SIBO Breath Test UK
SIBO Breath Test UK (Hydrogen & Methane) — At‑Home Breath Testing UK
If you’re living with persistent bloating, gas, abdominal discomfort, or irregular bowels, a non‑invasive SIBO breath test can help clarify whether Small Intestinal Bacterial Overgrowth (or methane‑predominant intestinal overgrowth) is part of the picture.
Our SIBO breath test kit is conducted at Hone and can be delivered all over the UK and in London allowing you to conduct the test comfortably in your own home. The results take 3 days and when they are back you can book a consultation with our SIBO specialist.
To arrange a private SIBO test in the UK, please contact us at help@nutritionandvitality.co.uk or call us at 0345 129 7996.
What is a SIBO test?
A SIBO test is a non-invasive breath test that helps detect small-intestinal bacterial overgrowth (SIBO) by measuring the gases (hydrogen and methane) you exhale after drinking a sugar solution.
If too many microbes are present in the small bowel, they ferment the test sugar and release gases that show up in your breath a little while later. The laboratory measures these gases and plots a curve over time. We then interpret the pattern alongside your symptoms and history.
- Hydrogen (H₂): Often associated with diarrhoea‑predominant symptoms, urgency, bloating, and noisy gut sounds.
- Methane (CH₄): Produced by methanogenic archaea (not bacteria), often linked with constipation, slower transit, and a feeling of incomplete emptying.
- Mixed patterns: Many people show both gases, which can explain alternating bowel habits or complex symptom profiles.
Unlike stool tests, which mostly reflect the large intestine, a breath test helps infer what may be happening in the small intestine, which is where SIBO/IMO matters most for symptoms after eating.
Substrates
We offer both Glucose or Lactulose
Glucose: higher specificity (fewer false positives), but may miss overgrowth farther down the small intestine.
Lactulose: samples the whole small bowel better, but can be more prone to false positives if interpretation isn’t careful.
How do you test for SIBO at home?
The day before your test you follow a simple low-fermentation diet, then fast for 12 hours overnight.
On the morning of the test you will take a relaxed, normal breath and blow into the first collection tube to record a baseline.
You then drink the small test solution (lactulose or glucose, as provided) and, from that point, you give further breath samples at regular intervals, every 20 minutes for around three hours.
When you’ve finished, everything is posted or couriered to the UK laboratory the same day.
The lab measures hydrogen and methane in each sample and plots a time curve; we interpret that pattern alongside your symptoms and history to explain what it means and what to do next.
Most people get results within two-three working days.
Who Can Benefit from a home SIBO Home Test kit ?
SIBO can lead to a range of uncomfortable digestive symptoms, including:
- Bloating and excessive gas
- Diarrhea or constipation
- Abdominal pain or discomfort
- Malabsorption of nutrients, leading to vitamin deficiencies
If you are looking for the root cause of these symptoms a SIBO test may shed some light on why you are experiencing these symptoms.
SIBO Test at home- UK
Testing for Small Intestinal Bacterial Overgrowth (SIBO) at home is a convenient and reliable way to diagnose the condition. We can give you a kit when you have a consultation to take home or we can post one to you.
Who should test for SIBO?
You may benefit from a SIBO breath test if you experience any of the following on a persistent basis (8–12 weeks or more):
- Bloating or visible distension that worsens after meals or by evening
- Excess gas, abdominal discomfort, cramps, or a sense of tightness
- Diarrhoea, constipation, or alternating bowel habits
- Nausea, reflux/heartburn, early fullness (“food sits there” feeling)
- Sensitivity to high‑FODMAP foods (onions, garlic, beans, wheat), milk, certain fruits, or sugar alcohols (sorbitol/xylitol)
- History clues that raise suspicion:New GI symptoms after food poisoning or traveller’s diarrhoea
- Long‑term use of PPIs (acid suppressants), frequent antibiotics, or opioid pain medicines
- Prior abdominal surgery (adhesions), endometriosis, or connective‑tissue disorders
- A diagnosis of IBS that hasn’t responded to basic diet changes
- Unexplained nutrient deficiencies (B12, iron) or unintentional weight loss
There are a number of conditions that have been associated with small intestinal bacterial overgrowth:
- Irritable Bowel Syndrome (IBS)
- Rosacea
- Acne
- Diabetes
- Appendix removal
- Pancreatic insufficiency
- Crohn’s disease
- Food poisoning/gastroenteritis
- Gallbladder removal
- Opiate use
- Chronic use of Proton Pump Inhibitors (PPIs)
- Tingling sensation (pins and needles)
- Endometriosis
- Helicobacter pylori (H. pylori) infection
How much does a SIBO test at Home cost? Hydrogen Breath Test Cost
The cost of the Hydrogen Breath test at home is £165. This is one of the most affordable tests on the market.
