Patients with a range of clinical presentations often mention digestive symptoms as a secondary complaint. Whilst focusing on the primary presentation, physicians and surgeons might consider referring patients to a specialist gastroenterologist for endoscopy and other investigations.
In the appropriate setting, direct referral to MIGe Diagnostics for a minimally invasive investigation might hasten the patient journey, whilst retaining continuity of care.
Video capsule endoscopy allows inspection of the oesophageal epithelium and gut mucosa from mouth to anus and a range of breath tests can detect H Pylori, measure gastric motility, disaccharidase insufficiency, small intestinal bacterial overgrowth and pancreatic functional capacity. Vagus tone and the integrity of autonomic balance (a physiological measure of wellbeing and stress) can be evaluated using Bodyguard2, a wearable device that tracks and analyses three day heart rate variability.
Light transmission through fibre-optic bundles was a defining technology of the 20th Century. This enabled the development of the endoscope, a device that magically illuminated the pitch blackness of the digestive tract, allowing direct visualisation of normal or abnormal mucosa. The endoscope has to be manually pushed through the organ and the physical constraints of the instrument limits the depth to which the instrument can be passed. Current endoscopes are designed to examine the oesophagus, stomach and duodenum and large intestine. This instrument cannot inspect the lining of the 5 metres of small intestine.
The 21st Century has witnessed the remarkable impact of miniaturisation and wireless video transmission. The video capsule is a scouting device propelled by a natural bowel movement from the mouth to rectum. During its 7 metre journey, an LED light source illuminates the bowel wall and a tiny chip camera transmits a wireless signal to a video recorder, capturing the entire journey.
Painless video capsule changes the clinical pathway, allowing a preliminary step for the gastroenterologist to determine whether or not an interventional fibre-optic endoscopy is required to biopsy, removed a polyp or stop bleeding or whether a more physiological approach is indicated. Video capsule powers the pathway.
Lactose (dairy) intolerance = lactose hydrogen breath test
Small bowel bacterial overgrowth (SIBO) = glucose hydrogen breath test
Helicobacter pylori = 13C-urea breath test (Diabact UBT) – a 10 minute breath test
Gastric emptying = 13C – Sodium-Acetate breath test
Quantitative pancreatic function = 13C-Mixed Triglyceride test
Quantitative liver function = 13C-Methacetin breath test
Stable isotope breath testing:
Stable isotope breath testing provides a reliable measure of Helicobacter pylori infection, gastric emptying, liver and pancreatic function. Use of 13C labelled non-radioactive substrates provides safe and easy access to metabolic function tests without the need to refer to a nuclear medicine department. MIGe Diagnostics offers the following:
Test for presence of Helicobacter pylori
Helicobacter pylori testing is indicated in patients presenting with dyspepsia. Faecal antigen testing is cumbersome, whereas breath testing involves swallowing a small tablet of non-radioactive 13C isotope-labelled urea (‘Diabact’) with a result available in 10 minutes.
Isotopically labelled urea is metabolised into carbon dioxide and ammonia by the enzyme urease, which is produced by the bacteria Helicobacter pylori. The available non-radioactive 13C isotope, now in the form of 13CO2, diffuses into the blood to be transported to the lungs, where it is exhaled in the breath to be capture during sampling. An increased ratio of 13C is conclusive proof of the presence of Helicobacter pylori in the patient’s stomach.
Diabact UBT – 13C Urea Breath Test
Diabact UBT is a proprietary formulation from Kibion, with several advantages in a clinical setting:
• no need for a test meal
• only 10 minutes wait
• high specificity (100%)
• high sensitivity (99%)
• result immediately available
The patient should have fasted for 6 hours prior to the test and not have taken PPI for 2 weeks before the test is performed. Antibiotic treatment should have been discontinued one month before testing.
Liquid gastric emptying test 13C-Sodium-Acetate
13C-Sodium-Acetate is administered together with a liquid or semi-solid test meal. After passing through the stomach, where it is not absorbable, absorption occurs in the small intestine and metabolised in the liver. About 50% enters the body´s bicarbonate pool and is exhaled. As the rate-limiting step in this process is the stomach-emptying rate, this test is a reliable application to assess liquid gastric emptying.
Applications of 13C-Sodium-Acetate Breath Test
The 13C-Sodium-Acetate Breath Test is very useful for the investigation of functional dyspepsia and autonomic diabetic neuropathy and gastroparesis.
The patient should have fasted for 10 hours prior to the test and should not drink carbonated water or soft drinks prior to the test since, these can interfere with the results.
A further test may help to complete the picture. Heart rate variability (HRV) monitoring can be useful to investigate the brain-gut axis.
The autonomic nervous system plays an important role in regulating digestion. In general, the parasympathetic vagus nerve stimulates digestion, growth and recovery whilst the sympathetic (“fight or flight”) autonomic nerves are inhibitory. The vagus acts as a brake on the fight and flight reaction, only allowing the sympathetic response to emerge in the face of danger, stress and anxiety.
There is considerable evidence that autonomic nervous balance is disturbed in disorders such as irritable bowel syndrome and functional dyspepsia, where stress and anxiety are thought to play an important role.
Our heart rate varies between inspiration and expiration and this phenomenon, known has “heart rate variability”, is a healthy physiological response that is altered in the face of physical and emotional stress.
Measuring the variability, with FirstBeat Bodyguard2, provides a physiological measure of stress and its relationship to daily activities, which opens a window to measuring autonomic balance.
By providing patients with an illustrated print out and by illustrating the relationship between HRV and the patient’s diary of daily activity, meals, mood and sleep, it is possible to identify triggers that might be contributing to the perception of gastrointestinal symptoms, and then work towards reversing these factors.
Further, the assessment of autonomic tone by measuring three day HRV may provide insights into a range of patients presenting with medically unexplained symptoms.