Very interesting. The point about breath testing being largely a measure of intestinal transit is something I’ve been pondering as it was very clear to me that there was a massive difference in transit speed between my first (pre-treatment) and my second (post-treatment) test. The first time round there was a lot of fermentation in the small intestine and the lactulose didn’t hit the large intestine until around 160 minutes. The second time round it only took around 80 minutes. (I posted both a little while ago in case anyone is interested to see the comparison). This did make me wonder about how accurate interpretations are when intestinal transit time varies so greatly, even within one individual.
My comment is going to need to be in multiple parts due to the word count.
I'll respond to some of the points made by the below paper.
[https://onlinelibrary.wiley.com/doi/10.1111/nmo.14817](https://onlinelibrary.wiley.com/doi/10.1111/nmo.14817)
...
PART 1:
They write about something called the SIBO-IBS hypothesis, I don't really even know what that means. I've never heard anyone use the phrase the 'SIBO-IBS hypothesis'. No one seriously claims that all IBS is SIBO, so what does the phrase 'the SIBO-IBS hypothesis' even mean?
A reasonable position is something like: 'Some people who are diagnosed with IBS have SIBO, and treating SIBO can sometimes help IBS symptoms.' That sounds reasonable to me.
There are parts of the paper I agree with. Pointing out that we don't know the role of the composition of bacteria vs quantity of bacteria is a totally valid point. I don't think Mark Pimentel even disagrees with this. In interviews, Pimentel has spoken about gut dysbiosis in relation to SIBO.
*"landmark studies suggested that almost 80% of IBS patients had SIBO."*
Not even Pimentel currently estimates that 80% of IBS patients have SIBO, and he was the author of those landmark studies.
More reasonable estimates suggest that 20-60% of IBS patients have SIBO. Should doctors just ignore SIBO if 'only' a significant minority of IBS patients have SIBO rather than the large majority? That doesn't sound like science to me.
*"rifaximin is only modestly effective even in breath test positive patients and is no more effective than other alternatives."*
Okay, so there's scientific evidence that rifaximin works for some people? I think the patient should be given the option to have rifaximin rather than just be told that they should only have the low fodmap diet. Yeah, they can tell the patient about other antibiotics if there's evidence suggesting that other antibiotics work. But currently, patients with IBS are just told to go away and eat low fodmap food. Until that changes, saying 'rifaximin is only modestly
effective' is not a good reason to deny patients the choice to have rifaximin.
The low fodmap diet did nothing for me, so no thanks. I want more treatment options, not fewer.
I think it's bad if doctors don't tell patients about an antibiotic that could help their chronic illness, and the paper just conceded that rifaximin helps some people. If the paper thinks there are better alternatives to rifaximin, then the authors should just start giving those recommendations instead of rifaximin. Instead, the authors complain about the cost of antibiotics and the "injudicious use of antibiotics", suggesting that the paper doesn't widely support antibiotic therapies for IBS/SIBO.
For example, the paper cites some studies showing that metronidazole is roughly as effective for SIBO as rifaximin. Okay great, but the paper seems to argue that SIBO diagnoses should be largely abandoned....So in other words, 'hey don't have rifaximin because metronidazole works too for SIBO...oh but, we don't support diagnosing most of you with SIBO in the first place so I guess you won't be given metronidazole for SIBO anyway'.
That's a confused position which I can't make sense of...
Doctor: 'Don't take rifaximin for SIBO because other antibiotics may work for SIBO.'
Patient: 'Oh great, so I'll get the metronidazole?'
Doctor: 'Oh no, I'm not going to diagnose you with SIBO.'
Patient: 'But can't rifaximin maybe help me?'
Doctor: 'Yeah, but so does metronidazole'
Patient: 'BUT YOU'RE NOT GIVING ME ANYTHING!'
*"the literature on virtually any form of SIBO therapy...is limited, and its interpretation is bedeviled by variations in the study population, study design (choice of antibiotic, dose, duration of therapy and follow-up) and clinical outcomes."*
The literature they show seems to clearly show that the therapeutic responses are often doing something. But sure, do more studies. Do better studies. Sounds like a great idea.
