Testing Instructions

Breath Testing

The Hydrogen/Methane Breath Test with lactulose challenge is used to diagnose SIBO. This test can be performed in at a hospital or clinic lab, but take home collection kits have become available and more commonly used. The test is performed after the cessation of certain medications that interfere with your regular intestinal motility, digestion, and microflora balance. A 1-2 day preparation diet is also required. We will outline SIBO collection instructions below and have included a video that should be watched before performing a SIBO test.

Sugar (fructose, sucrose and lactose) Breath Collection Instructions


SIBO Breath Test Collection Instructions

Prep Diet


The number of people with IBS and SIBO


SIBO Testing
Non-Invasive home collection.

Get Started

SIBO Breath Test Guidelines

Process Overview

Watch Breath Collection Video

We recommend watching the video twice– now and just before performing the test.

Follow the 1-2 Day Prep Diet

See Prep Diet Section

Don’t Forget- Watch the Breath Collection Video Again


Perform Test

See Before Testing section

Return Your Breath Specimens & Patient Intake Form

Place them and your completed form in the same box they arrived in and mail back (USPS) to Neurovanna. Specimens must be received by the lab within 7 days of collection.

Neurovanna Analyzes Your Breath Specimens

A custom report is completed within 1-3 business days of receipt of your specimens.

Test Results are Sent to the Healthcare Provider

Call your ordering practitioner if you have questions. We can also assist you with any collection questions by calling 1-651-342-0427.


Testing must be received by clinic 7 days after completing the test! It is recommended to mail out ASAP.


Mail Specimens to (USPS postage included)

Neurovanna                                                                                                                               105 New England Place, Suite 220                                                                                   Stillwater, MN 55082



Before Testing

If you are not able to comply with these guidelines, you may not be a candidate for a breath test. Your doctor can assist you in determining if another test without these preparation limits is more suitable.

4 Weeks (28 days) Before Test

No antibiotics (unless otherwise instructed by your healthcare provider)



2 Weeks (14 days) Before Test

No antifungals or natural antimicrobials (unless otherwise instructed by your healthcare provider)




Surgery, colonoscopy, enemas or colonics


4 Days Before Test

Avoid all laxatives. This includes probiotics, vitamin C and magnesium being taken specifically to induce a laxative effect.


1 Hour Before and During Test

No smoking, including second-hand smoke

No sleeping

No vigorous exercise

Prep Diet

Before you start the SIBO breath test, a 1-2 day preparation is required consisting of a 1-2 day (12-36 hours) restricted diet and a 12-hour fasting period (stop eating in the early evening the day before testing and do not eat until after you test the following morning).

If you are uncertain if something will affect the test, avoid the product/food or consult your healthcare provider prior to starting the test.

Follow the diet determined by your healthcare provider.

  • Constipation: Follow the SIBO preparation diet for 2 days (36 hours plus overnight fasting).
  • Diarrhea: Follow the SIBO preparation diet for 1 day (12 hours plus overnight fasting).

The goal of the SIBO preparation diet is to starve bacteria in order to produce the best test results. SIBO bacteria love plant products and sugars, so the only foods that you can have are those listed below- if it is not on this list, DO NOT eat it.

First 12 or 36 Hours (Restricted Diet)

Limit your foods to those below and nothing else.

Plain water, coffee, tea (no sugar/ artificial sweeteners or cream added)



Baked, broiled, slow-cooked chicken, fish or turkey (sales and pepper only; no butter or oils)


Meat broth (i.e., broth from slow-cooked meat) (no bone/vegetable broth allowed)


Plain steamed white rice



Eggs (salt and pepper only; no butter or oils)


Last 12 hours, Overnight (Fasting Before the Test)

Stop eating the evening before the morning of your test; similar to a fasting blood draw. The last 12 hours DO NOT eat or drink anything except water.

Frequently Asked Questions

Patients with Type I: Do not take the glucose test. A lactulose test requires a test order by a prescribing practitioner.

Patients with Type II: Do not take medications the day of test and start the test as early as possible in the morning. Lactulose can be used, but requires a lab order by the prescribing practitioner.



There are two common substrates used for the breath testing challenge- glucose and lactulose.

Glucose is the most commonly used substrate due to having 11.1% greater sensitivity than lactulose. Glucose’s improved sensitivity is attributed to its ability to be absorbed in the small but not the large intestines. Glucose’s exclusive small intestinal absorption reduces false interpretations of colonic gas production in cases of rapid or delayed bowel transit.

Lactulose has a 4% greater specificity than glucose and is absorbed in both the small and large intestines. Lactulose’s ability to be absorbed in both intestines allows for interpretation of double peaks of activity but can also lead to more false positives when double peaks are absent. Lactulose is a prescriptive item in the USA, regulated by the FDA and requires lawful prescribing by a practitioner.

  • Glucose: Most sensitive, slightly less specific, measures only small intestinal bacterial activity, can raise blood sugars levels and does not require a prescription.
  • Lactulose: Less sensitive, slightly more specific, measures both small and large intestinal bacterial activity, does not cause blood sugar levels to rise and requires a prescription.


Lactulose is a man made sugar that humans cannot digest, but SIBO bacteria love. It acts like a fertilizer for SIBO bugs. Drinking lactulose will not cause the same “sugar-high” as sugars that humans can digest (like sucrose or fructose).

Lactulose also acts as a laxative, so some people may experience effects of needing to use the restroom during the test. Some people may experience an increase in symptoms associated with SIBO activity (like bloating, gas).

Lactulose requires a prescription for use. Glucose does not require a prescription.


No. Lactose is the sugar from milk, while lactulose is man made and has a completely different chemical makeup. However, the liquid lactulose solution that comes with the SIBO kits does contain 1.2 grams of lactose in it.

People who are severely lactose intolerant should ask their doctor if this test is right for them.


PPIs (Proton Pump Inhibitors such as Prilosec, Nexium, and Prevacid)

  • If the patient has been on a PPI for a few months or more, the patient may stay on the medication and leave a note listing the medication in his/her kit when it is sent back.
  • If the patient takes it as needed or just started the medication, he/she should be off the medication for the preparation period and the day of the test.

H2 Blockers (such as Zantac, Pepcid, Tagamet)

  • If the patient has been on H2 blockers for a few months or more, the patient may stay on the medication and leave a note listing the medication in his/her kit when it is sent back.
  • If the patient takes it as needed or just started the medication, he/she should be off the medication for the preparation period and the day of the test.

Narcotics- Do not take these the day of the test.

Laxatives (such as Metamucil, Dulcolax, Ex-Lax)- Stop taking one day before taking the test.

Antibiotics- Stop taking 2 weeks before taking test.

Probiotics- Stop taking 5 days before taking the test.




The only seasonings allowed are salt and pepper, in moderation.


No, gum is not allowed during any part of the preparation period.


No, the test must be back at the lab 7-days after collecting. It is recommended to mail out immediately, but a delay of 3-5 days is typically fine.


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