Minimally Invasive Image-Guided Gut Transport Function Measurement Probe

Area of Science:

• Gastroenterology
• Biomedical Engineering
• Medical Diagnostics

Background:

• Increased gut permeability is linked to various diseases, including celiac disease, type II diabetes, and inflammatory bowel disease.
• Current methods like the lactulose to rhamnose ratio (L:R) test have limitations, including inability to assess spatial heterogeneity and challenges in specific populations.
• Existing tests require additional immunoassays and are difficult to administer to infants and small children.

Purpose of the Study:

• To develop and demonstrate a minimally invasive probe for real-time, localized evaluation of gastrointestinal permeability.
• To overcome the limitations of current dual sugar absorption tests for measuring gut permeability.
• To provide a method for assessing gut permeability in unsedated subjects, including infants and children.

Main Methods:

• A 1.2 mm diameter, minimally invasive probe featuring an Ag/AgCl electrode, optical probe, and perfusion channel was developed.
• The probe was deployed transnasally in unsedated swine models using a transnasal introduction tube (TNIT).
• Gut potential difference (GPD) was measured using Lactated Ringer's solution for ionic contact and M-mode OCT for electrode-tissue confirmation.

Main Results:

• The GPD probe successfully measured gut potential difference in the duodenum of swine, with values of -13.1 ± 2.8 mV.
• Glucose perfusion significantly modulated duodenal GPD by -10.5 ± 2.4 mV (p < 0.001), demonstrating the probe's responsiveness.
• M-mode OCT imaging confirmed accurate electrode contact with the gut mucosa, crucial for reliable GPD measurements.

Conclusions:

• A novel, image-guided GPD probe offers a minimally invasive approach for real-time, localized gastrointestinal permeability assessment.
• This method is suitable for use in unsedated subjects and addresses key limitations of existing permeability tests.
• The developed GPD probe technology holds promise for improved diagnosis and management of gastrointestinal disorders.