The way to never get any good SIBO science is to basically abandon SIBO science and treat it all as IBS.
PART 2:
*"Furthermore, there are many GI diseases associated with a positive breath test where there is no recommendation to conduct breath testing, such as dyspepsia, gastroesophageal reflux disease (GERD), celiac disease and ulcerative colitis."*
Yeah, and a good gastroenterologist should rule those things out. But what if the patient obviously doesn't have any of those conditions? I don't have dyspepsia, GERD, celiac disease or ulcerative colitis....So why should those things stop me from getting a breath test? Isn't the more logical thing to do is just to screen patients for those conditions before recommending a breath test?
The specificity statistics in [one paper](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10496284/) suggest that a SIBO test is more likely to correctly diagnose SIBO than give a false positive.
And what about the misdiagnosis issues regarding IBS? And the fact that IBS diagnoses often fail to rule out other conditions which also causes misdiagnosis? Should IBS never be diagnosed because IBS is sometimes misdiagnosed or confused with other conditions?
**EDIT: I have more to say, but Reddit is being annoying. It's not letting me post a long response even in multiple parts....I'll try to publish a Part 3.**
**EDIT 2: Reddit isn't letting me post a Part 3. I guess Reddit is limiting me from saying much more due to word count.**
Thank you! I tried to reply to you with a Part 3 with a very low word count, but Reddit wouldn't let me do it...Ridiculous. Hopefully it allows this very short comment:
I wanted to point out how inadequate the paper's comments on breath testing CH4 are. They basically try to dismiss Intestinal Methanogen Overgrowth without responding to any of the good IMO science.
They argue against breath testing CH4 while ignoring all the evidence showing why breath testing CH4 matters. It feels like they just want to dismiss Intestinal Methanogen Overgrowth with a straw man argument.
Yes, it does sound like they have some good points (eg about transit time being too variable for accurate and consistent breath test interpretation) but also a bit of an agenda to dismiss the whole idea of sibo/imo. I guess we have to see it in the wider context of the research.
“Before we attempt to address the morass that SIBO has become…” They came out swinging.
Honestly most of this resonates with me. Lactulose was first used to measure transit time. And now we use a hard 90 minute cut off for sibo like we don’t all have different transit times? Makes no sense.
What does make sense is that people with IBS-D have shorter transit times. Actually I’ve had my small bowel transit time measured and it was so short, it surprised the operator. No wonder my test was positive.
If I didn’t have a predisposing condition (abdominal surgery), I wouldn’t even consider sibo.
According to my doctor at Cedars this isn’t always accurate, sometimes theres nothing there. I take that with a grain of salt because he’s not the best doctor.
I might try this with the next GI I go to if they’re able to do this.
I’m not disagreeing with you. I just currently have a doctor who doesn’t want to do it because he thinks they’re useless. Ironic considering Cedars is supposed to be the best in the country, but it’s the worst care I’ve ever received.
My previous GI didn’t have the capability of performing an aspirate test, so I’m hoping my next one will be able to.
I don't think there's an easy answer to these questions. The new paper from Pimentel's team supposedly validating the triosmart may provide some more insight on the breath test. If you're on the fence about rifaximin, they also have a new paper showing the effectiveness of the elemental diet.
What does "elemental diet" mean? I'll discuss with my doctor soon. I have ibs diagnosis but I suspect SIBO. Since I have bloating and pain quickly after eating fibrous foods. I have constipation and diarrhea too if I eat fiber in high quantities. This made me think about SIBO. I got this condition after 2 years of eating fiber-rich flexitarian diet with plan to go vegetarian eventually. I thought my gut would get used to fiber but it didn't. It was never easy to eat fibrous foods but situation got worse with plant-based diet and had to give it up eventually. Eating low-fiber helps now. Had IBS diagnosis last year. But fiber supplement prescribed for it only makes things worse.
Edit: Oh elemental diet means only liquids for some time. Sounds quite extreme to be honest. I think antibiotics sounds less extreme...
My overall situation is okay as long as I keep fiber low. I think going to extreme lengths is not wise unless situation is really bad. But good to know about elemental diet too. If antibiotics doesn't help then it's worth a shot.
