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The IBS & Gut Disorder Centre

SIBO Testing UK - Hydrogen Breath Test

How do you conduct SIBO testing for Small Intestinal Bacterial Overgrowth?

The test for SIBO is called a Hydrogen Breath test. This test can be conducted using Lactulose or Glucose. The test is also called a Lactulose Breath test or a Glucose Breath Test. The SIBO test can be posted all over the UK.

What does the Hydrogen Breath Test (SIBO Test) measure?

The Hydrogen Breath test measures two different gases Hydrogen and Methane. These gases are produced by bacteria should they be present in large quantities in the small intestine. If Hydrogen and Methane are produced they will diffuse into the blood, and then into the lungs, for expiration.

How is the Hydrogen Breath test (SIBO test) conducted?

The first step involves following a low-fibre diet and fasting for 14 hours. You will then need to drink a solution called Lactulose or Glucose. This is a very sweet solution that tastes like sugar. Breath samples are taken at 20 minute intervals for the period of 3 hours.

The Hydrogen Breath tests are inexpensive and can be done at our clinic in central London or at home. The SIBO breath test is very easy to complete. If you do this test at home we will send you a you tube video to follow step-by-step.

Does the NHS test for SIBO?

The answer is Yes and No. SIBO is becoming more mainstream, however many GPs still do not know much about the condition. If you are offered SIBO testing it will be via a gastroenterologist and there may be long waiting times on the NHS.

The majority of SIBO testing conducted on the NHS tends to use glucose as the sugar solution. This may be problematic and produce false negatives. Glucose is usually absorbed within the upper portion of the small intestine (only the top two feet ) so if hydrogen and/or methane are detected in this test it indicates an overgrowth in upper end of the small intestine, closest to the stomach.

The problem with the glucose breath test is that is is unable to identify the growth of bacteria it in the last section or distal end of your small intestine. This means the test may produce a false negative result.

Because of the large amount of symptom overlap of SIBO with other gastrointestinal conditions like IBS, it is important that proper testing is done to ensure a correct diagnosis and treatment. If symptoms point to SIBO, then a breath test is usually requested.

If you would like to test for SIBO, please contact our clinic- ibsandgut@gmail.com

What is the difference between the Lactulose and Glucose Breath test when testing for SIBO?

The lactulose breath test has the advantage that the lactulose is able to travel throughout the entire small intestine. This is important as you will be able to detect if there is bacteria is present in the ileum (the final section of the small intestine) where small intestinal bacterial overgrowth often occurs. However for some people, the speed at which food move through their intestines can be very rapid, causing lactulose to reach the colon too quickly. This can sometimes result in a false positive result.

A false positive result may occur if you have frequent diarrhea or know that you tend to experience a faster transit time. Lactulose can have a laxative effect on the body and can indeed increase transit time and help with constipation. This may be why some people feel better after the SIBO test.

Should I use a Glucose Breath test instead?

The problem with the glucose breath test is that is is unable to identify the growth of bacteria it in the last section of your small intestine. This means the test may produce a false negative result. We recommend that you book a consultation with a professional so we can give you our expert advice on the most appropriate test to use for your symptoms.
(1, 3).

Does SIBO testing include Hydrogen sulfide?

There is another gas called Hydrogen Sulfide that may also be linked with Small Intestinal Bacterial Overgrowth. Unfortunately at present this gas cannot be detected through standard SIBO tests. A SIBO test result with a completely flat line of hydrogen and Methane may possibly be linked to Hydrogen Sulfide production.

If you have many of the symptoms of SIBO such as wind, flatulence or bloating or you have noticed an unpleasant smell similar to sulfur, then hydrogen sulfide overgrowth might be an issue. We recommend anti-bacterials and a low-sulfur diet to help you. Some patients who experience body pain, constipation, bladder irritation, tingling and numbness in their extremities, sulfur smelling gas may have indeed have Hydrogen Sulfide overgrowth.

If my results have a flat-line could this still mean I have a bacterial overgrowth?

There is a still a lot of research to be done but it appears that for some patients there is a third gas called Hydrogen Sulfide that may be linked to small intestinal bacterial overgrowth.

What is SIBO?