How do I know if I have SIBO?
A characteristic rise in gases within 90 minutes —matched to your symptoms—supports a SIBO diagnosis or methane-predominant overgrowth (often linked with constipation).
Can you test for SIBO on the NHS?
It is possible to test for SIBO on the NHS, normally your GP will need to refer you to a Gastroenterologist. However waiting times can be extensive. At the time of writing GPs still do not test for SIBO on the NHS.
Can you test for SIBO in your London clinic?
It is no longer possible to conduct the SIBO test in our London clinic, however we can provide you with a SIBO home test kit during your consultation in our London clinic to take home.
Do you offer a Glucose SIBO Test?
Yes we offer a Glucose SIBO test and the fee is £165.
Causes of SIBO
Several factors can contribute to SIBO, including:
- Food poisoning or gastroenteritis
- Low stomach acid due to acid-suppressing medications (e.g., Omeprazole, Lansoprazole)
- Crohn’s disease
- Stress
- Gallbladder removal
- Hypochlorhydria (low stomach acid)
- Surgery
- Constipation
- Lack of pancreatic enzymes
How can I treat SIBO?
Unfortunately SIBO can relapse the treatments available are listed below
- Herbal antibiotics including Oregano oil for SIBO- these are effective supplements to combat SIBO
- Following specific SIBO Diets such as Low FODMAP diet
- Taking antibiotics such as Rifaximin and or Neomycin- unfortunately these are not readiy avaialble on the NHS
- Taking motility agents such as Prucalopride/ Ginger
- Taking supplements to improve Hypochlorhydria (low stomach acid)
- Addressing underlying causes such as stress/ constipation/ medications
- Using an elemental diet- this involves drinking shakes that contain pre-digested carbohydrates, proteins and fats.
What is Methane SIBO?
This means that your test will have elevated levels of methane gas. Methane is produced by specific bacteria, primarily Methanobrevibacter smithii.
The most common symptoms are constipation and bloating and slower gastrointestinal transit times due to the effects of methane, leading to constipation.
How does the SIBO Breath Test work?
Preparation
- Diet Restrictions: In the 24 hours leading up to the test, you’ll be instructed to follow a specific diet, consisting of simple, easily digestible foods like plain white rice or chicken, to minimize gas production.
- Fasting: You’ll need to fast for 12 hours before the test, which means no food or drink (other than water).
- Medications: You may need to stop certain medications, such as antibiotics, probiotics, and laxatives, for a specified period (usually 2 weeks), as they can affect the test results.
Starting the test
Baseline Breath Sample: The test starts by blowing into a tube to provide a baseline breath sample, which will measure the amount of hydrogen and methane gases in your breath.
Ingesting the Test Solution
You’ll drink a solution of either lactulose or glucose. These are non-absorbable sugars that pass through the small intestine and act as a substrate for bacterial fermentation if there is an overgrowth.
Breath sample collection
After drinking the solution, you’ll be asked to provide breath samples at regular intervals, every 20 minutes, for around 3 hours. The breath samples are collected using a tube or small bag, and the amount of hydrogen and methane gases exhaled is measured.
Analysis
- The test measures the levels of hydrogen and methane in your breath. In people with SIBO, the bacteria in the small intestine ferment the sugar (glucose or lactulose), producing elevated levels of these gases.
- If the gases increase significantly within the first 90 minutes of the test, it suggests bacterial overgrowth in the small intestine.
What is the difference between Lactulose and Gluclose?
Lactulose and glucose are both used to test for Small Intestinal Bacterial Overgrowth (SIBO), but they are effective for different parts of the small intestine. The glucose breath test is better for detecting overgrowth in the upper small intestine because it is quickly absorbed there. If bacteria are present, they will ferment the glucose, producing hydrogen or methane gases that can be measured in breath samples. This test provides faster results and has a lower chance of false positives.
In contrast, the lactulose breath test is more reliable for finding overgrowth in the lower small intestine. Since lactulose is not absorbed, it travels further down the digestive tract. This test can give a more complete picture of bacterial overgrowth, but it may take longer to show results and has a higher risk of false positives due to fermentation in the colon.
How can I order a SIBO home test kit?
