Concierge breath testing · London
Private hydrogen breath test in London, the standard test for SIBO, lactose and fructose intolerance.
The non-invasive reference test for SIBO, lactose and fructose intolerance — with a proper dietary and antibiotic plan when we find a cause.
Why patients choose us
- 01
We explain, not just report
A consultant gastroenterologist or dietitian talks you through the curves — not just a graph and a number.
- 02
No bundle upselling
A focused test that answers your question — not a five-hundred-pound intolerance kit if a targeted breath test is what you need.
- 03
Accredited providers only
Calibrated analysers, North American Consensus cut-offs, and an onward FODMAP-diet pathway when the test is positive.
Indicative pricing
What private hydrogen breath tests cost in London.
Indicative ranges across our partner clinics. Send the details and we quote firm figures across two or three options.
In short
A lactose or fructose test in our network: £220–£450, with results same-day.
| Test or substrate | Indicative range | Duration | Results turnaround |
|---|---|---|---|
| Lactose breath test | £220–£450 | 3 hrs | Same-day |
| Fructose breath test | £220–£450 | 3 hrs | Same-day |
| SIBO (lactulose or glucose) | £280–£550 | 3–4 hrs | Same-day |
| SIBO + methane | £300–£600 | 3–4 hrs | Same-day |
| Combined lactose + fructose day | £400–£800 | Half-day | Same-day |
| Breath test + dietitian consultation | £450–£900 | 90 min + test | Same-day |
Prices vary by clinic, whether methane is measured and whether a dietitian consultation is included. We come back with a firm quote within one working day.
The problem
Bloating is not a diagnosis.
Plenty of clinics will run a breath test. Choosing the right substrate, preparing you properly and building the plan that follows — that is the part that matters. That is what we do.
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Not sure which substrate?
Tell us the symptoms and we suggest lactose, fructose, lactulose or glucose — and whether methane needs to be measured.
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Worried about a positive?
We explain the curve, apply the North American Consensus cut-offs, and build a FODMAP or antibiotic plan.
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Want it done properly?
Calibrated analysers, twelve-hour fast, four-week antibiotic washout, three hours of sampling — done the way the guidelines say.
The journey
From enquiry to results — what happens, in order.
One clinician from first message to explained results — usually within a week.
Phase 1 · Before your test
Concierge, off-stage for you
Phase 2 · On the day
Three hours in clinic
Phase 3 · After
Concierge, back on
- 01
Before
You tell us what is going on
A short, confidential form. Symptoms, any existing results, and what you want to understand.
- 02
Before
We recommend the right substrate
Within one working day: lactose, fructose, lactulose or glucose — and whether methane should be measured too.
- 03
Before
Preparation instructions
Diet, medication and antibiotic washout instructions arrive in plain English before your appointment.
- 04
On the day
Fasted arrival and baseline
You arrive fasted. A baseline breath sample is taken before you drink the test substrate.
- 05
On the day
Breath samples every 20 minutes
Breath samples are collected every 20 minutes for three hours in a calm clinic environment.
- 06
After
Results reviewed
The curves are interpreted against North American Consensus (2017) cut-offs by a consultant gastroenterologist.
- 07
After
We explain them
We talk you through the findings and arrange a FODMAP-diet plan or antibiotic course when indicated.
Typical end-to-end: under a week. Urgent cases: a few days.
What it shows
Find the substrate that matches the symptom.
Breath tests answer very specific questions. These are the reasons people come to us most.
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Bloating
Persistent bloating that follows a clear food pattern — the classic reason to test.
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Excess gas after specific foods
Wind and flatulence tied to dairy, fruit or bread rather than everything you eat.
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Diarrhoea
Loose stools that follow lactose, fructose or a broader carbohydrate trigger.
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Suspected lactose intolerance
Confirm or exclude lactose malabsorption before cutting dairy out of your diet for life.
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Suspected fructose intolerance
Test for fructose malabsorption when fruit, honey or high-fructose foods trigger symptoms.
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Suspected SIBO
Small intestinal bacterial overgrowth — the missing diagnosis in many stubborn IBS cases.
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Chronic IBS with post-antibiotic origin
IBS-like symptoms that started after a course of antibiotics or gut surgery.
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Red flag symptoms
Weight loss or night sweats — do not delay for a breath test; see a GP.
Available substrates
The breath tests we arrange most.
What each option is actually for.
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Lactose breath test
Standard 25 g lactose challenge to detect lactose malabsorption over three hours.
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Fructose breath test
Standard 25 g fructose challenge to detect fructose malabsorption over three hours.
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SIBO lactulose
Lactulose challenge — the more sensitive substrate for small intestinal bacterial overgrowth.
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SIBO glucose
Glucose challenge — the more specific substrate, favoured in proximal-bowel SIBO.
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SIBO + methane
Adds methane measurement to detect methane-dominant overgrowth (IMO) linked to constipation.
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Combined lactose + fructose
Two sequential challenges in a single half-day appointment when both are suspected.
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Breath test + dietitian
The test plus a 90-minute HCPC-registered dietitian consultation to build the FODMAP plan.