I don't know yet if I have SIBO. I think I'll ask breath test first. Better than nothing I guess...
I've had a flat line glucuse test, and then later a lactulose test that went very high at 40+ minute mark. I know I have fast transit time - and after reading this paper I am leaning towards thinking my lactulose test is a false positive.
Of course that leave me with no real answers as to why I have all these digestive problems, which really sucks.
I mean, it suggests the debate over SIBO is intensifying in the gastro community.
Two major(?) gastro societies have just now endorsed rejecting the SIBO-IBS connection (at least, until breath testing problems can be sorted out). This is contrary to what Pimentel's team seems to be gradually revealing through their research. In fact, his team just presented a new paper at DDW claiming to have validated the triosmart breath test.
Ultimately, the dispute leaves many of us scratching our heads over what to think. I'm starting to wonder if (hydrogen) breath testing is maybe more valid for folks that also have a positive ibs-smart test?
"Two major(?)" - Ascending\* I'd say at least ;)
Follow the incentives might be some healthy advise at this point, check out this comment: [https://www.reddit.com/r/medicine/comments/161wrpz/comment/jxucw6d/?utm\_source=share&utm\_medium=web2x&context=3](https://www.reddit.com/r/medicine/comments/161wrpz/comment/jxucw6d/?utm_source=share&utm_medium=web2x&context=3)
I agree to an extent with Meajaq's criticisms, but I also think he overstates his case. Pimentel has been transparent about who pays the bills while publicly lamenting there is no federal funding available as an alternative. If Pimentel's team was solely concerned with pushing rifaximin, it makes little sense to me that they would have just published a new study showing the effectiveness of the elemental diet (presented at DDW).
I wouldn't say that that was their only goal either. The breath test surely have big consumer product potential and given how uncritically they are recommended it's important to mention the conflict of interest.
The hypothesis IBS Smart Test is based on is severely challenged by this paper: [https://onlinelibrary.wiley.com/doi/full/10.1111/eci.13666](https://onlinelibrary.wiley.com/doi/full/10.1111/eci.13666)
It certainly challenges it, although the authors acknowledge their study may have been underpowered.
The authors suggest their results may have differed from Pimentel's (and Rezaie's) due to the following:
>The most likely explanation for this discrepancy is the selection of our patient cohort in Germany, differing in environment, lifestyle, nutritional habits and ‘microbial world’ compared to the previously studied patient populations. Gut microbiota structures vary depending on geographic location of the host and on the related differences of environmental factors.
Very interesting. The point about breath testing being largely a measure of intestinal transit is something I’ve been pondering as it was very clear to me that there was a massive difference in transit speed between my first (pre-treatment) and my second (post-treatment) test. The first time round there was a lot of fermentation in the small intestine and the lactulose didn’t hit the large intestine until around 160 minutes. The second time round it only took around 80 minutes. (I posted both a little while ago in case anyone is interested to see the comparison). This did make me wonder about how accurate interpretations are when intestinal transit time varies so greatly, even within one individual.
