Table 1.
Diagnostic opportunities of the mucosa categorized by different conditions
| Key opportunities | Current clinical approaches | Mucosal signals with potential diagnostic value |
|---|---|---|
| Reproductive tract | ||
| Conception and fertility planning and management | Body temperature measurement; qualitative inspection of vaginal mucosa; digital pelvic exam |
Mucosa properties: vaginal mucus impedance, stiffness and viscosity Temperature: real-time monitoring of basal body temperature Biochemical: uterus pH and oxygen levels Mechanical: pressure-based detection of cervical tenderness, uterus size and uterus stiffness Electrical: measuring uterine contractile activity to predict delivery time and identify abnormal labour |
| Reproductive cancer | Tissue biopsy | Biochemical: protein biomarkers associated with different cancers; DNA and RNA sensors for detecting mutations and viral infections associated with cancers (for example, HPV) |
| Dysbiotic environments associated with infection | Digital pelvic exam; imaging vaginal secretions; vaginal pH measurements | Biochemical: vaginal pH levels; quantity and diversity of bacteria in vaginal flora |
| Urinary tract | ||
| Urinary incontinence and overactive bladder | Self-reporting; post-void residual measurement |
Mechanical: bladder pressure and strain detection Electrical: impedance measurements of bladder volume; electrophysiological indicators of bladder disease |
| Acute kidney injury | Blood panel; cytology and evidence of casts (aggregates of cells) |
Biochemical: creatine detection in kidneys Mechanical: direct measurement of pressure and strain exerted on kidneys |
| Bladder cancer | Cytology evaluation using cystoscopy |
Biochemical: urine protein biomarkers Mucosa properties: colour abnormalities in bladder mucosa |
| Kidney stones | Blood panel; urinalysis; imaging | Biochemical: Ca levels in kidneys; mineral levels, white blood cells and bacteria in urine |
| Digestive tract | ||
| GERD | Endoscopy and imaging; ambulatory acid (pH) test; oesophageal manometry |
Mucosa properties: oesophageal mucus impedance Biochemical: oesophageal pH level; cell-type evaluation Electrical: impedance measurements of luminal content |
| GI motility disorders | Endoscopy; Helicobacter pylori (breath) test; stool test |
Electrical: EGG; slow-wave activity Mechanical: pressure recording in GI tract Biochemical: pH and gas in stomach and Ca2+ in intestines |
| GI cancer | Tissue biopsy; endoscopy or colonoscopy; imaging |
Biochemical: protein, DNA or RNA biomarkers associated with GI cancers Mucosa properties: elastic modulus of stomach for gastric cancer; hardness of colon for colorectal neoplasms |
| Peptic ulcer | Endoscopy; imaging; H. pylori tests |
Mucosa properties: mucosal quality and elastic modulus for H. pylori-related gastric and duodenal ulcers Biochemical: protein, DNA or RNA sensors for detecting bacterial infections associated with ulcers (for example, H. pylori) Vascular dynamics: GI mucosal blood flow |
| GI inflammation (for example, gastritis and IBD) | H. pylori tests; stool or blood test; imaging; endoscopy or colonoscopy |
Mucosa properties: mucosal integrity, impedance, stiffness Biochemical: protein, DNA or RNA sensors for inflammation-relevant biomarkers; sensing of macronutrients or metabolites levels Vascular dynamics: GI mucosal blood flow |
| GI ischaemia | Imaging |
Vascular dynamics: GI mucosal blood flow Biochemical: oxygen sensing for intestinal oxygen tension |
| Gut–brain axis | Intravital Ca2+ signal imaging of the gut |
Electrical: electrophysiology Biochemical: neurotransmitter sensing (for example, dopamine) in the gut |
| Respiratory tract | ||
| COPD and cancer | Pulmonary function tests; chest imaging; arterial blood gas analysis; spirometry; tissue biopsy |
Mechanical: monitor pressure within lung and bronchial airflow Biochemical: protein, DNA or RNA sensors for disease-relevant biomarkers; pulmonary oxygen levels Vascular dynamics: arterial blood vessel diameter; blood pressure of femoral artery Mucosa properties: modulus of bronchial airway walls; stiffness of trachea rings |
| Tuberculosis | Physical exam; blood, skin or sputum tests; imaging | Biochemical: protein, DNA or RNA sensors for detecting MTB |
| Asthma | Physical exam; spirometry; exhaled nitric oxide test |
Mechanical: pressure within lung and bronchial airflow Mucosa properties: pulmonary mucus impedance, viscosity, colour |
| Pneumonia | Physical exam; blood or sputum tests; imaging; pulse oximetry; RT-PCR |
Mucosa properties: pulmonary mucus impedance, viscosity, colour Biochemical: protein, DNA or RNA sensors for detecting viral infections associated with pneumonia (for example, SARS-CoV-2, MERS and SARS in respiratory mucus); oxygen levels |
COPD, chronic obstructive pulmonary disease; EGG, electrogastrogram; GERD, gastro-oesophageal reflux disease; GI, gastrointestinal; HPV, human papillomavirus; IBD, inflammatory bowel disease; MERS, Middle East respiratory syndrome; MTB, Mycobacterium tuberculosis bacteria; RT-PCR, reverse transcription polymerase chain reaction; SARS, severe acute respiratory syndrome.