Small intestinal bacterial overgrowth (SIBO) is a painful condition of the gut caused by the presence of excessive numbers of bacteria in the small intestine. The small intestine is where most of the digestion and absorption of food and nutrients happens. Unlike the colon which is part of the large intestine and proliferates with bacteria, the small intestine is normally sparsely populated by bacteria. Bacterial overgrowth can happen when bacteria move from the large intestine to the small intestine or when naturally occurring bacteria in the small intestine grow out of control.

In a healthy individual, the body will try and remove large concentrations of bacteria from the small intestine using a migrating motor complex, MMC to sweep out the bacteria. SIBO can develop when the normal control mechanisms that keep the growth of bacteria in check are disrupted.

What are the causes of SIBO?

A common cause of SIBO may be due to the production of low levels of stomach acid. If you have experienced chronic or acute stress, for prolonged periods of time, you may not have produced adequate amounts of hydrochloric acid as needed.

The medical term is know as Achlorhydria (lack of Hydrochloric acid). Some people who have had an Helicobacter pylori infection are at risk of low stomach acid. In a healthy person production of HCl (stomach acid) will help eradicate any incoming bacteria.

For some people SIBO can develop after use of medications that reduce stomach acid production. These include proton pump inhibitors such as Omeprazole, Lanzaprozole. The over-use of these medications may cause bacterial overgrowth in the duodenum and stomach. Proton pump inhibitors may also accelerate the intestinal transit causing diarrhea.

Another cause may be due to food poisoning- If you have had Campylobacter or Acute Gastroenteritis this may affect or damage the MMC - motor migrating complex. The MMC is a little bit like a wave or a broom stick that clears out bacteria into the large intestine. If it is not working properly you are more likely to have an overgrowth of bacteria. Research indicates that the malfunctioning of the MMC may be occur post food poisoning.

  • Pancreatic exocrine insufficiency, (lack of pancreatic enzymes). If you are not producing adequate amounts of enzymes to break down your food, this deficiency may lead to a a bacterial overgrowth
  • There are many medical conditions that have been linked with SIBO. These include gastroparesis (delayed stomach emptying), irritable bowel syndrome, Crohn’s disease, coeliac disease and small bowel dysmotility. Motility is a big issue for patients with SIBO- either too fast or too slow
  • Other conditions include people with a suppressed immune system
  • Decrease in Bile acids- this is because bile acids may prevent the growth of bacteria
  • Stress because it reduces the motility of the intestine potentially causing an overgrowth
  • Problems with your IIleocecal Valve-the latter prevents a backflow of bacteria from large intestine to small intestine
  • There may be some adhesions or strictures that have formed after surgery that cause the bacterial overgrowth. This may happen with patients who have Appendicitis, Endometriosis, Cancer, or inflammatory bowel disease.

What are the symptoms of SIBO?

The signs and symptoms of SIBO are non-specific and are similar to other digestive disorders such as irritable bowel syndrome (IBS), lactose intolerance and fructose malabsorption. Common complaints include:

  • Abdominal pain and discomfort
  • Bloating
  • Indigestion
  • Diarrhoea
  • Constipation
  • Excessive gas and flatulence
  • Unintentional weight loss
  • Belching

  • Anxiety or brain fog
  • Malabsorption, Anemia (Iron, B12, Ferritin deficiency)
  • Inability to tolerate high fibre foods including vegetables, broccoli, beans, lentils, onions and garlic
  • Leaky gut leading to joint pain, or body pain rashes on skin and severe food intolerances

  • Rosacea

    Is there a link between Irritable Bowel Syndrome and SIBO?

    The causes of irritable bowel syndrome are still unknown. However without a doubt, symptoms of SIBO and IBS are very similar. earlier, SIBO is frequently found in 30-85% of patients fulfilling criteria of irritable bowel syndrome (30%-85%)[9-11,14,15,]. Dr Pimental believes that SIBO is the primary cause of irritable bowel syndrome.

    Is there a link with Coeliac disease and SIBO?

    A wide range of 9% to 55% (10) of patients have been diagnosed with SIBO as a complication of coeliac disease. If you are not responding to a gluten-free diet you may wish to test for SIBO.

    Is there a link with Chrons disease and SIBO?
    SIBO is found in about 25% of patients with Crohn’s disease (11,12) . In fact the symptoms of SIBO are very similar to Crohn’s disease ( increased bowel movements and lower body weight).