Order a SIBO Test Kit
You can order an at-home SIBO breath test kit by e-mailing help@nutritionandvitality.co.uk or calling 0345 1297996
The kit includes:
Breath collection tubes or bags
A sugar solution (usually lactulose or glucose)
Detailed instructions on how to perform the test at home
- Order Your Kit: Purchase your SIBO test kit online, and it will be shipped directly to your address.
- Collect Samples: Follow the included instructions to collect breath samples at home.
- Send It Back: Return your samples to our accredited laboratory for analysis.
- Receive Results: You will receive your results via email within 2-3 days.
Can I get a SIBO test on the NHS?
While the test is available through the NHS, obtaining a referral can be challenging as many GPs are still not well-versed in this condition and you may need to wait 6 months or more.
Cheapest and Fastest SIBO Test UK
Affordability: We pride ourselves on offering one of the cheapest SIBO test in the UK without compromising on quality.
- Speed: The results will tale 2-3 days and will be e-mailed to you.
What is Hydrogen Sulfide SIBO?
Hydrogen Sulfide SIBO is a type of Small Intestinal Bacterial Overgrowth where bacteria produce excess hydrogen sulfide gas. Unlike typical SIBO, which involves hydrogen or methane-producing bacteria, this type is linked to bacteria that produce hydrogen sulfide, known for its sulfur or “rotten egg” odour.
Key Features
- Symptoms: Diarrhoea, sulphur-smelling gas, abdominal pain, and sometimes systemic symptoms like fatigue, body pain, and bladder irritation.
What are the symptoms of SIBO?
Typical symptoms include:
- Abdominal pain
- Feeling bloated or full, even after small meals
- Struggling with diarrhea or constipation
- Unexplained weight loss, without trying
- Trouble digesting high-fiber foods like broccoli, beans, onions, or garlic
- Constant belching, excess gas, or embarrassing flatulence
- Mental fogginess
- Iron or B12 deficiencies, signaling poor nutrient absorption
- Leaky gut symptoms, like joint pain, skin rashes, or severe food intolerances
- Skin conditions like rosacea flaring up for no clear reason
- Restless Legs
- Fatigue
Why should I take a SIBO test?
Performing a SIBO home test has numerous benefits:
- If you do not wish to wait for a referal from your GP to a Gastroenterologist, it is best to take the matter into your hands
- If you are keen to understand what is causing your symptoms such as bloating, constipation, diarrhoea
Can SIBO cause IBS?
Did you know that between 30% to 80% of people with IBS symptoms including diarrhoea, constipation, gas, bloating, and flatulence may actually be suffering from SIBO? Testing for SIBO can be a crucial step in identifying the root cause of digestive issues that are often misdiagnosed as Irritable Bowel Syndrome (IBS).
What is SIBO?
SIBO (Small Intestinal Bacterial Overgrowth) is defined by the World Journal of Gastroenterology as an “increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract.” In a healthy digestive system, the body removes excess bacteria from the small intestine through a process called the Migrating Motor Complex (MMC).
When this process is impaired, bacteria can build up, leading to symptoms like gas, bloating, diarrhea, and constipation. The bacteria that has overgrown in the small bowel normally lives in your large bowel.
The bacteria tend to cause symptoms such as bloating and gas as they feed off the sugars in the foods that you eat particularly carbohydrates.
If you’re experiencing these symptoms, a SIBO test in London could help identify the underlying issue and guide effective treatment.
SIBO Specialists. If you have tested positive for small intestinal bacterial overgrowth and would like to get treated please contact our sister clinic the IBS and Gut disorder Clinic and they will book you in with a SIBO specialist in London or by means of a virtual consultation.
Have any questions? Call us now!
0345 1297996
FAQ
How is the SIBO Home Test performed?
At the start of the test, you will need to blow into a balloon with a breath of air. The laboratory will then measure hydrogen and methane from your breath sample. Breath samples are collected 10 times over a 3 hour period. Before doing the hydrogen breath test you will need to fast for 12 hours and eat a low-fibre diet. We will send you full instructions.
What does the test measure?
The test is designed to measure levels of methane and hydrogen in your breath. If these exceed a certain level this is diagnostic of SIBO.
How common is SIBO?
Research indicates that up to 60% of patients with IBS have SIBO.
What is the treatment of SIBO?
You will need to see a professional and take anti-bacterials -Rifaximin or natural herbal remedies may be helpful. We also recommend a low-fodmap diet. If you would like to book a consultation with us please contact or call us on 0345 1297996.
Is diet important to reduce symptoms of SIBO?
Yes, diet is very important. You may need to follow a low-fodmap or SCD diet to help eradicate the bacteria. It is important that you find suitable replacements and still eat in a balanced way. Our consultants can help you.