SIBO Testing, Diet and Recovery in Australia
This guide is for Australians experiencing persistent bloating, excess gas, abdominal discomfort, constipation, diarrhoea or food-related digestive symptoms who want to understand whether SIBO may be part of the picture.
I’m Ola Krawczyk, an ATMS Accredited Clinical Nutritionist and SIBO-Certified Nutritionist who completed advanced training through Dr Nirala Jacobi’s SIBO Mastery Program.
Nutrition support works alongside assessment and treatment from your GP or gastroenterologist—it does not replace medical diagnosis or care.
In short: Small intestinal bacterial overgrowth, or SIBO, describes excessive numbers or an altered population of bacteria in the small intestine that contribute to symptoms. In Australia, it is commonly investigated using a glucose or lactulose breath test measuring hydrogen and methane.
Nutrition support may involve three broad stages: assessing your current diet and symptoms, making temporary symptom-guided adjustments during medical management, and gradually rebuilding variety and nutritional adequacy afterwards.
Online consultations are available across Australia.
What is SIBO—and what is it not?
SIBO stands for small intestinal bacterial overgrowth. It may contribute to bloating, gas, abdominal discomfort, diarrhoea, constipation, nausea or uncomfortable fullness after eating.
These symptoms do not always mean SIBO. They may also occur with IBS, coeliac disease, constipation, food intolerances or other digestive conditions. A stool microbiome test is also not the same as a SIBO breath test.
Read more about why SIBO may develop or compare SIBO and IBS.
How is SIBO tested in Australia?
SIBO is commonly investigated using a hydrogen and methane breath test. Most tests can be completed at home. You follow the preparation instructions, collect a breath sample, drink glucose or lactulose, then collect more samples over the next few hours.
The laboratory measures gases produced when microorganisms ferment the test sugar:
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Hydrogen: may support a SIBO pattern and is often linked with bloating or diarrhoea.
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Methane: is more often linked with constipation. The more accurate name is intestinal methanogen overgrowth, or IMO.
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Hydrogen sulfide: may be linked with diarrhoea, but it is not measured by many standard Australian tests and interpretation is still developing.
Glucose is absorbed earlier in the small intestine. Lactulose travels further through the digestive tract. Neither test is perfect, so results should be considered together with your symptoms, bowel habits and health history.
Who can arrange a test, what does it cost and how long does it take?
A GP, gastroenterologist or qualified health professional may arrange testing. Some Australian laboratories also accept direct orders.
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A single home breath test is commonly around $195 ex GST, although prices vary.
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Results are often available within several business days after the laboratory receives the samples.
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Always follow the instructions supplied with your test kit, as preparation can affect the result.
What should you eat during each phase?
There is no single diet that suits everyone with SIBO. Food choices should be based on symptoms, bowel habits, nutritional needs and medical care.
Phase 1: assess and prepare
Before removing more foods, review what you are eating, your symptoms, bowel habits and test results. The priority is regular, nourishing meals with enough protein, energy and nutrients.
Phase 2: manage symptoms
Temporary changes to portions, fibre or fermentable carbohydrates may reduce discomfort. Simple meals might include a tolerated protein, rice or potato, cooked vegetables and a healthy fat such as olive oil.
A low-FODMAP-style approach may help some people, especially when IBS overlaps, but it is not a treatment for SIBO and should not become a strict long-term diet.
Phase 3: reintroduce and personalise
As symptoms settle, foods are gradually reintroduced. The aim is to find the widest range of foods and portions you can comfortably enjoy—not stay on a small “safe food” list forever.
A personalised 7-day meal plan can turn your recommendations into practical meals.
How do you rebuild after SIBO treatment?
Recovery is not one universal “gut repair protocol.” A practical rebuilding plan may include:
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Reintroducing foods gradually, one change at a time
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Increasing plant variety at a pace you tolerate
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Eating enough protein, fibre, energy and key nutrients
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Supporting regular bowel movements with food, fluids and movement
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Reviewing meal timing without using unnecessary fasting rules
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Reassessing persistent symptoms instead of repeatedly restricting food
Probiotics, prebiotics and supplements are not automatically suitable for everyone. They should be selected for your individual needs and stage of care.
Why can SIBO come back?
SIBO may return when an underlying contributor is still present. Possible factors include slow gut movement, ongoing constipation, previous abdominal surgery, some health conditions or medicines, and a different or overlapping digestive problem.
Low stomach acid is sometimes discussed as a cause, but symptoms alone cannot confirm it. Acid supplements are not appropriate for everyone. Read what happens when stomach acid is too low and speak with your doctor before changing medication.
Reducing the chance of recurrence means looking beyond the breath-test result and addressing the reasons the problem may have developed.
Where do thyroid health and perimenopause fit?
Thyroid conditions and perimenopause do not automatically cause SIBO, but their symptoms can overlap. Slower bowel movement, constipation, fatigue, bloating and appetite changes may all affect the bigger picture.
Thyroid nutrition support and perimenopause nutrition support consider digestive symptoms alongside your nutritional needs, health history and medical care.
Questions people often ask
How do I know whether I have SIBO?
Symptoms alone cannot diagnose SIBO. Your symptoms, medical history and bowel habits should be assessed, with breath testing used when appropriate.
Is a stool microbiome test the same as a SIBO test?
No. A stool test mainly reflects the large intestine. A breath test looks for gas patterns that may suggest fermentation in the small intestine.
What should I eat if I have SIBO?
There is no universal food list. Aim for adequate protein, energy, nourishing carbohydrates, healthy fats and the widest range of plants you currently tolerate.
Do I need a low-FODMAP diet?
Not always. It may temporarily reduce symptoms for some people, but it should include food reintroduction rather than long-term restriction.
What should I do during a flare?
Choose simple meals you tolerate, stay hydrated and consider recent changes such as constipation, illness, medication, stress or new supplements. Seek medical advice for severe, new or persistent symptoms.
Can SIBO return after treatment?
Yes. Recurrence may happen when slow motility, constipation or another underlying factor has not been addressed.
Can a Clinical Nutritionist help?
A Clinical Nutritionist can help you understand your food intake and test results, manage symptoms while eating adequately, and gradually rebuild food variety. Medical diagnosis and treatment remain with your GP or gastroenterologist.
Working together
If you would like this mapped to your own test results and symptoms, that is what SIBO nutrition support is for.
Not sure whether this is the right starting point? Book a free 15-minute health assessment or contact Clinical Nutrition by Ola.
Important health information
This page provides general nutrition education and does not diagnose or treat SIBO or replace medical advice. Speak with your GP or gastroenterologist about testing, treatment, medication changes or concerning symptoms.
About Ola Krawczyk
Ola Krawczyk is a Polish-Australian Clinical Nutritionist, ATMS Accredited Member, SIBO-Certified Practitioner and Microba Certified Practitioner. She provides online consultations across Australia in English and Polish.
Last reviewed: 5 September 2026
References
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Pimentel M, et al. ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. 2020.
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Quigley EMM, et al. AGA Clinical Practice Update on Small Intestinal Bacterial Overgrowth. 2020.
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Rezaie A, et al. North American Consensus on Hydrogen and Methane Breath Testing. 2017.
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Hammer HF, et al. European Guideline on Hydrogen and Methane Breath Tests. 2022.