Small intestinal bacterial overgrowth (SIBO) is a condition that’s been around for decades but only recently gained recognition among medical practitioners. SIBO is caused by excessive amounts of bacteria in the small intestine, causing digestive issues.1 It’s often mistaken for other digestive conditions like irritable bowel syndrome (IBS).2
Treatment for SIBO is complex and depends on the type of bacteria and gas present in the gut. Methane SIBO is characterized by the presence of methane gas, causing constipation, severe bloating, and other gut symptoms.
If you are struggling with SIBO or suspect you may have it, it’s essential to see a qualified healthcare provider to create a treatment plan designed for you. Here’s what you should know about treating methane SIBO.
What is SIBO?
Small intestinal bacterial overgrowth (SIBO) is when you have more bacteria in the small intestine than should be there. When this bacteria ferments carbohydrates, it produces gas, which can cause bloating, abdominal pain, diarrhea, or constipation.1
SIBO can also be associated with extraintestinal symptoms (outside the intestines) like fatigue, joint pain, headaches, and skin rashes.3
What Causes SIBO?
The cause of SIBO can vary from person to person but can include the following: 1 4 5 6
- Alterations in digestive enzymes that usually provide antibacterial protection in the small intestine.
- Dysmotility, meaning the muscles of the small intestine are not working as they should, so bacteria may not properly move through the digestive tract.
- Structural abnormalities such as a hernia or scar tissue.
- Immune system issues that might impair the ability to clear bacteria from the small intestine.
- Certain medications alter normal gut bacteria, affect motility, or lower stomach acid, like antibiotics or antacids.
- Inflammation or alterations in the cells that line the gut wall that usually protects against pathogenic bacteria.
- An impaired ileocecal valve, where the pressure of the valve between the small and large intestines that usually keeps bacteria from moving in the wrong direction, is low.
- Abdominal surgery.
- Certain medical conditions slow motility (gastroparesis), like hypothyroidism or type 2 diabetes.
What is Methane SIBO?
There are two main types of SIBO: hydrogen and methane predominant. Both types refer to the gas that the microbes produce. Methane SIBO means there is an overgrowth of organisms that make methane a byproduct.1
More recently, methane SIBO is referred to as intestinal methane overgrowth (IMO) because the overgrowth isn’t technically bacteria. The organisms that produce methane are called archaea; they aren’t bacteria but different, distinct types of organisms.1
Archaea don’t ferment fiber like your bacteria but instead create methane gas from ingesting hydrogen, a byproduct of bacterial fermentation. Too much methane leads to symptoms like constipation and bloating.
This can complicate diagnosis because someone with methane SIBO may also have hydrogen SIBO (an overgrowth of bacteria that produce hydrogen). In this case, hydrogen-producing bacteria make excess hydrogen to feed archaea and make methane gas, so there is an overgrowth of both.1
Hydrogen vs. Methane SIBO Symptoms
A general distinction is often made between hydrogen vs methane SIBO related to symptoms. Hydrogen SIBO symptoms tend to include more abdominal pain and diarrhea. In contrast, people with methane SIBO tend to have constipation, bloating, and gas from slow motility.7 It’s also possible to have a mix of all symptoms.
Some research suggests that methane gas can slow down transit time in the intestines, which means it takes longer for food to move through—leading to constipation and bloating.8 The more things slow down, the more bacteria can grow as the gut bacteria are not moving through the intestines, causing a vicious cycle.
How is Methane SIBO Treated?
Treatment for SIBO takes time, multiple interventions, and sometimes a combination of therapies. Nutrition-related interventions support symptom management while addressing SIBO. Unfortunately, relapses are common if the root cause isn’t addressed, whether related to a problem with motility, a structural issue, or something else.
Working with a dietitian and a GI doctor who understands SIBO can help you understand how to reduce methane in the gut and develop a diet plan that works for you. The plan following treatment is nearly as important as the treatment itself and should include microbiome support to prevent recurrences.
Antibiotics are the primary medicine-based approach for treating SIBO and reducing the overgrowth of bacteria. Rifaxamin (Xifaxan) is an antibiotic often used to treat SIBO, but its success rate jumps to 85% percent when Rifaxamin is combined with Neomycin, another type of antibiotic.10
The problem is that while Rifaxamin is known to cause less damage to the healthy bacteria in the gut, Neomycin is broad-spectrum, which means it kills much more than SIBO-related bacteria. Weighing the pros and cons of this approach is a conversation you can have with your provider.
