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What is the Prep Diet? 

Click here for the prep guide. The SIBO breath test involves a 24-48 hour prep diet. This means 24-48 hours prior to your test.

Some practitioners may suggest a longer prep depending on how fast your intestinal tract moves along i.e. constipation. However, that is something you would have to discuss with your practitioner OR you can email SIBO CLINIC CANADA at info@sibocliniccanada.com for help.

During this prep, stop taking all non-essential medications, supplements, and probiotics. This includes over the counter pain medications, allergy medications, and antacids. If you don’t know what medication is considered essential, consult your prescribing physician. The goal is to starve the bacteria for a day in order to produce the best results when doing the test. Bacteria fuel on plant products and sugars, so the only foods that you can have on the prep diet are listed here – if it is not on this list DO NOT eat it: 

  • Any meat/poultry/fish/seafood that is not cured or brined
  • Plain, steamed white rice
  • Eggs
  • Clear meat broth (made only from the meat, no bone/cartilage or vegetables)
  • Fats/oils (coconut/olive/vegetable oils, butter, or lard)
  • Salt and Pepper (no other herbs/spices)
  • Weak black coffee and/or weak black tea (plain, no sweeteners or cream, NO green or herbal teas)
  • Plain water (no mineral water or water with additives)
  • Vegans or vegetarians can add a little tofu or soak lentils

The prep diet is incredibly restrictive. I really can’t replace things on it?

No. Any changes to the diet can affect the results of the test. The manufacturer of the SIBO test created the prep diet based on their research and testing. Only the things on the prep diet are allowed to get the cleanest results for the SIBO test.

Do I have to eat everything on the prep diet?

No. If you do not eat grains, for example, do not consume the rice. If you do not eat eggs, then do not start just for this diet. Eat things on this list, but only of what you would normally eat.

Can I eat cheese on the prep diet?

Many practitioners may will modify your diet to what they feel is the best test for you. We at SIBO CLINIC CANADA only go by what the manufacturer of the SIBO test (Qiuntron) has worked with to create the guidelines for the test. If your practitioner has a specific modification (such as hard cheeses) then you must discuss it with them, as we cannot give advice about foods outside of the manufacturer’s guidelines. However, although cheese is a form of dairy, and dairy is not on the list of foods to consume because of the lactose-containing sugar, hard aged cheeses have minute traces of lactose, and the more aged the cheese, the less lactose it contains. If you do find the prep diet far too constrictive, and feel the need to have cheese, please proceed with caution and make sure the cheese is non-processed aged cheese.

Can I eat brown rice/quinoa/etc?

The only grain acceptable on the prep diet is plain, white Basmati or Jasmine rice because they have the lowest glycemic index of all rice). Other rice/grains have a higher level of fiber and macromolecules that SIBO bacteria like to eat. Any substitutions can give inaccurate test results. If you normally do not eat rice, do not eat any during the prep diet.

What if I’m a vegetarian/vegan?

The SIBO prep diet specifically cuts out plant products and sugars in order to starve the bacteria for a day prior to taking the test, which will give you the most accurate results. If you do not adhere to the diet, the bacteria may not react during the test, leading to possible false negative results. If you do not normally consume poultry/meat/eggs, please consult with nutritional expert to determine your options.

Why is the meat broth so specific on the prep diet?

Regular bone broth is often cooked with cartilaginous bones or meat.  When cooked, polysaccharides (specifically glucosaminoglycans or GAGs) from the cartilage leech into the bone broth and can feed a bacterial overgrowth and therefore be problematic for people with SIBO.

It is important that if you consume meat broth for the prep diet, it must be made from ONLY the meat. There cannot be any bone or cartilage included, and it cannot have any vegetables or herbs (aside from salt and pepper) in it. Most store bought broths have ingredients that are not appropriate for this prep diet, so homemade broth is the best decision.

Can I eat cured meats/lox/sausage?

Any meat ingested must be made without any added sugars/brines/cures/etc. to avoid contaminating the prep diet. Avoid meats like deli-meat, lox, and pre-prepared meats that have any other herbs and spices besides salt and pepper. Meats like sausage usually have other herbs or sugars in them and should be avoided during the prep diet.

Can I eat sushi?

The sashimi fish is fine on the prep diet, when eaten alone and without sauce. The rice in Nigiri is usually made with sugar-based binders to make it stick together better, and thus should be avoided on the prep diet. The only exception is home-made Nigiri with steamed white rice and no sauces. Sushi rolls are very much to be avoided.

What about smoking/alcohol?

If you are a smoker, of tobacco or cannabis, there is no recommendation to stop use during the prep diet. However, do not smoke anything for at least one hour prior to taking the breath test, or during the time of the test (4 hours total). If you ingest cannabis in edible form, it must be avoided during the prep diet. Smokeless tobacco (chew) should be avoided during the prep diet and prior to the test as well. Avoid all alcohol during the prep diet.

Hydrogen Sulfide (H2S) testing? 

We don't test for Hydrogen sulfide yet. It is coming soon. However, please read the following information of what we see as current

1. Cost: H2S SIBO testing can be more expensive than traditional hydrogen and methane SIBO testing. The cost can vary depending on the specific test and the laboratory. The higher price might concern individuals trying to manage their healthcare expenses.

2. Accuracy: H2S SIBO testing methods are still evolving, and accuracy and reliability may have limitations. Some tests have a higher false positive or false negative rate than hydrogen and methane testing. This can make it challenging to diagnose H2S SIBO based solely on testing results confidently.

3. Drawbacks of H2S Testing:

  • Limited Research: Compared to hydrogen and methane SIBO, more research and clinical experience with H2S SIBO needs to be done. This can make it harder to interpret the results and understand the implications of a positive or negative test.
  • Interpretation Challenges: Interpreting H2S SIBO test results can be more complex. Various bacterial strains can produce different levels of H2S, and the significance of those levels can sometimes be clarified. This complexity can lead to uncertainty in treatment decisions.
  • False Positives/Negatives: As mentioned earlier, accuracy can be a concern. False positives and negatives can lead to misdiagnosis or delay appropriate treatment.
  • Treatment Approach: The treatment approach for H2S SIBO might differ from traditional hydrogen and methane SIBO. However, due to the evolving nature of H2S testing and limited clinical guidelines, healthcare practitioners might have varying approaches to treatment.
4. Advantages of Hydrogen and Methane Testing:
  • Established Methods: Hydrogen and methane SIBO testing methods have been used longer and are more commonly found in clinical practice.
  • Clearer Guidelines: Treatment protocols for hydrogen and methane SIBO are better defined due to the larger body of research and clinical experience.
  • Cost: Hydrogen and methane testing is generally more cost-effective, making it more accessible for individuals.

In summary, while H2S SIBO testing might offer valuable insights into certain cases, some challenges and uncertainties are currently associated with its use. If you're considering SIBO testing, discussing your options with a healthcare practitioner knowledgeable about SIBO and the available testing methods may be a good idea. They can help you decide based on your specific symptoms, medical history, and each testing approach's potential benefits and drawbacks.


Small Intestinal Bacterial Overgrowth (SIBO) occurs when there is an abundance of bacteria present in the small intestine. The small intestine is crucial for the digestion and absorption of nutrients. However, when there is an imbalance with an excess of bacteria, often stemming from migration from the large intestine, it disrupts the digestive process. This disturbance can manifest in various health issues you might currently be facing. Intriguingly, research suggests that as many as 80% of individuals diagnosed with Irritable Bowel Syndrome (IBS) may actually have underlying SIBO.