SIBO – or Small Intestinal Bacterial Overgrowth – is a serious condition in which there is too much bacteria and/or the wrong type of bacteria in the small intestine. There are two types of SIBO: hydrogen SIBO and methane SIBO.
This is part of a series about treating SIBO. If you missed the last parts of the series, you can catch up here:
- Part 1: What is SIBO?
- Part 2: Symptoms of SIBO
- Part 3: Causes of SIBO
- Part 4: Diagnosing SIBO
- Part 5: Breath Tests for SIBO
Key Points about the Two Types of SIBO
- SIBO can be methane-producing, hydrogen-producing, or both
- Bacteria produces hydrogen
- Archaea produces methane
- Hydrogen SIBO usually causes diarrhea
- Methane SIBO usually causes constipation
- Breath tests for SIBO will measure levels of methane and hydrogen
Hydrogen vs. Methane SIBO
One way to test for SIBO is to have a hydrogen and methane breath test (learn more about SIBO breath tests here). First, your baseline hydrogen and methane levels are tested. Then you will take a sugary substance (lactulose) and have your levels tested again.
UPDATE:
Good news! There are now SIBO breath tests that you can order directly without a doctor’s order! While I’m a HUGE fan of having a doctor’s guidance, I understand the need to know whether you have SIBO or not before you invest in a practitioner.
You can order the test directly and it will be sent to your home with instructions on how to take it and how to send it back and get your results!
If your hydrogen levels are high, then you may have Hydrogen-dominant SIBO. If your methane levels are high, then you may have Methane-dominant SIBO. A diagnosis of Hydrogen SIBO or Methane SIBO doesn’t mean you only have that type of gas present. You can have both types of gases, just one is more dominant than the other.
*Note I say “may have SIBO” because high breath test levels can indicate other problems as well, not just SIBO.
What’s the Difference between Hydrogen and Methane SIBO?
In a healthy gut, food is broken down and absorbed into the blood through the small intestinal wall. With SIBO, there is too much bacteria in your small intestines, and/or the wrong type of bacteria. Bacteria causes unabsorbed carbohydrates in food to ferment before they can be broken down. The process of fermentation creates hydrogen gas as a byproduct. So, if you have too much bacteria in your small intestines, then you will have high levels of hydrogen – hence the hydrogen breath test for SIBO.
But things aren’t that simple. Stay with me… Your small intestines can also contain archaea. Archaea feed off of hydrogen. They produce methane as a byproduct. This helps reduce the levels of hydrogen in the body. This is why you can have a negative hydrogen test and still have SIBO.1
What are Archaea?
Archaea are single celled organisms which lack a nucleus. They are actually pretty cool in that they’ve been found in virtually all places where anaerobic degradation of organic compounds occurs. They’ve even been found in the extreme heat of ocean floor vents! Up until recently, archaea were considered a bacteria. However, they are a completely different kingdom than bacteria.2
When you eat fiber, the bacteria in your gut start to ferment it. The fermentation produces hydrogen. What do archaea feed off of? Hydrogen! When the archaea consume the hydrogen, they produce methane as a byproduct. In this sense, archaea help reduce the amount of hydrogen gas in our colon – but the methane can have its own negative effects.
A compound which creates methane in the body is called a methanogen. The process of forming methane is called methanogenesis. Some animals rely on methogen-forming archaea. One example is cows which produce a huge amount of methane because of all the bacteria in their stomach which ferment grass. The archaea love the hydrogen from all the fermentation going on. They proliferate and produce methane, which comes out as flatulence. Methane is actually very flammable — don’t get any ideas 🙂
This is a very simplified description of methane production in our bodies, and there are many more pathways involved with methane metabolism. However, for the sake of understanding SIBO, this should be enough.