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Post-treatment SIBO recheck
Repeat breath test after antibiotic therapy to confirm eradication.
Our vetted London network
A small panel of clinics, we picked them.
Consultant-led breath testing on calibrated analysers, with a fast-track dietitian route for anyone who tests positive.
Selection criteria
How we choose every clinic in our network.
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Consultant gastroenterologists or HCPC-registered dietitians supervising every test
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Calibrated breath-test analysers used by every clinic in our network
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North American Consensus (2017) cut-offs applied to hydrogen and methane readings
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Onward FODMAP-diet pathway or antibiotic plan when the test is positive
Preparation and practicalities
Simple to sit — if you follow the preparation.
Breath tests are non-invasive and safe, but preparation is everything — diet, fasting, antibiotics and timing all change the result. We tell you exactly what to do.
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Special diet the day before
A low-fibre, low-fermentable-carbohydrate diet the day before the test — we send you the exact list.
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Fast for 12 hours
Nil by mouth other than water for the twelve hours immediately before the appointment.
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No smoking or exercise
No smoking or strenuous exercise on the morning of the test — both alter breath hydrogen.
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No antibiotics for 4 weeks
Antibiotic use within four weeks makes the test unreliable — reschedule if you have been on a course.
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No probiotics for 2 weeks
Stop probiotic supplements and fermented-food supplementation for two weeks before the test.
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No laxatives for 1 week
Stop laxatives and prokinetics for a week — they alter transit and skew the curve.
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Breath samples every 20 minutes
Samples are taken at baseline and every twenty minutes for three hours; you will be in the clinic throughout.
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Pregnancy
Not routinely performed in pregnancy without prior gastroenterology advice — tell us if you are pregnant.
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Share prior GI investigations
Always share any prior endoscopy, imaging or motility studies — they change how we interpret the curve.
Reading your report
A breath-test curve can look intimidating. It isn’t.
However many time points are plotted, the report follows the same four parts.
A quiet reminder
Read the impression first — the rest is the working.
If you would like us to talk you through the curve before any follow-up, just ask.
- 01 Header
Your details, indication and diet prep
Your details, the clinical question and confirmation that the preparation diet was followed.
- 02 Technique
Substrate and duration
Which substrate was used (lactose, fructose, lactulose or glucose), the dose and the total test duration.
- 03 Findings
Baseline, rise-time and peak
Baseline hydrogen and methane, the time to rise, the peak value, and how these compare with consensus cut-offs.
- 04 Impression
The conclusion: read this first
Positive or negative, and the dietary or antibiotic plan that follows from the result.
Recognised by major UK insurers
Cover varies by policy. Where testing is medically indicated we confirm cover with your insurer before booking.
Frequently asked
Everything we get asked about breath tests.
Quick answers on diet, fasting, antibiotics, pregnancy, cost, referral, results, SIBO and when to see a GP urgently.
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What does a hydrogen breath test measure?
It measures hydrogen (and often methane) in your breath after you drink a sugar substrate. Human cells cannot produce these gases — only gut bacteria can, so a rise in breath hydrogen or methane after a sugar challenge points to malabsorption or bacterial overgrowth in the small intestine.
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What diet do I need to follow beforehand?
The day before the test you follow a low-fibre diet free of fermentable carbohydrates — no beans, pulses, onions, bran, wholegrains, milk, fruit or honey. We send you the exact food list when you book. On the morning of the test you have nothing but water.
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How long do I need to fast?
Twelve hours nil by mouth other than plain water. If your appointment is at 9am, stop eating at 9pm the night before. You can drink water up to the moment you arrive.
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What about antibiotics before the test?
Antibiotics wipe out the gut bacteria that produce the gas we are measuring, so any antibiotic course within four weeks of the test makes it unreliable. If you have had antibiotics recently, tell us and we will reschedule.
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Can I have a breath test in pregnancy?
Hydrogen breath tests are not routinely performed in pregnancy without prior gastroenterology advice. Tell us if you are pregnant and we will discuss whether it is the right test at the right time.
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How much does a hydrogen breath test cost in London?
A lactose or fructose breath test costs £220–£450, a SIBO test £280–£550, and a SIBO test with methane £300–£600. A combined lactose + fructose half-day is £400–£800. We quote a firm figure within one working day once we know which substrate you need.
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Do I need a referral?
Most breath tests accept self-referral. Where symptoms point to something more urgent, we can arrange a fast-track consultant gastroenterologist consultation first.
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How quickly do I get results?
You get the interpreted result on the same day. A full written report reviewed by a consultant gastroenterologist follows within a few working days, along with the dietary or antibiotic plan if the test is positive.
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What is SIBO?
SIBO — small intestinal bacterial overgrowth — is an excess of bacteria in the small intestine, where relatively few should live. It causes bloating, gas, diarrhoea or constipation, and often masquerades as treatment-resistant IBS. A lactulose or glucose breath test is the standard non-invasive way to diagnose it.
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When should I see a GP urgently instead?
Unintentional weight loss, night sweats, rectal bleeding or a persistent change in bowel habit need urgent GP review — not a breath test. We will tell you if that is the right route rather than take your money.
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