IMO (Intestinal Methanogen Overgrowth) is the new Methane SIBO
IMO (Intestinal Methanogen Overgrowth) is a type of overgrowth in the small intestine, initially known as Methane SIBO. Now referred to as the new Methane SIBO, IMO is a condition marked by an Overgrowth of Methanogenic microbes (Archaea) in the intestinal tract. Understanding the root causes, symptoms, and holistic approaches to managing this condition is crucial for those seeking relief. This article explains what is IMO, how it gets diagnosed, different treatment approaches, and its connection to SIBO.
What is IMO?
IMO, short for Intestinal Methanogen Overgrowth, represents an imbalance in the microbial community within the gut. This condition involves the excessive growth of methanogenic microorganisms, particularly in the small intestine, although not solely. Like SIBO, which is characterized by an overgrowth of bacteria, IMO shifts the delicate balance of the gut microbiome.
Initially, IMO was called SIBO Methane dominant or SIBO-C, however over time scientists found that these microbes secreting Methane gas were not bacteria (the “B” in the acronym SIBO) but rather organisms called Archaea (Methanobrevibacter smithii). These organisms can also be problematic if present in high counts in the large intestine as well (as opposed to the Small Intestine only, the “SI” in the acronym SIBO). Hence, the name change. Hope I didn’t lose you there. Ultimately, it is still classified by most practitioners under the SIBO umbrella.
Diagnosing IMO (Methane SIBO)
Finding out if someone has IMO is done the same way we can determine if SIBO is present: by doing a SIBO Breath Test. If you’re being tested for SIBO, make sure your practitioner orders a test that includes both hydrogen AND methane gas readings. The main diagnostic method is a breath test that measures methane levels, as methane is a key byproduct of methanogenic microbes (Methanobrevibacter smithii).
If the reading of Methane gas gets over 10ppm anywhere during the 3-hour test, then it is considered as Positive for IMO (Methane SIBO). The diagnosis also usually involves a comprehensive assessment of the patient's symptoms and correlation with the test results.
IMO (Methane SIBO) Symptoms
Usually, patients with IMO will present with chronic constipation symptoms as opposed to Hydrogen SIBO which is more leaning towards diarrhea. However this is not always the case, and you could still have Methane SIBO (IMO) and diahrrea or Hydrogen SIBO and constipation. In general, we can easily distinguish hydrogen-dominant SIBO from IMO or methane-dominant SIBO as they manifests in distinct ways.
Key indicators of IMO include:
Constipation: Methane gas slows transit time, leading to constipation in individuals testing positive for methane SIBO.
Bloating and Gas: Although archaea consume hydrogen, theoretically reducing gas volume, sustained bloating is a common symptom. Slow motility, caused by constipation, may trap gas in the GI tract longer than in diarrhea-dominant SIBO.
Unexplained Weight Gain: Methane-producing archaea, also known as obesogens, extract additional calories from the diet, contributing to weight gain.
Causes of IMO (Methane SIBO)
The prominent species in IMO, methanobrevibacter smithii, thrive on hydrogen produced by bacterial fermentation of fiber. They basically “eat hydrogen gas” and produce “methane gas” as a byproduct. This is why whenever there is IMO, meaning an overgrowth of these methane-producing critters, it is often accompanied by bacterial overgrowth. The causes of IMO are thus thought to be the same as for SIBO:
slow motility
impaired digestion
adhesions and/or obstructions in the intestinal tract
certain medications
Treatment Approaches for IMO (Methane SIBO)
Methanogens are tough critters to kill and ideally you need to work with someone who specializes in SIBO. Addressing IMO involves multifaceted treatment strategies aimed at restoring microbial balance in the gut. Usually w look into the diet,
Dietary modifications is definitely an important aspect, with the implementation of a diet that discourages the proliferation of methanogenic microbes, whilst avoiding the worsening of constipation. Additionally, antimicrobial agents, both pharmaceutical and herbal, may be employed to target the overgrowth. Prokinetic agents that enhance gut motility are also often integrated to prevent SIBO relapse.
Let’s start with diet, then moving on to treatment and finally microbiome support and prevention.
Diet for IMO (Methane SIBO)
Given that archaea feed off hydrogen gas, it raises the question: what feeds hydrogen-producing bacteria? The answer is fermentable carbohydrates. This is why diets such as Low FODMAP are commonly recommended to reduce fermentable fiber for individuals with SIBO. However, when dealing with IMO (methane SIBO) linked to constipation, reducing fiber can exacerbate the issue.
