There are three types of fermented gas found in the gut microbiome (hydrogen, methane, and hydrogen sulfide) that, when elevated, can suggest bacterial overgrowth and indicate common gastrointestinal conditions. Bacterial overgrowth can occur when hydrogen, methane, and/or hydrogen sulfide is elevated past a certain threshold. When methane is elevated, this suggests a condition called intestinal methanogenic overgrowth (IMO) and usually presents itself as constipation.
What Is Methane?
Methane (CH4) is a colorless, odorless gas that is produced by certain microorganisms, geological processes, and by human activities like farming. It is also produced naturally in the human body.
What Is Intestinal Methanogenic Overgrowth (IMO)?
Intestinal methanogenic overgrowth is the presence of excessive amounts of archaea known as methanogens in the small intestines, large intestines, and/or colon. In the past, IMO was often diagnosed broadly as small intestinal bacterial overgrowth (SIBO). IMO was previously called “methane SIBO;” however; that term isn’t quite accurate. Methanogens are not bacteria (the “B” in SIBO) but are archaea, a group of single-celled organisms lacking a defined nucleus.
What Are the Symptoms of Intestinal Methanogenic Overgrowth (IMO)?
Patients with IMO usually report a level of constipation as their main complaint, but other symptoms of IMO include:
These symptoms are usually experienced once a week or more for at least four weeks. IMO also shares many symptoms with IBS-C (constipation-predominant irritable bowel syndrome) and IBS-M (mixed-diarrhea/constipation irritable bowel syndrome). One of the most important and distinguishing features of note for IMO, as opposed to a diagnosis of IBS or SIBO, is the patient’s degree of constipation.
What Causes IMO?
Bacterial overgrowth can be a complex result of various medications and conditions. The causes of IMO overlap with the causes of SIBO; however, more research is being done to determine the distinct causes of IMO.
How Do You Test for IMO?
If you think you might be suffering from IMO, your provider may suggest a breath test to better understand what is going on in your gut. Breath testing is a way for healthcare providers to identify certain conditions related to the gut microbiome by analyzing gases in patients’ exhaled breath.
trio-smart is a doctor-ordered, mail-in breath test used to measure the three primary fermented gases in the microbiome - hydrogen, methane, and hydrogen sulfide - associated with conditions like SIBO, IMO, and excess hydrogen sulfide. Learn more about the trio-smart breath test here.