Interestingly, we don’t start producing methane until we are about 3 years old. And not everyone produces methane. Depending on which study you go by, about 33% to 72% of adults produce methane.3
Problems Caused By Methane
For a long time, people thought that methane was a completely harmless substance in the body – other than causing flatulence and a bit of bloating. However, research is starting to show that high levels of methane may be linked to certain health issues. The main problem caused by methane is constipation (though constipation can be caused by numerous other things). Because methanogens cause a higher production and absorption of short-chain fatty acids, they are also linked to obesity.
Hear that? Methane is linked to obesity. In one study, mice were given a methane-producing archaea and it caused an increase in body fat. In human studies, it was shown that subjects with higher methane levels in their breath tests had higher BMIs.5
When it comes to methane and digestive disorders like SIBO, there still isn’t much research. However, evidence shows a strong link between methane-producing archaea and SIBO.
As Chris Kresser points out, methane-producing archaea is present in 45% of people with SIBO. Not only that, but the amount of methane produced by people with SIBO is higher.6
Is it the archaea themselves which are the cause of the problem? Or are the archaea thriving because they have so much hydrogen to consume because of a bacterial overgrowth? We still need further research to answer these questions, but the answer is probably that both too much bacteria and archaea cause problems. That is why experts like Chris Kresser recommend taking steps to eliminate both bacteria and archaea from the small intestine for treating SIBO.
How This Affects Treatment of SIBO
As a patient, you probably don’t need to know about all the scientific differences between archaea and bacteria and how they produce hydrogen and methane. However, it is good to know why your doctor is testing for hydrogen and methane (if your doctor orders only a hydrogen test, insist on getting a methane test too! If the archaea is eating up all the hydrogen, you will have a false negative with the hydrogen test!!!). It is also important to understand that each type of SIBO can have different symptoms.
Here is a picture of my first SIBO breath test. You can see that methane levels are high, not hydrogen — which is why it is so important to test for both hydrogen and methane!
Methane is strongly linked to constipation. So, the following is usually true of the symptoms of SIBO:
- Constipation = methane SIBO
- Diarrhea = hydrogen SIBO
Because of these symptoms, you will often hear the terms SIBO-C (for constipation) and SIBO-D (for diarrhea).
This chart shows the prevalence of constipation and diarrhea in patients with high levels of hydrogen, methane, and both. H2 = hydrogen. CH4 = Methane.
You also need to know that the treatment for SIBO is different depending on whether it is methane or hydrogen producing. Most of the archaea which produce methane are somewhat resistant to the antibiotics used to treat SIBO. So, if your problems are caused by archaea overgrowth, then taking those antibiotics aren’t likely going to cure your SIBO, even if you take multiple rounds. Because of this, methane SIBO is definitely the most difficult to treat because of archaea’s resistance to antibiotics.
Actually, antibiotics alone aren’t likely to cure SIBO. Sure, if you take enough rounds of them, you will kill off the bacteria. But antibiotics don’t fix the root problem which allowed bacteria to proliferate in the first place, so the SIBO is just likely to come back (hence the high recurrence rate for SIBO). We talked about this in part 3 about the causes of SIBO. In the next parts of the series,we will get into the comprehensive steps you need to get rid of SIBO for good, including antibiotics, diet, and lifestyle changes.
Ready to eliminate SIBO once and for all? Get your copy of The SIBO Solution: Your Comprehensive Guide to Eliminating Small Intestinal Bacterial Overgrowth by clicking HERE. You’ll also receive a BONUS SIBO Detox Support Guide mini ebook with your purchase.
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I tested positive for sibo. My main symptom is painful trapped gas. I can’t expel it rectally. Is this common with sibo?
Yes, because the gas is produces in the small intestine (at the top), not in the large intestine (at the bottom) where it can be expelled rectally. I sometimes drink a tsp of baking soda in water to help burp up the gas.
Hi!