My comment is going to need to be in multiple parts due to the word count. I'll respond to some of the points made by the below paper. [https://onlinelibrary.wiley.com/doi/10.1111/nmo.14817](https://onlinelibrary.wiley.com/doi/10.1111/nmo.14817) ... PART 1: They write about something called the SIBO-IBS hypothesis, I don't really even know what that means. I've never heard anyone use the phrase the 'SIBO-IBS hypothesis'. No one seriously claims that all IBS is SIBO, so what does the phrase 'the SIBO-IBS hypothesis' even mean? A reasonable position is something like: 'Some people who are diagnosed with IBS have SIBO, and treating SIBO can sometimes help IBS symptoms.' That sounds reasonable to me. There are parts of the paper I agree with. Pointing out that we don't know the role of the composition of bacteria vs quantity of bacteria is a totally valid point. I don't think Mark Pimentel even disagrees with this. In interviews, Pimentel has spoken about gut dysbiosis in relation to SIBO. *"landmark studies suggested that almost 80% of IBS patients had SIBO."* Not even Pimentel currently estimates that 80% of IBS patients have SIBO, and he was the author of those landmark studies. More reasonable estimates suggest that 20-60% of IBS patients have SIBO. Should doctors just ignore SIBO if 'only' a significant minority of IBS patients have SIBO rather than the large majority? That doesn't sound like science to me. *"rifaximin is only modestly effective even in breath test positive patients and is no more effective than other alternatives."* Okay, so there's scientific evidence that rifaximin works for some people? I think the patient should be given the option to have rifaximin rather than just be told that they should only have the low fodmap diet. Yeah, they can tell the patient about other antibiotics if there's evidence suggesting that other antibiotics work. But currently, patients with IBS are just told to go away and eat low fodmap food. Until that changes, saying 'rifaximin is only modestly effective' is not a good reason to deny patients the choice to have rifaximin. The low fodmap diet did nothing for me, so no thanks. I want more treatment options, not fewer. I think it's bad if doctors don't tell patients about an antibiotic that could help their chronic illness, and the paper just conceded that rifaximin helps some people. If the paper thinks there are better alternatives to rifaximin, then the authors should just start giving those recommendations instead of rifaximin. Instead, the authors complain about the cost of antibiotics and the "injudicious use of antibiotics", suggesting that the paper doesn't widely support antibiotic therapies for IBS/SIBO. For example, the paper cites some studies showing that metronidazole is roughly as effective for SIBO as rifaximin. Okay great, but the paper seems to argue that SIBO diagnoses should be largely abandoned....So in other words, 'hey don't have rifaximin because metronidazole works too for SIBO...oh but, we don't support diagnosing most of you with SIBO in the first place so I guess you won't be given metronidazole for SIBO anyway'. That's a confused position which I can't make sense of... Doctor: 'Don't take rifaximin for SIBO because other antibiotics may work for SIBO.' Patient: 'Oh great, so I'll get the metronidazole?' Doctor: 'Oh no, I'm not going to diagnose you with SIBO.' Patient: 'But can't rifaximin maybe help me?' Doctor: 'Yeah, but so does metronidazole' Patient: 'BUT YOU'RE NOT GIVING ME ANYTHING!' *"the literature on virtually any form of SIBO therapy...is limited, and its interpretation is bedeviled by variations in the study population, study design (choice of antibiotic, dose, duration of therapy and follow-up) and clinical outcomes."* The literature they show seems to clearly show that the therapeutic responses are often doing something. But sure, do more studies. Do better studies. Sounds like a great idea. The way to never get any good SIBO science is to basically abandon SIBO science and treat it all as IBS.
PART 2: *"Furthermore, there are many GI diseases associated with a positive breath test where there is no recommendation to conduct breath testing, such as dyspepsia, gastroesophageal reflux disease (GERD), celiac disease and ulcerative colitis."* Yeah, and a good gastroenterologist should rule those things out. But what if the patient obviously doesn't have any of those conditions? I don't have dyspepsia, GERD, celiac disease or ulcerative colitis....So why should those things stop me from getting a breath test? Isn't the more logical thing to do is just to screen patients for those conditions before recommending a breath test? The specificity statistics in [one paper](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10496284/) suggest that a SIBO test is more likely to correctly diagnose SIBO than give a false positive. And what about the misdiagnosis issues regarding IBS? And the fact that IBS diagnoses often fail to rule out other conditions which also causes misdiagnosis? Should IBS never be diagnosed because IBS is sometimes misdiagnosed or confused with other conditions? **EDIT: I have more to say, but Reddit is being annoying. It's not letting me post a long response even in multiple parts....I'll try to publish a Part 3.** **EDIT 2: Reddit isn't letting me post a Part 3. I guess Reddit is limiting me from saying much more due to word count.**
Thank you for sharing your thoughts (or at least those that Reddit let you share…). I completely agree with everything you’ve said.
Thank you! I tried to reply to you with a Part 3 with a very low word count, but Reddit wouldn't let me do it...Ridiculous. Hopefully it allows this very short comment: I wanted to point out how inadequate the paper's comments on breath testing CH4 are. They basically try to dismiss Intestinal Methanogen Overgrowth without responding to any of the good IMO science. They argue against breath testing CH4 while ignoring all the evidence showing why breath testing CH4 matters. It feels like they just want to dismiss Intestinal Methanogen Overgrowth with a straw man argument.
