Bedfont® Scientific Limited hosted an insightful webinar Mastering Gut Health: Understanding SIBO, Carbohydrate Malabsorption, and Accurate Gastrointestinal Investigation. Gastrointestinal Physiologist and Bedfont® Medical Advisory Board member Melissa Dooley, led the discussion and shared valuable information on various gastrointestinal disorders and the importance of not self-diagnosing.
Melissa Dooley began her career as a Gastrointestinal Physiologist at St. James’s’ Hospital Dublin, and developed a keen interest in Small Intestinal Bacterial Overgrowth (SIBO). Melissa is a member of both the Irish Institute of Clinical Measurement Scientists and the British Society of Gastroenterology, as well as the founder and director of Gastrolife Clinic in Ireland.
The webinar covers some important topics:
- SIBO & dietary malabsorption
- Finger-prick food intolerance testing. Does it play a supporting role in clinical testing, or is it a costly test without scientific evidence?
- Food allergies vs food intolerances
- Home breath testing devices & regulations
Small Intestinal Bacterial Overgrowth (SIBO) What is it?
SIBO occurs when there are higher numbers of bacteria in the small intestine. Too much bacteria here can interfere with the digestion and the absorption process. Bacteria, however, can also provide some benefits, such as:
- Production of micronutrients
- Aiding metabolism or activation of medicines
- Biotransformation of bile salts
- Fermentation of indigestible polysaccharides
Prevention of luminal colonisation by pathogenic microorganisms
What causes SIBO?
One of the most common causes is a dysfunction of the normal intestinal motility. Slow movement through the intestines allows bacteria to grow, causes of this can be:
- History of food poisoning
- Diabetes
- Certain medications
- Nerve damage
However, in some cases, the cause can be unknown. Melissa continues to discuss the consequences of SIBO, which include the dampening of villi, protein and carbohydrate malabsorption and B12 deficiency to name a few.
How can we test for SIBO?
The ‘Gold standard’ of SIBO diagnosis, culturing jejunal aspirate, is limited because many bacteria species do not grow in routine culture media, not to mention how invasive and costly this procedure is. The hydrogen breath test was developed due to difficulty accessing the small intestine and is used to detect SIBO and dietary malabsorption.
How can breath samples tell me what is happening in my intestines?
During metabolism, all cells produce carbon dioxide, however, only bacteria produce hydrogen and methane as metabolic by-products. These gases pass through the walls of the intestine into the blood. Once the blood reaches the lungs, a gas exchange occurs, allowing these gases to be detected in exhaled breath.
How to take a SIBO or malabsorption test
A hydrogen and methane breath test (HMBT) device is used. The GastroCH4ECK® Gastrolyzer® measures the amount of hydrogen or methane gases in the exhaled breath. Before the start of the breath test, the patient must follow a strict protocol. This includes a restricted diet followed by a fasting period. Not adhering to the protocol can result in an elevated baseline recording or a false positive result.
Before drinking the relevant substrate, a baseline breath sample is taken. The substrate ingested is mixed with 250ml of water and the type of substrate depends on the test being taken. The substrates can be either:
- Glucose
- Lactulose
- Sucrose
- Sorbitol
Breath samples are then taken at 15-30-minute intervals, depending on the test and can take up to 4 hours depending on the type of test. Treatment can involve antibiotics or dietary changes, depending on the test type and results.
Fructose malabsorption
Fructose malabsorption is a dietary disability of the small intestine. Most people can absorb between 25g-50g of fructose in one sitting, however, in people who suffer from fructose malabsorption, their small intestine fails to absorb fructose properly, resulting in the fructose travelling to the large intestine where it has to be metabolised by the bacteria there. This then increases the hydrogen and methane gases released by the bacteria. Possible causes of fructose malabsorption are:
- Inherited or acquired abnormality of the fructose-transporting protein
- Overuse of high fructose corn syrup or fruit juices in children
- SIBO
- Celiac disease
- Chemotherapy or radiation
- Dumping syndrome
Symptoms of fructose intolerance can include:
- Bloating
- Diarrhoea
- Constipation
- Flatulence
Unfortunately, there is no known cure, but an appropriate diet would help. Foods that have a high content of glucose will help absorb fructose.