    Is there a cure for SIBO?

    In many cases, SIBO can be successfully treated by directly addressing the bacterial overgrowth. The most common first-line antibiotic prescribed is Rifaximin. The problem with antibiotics is that they are not always initially effective with one study finding that in people with SIBO-related IBS, two-thirds had to be retreated with Rifaximin, with some needing re-treatment up to 5 times. This raises the very serious concern of developing bacterial antibiotic resistance.

    We have successfully used herbal treatments such as oil of oregano, lemon balm, and red thyme oil, we have found these to be an effective alternative treatment for SIBO. A 2014 study found that herbal treatments were just as effective as the antibiotic Rifaximin in treating SIBO. And from the same study, herbal treatments were just as effective as triple antibiotic therapy in people that did not respond to rifaximin.


    These can also very important as well when treating SIBO.

    What are prokinetics?
    The term prokinetic means simply to promote movement and, in the context of the gastrointestinal tract. These are not be confused with laxatives. A prokinetic is useful to stimulate the MMC complex- motor migrating complex and is best taken at bed before fasting and help clear bacteria out of the small intestine.

    Some examples include:
    • Ginger root and ginger formulas (1000 mg )
    • Motility activator-This is less likely to cause side-effects with patients who have acid reflux.
    • Pure encapsulations-MotilPro
    • Bio-Mi Kinetic

    The Importance of Diet and SIBO

    Dietary changes are also an important part of managing SIBO. Because bacteria feed on carbohydrates, then a diet that aims to reduce these can help. A low FODMAP diet is sometimes recommended to treat SIBO and which also has proven effective in treating IBS. FODMAPs are short-chain carbohydrates such as lactose, fructose, fructans (long chains of fructose molecules) and sugar alcohols that are commonly present in dairy products, grains, legumes and certain fruits and vegetables. The reduction in fermentable carbohydrates in the diet helps to starve excess bacteria of their important food source.

    Following the low FODMAP diet for extended periods of time may lead to a reduction of healthy gut bacteria know as Bifidobacteria. Therefore it is important after treatment SIBO and following a low-fodmap diet to take probiotics to replenish the concentration of healthy gut bacteria (7). The low FODMAP may also results in calcium deficiency.

    The elemental diet is another option for people with SIBO. The diet supplies nutrients in an easy-to-digest form. The easier and quicker digestion and absorption of nutrients mean there is less available for bacteria to feed off. In a 2-week study of people with SIBO-related IBS trialling an elemental diet, 80 percent returned a normal lactulose breath test after 1 month.

    With SIBO, different dietary changes work for different people. That is where working with an experienced nutritionist to assist in tailoring changes to your diet to manage symptoms of SIBO can be of help. Please contact us at ibsandgut@gmail.com

    The SIBO breath test (Small Intestinal Bacterial Overgrowth) is also an excellent test that is now available and is also of tremendous benefit to IBS sufferers.

    How can I order a SIBO test?

    If you would like to do book in SIBO test, at our clinic please contact us by e-mail-ibsandgut@gmail.com or by phone - 0345 1297996 and we can arrange a consultation. We recommend using a lactulose breath test or a hydrogen breath test, however we do offer glucose testing as well.

    According to Dr Mark Pimental, up to 84% of patients with IBS had evidence of SIBO. In my clinical experience, at least 40% of patients who have IBS and have taken the SIBO test do test positive for SIBO. There has also been a study (16), conducted by Dr. Mark Pimentel, published in Gastroenterology that claims that 84% of IBS patients have abnormal lactulose breath tests.

    The NHS still does not routinely test for SIBO, but it is certainly worth investigating if you have been diagnosed with IBS.

    How common is SIBO?

    The prevalence of SIBO ranges from 30-85%.

    The prevalence of SIBO in patients with coeliac disease non-responding to a gluten-free diet was as high as 50%. In liver cirrhosis, SIBO was diagnosed in more than 50% of cases. In a small study on elderly people (70 to 94 years old) who had lactose malabsorption, SIBO was documented in 90%.

    We usually recommend booking an initial consultation prior to ordering any tests. We recommend this so we can assess your symptoms and medical history before advising the most appropriate tests for you. However if you would just like to order a test we can certainly organize that for you.

    We see patients by appointment in the UK at 9 Weymouth Street, London, W1W 6DB, but can also help people living elsewhere by means of postal, telephone or email consultations.