I’ve recently tested positive for both hydrogen and methane on my breath test ????. I have cramping, bloating, constipation and diarrhea. My main issue is a strong stitch that emits from my stomach (I guess). This stitch is unbearable and makes it very hard for me to often function throughout the day because, others smell it as well. I’ve been prescribed Rifaximin but, cannot start treatment for another 4-5 weeks because I’m currently on antibiotics for strep throat ????. I’m also following the Fodmap diet closely. I wanted to know is there anything else out there that can help with the smell as it is taking over my life ????. Please help!
I wanted to say you’re not alone. I have the same problem and today I tested again and finally got rid of my methane bacteria. Still have hydrogen type sibo but no more methane so I guess there is hope. I hope after completing the new round od Rifaximin I will see improvement in the odor too. Let me know if you try something that works for you. My doctor prescribed a prokinetics this time around erythromycin but no probiotics. I’ll keep your posted
Hi. I’m celiac with lactose intolerance. I’ve been on a gluten/lactose free diet for 30 years. I eat mainly organic. I suspect SIBO, candida ,leaky gut etc. I’ve done the elimination diet FODMAP diet off and on my whole life. I suffer from a condition about every month and a half where I get constipated and produce an uncontrolled seepage of ammonia/ cat urine smell from my rear. Slightly raised heartbeat,insomnia and overactive saliva glands. Lasts for 7-14 days. It seems like when ever I tweek my diet and try to eat healthier the condition surfaces. Does this sound familiar to anyone? I’m at my wits end.
It sounds a bit familiar to me because I also thought I was eating healthily, but after a year of eating salad every evening I began to get haemorrhoids from it. Now I just heard of lectins for the first time in my life and am reading around the internet, and realising that many of the common foods we eat and consider healthy actually contain large amounts of toxic lectins. Raw foods are generally considered to be really healthy, but cooking actually destroys a big fraction of most lectins. Unfortunately, there is not enough research on all the many negative health effects of lectins in our diet, and different people are sensitive to different classes of them, depending on genetics. You are probably also very sensitive to wheat germ agglutinin like I am, but you need to try and figure out which others you react to. Good luck!
Hi,
When taking herbal remedies to treat SIBO should you be on the SIBO diet? When I took the Xifaxan my Doctor had me eat a high carb diet so the bacteria would eat up the medication….
I too have been diagnosed with sibo methane but have uncontrollable diarrhea. Can anyone explain why or what treatment i should follow?
THis is ruining my life. People cover their nose when im around them. This methane stench fills an entire room and I don’t know what to do. I hold my breath constantly because I don’t want to expel this foul odor. It has to be one of the worst odors in the world. Someone please help. I have never had this problem until I reached adulthood and it is affecting everything and everyone around me.
Hollywood Homestead, I recently tested positive for SIBO. But I’m confused because although I do have diarrhea at times, my primary symptoms are sulfur burps (ugh, so gross) followed by vomiting, on average every 5 days since February. Have you come across anyone with these symptoms? I tested negative for H. Pylori and Giardia, and biopsies of my stomach and duodenum were normal. I did the barium swallow test which showed very low reflux. My doctor was quick to prescribe rifaximin and told me to take prilosec (sp?) for the reflux, which I didn’t even know I had and doesn’t effect my day to day well being. I just started the SIBO diet a few days ago and will do it for 8 weeks and then I will take the SIBO test again. But I’m just wondering if there is something else that might be an issue since my symptoms sound different from everyone else’s!
Have you been tested for celiac disease or ever tried going off of gluten completely? My daughter had some of this, as did a friend of hers. Both were celiac. Sometimes the symptoms aren’t clear – and certainly not the same for everyone. I hope this is helpful…
I tested positive for both Hydrogen AND Methane SIBO … I am on round #3 of Rifaxim and am taking Berberine 500 and probiotics but I can’t seem to get any relief for more than a few days. What can I do??
i had 3 negative breath tests but have chronic bloating and constipation if i dont take daily magnesium. fibers make me bloat up like crazy. i take high dose probiotics daily since they help with my histamine issues and keep my stools regular but not sure if they are a bandaid or if they are actually keeping me healthy. once i stop probiotics i develop thin irregular stools. anyone know whats wrong with me and what i should try next? i dont eat gluten, dairy, soy or eggs and pretty much eat the same 6 foods every day. thanks
Um…I was diagnosed with hydrogen SIBO and NEVER have diarrhea. I suffer big time from constipation. Explain?
me too
Same here!