According to some research, herbal antimicrobials like Allicin or Neem that contain natural compounds to kill off bacteria may be as effective as antibiotics.11 Once again, this is a case-by-case basis that should be discussed with your doctor or health care practitioner before you start any treatments.
Either way, medication should only be one part of a plan to address SIBO and prevent relapse.
Methane SIBO Diet
The methane SIBO diet should be personalized to your symptoms, as food sensitivities worsen while symptomatic. The good news is that treating SIBO root causes improves food sensitivities.
In the meantime, eating foods that limit fermentable carbohydrates available to the bacteria can help lower symptoms, including:
- Low FODMAP. FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) are short-chain carbohydrates that can be difficult to digest. A low FODMAP diet has been found to improve methane SIBO symptoms.1
- Specific carbohydrate diet. The specific carbohydrate diet (SCD) also limits specific carbohydrates and prebiotics. It’s more restrictive, so it shouldn’t be the first diet change, although some people with complex cases may find it helpful.
- SIBO-specific diet. Developed by Dr. Alison Siebecker, a SIBO expert, this diet is a mix of low FODMAP and SCD, so it’s the most restrictive but may help people with complex cases or lots of food sensitivities.
Since these patterns restrict the foods needed for a healthy microbiome long-term, you don’t want to stay on the elimination phase too long as it’s overly restrictive and could even make SIBO constipation worse. Slow, reintroduction of potentially problematic foods is key to finding what works for you (and working with a dietitian is incredibly important for guidance).
In some instances, an elemental diet may be used. An elemental diet is a medically-supervised liquid diet that eliminates all but the most basic food components. Protein, carbohydrates, and fats are already broken down, making them easy to digest.12
The plus side is that the elemental diet appears incredibly effective when followed correctly, but the downside is that it’s expensive and hard for some people to follow.
- Probiotics. Using probiotics with SIBO is controversial because, in some cases, adding more bacteria to the gut can worsen symptoms and increase methane.13 However, some research suggests that certain strains of probiotics may help by supporting a healthy balance of beneficial bacteria, reducing inflammation, and lowering methane levels.6
- Prebiotics. Prebiotics are the food that probiotics need to survive. There are multiple types of prebiotics found in foods like asparagus, artichoke, and chicory root. Still, many people can’t tolerate these foods, so supplements (starting in small amounts) may help.
The prebiotic partially hydrolyzed guar gum has been well studied for its role in supporting gut health and helping with constipation.14 It also increases SCFA production, the metabolites produced by bacterial fermentation. Butyrate, an SCFA, is known to help reduce methane and support healthy gut motility.15
- Pro-motility agents. Daily bowel movements are essential for SIBO treatment and prevent relapses. Certain botanicals like ginger, bitters, or peppermint and nutrients like magnesium and vitamin C may help keep bowels moving to reduce methane levels in the gut.16
Stress and sleep are always important considerations when supporting health. Implementing stress-reducing activities and getting 7-8 hours of sleep every night can benefit SIBO treatment.
Additionally, some research suggests stimulating the nervous system to help gut motility is essential to supporting methane SIBO. One way to do this is by activating the vagus nerve, the primary nerve connecting the brain and digestive system.17 This is, again, a complex topic and worth discussing with your practitioner, but gargling, gagging, and singing are simple methods to exercise the vagus nerve.
Testing for Methane SIBO
Testing for SIBO requires a breath test that measures the amount of hydrogen or methane gas produced in the breath after drinking a test solution containing lactulose or glucose.1
Breath is measured at baseline (when you first start the test) and at regular intervals for the next three hours. Lactulose or glucose is fermented, and hydrogen or methane gas will be produced if bacteria are overgrowth in the small intestine. Someone with SIBO will have higher amounts expelled in their breath than those without. 1
Breath tests aren’t perfect because they may not catch all cases, and the research is still exploring the best way to diagnose. Still, they are worth exploring if you have digestive issues.1
The general consensus for test interpretation is: 1
- Hydrogen levels over 20 ppm by 90 minutes are considered positive for hydrogen SIBO.
- Methane levels over 10 ppm at any point during the test are considered positive for methane SIBO.
Working with a Dietitian to Treat SIBO
SIBO is a condition where professional support is essential for accurate diagnosis and individualized treatment plans. You can find information about all the options discussed above, but a practitioner can personalize the approach and hold your hand throughout the process.
A dietitian with experience supporting SIBO treatments can help create a customized methane SIBO diet plan while incorporating supplements to help promote balance and health in the gut as needed. Nourish offers individualized nutrition services online and accepts major insurance plans. Book an appointment today and get started.