    The IBS & Gut Disorder Centre
    9 Weymouth Street
    London W1W 6DB
    0345 129 7996

    Contact Us

  • References

    1. Clin Gastroenterol Hepatol. - Breath testing for small intestinal bacterial overgrowth: maximizing test accuracy.

    2. Eur J Gastroenterol Hepatol. - Breath tests in the diagnosis of small intestinal bacterial overgrowth in patients with irritable bowel syndrome in comparison with quantitative upper gut aspirate culture.

    3. Gut Liver. - Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge between Functional Organic Dichotomy.

    4. Dig Dis Sci. - Comparison of scintigraphy and lactulose breath hydrogen test for assessment of orocecal transit: lactulose accelerates small bowel transit.

    US National Library of Medicine - Small Intestinal Bacterial Overgrowth: A Comprehensive Review.

    US National Library of Medicine - How to Interpret Hydrogen Breath Tests.

    Springer Link - Effects of Rifaximin Treatment and Retreatment in Nonconstipated IBS Subjects.

    US National Library of Medicine - Herbal Therapy Is Equivalent to Rifaximin for the Treatment of Small Intestinal Bacterial Overgrowth.

    US National Library of Medicine - Efficacy of the low FODMAP diet for treating irritable bowel syndrome: the evidence to date.

    Springer Link - 14-Day Elemental Diet Is Highly Effective in Normalizing the Lactulose Breath Test

    7. US National Library of Medicine - Staudacher HM, Whelan K: Altered gastrointestinal microbiota in irritable bowel syndrome and its modification by diet: probiotics, prebiotics and the low FODMAP diet.

    8. US National Library of Medicine - Lazzini S, Polinelli W, Riva A, Morazzoni P, Bombardelli E: The effect of ginger (Zingiber officinalis) and artichoke (Cynara cardunculus) extract supplementation on gastric motility: a pilot randomized study in healthy volunteers.

    9. Pimentel, Am J Gastroenterology 2000, 2003)(Pimentel, 2006)

    10. Small intestinal bacterial overgrowth syndrome- World Journal of Gastroenterology

    Jan Bures, Jiri Cyrany, [...], and Marcela Kopacova

    11. Castiglione F, Rispo A, Di Girolamo E, Cozzolino A, Man- guso F, Grassia R, Mazzacca G. Antibiotic treatment of small
    WJG| www.wjgnet.com
    Bures J et al . Small intestinal bacterial overgrowth syndrome
    bowel bacterial overgrowth in patients with Crohn's disease.
    Aliment Pharmacol Ther 2003; 18: 1107-1112

    12. Lin HC. Small intestinal bacterial overgrowth: a framework for understanding irritable bowel syndrome. JAMA 2004; 292: 852-858
    Lupascu A, Gabrielli M, Lauritano EC, Scarpellini E, San- toliquido A, Cammarota G, Flore R, Tondi P, Pola P, Gas- barrini G, Gasbarrini A. Hydrogen glucose breath test to detect small intestinal bacterial overgrowth: a prevalence case-control study in irritable bowel syndrome. Aliment Pharmacol Ther 2005; 22: 1157-1160

    13. Pimentel M, Chow EJ, Lin HC. Eradication of small inte- stinal bacterial overgrowth reduces symptoms of irritable bowel syndrome. Am J Gastroenterol 2000; 95: 3503-3506

    14.Ford AC, Spiegel BM, Talley NJ, Moayyedi P. Small intestinal bacterial overgrowth in irritable bowel syndrome: systematic review and meta-analysis. Clin Gastroenterol Hepatol 2009; 7: 1279-1286

    15. Mann NS, Limoges-Gonzales M. The prevalence of small intestinal bacterial overgrowth in irritable bowel syndrome. Hepatogastroenterology 2009; 56: 718-721

    16. Gastroenterology - William L Hasler, M.D: Lactulose breath testing, bacterial overgrowth, and IBS: just a lot of hot air?

    17. Curr Opin Gastroenterol. 2014 May; 30(3): 332–338.
    Bile Acids and the Gut Microbiome
    Jason M. Ridlon,1,2 Dae Joong Kang,1 Phillip B. Hylemon,1,2 and Jasmohan S. Bajaj2,3,*

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