To test for fructose intolerance, the patient would need to ingest 25g of fructose in 250ml of water. Breath samples would then be taken at 30-minute intervals over 3 hours.
Lactose malabsorption
Lactose is normally hydrolysed into glucose and galactose, which is readily absorbed in the jejunum. Lactose needs to be hydrolysed in the small intestine by lactase. If the lactase enzyme is lacking, the lactose will not be completely hydrolysed and result in lactose malabsorption. Symptoms of lactose malabsorption can include:
- Distension
- Cramps
- Flatulence
Lactose malabsorption is the most common intolerance, affecting almost half the world’s population.
Food allergies vs food intolerances
Often people confuse a food intolerance and a food allergy. A food intolerance can be caused by a change of routine, hormones, and eating out. Symptoms can be quite disruptive to someone’s life and lead them to avoid social activities due to the unpredictability of the symptoms. Because of this, many sufferers will turn to the internet for a quick and easy solution.
An intolerance is where the enzymes in the gut responsible for breaking foods down are deficient, defective, or there is an issue with the mechanism that transports the molecules through the small intestine. Symptoms are:
- Abdominal pain
- Discomfort
- Diarrhoea
Common food intolerances are:
- Lactose
- Fructose
- Sucrose
- Sorbitol
It’s important not to self-diagnose as many conditions can cause similar symptoms to irritable bowel syndrome (IBS) & SIBO, but they will have different treatments and management. It’s always important to visit your GP or healthcare professional. A food intolerance can be diagnosed by an elimination diet or a breath test.
There is a significant difference between a food intolerance and a food allergy. A food allergy is a reaction involving the immune system, symptoms can be:
- Rash
- Itching
- Breathing difficulties
If you have a food intolerance you may be able to consume a small amount of the food, however, with an allergy you must avoid these foods as food allergies can be fatal. Food allergies can be tested through skin prick allergy testing or an elimination diet.
Tests currently not recommended by healthcare professionals for food intolerances are finger prick tests and hair analysis tests, as these do not have any supportive scientific evidence.
Breath testing is the recommended method for detecting lactose malabsorption for several reasons. If you proceed with an elimination diet and remove milk, you may still ingest lactose which can be found in many unsuspecting foods such as:
- Hot dogs
- Breaded chicken
- Sweets
So even if the patient attempts to remove lactose from their diet, they can un-intentionally ingest lactose.
Other test methods can include:
- Endoscopic biopsies (invasive & costly)
- Blood test (repeated every 30 minutes)
- Stool acidity test (infants, young children)
Home breath testing devices
Home breath testing devices were more widely optimised due to the COVID-19 pandemic, to prevent waiting list delays and people felt safer taking the tests at home. There are several benefits of home testing kits, such as:
- Living far from the clinic and difficulty getting there
- Difficulty getting time off work
- Childcare issues
- Difficulties leaving the house with symptoms
However, the limitation of a home test could be that the patient doesn’t collect their samples correctly, resulting in the test having to be retaken. Therefore, patients must be provided with very clear and precise instructions to follow.
There are many home testing devices available now, but using one of these devices without the advice or guidance of a healthcare professional could result in self-interpretation, misdiagnosis, and incorrect preparation, leading to unnecessary avoidance of important food groups.
Home testing devices must be sourced from a reputable healthcare professional, who can discuss the results or provide a report for the treating medical professional. This will ensure an appropriate follow-up is conducted to make sure the patient doesn’t end up with a nutritional deficiency due to self-diagnosis.
There are many factors involved in diagnosing and treating gastrointestinal conditions. Melissa has highlighted these conditions and discussed the importance of not self-diagnosing, watch the full webinar now: