Trends Mol Med. 2020;26(11):1034-1046. doi:10.1016/j.molmed.2020.06.006