Gut and SIBO testing, Australia-wide
You have probably had tests before. A stool test that told you your gut was unbalanced. A breath test someone read to you in five minutes and turned into a protocol. Bloods your GP said were normal.
None of that is the same as being understood.
Testing here is not a product. It is a clinical step inside the Nourished Gut Program, chosen because the result will change what we do next.
When testing is worth doing, and when it is not
Testing is not automatic here. Some people arrive with a clear enough history, symptom pattern and treatment record that we can begin without it.
We recommend a test when the answer will change the plan. That is the whole rule.
A test earns its place when it does one of these things:
- Tells us which overgrowth phenotype we are treating, because hydrogen and methane respond to different agents
- Shows what was depleted by previous antimicrobial rounds or years of restriction, so we know what to rebuild
- Rules out something that needs a GP or gastroenterologist rather than a naturopath
- Gives us a starting point we can measure against later
If a result would not change a single decision, we do not ask you to pay for it. You have already spent enough on tests that sat in a drawer.
More data is not the goal. Better clinical decisions are.
SIBO and IMO breath testing
Breath testing measures the gases produced when bacteria or archaea ferment a test substrate in your small intestine. Which gas comes up determines the treatment.
Hydrogen
Bacterial, and more often associated with looser stools and urgency. Produced when bacteria ferment carbohydrate in the small intestine.
This is the phenotype most people picture when they hear the word SIBO, and it is the one most protocols are written for.
Methane, or IMO
Produced by archaea rather than bacteria, which is why it is now called intestinal methanogen overgrowth. Strongly associated with constipation.
It responds to different agents than hydrogen. Treating it as though it were hydrogen SIBO is one of the most common reasons a protocol fails.
Hydrogen sulphide
A third gas, associated with diarrhoea and sulphur intolerance. It is not currently measurable by breath testing in Australia, and the diagnostic criteria have not been validated.
Where the pattern fits, it is recognised and treated clinically. We will not sell you a test for it.
Why we run more than one substrate
Glucose is absorbed higher up and is the more specific of the two standard substrates. Lactulose travels further and picks up overgrowth the glucose test can miss. Running both shows us where in the small intestine the fermentation is happening.
Where fructose malabsorption is also in the picture, we add fructose as a third substrate. That separates malabsorption which is primary from malabsorption which is secondary to an overgrowth. Those two situations need different plans, and glucose and lactulose alone will not tell you which one you have.
What a breath test can and cannot tell us
Breath testing is a clinical signal, not a definitive diagnosis, and we will not pretend otherwise. A 2024 appraisal in Neurogastroenterology and Motility was openly critical of how breath tests are used in IBS, because transit time and substrate dose both influence the result.
We take that seriously. A breath test is read alongside your history, symptom pattern, treatment response and bloods. It never stands alone.
Testing is completed at home and posted back to the laboratory, so it works anywhere in Australia.
Comprehensive microbiome testing
Metagenomic stool testing shows what is actually living in your large intestine, including species, functional capacity and markers of gut inflammation.
Karly has completed advanced microbiome training and has presented to other practitioners on how to read these reports. That matters, because this is the part of testing most commonly misread.
An international expert consensus published in The Lancet Gastroenterology and Hepatology in 2025 concluded there is not yet enough evidence to recommend routine microbiome testing for everyone, and specifically discouraged patients ordering these tests for themselves without clinical guidance.
We agree with both points. Microbiome testing is not a diagnosis, and there are no validated normal ranges to hold you to.
What it does well is show the state of your microbial diversity and function after everything you have been through. That tells us what needs rebuilding, and in what order. It is a restoration question rather than a diagnostic one, which is exactly what the Feed Forward methodology is built to answer.
Our comprehensive functional blood panel
Standard pathology is where we catch the things that get missed when everything is blamed on IBS.
This is not an off-the-shelf panel. Karly designed it specifically for complex gut cases, and it assesses 50+ biomarkers in a single collection. Iron studies and full thyroid function, not just TSH. Inflammatory markers, B12 and folate, coeliac screening, hormones, immune markers, and the nutrient status that years of restricted eating quietly erodes.
We read these against research-informed functional ranges, not only the laboratory's reference range. A result inside the range is not the same as a result that supports the way you want to feel.
Most people who come to us have had bloods before and been told everything was fine. Usually the problem was not the interpretation. It was that nobody ordered enough of the right markers to see the pattern.
Collection is at a pathology centre near you, so this works wherever you are in Australia.
What actually happens after your results come back
This is the part most people have never had, and it is the reason our clients stop test-hopping.
