Your gut tells its story one exhale at a time.
A hydrogen breath test reads the gas your gut bacteria make when they meet a sugar they can't digest — no needles, no scoping, just breathing into a bag every fifteen minutes.
Gas your body can't make on its own
Human cells don't produce hydrogen. Bacteria do — and only when they get hold of sugar your small intestine failed to absorb. That gas has nowhere to go but into your bloodstream, up through your lungs, and out.
You drink a measured sugar
Lactose, fructose, or glucose — chosen based on what we're screening for.
Undigested sugar reaches your gut bacteria
If your body can't break it down upstream, it passes through intact.
Bacteria ferment it, releasing hydrogen
This is the same fermentation that happens in bread dough or a compost pile.
The gas surfaces in your breath
We measure it every 15–20 minutes to trace the exact rise.
Three conditions, one breath
The same protocol, run with different sugars, can point to three separate causes behind bloating, cramping, and irregular digestion.
Lactose Intolerance
Tests whether your body produces enough lactase to break down the sugar in milk and dairy.
Substrate: LactoseFructose Malabsorption
Checks how well your small intestine absorbs fruit sugar, often behind reactions to apples, honey, and soft drinks.
Substrate: FructoseSIBO
Screens for small intestinal bacterial overgrowth — bacteria colonising a part of the gut where they shouldn't thrive.
Substrate: GlucoseWhat actually happens in the chair
The order matters — every reading is measured against the one before it, so the sequence is fixed from arrival to your last breath sample.
Baseline breath
Before anything else, you breathe into a collection bag so we know your resting hydrogen level.
T0Drink the substrate solution
A measured dose of lactose, fructose, or glucose dissolved in water, based on what your doctor wants screened.
T0 + 2 minBreathe every 15–20 minutes
You stay on-site and provide a fresh sample at regular intervals while we chart how your hydrogen shifts.
T15 → T180Report & doctor read
Your curve is plotted against the diagnostic threshold and reviewed, with results usually ready the same day.
Same dayGetting ready matters as much as the test itself
Certain foods and medicines feed the same bacteria we're trying to measure, which can throw off your reading. Follow this the day before your appointment.
Do this
- Fast for 8–12 hours before your slot — water is fine
- Eat a plain dinner the night before: rice, chicken, or fish
- Arrive without perfume or strong scents near the mouth
- Bring your doctor's referral, if you have one
Avoid beforehand
- Antibiotics for 4 weeks prior, unless your doctor says otherwise
- High-fibre foods, beans, and whole grains the day before
- Smoking on the morning of the test
- Strenuous exercise right before your appointment
Reserve a three-hour window at a centre near you
Slots run through the morning so results can go out the same evening. Walk-ins are accepted where space allows, but a booking guarantees your seat.
Before you book
No. It's entirely breath-based — you drink a sweet solution and breathe into a bag at intervals. No needles, no fasting beyond the night before.
Most protocols run 2–3 hours, since we need to sample your breath every 15–20 minutes to see the full curve, not just one point.
Yes, it's commonly used for children too, with a dose adjusted to their weight. A parent stays on-site for the full session.
The report gives your doctor a clear diagnosis — dietary guidance is something to work through with them afterward, based on your result.
It helps but isn't required. You can book directly and share the report with your doctor afterward, or bring a referral if you already have one.