You might have your functional doctor run the extended breath test. Think it was 8 hour collection? My methane didn’t hit the chart until the very end of the collection period. Had we done the three hour, it would have been a false negative for Methane.
I was diagnosed methane positive SIBO after sudden onset of bloating with long term history of IBS. I was treated with Xifaxin and Neomycin x14 days then did herbals for 1 month. Only time I had some relief of bloating was while on the 10 day pharmaceuticals but it came back with in 1 week. I have since re done the Lactulose breath test twice and both negative. Why would my bloating still be so severe? My belly is almost normal in the morning but as soon as I eat, even on restrive diet, I bloat. Should I be retreated based on symptoms alone?
Hello. Could you please clarify something. In the case of constipation I know, I understand how it happens with SIBO… The food sits there unprocessed while the bacteria eat at it. However, I don’t exactly get what happens with diharea. If you get diharea 5 mins after ingesting anything it seems to me that the body is iritated by what tou have ingested & tries to get rid of it. Since the trigger has been pushed out immediately, how does the bacteria feed & proliferate, I just don’t get it. Would appreciate some clarifications as well as some pointers on how to increase weight while with SIBO d.
Many thanks!
I am curious what herbal remedies are used, suggested to treat SIBO. I tested Hydrogen positive- had 3 spikes in the 10 rounds. My numbers over 3 hours recorded every 20 minutes: 0,2,4,2,15,44,84,92,90, 41.
Hello.
5 years ago I was infected with giardia. The infection was not treated for the first 2 years. Then I took multiple antibiotic courses and my stool antibody analyses (taken 2 times) showed that giardia is gone.
However, my gut dysbiosis is still untreated. I have mild constipation (I use magnesium to relieve it), bloating and my stool is usually green or dark green. I also have an occassional belching and heartburn. Those symptoms are not severe and aren’t bother me much in daily life.
The main problem that I have is insomnia and depression which progresses since I was infected 5 years ago. For the last year it has become more severe, and I have anhedonia, irritability and concentration problems now. I think its due to neurotransmitter imbalances and possible brain shrinkage that was caused by prolonged malabsorption and stress.
Last time I visited my gastroenterologist I got diagnosis: IBS with constipation. I took multiple courses of probiotics and prebiotics without success. However, it seems that I sleep better when I take probiotics with lactobacilus.
My stool test shows that I have very low lactobacilus level. Everything else is in optimal range. Candida is not found in the stool.
I now suspect that I have SIBO-C. Do you think that it can be the cause of my symptoms? The problem is that only breath test for SIBO that is available in my location is hydrogen breath test with lactulose. There is no methane test. Should I take hydrogen-only test if never had diarrhea?
I was negatively tested for h.pylori during gastroscopy. I’m planning to take stool test also.
I will appreciate any help. Thanks.
I just found out today that my hydrogen test for SIBO came back positive. The Dr. did not contact me, but the office personnel. She stated that they were ordering an antibiotic and were checking to see if insurance covered it. I asked her what my numbers were and if the Dr. planned on a specific diet which I read is vital for healing. She stated that she did not know the# and that I should take the antibiotic for 2 weeks ,see how I feel and then discuss diet. Shouldn’t the diet start now too? Also, I did not know about hydrogen& methane. How do I know if I was tested for both? The test was 3 hours long & there were 10 test tubes. Would you suggest that I look for another type of DR. who deals with SIBO? I think my gastro is going to just give me drugs and I know there will be recurrence. I have been reading all the articles up to 7 so far. I have had a multitude of illnesses and weird conditions for a few years now and it sounds like they are all connected to SIBO! Not one physician even mentioned this test until this month…although,one told me I just needed cognitive behavior therapy, that there was nothing really wrong with me! Thanks for this website, it is very informative!