- Pimentel, M., Saad, R. J., Long, M. D., & Rao, S. S. C. (2020). ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. The American journal of gastroenterology, 115(2), 165–178. 1
- Ghoshal, U. C., Shukla, R., & Ghoshal, U. (2017). Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge between Functional Organic Dichotomy. Gut and liver, 11(2), 196–208.
- Losurdo, G., Salvatore D'Abramo, F., Indellicati, G., Lillo, C., Ierardi, E., & Di Leo, A. (2020). The Influence of Small Intestinal Bacterial Overgrowth in Digestive and Extra-Intestinal Disorders. International journal of molecular sciences, 21(10), 3531.
- De Block, C. E., De Leeuw, I. H., Pelckmans, P. A., & Van Gaal, L. F. (2006). Current concepts in gastric motility in diabetes mellitus. Current diabetes reviews, 2(1), 113–130.
- Bures, J., Cyrany, J., Kohoutova, D., Förstl, M., Rejchrt, S., Kvetina, J., Vorisek, V., & Kopacova, M. (2010). Small intestinal bacterial overgrowth syndrome. World journal of gastroenterology, 16(24), 2978–2990.
- Achufusi, T. G. O., Sharma, A., Zamora, E. A., & Manocha, D. (2020). Small Intestinal Bacterial Overgrowth: Comprehensive Review of Diagnosis, Prevention, and Treatment Methods. Cureus, 12(6), e8860.
- Pimentel, M., Lin, H. C., Enayati, P., van den Burg, B., Lee, H. R., Chen, J. H., Park, S., Kong, Y., & Conklin, J. (2006). Methane, a gas produced by enteric bacteria, slows intestinal transit and augments small intestinal contractile activity. American journal of physiology. Gastrointestinal and liver physiology, 290(6), G1089–G1095.
- Triantafyllou, K., Chang, C., & Pimentel, M. (2014). Methanogens, methane and gastrointestinal motility. Journal of neurogastroenterology and motility, 20(1), 31–40.
- Rezaie, A., Buresi, M., Lembo, A., Lin, H., McCallum, R., Rao, S., Schmulson, M., Valdovinos, M., Zakko, S., & Pimentel, M. (2017). Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. The American journal of gastroenterology, 112(5), 775–784.
- Low, K., Hwang, L., Hua, J., Zhu, A., Morales, W., & Pimentel, M. (2010). A combination of rifaximin and neomycin is most effective in treating irritable bowel syndrome patients with methane on lactulose breath test. Journal of clinical gastroenterology, 44(8), 547–550.
- Chedid, V., Dhalla, S., Clarke, J. O., Roland, B. C., Dunbar, K. B., Koh, J., Justino, E., Tomakin, E., & Mullin, G. E. (2014). Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Global advances in health and medicine, 3(3), 16–24.
- Pimentel, M., Constantino, T., Kong, Y., Bajwa, M., Rezaei, A., & Park, S. (2004). A 14-day elemental diet is highly effective in normalizing the lactulose breath test. Digestive diseases and sciences, 49(1), 73–77.
- Kumar, K., Saadi, M., Ramsey, F. V., Schey, R., & Parkman, H. P. (2018). Effect of Bifidobacterium infantis 35624 (Align) on the Lactulose Breath Test for Small Intestinal Bacterial Overgrowth. Digestive diseases and sciences, 63(4), 989–995.
- Polymeros, D., Beintaris, I., Gaglia, A., Karamanolis, G., Papanikolaou, I. S., Dimitriadis, G., & Triantafyllou, K. (2014). Partially hydrolyzed guar gum accelerates colonic transit time and improves symptoms in adults with chronic constipation. Digestive diseases and sciences, 59(9), 2207–2214.
- Ohashi, Y., Sumitani, K., Tokunaga, M., Ishihara, N., Okubo, T., & Fujisawa, T. (2015). Consumption of partially hydrolysed guar gum stimulates Bifidobacteria and butyrate-producing bacteria in the human large intestine. Beneficial microbes, 6(4), 451–455.
- Kim, Y. S., Kim, J. W., Ha, N. Y., Kim, J., & Ryu, H. S. (2020). Herbal Therapies in Functional Gastrointestinal Disorders: A Narrative Review and Clinical Implication. Frontiers in psychiatry, 11, 601.
- Bonaz, B., Bazin, T., & Pellissier, S. (2018). The Vagus Nerve at the Interface of the Microbiota-Gut-Brain Axis. Frontiers in neuroscience, 12, 49.
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