- A dedicated Report of Findings session. Not a rushed summary at the end of a consult. A session where we walk through what each result means for you, what it explains about the last few years, and what we are going to do about it.
- A protocol built from your results, not a template. Antimicrobial choice, dosing and duration are matched to your phenotype. Restoration support is matched to what your microbiome actually shows. Your SIBO Restore Diet stage is set by your symptom load and treatment phase, not a generic food list.
- A plan that moves. Results tell us where to start. They do not lock you in. As your symptoms change across six months, your protocol and dietary stage change with them, with a practitioner watching rather than you guessing at home.
- Your results belong to you. You keep every report and every interpretation. If you work with another practitioner later, it goes with you.
You don't need more information. You need someone in it with you.
Why we retest at six to twelve months
Clearing an overgrowth is not the same as fixing the conditions that allowed it.
The most-cited research on this followed 80 people who had successfully cleared SIBO with antibiotic treatment. Breath tests turned positive again in 12.6% by three months, 27.5% by six months and 43.7% by nine months (Lauritano et al., American Journal of Gastroenterology, 2008).
That is one study, and it defines recurrence by breath test rather than by how people felt. We are not going to overstate it. But it matches what we see clinically, and it is why this program runs for six months rather than six weeks.
So we retest between six and twelve months, depending on your case. Not to find something wrong. To confirm that what we rebuilt has held.
Retesting usually tells us one of three things:
- It held. Diversity has improved and gases have stayed down. We move you into maintenance and digestive resilience.
- It partially held. Something is drifting. We adjust early, while it is small, instead of waiting for a full relapse.
- A driver is still active. Motility, structure or another root cause needs addressing before restoration can hold. This is usually why previous rounds of treatment failed.
There is no professional guideline that sets a retesting interval, and any clinic telling you there is one is overstating the evidence. Six to twelve months is our clinical position, based on recurrence data and on what we see in practice.
Most protocols focus on killing. Very few focus on rebuilding, and almost none check whether the rebuild lasted.
What testing costs
We publish this because you should be able to see it before you book anything.
Testing is charged at cost. We do not mark it up. You pay the laboratory directly, and we quote you the exact figure before anything is ordered.
SIBO and IMO breath test
$260 to $360, priced by how many substrates your case needs. At-home kit, posted to you.
Comprehensive functional blood panel
Approximately $315 for 50+ biomarkers, collected at a pathology centre near you.
Comprehensive microbiome test
Approximately $485. At-home collection kit, posted to you.
Each figure moves depending on what your case actually needs. We do not run markers for the sake of it, and you will never be handed a blanket testing bundle.
Blood testing may cost you less than this. Many markers on the panel can be rebated by Medicare when requested through your GP, and if you have had recent bloods we will use those rather than repeat them.
There is no Medicare rebate for SIBO breath testing or microbiome testing in Australia. Some private health funds offer partial rebates for breath testing, so it is worth asking yours.
Most clients use one or two of these, not all three. Testing sits on top of your Nourished Gut Program investment, at cost, and only where it will change your plan.
Testing is offered inside the program, not as a standalone service
We do not sell test kits.
That is deliberate, and it is worth explaining. A test result without a practitioner who knows your history, your treatment record and your dietary stage is how most people end up with another protocol that does not hold. It is how you get handed a list of bad bacteria and eleven supplements.
The 2025 international consensus made the same point from the other direction, recommending that microbiome testing be requested by a practitioner rather than by patients directly.
So testing here comes with the planning, the interpretation, the protocol and the six months of support that make the result mean something.
If you want a test kit alone, we are not the right clinic, and we would rather tell you that now.
Frequently asked questions
Do I have to do testing to work with Nourished Gut Clinic?
How much does a SIBO breath test cost in Australia?
How much does the blood panel and microbiome testing cost?
Do you test for hydrogen sulphide?
Can I order a test without joining the program?
Do I need to travel to a clinic to do the tests?
What is the difference between SIBO and IMO?
Why do you retest at six to twelve months?
Not sure which testing you actually need?
That is the right question, and it is what the Digestive Strategy Session is for. It is a free 20 minute telehealth call. You complete a short application, we review it properly, and if we are a fit we talk through what testing would and would not tell us in your case.
If the Nourished Gut Program suits your case, you will be told. If it does not, you will be told that too.
Not ready yet? Start with the free 3-Day Bloat Fix, or read about SIBO treatment with a naturopath.
Nourished Gut Clinic · Telehealth across Australia · hello@karlyraven.com