This is not something those with hydrogen-dominant SIBO typically need to consider, but individuals with SIBO and constipation face a different dietary challenge. Lowering fiber intake also diminishes Short Chain Fatty Acids (SCFA) such as butyrate, which research has correlated inversely with methane levels. Butyrate also promotes bowel transit, meaning it increases colonic motility and helps with constipation.
This shows the importance of not completely eliminating fiber for methane SIBO. Diets like Low FODMAP may lead to complications if not appropriately adjusted. It becomes crucial to attempt to increase polyphenols and certain types of fiber, where tolerated, to nourish beneficial bacteria associated with improved motility and reduced methane production.
Some of the foods I recommend incorporating, based on tolerance, include:
Psyllium Husk & Flax seeds
Berries
Pomegranate
Kiwis
Nuts and seeds
Broccoli
Zucchini
Quinoa, Brown rice, Buckwheat
Green tea
Soy products for isoflavones : Tempeh, Tofu, Miso
Treatment Options for IMO (Methane SIBO)
Antibiotics:
A combination of Rifaximin and Neomycin shows effectiveness against IMO, but there are definitely concerns about Neomycin being a broad-spectrum antibiotic and wiping out the beneficial bacteria, resulting in microbiome damage. In countries where Neomycin can’t be found or prescribed, there has also been studies done with Metronidazole (Flagyl). Treatment lasts 2 weeks.
I want to highlight that Rifaximin (Xifaxan in USA and Xaxine in Canada) is recognized for its narrower spectrum compared to others antibiotics more frequently prescribed, and its absorption is predominantly limited to the upper GI tract. It is even considered a eubiotic, which means it is able to reduce bacterial virulence but also has anti-inflammatory properties and has been demonstrated to positively modulate the gut microbial composition! This is a great option for people with Hydrogen-dominant SIBO only. For IMO or Methane SIBO cases, relying solely on Rifaximin has not been a successful treatment.
Natural Herbal Antimicrobials
Targeted blends or protocols containing high dose allicin (garlic) and either oil of oregano, cinnamon, neem or thyme have been effective, less aggressive alternatives. There is also another formulation called Atrantil, which has shown to be very effective to reduce Methane gas in some people, and totally useless for others. The only way to know if your microbiome will benefit from it is to try it for yourself. Generally speaking, Allicin tends to be more effective but it is not always well tolerated. Treatment usually lasts 4-6 weeks.
Elemental Diet for Methane SIBO
A liquid diet of pre-digested nutrients that effectively starves bacteria, especially effective for stubborn cases with high gas levels. Treatment lasts 2-3 weeks. Read more about the elemental diet here.
Microbiome Support and Prevention
The support and prevention part of the treatment plan is what most people trying to treat themselves on their own (or even working with a practitioner not trained in SIBO) mistakenly skip or omit. These tools can make the difference between a sucessful treatment and a failed one. Relapse in SIBO is also very common, so making sure it doesn’t come back should definitely be an area of focus.
Prebiotics: Partially hydrolyzed guar gum (PHGG) and Galacto-oligosaccharides (GOS) can help balance the microbiome and have been shown to reduce Methane gas levels.
Probiotics: Specific strains like Bifidobacterium lactis and Lactobacillus reuteri can aid in reducing methane levels.
Digestive Support
Methane-dominant SIBO often causes constipation. So, while we are eradicating and healing from SIBO, we need to make sure we are managing the constipation and supporting digestion and motility.
Managing Constipation: Magnesium, vitamin C, and enemas help keep the bowel clear during treatment.
Supporting Digestion: Stomach acid support, digestive enzymes, and bile boosters (cholagogues, ox bile, TUDCA) aid digestion and nutrient absorption.
A Note on Stress and Digestion
Another element of promoting digestion is ensuring adequate rest and minimizing stress. The focus here is on enhancing blood circulation to the gastrointestinal (GI) tract and boosting the parasympathetic tone in the enteric nervous system (ENS). When the body is under stress, it tends to prioritize certain functions, such as directing blood flow to muscles (for activities like running away from a tiger), while de-prioritizing others, like digestion. In other terms, maintaining a relaxed state, particularly before meals, can enhance the digestive process. Practices such as meditation, breathing exercises, and yoga are also effective in reducing stress and enhancing digestion.
Natural Remedies and Lifestyle Adjustments
Natural remedies and lifestyle adjustments play a vital role in managing IMO. As part of a long-term approach, probiotics, prebiotics, and fermented foods also contribute to fostering a healthy gut microbiome. Lifestyle changes, such as stress management and regular exercise, are also recognized for their positive impact on gut health.
In conclusion, navigating IMO (or Methane SIBO) demands a tailored, holistic approach that addresses root causes, dietary considerations, and eradication strategies. Consulting with a knowledgeable SIBO Practitioner is essential for effective management and long-term relief.
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