Hydrogen and Methane breath tests are based on the fact that there is essentially no source for hydrogen or methane gas in the human body other than bacterial metabolism of carbohydrates. The hydrogen and methane produced in the intestine is absorbed into the blood, and is exhaled through the lung. The tests exploit the fact that with reduced absorption of a specific sugar, this sugar travels downstream in the gut and ends up in the large intestine/colon and gets fermented there, with resultant abnormal hydrogen/methane levels recorded on the breath test. Similarly, if bacteria are present in the small intestine (which is abnormal = small intestinal bacterial overgrowth, SIBO) the sugars, instead of getting all absorbed, give rise to abnormal hydrogen/methane levels that can be measured.
LACTOSE INTOLERANCE
Lactose Intolerance is a very common condition, (especially in people with Asian, West African, Arab, Jewish, Greek and Italian descent). It is not to be confused with a dairy allergy (which is an allergic reaction to milk protein). Lactose Intolerance describes the partial or complete inability to metabolize milk sugar (lactose) which is present in all mammalian milk types (cow, sheep , goat etc). It is reflective of a partial or complete lack of the enzyme needed to split this sugar (Lactase). As a result of not being able to break this sugar down and absorb it, the sugar molecules reach the lower small intestine and cause symptoms like bloating, gas, cramping, nausea and loose stools, among others. This condition can be responsible for irritable bowel –type symptoms, it very often is part of the symptoms of celiac disease (not the cause of celiac disease, however!), and can be also a (transient or persistent) symptom after bowel infections/diarrheal illnesses or antibiotic therapy. Lactose Breath Testing can diagnose this condition quite accurately.
Treatment primarily consists of avoiding lactose-containing foods and/or supplementation of the Lactase enzyme with meals. Treatment should be conducted and monitored by a qualified physician.
SIBO (Small Intestinal Bacterial Overgrowth)
Usually, the acid environment of the stomach kills most bacteria, so there is a very low bacterial count in the small intestine. However, in hypo- or achlorhydria (lack of acid production in the stomach, or with treatment of acid-related disorders, like ulcers or acid reflux) bacteria may pass into the small intestine and colonize that area. Alternatively, conditions with abnormal motility (where bowel contractions and transport are slower or faster) or previous surgeries permit bacteria to invade the small intestine from the colon. These conditions can lead to an increase in bacterial count to over 105 (100,000) bacteria per milliliter (mL) of intestinal contents, which defines the condition called “bacterial overgrowth.” The bacteria can thrive in the rich nutritional environment of the small intestine, and interfere with the normal breakdown and absorption of nutrients, specifically complex carbohydrates/sugars. This leads frequently to symptoms that are similar to carbohydrate malabsorption (lactose intolerance or fructose malabsorption). It also destroys some vitamins, interferes with the absorption of fatty acids and competes for sugars and other foodstuff ordinarily absorbed in the upper part of the small intestine. Thus, it is a significant digestive disturbance which can be treated, but only if it is diagnosed. Breath Testing for SIBO (with glucose or lactulose as a substrate) is able to diagnose this condition, but it sometimes is a difficult diagnosis to make, given the many variables involved in nutrient metabolism.
> Patients with diabetes should book a SIBO breath test utilizing “Lactulose” as a substrate to avoid high blood sugar peaks (but sometimes will experience some diarrhea with this).
> Customers without diabetes, can book the breath test with “Glucose” as the substrate
Treatment should be conducted and monitored by a qualified physician.
Sucrose (also called saccharose) is a two-sugar chain composed of Glucose and Fructose which are bonded together. A more familiar name is table, beet, or cane sugar. Sucrose Intolerance involves a deficiency in the enzyme Sucrase-Isomaltase which is supposed to break the bond between the glucose and fructose molecules. When such two-molecule sugars are consumed, they must be broken down into single-molecule sugars by enzymes in the intestines before they can be absorbed. Monosaccharides, or single sugar units, are then absorbed directly into the blood.
A genetic form of the enzyme deficiency is common in the indigenous populations of Canada and Alaska (3-10%), but less common in European (0.1%). Other, more common forms of the deficiency are acquired and are frequently associated with irritable bowel syndrome, aging, or small intestinal disease (secondary sucrose intolerance). There are specific tests used to help determine if a person has sucrose intolerance. The most accurate test is the enzyme activity determination, which is done by biopsy of the small intestine. This is very accurate, but expensive, invasive and complicated. Another tests which can aid in the diagnosis is the sucrose breath test. It is easy to perform, and not costly -- but it is less sensitive and specific than the enzyme activity test. A deficiency of the enzyme may result in malabsorption of sugar, which can lead to potentially serious symptoms, including episodes of hypoglycemia (low blood sugar) -- and as a result of that patients can experience palpitations and anxiety. Since Sucrase-Isomaltase is involved in the digestion of starches, some patients may not be able to absorb starches as well. It is important for those with sucrose intolerance to minimize sucrose consumption as much as possible. Enzyme supplements may be taken as a substitute for the missing enzyme.
Fructose Malabsorption (or non-hereditary Fructose Intolerance)
Fructose malabsorption is fairly common, affecting up to 1 in 3 people. It is just as common in people with a diagnosis of irritable bowel syndrome as in the rest of the population, and symptoms are quite similar but generally triggered by intake of fructose – containing foods. In some cases, fructose malabsorption may be caused by diseases which cause intestinal damage, such as celiac disease. Fructose malabsorption is not to be confused with “hereditary fructose intolerance (HFI)” a rare, potentially fatal condition in which the liver enzymes that break up fructose are deficient. Fructose malabsorption may cause gastrointestinal symptoms such as abdominal pain, bloating, flatulence and diarrhea.
Fructose is absorbed in the small intestine without help of digestive enzymes. Even in healthy persons, however, only about 25–50 g of fructose per sitting can be properly absorbed. People with fructose malabsorption absorb less than 25 g per sitting. Simultaneous ingestion of fructose and sorbitol seems to increase the malabsorption of fructose. Fructose that has not been adequately absorbed is fermented by intestinal bacteria producing hydrogen, methane and carbon dioxide, as well as short-chain-fatty-acids. This abnormal increase in hydrogen may be detectable with the hydrogen and methane breath tests with fructose as a substrate.
As a result of fructose malabsorption, rapid bacterial fermentation in the small intestine occurs, leading to altered gastrointestinal motility (e.g. diarrhea), the formation of mucosal biofilms, and a change in the intestinal flora. These effects are additive if other poorly absorbed carbohydrates are present, such as sorbitol. The clinical significance of these events depends upon the individual susceptibility to such changes. There is also evidence that fructose malabsorption can cause decreased Tryptophan, Folic Acid and Zinc levels in the blood. Restricting dietary intake of free fructose and/or fructans (longer sugars containing fructose) may provide symptom relief in a high proportion of patients with such functional gut disorders.One has to be careful with the results of the Fructose Breath Test, because a negative result does not completely rule out that a trial of fructose restriction may help the patient (in other words, the sensitivity of the test is relatively low), while a positive result is very specific that such a trial is useful.
