Many of us are now very familiar with the role bacteria play in our digestive, and systemic, health, but not as many are likely familiar with the role of archaea. These little guys are responsible for the term ‘methane SIBO’.
What Are Archaea?
It has been estimated that about 33% of the world’s human population is considered to be methane producers
Archaea are single-celled microorganisms with a structure similar to bacteria. However, they are evolutionarily distinct from bacteria. Archaea are anaerobes, living in environments low in oxygen (e.g., water, soil), but have recently been described in the human intestine also.
Unlike bacteria, which primarily produce hydrogen, the archaea produce methane gas, and thus are sometimes referred to as ‘methanogens’. Also unlike our bacteria, where we have hundreds of different bacterial species, the human body harbors only a handful of methanogen species.
Interestingly, Archaea have been shown to be absent during infancy while omnipresent in school-aged children, suggesting that colonisation may result from environmental exposure during childhood.
In humans, methanogens have been studied in the gastrointestinal tract, mouth, and vagina, and considerable focus has shifted towards elucidating their possible role in the progression of diseaseconditions in humans (Chaudhary et al., 2018).
What Is Methane SIBO?
Watch my interview with Dr. Jacobi, AKA “The SIBO Doctor”:
Methane SIBO is a term used when elevated levels of methane gas have been found on a hydrogen breath test for small intestine bacterial overgrowth. A more appropriate team is IMO – intestinal methanogenic overgrowth. This is due to the fact that the overgrowth may be in the large or small intestine, and, the organisms that produce methane aren’t strictly bacteria but archaea.
What Causes High Methane Levels?
It is not fully understood what causes higher methane levels but possibilities include:
- High volume endurance training.
- Oxidative stress.
- A history of an eating disorder.
- Malabsorption of food due to poor digestion.
- Chronic constipation for other reasons than high methane levels.
The Role Of Methane In Health & Disease
Methane production in the gut is known to be associated with slow gut transit
The role of archaea in gut health and disease remains unclear. However, methanogens are associated with periodontal disease, and have been strongly associated with constipation.
Interestingly, elevated levels of methanogens have been found in obesity, but also in individuals who suffer with anorexia.
Convincing evidence is accumulating that links methanogenic populations of the gut to inflammation. Initial studies found that there is a correlation between methane excretion and IBD (Inflammatory Bowel Disease). In UC and CD patients, a mere 10 to 30% were methane producers, compared to 50% in control groups.
However methanogens have also been associated with periodontitis, diverticulitis, anorexia, obesity, and they have also been found in greater levels in elite cyclists compared to amateur cyclists. And most interestingly in this scenario the elite cyclists weren’t constipated.
However it is not that simple as methane has been associated with different symptoms as indicated in this great visual:
What is the difference between hydrogen and methane sibo?
A common question I get asked is what are the difference in hydrogen vs methane sibo symptoms?
- Hydrogen is more often associated with diarrhoea.
- Methane is more often associated with constipation.
Testing For Methane SIBO
There are two tests that may be helpful when suffering with digestive complaints, such as constipation.
Firstly, breath testing used to assess for small intestinal bacterial overgrowth, or SIBO for short, (a common cause of Irritable Bowel Syndrome) will look at both hydrogen and methane gases. When methane is elevated, especially throughout the test, it may indicate an overgrowth of archaea in the large intestine. Click here to order a breath test to assess for SIBO.
Secondly, you can assess levels of archaea (methane producing organisms) via stool testing. Click here to order a stool test from Healthpath.
Treating Methane SIBO
Traditional options include antibiotics such as Rifaximin and neomycin.
However, with methane dominant SIBO herbal treatment with antimicrobials has been found to be effective also. Options include:
- Oregano oil
- A specific type of fibre called partially hydrolysed guar gum
Methanogens in humans: potentially beneficial or harmful for health, Appl Microbiol Biotechnol. 2018 Apr;102(7):3095-3104
Archaea and the human gut: new beginning of an old storyWorld J Gastroenterol. 2014 Nov 21;20(43):16062-78
Archaea and the human gut: New beginning of an old story, Front Microbiol. 2017; 8: 355
Chaudhary et al., (2018) Methanogens in humans: potentially beneficial or harmful for health