I know this was long ago but what did you do and did you heal
My hydrogen is high, but not my methane. However, I have constipation not diarrhea. What would you do for that? Does this mean I have something else going on besides SIBO? How do I balance this? Thanks!
same here!
Same here!
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Hollywood Homestead I also don’t have constipation or diarrhea, just bloating (for 7 or so days now that won’t go away at all really, although it is somewhat less now that I am consuming no carbs). Are either of those required for SIBO? (I haven’t been diagnosed, just searching for an answer to my constant bloating). Thanks!
Hollywood Homestead yes I had a scope and negative to H pylori, I have a hiatal hernia but my research did turn up my symptoms for hernia
Lola, it’s possible but have you been tested for H Pylori? I would ask your docs to explore that as well.
Is it possible to have SIBo without any constipation or diarrhea? My symptoms are chronic bloating, distension, belching, upper intestinal discomfort and occasional reflux. My syptoms improved after a 4 R protocol but have slowly returned ….
Lola, it’s possible but have you been tested for H Pylori? I would ask your docs to explore that as well.
Hollywood Homestead yes I had a scope and negative to H pylori, I have a hiatal hernia but my research did turn up my symptoms for hernia
Hollywood Homestead I also don’t have constipation or diarrhea, just bloating (for 7 or so days now that won’t go away at all really, although it is somewhat less now that I am consuming no carbs). Are either of those required for SIBO? (I haven’t been diagnosed, just searching for an answer to my constant bloating). Thanks!
I read that if you reduce/kill the bacteria, then the archaea has nothing to eat and hence cannot produce the methane, but really stopping the bacteria would be the more ideal solution, but we dont’ know how to do that.
Hello. In the article you state that high breath test results acn indicate things besides SIBO. Can you elaborate on that? What else could be going on? Thank you:)
If my methane and hydrogen are both negative but the combined is positive what does that mean??? my ND says i need to treat it but i only have issues in the morning and no issues throughout day but do eat low fodmap and gluten free – but have no pain or gas with dairy.so don’t want to mess with my gut anymore if don’t need to as killing off all bacteria with the herbal protocol could lead to a disaster and sickly me all over again when i have worked so hard for 2 years to get well
Hi Madeline,
It depends on what lab you’re using as they all use different numbers as to what is positive vs negative. Zero would be amazing but as long as it’s within the negative range, THAT’s what you’re shooting for. Your progress sounds AMAZING thought!! Definitely would recommend you hit it again while it’s still (sort of) down.
Keep at it. Hope that helps!
Sylvie
Hi Madeline,
It depends on what lab you’re using as they all use different numbers as to what is positive vs negative. Zero would be amazing but as long as it’s within the negative range, THAT’s what you’re shooting for. Your progress sounds AMAZING thought!! Definitely would recommend you hit it again while it’s still (sort of) down.
Keep at it. Hope that helps!
Sylvie
What is the idea number for hydrogen or methan results? I’m assuming you are shooting for 0. Is that correct? The first time I tested (before the elemental diet) I was 138 hydrogen and 18 methane. After two weeks on the homemade elemental diet and herbal antibiotices my hydrogen decreased to 60 and methane to 11. To me, this is great progress (tell me if I’m wrong), and I plan to do the elemental diet again. I just don’t know what number I am ultimately shooting for. Would it be 0?
Hi Madeline,
It depends on what lab you’re using as they all use different numbers as to what is positive vs negative. Zero would be amazing but as long as it’s within the negative range, THAT’s what you’re shooting for. Your progress sounds AMAZING thought!! Definitely would recommend you hit it again while it’s still (sort of) down.
Keep at it. Hope that helps!
Sylvie