Lactose & SIBO breath tests
Measures gases in your breath after a sugar drink - showing whether gut bacteria are fermenting sugars they shouldn’t be.
TypeBreath
HowDrink a sugar solution, then breathe into tubes every 15–30 minutes for 2–3 hours.
How oftenWhen symptoms suggest it.
BeforeA special diet the day before and fasting overnight.
WhoPeople with bloating, gas or diarrhea after certain foods.
What your breath says about your gut
Gut bacteria ferment sugars and release hydrogen and methane, which you breathe out. Measuring them after a sugar drink can reveal intolerance or bacterial overgrowth.
Lactose
“Is it dairy?”
Rising gas after lactose suggests intolerance.
Intolerance
SIBO
“Too many bacteria in the small bowel?”
An early rise after the drink can suggest overgrowth.
Overgrowth
Limits
“How reliable is it?”
Prep and interpretation vary, so results are read alongside symptoms.
Use with context
Is it right for you?
Worth considering if…
- You get bloating or diarrhea after dairy.
- Your provider suspects bacterial overgrowth (SIBO).
A better option if…
- A simple dairy-free trial may answer the lactose question.
- Results for SIBO testing are debated - discuss before paying privately.
How it’s measured
Lactose breath test
Tests for lactose intolerance.
Glucose or lactulose breath test
Used for SIBO.
The full picture
What is it?
A test measuring hydrogen and methane in your breath after a sugar drink.
What type of test is it?
A breath test.
What does it measure?
Breath gases over time.
Why might someone consider it?
To check for lactose intolerance or bacterial overgrowth.
Who is it most relevant for?
People with bloating after certain foods.
How is it performed?
You breathe into tubes at set intervals.
How often might it be considered?
When needed.
What can the result help you understand?
Whether sugars are being fermented abnormally.
What are its limitations?
SIBO testing has limited accuracy and preparation affects results.
What should it be viewed with?
Symptoms, diet diary and other gut tests.
Where to get it
Through your provider
Ordered with a collection kit you use at home.
Lab services
e.g. Quest Diagnostics, Labcorp.
Gastroenterology clinics
For ongoing or complex symptoms.
Names are examples only, not endorsements. Your provider can often order the same test - and help interpret it.
Connected to
Questions to ask your provider
- Would a dairy-free trial be enough?
Ziva Health
One test is a snapshot. Ziva shows the whole story.
Ziva brings your lab results, wearables and daily readings together - and Isabella tells you what’s changing and what to ask your provider next.
Refer Ziva to my provider / care team
Is your provider not on Ziva yet? Send them a link in under a minute - once they join, they’ll see your Lactose & SIBO breath tests result alongside your other trends and get alerts directly.
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Bring your Ziva 30-day report to your next appointment - your Lactose & SIBO breath tests result and daily trends in one view, so the conversation starts with the full picture.
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Being listed doesn’t mean everyone needs this test. Educational only — not medical advice. Results should be interpreted with a qualified clinician. ← Back to Know What to Test