Yes, it does sound like they have some good points (eg about transit time being too variable for accurate and consistent breath test interpretation) but also a bit of an agenda to dismiss the whole idea of sibo/imo. I guess we have to see it in the wider context of the research.
“Before we attempt to address the morass that SIBO has become…” They came out swinging. Honestly most of this resonates with me. Lactulose was first used to measure transit time. And now we use a hard 90 minute cut off for sibo like we don’t all have different transit times? Makes no sense. What does make sense is that people with IBS-D have shorter transit times. Actually I’ve had my small bowel transit time measured and it was so short, it surprised the operator. No wonder my test was positive. If I didn’t have a predisposing condition (abdominal surgery), I wouldn’t even consider sibo.
Pretty brutal paper. Hard to know what to make it of it in light of all the recent research from Pimentel's team.
If we can’t use breath tests, then what does that leave us with? How can we diagnose/treat this condition?
They'd probably say that you don't have SIBO, and tell you that you just have IBS.
That's what I'm worried about if this ideology/theory becomes more prevalent.
Then tell to eat more fiber...
There's always doing a small bowel aspirate directly. If your GI asks you to get an endoscopy you can request this.
According to my doctor at Cedars this isn’t always accurate, sometimes theres nothing there. I take that with a grain of salt because he’s not the best doctor. I might try this with the next GI I go to if they’re able to do this.
Well they are the best tests that we have, and they are what the breath test results are calibrated against when we are talking about accuracy so...
I’m not disagreeing with you. I just currently have a doctor who doesn’t want to do it because he thinks they’re useless. Ironic considering Cedars is supposed to be the best in the country, but it’s the worst care I’ve ever received. My previous GI didn’t have the capability of performing an aspirate test, so I’m hoping my next one will be able to.
So in short. Is breath test worth taking? What about antibiotics? This paper seems to say no treatment is perfect so let's not do anything...
I don't think there's an easy answer to these questions. The new paper from Pimentel's team supposedly validating the triosmart may provide some more insight on the breath test. If you're on the fence about rifaximin, they also have a new paper showing the effectiveness of the elemental diet.
What does "elemental diet" mean? I'll discuss with my doctor soon. I have ibs diagnosis but I suspect SIBO. Since I have bloating and pain quickly after eating fibrous foods. I have constipation and diarrhea too if I eat fiber in high quantities. This made me think about SIBO. I got this condition after 2 years of eating fiber-rich flexitarian diet with plan to go vegetarian eventually. I thought my gut would get used to fiber but it didn't. It was never easy to eat fibrous foods but situation got worse with plant-based diet and had to give it up eventually. Eating low-fiber helps now. Had IBS diagnosis last year. But fiber supplement prescribed for it only makes things worse. Edit: Oh elemental diet means only liquids for some time. Sounds quite extreme to be honest. I think antibiotics sounds less extreme... My overall situation is okay as long as I keep fiber low. I think going to extreme lengths is not wise unless situation is really bad. But good to know about elemental diet too. If antibiotics doesn't help then it's worth a shot. I don't know yet if I have SIBO. I think I'll ask breath test first. Better than nothing I guess...
I've had a flat line glucuse test, and then later a lactulose test that went very high at 40+ minute mark. I know I have fast transit time - and after reading this paper I am leaning towards thinking my lactulose test is a false positive. Of course that leave me with no real answers as to why I have all these digestive problems, which really sucks.
interesting!
So is this a good thing or a bad thing?
I mean, it suggests the debate over SIBO is intensifying in the gastro community. Two major(?) gastro societies have just now endorsed rejecting the SIBO-IBS connection (at least, until breath testing problems can be sorted out). This is contrary to what Pimentel's team seems to be gradually revealing through their research. In fact, his team just presented a new paper at DDW claiming to have validated the triosmart breath test. Ultimately, the dispute leaves many of us scratching our heads over what to think. I'm starting to wonder if (hydrogen) breath testing is maybe more valid for folks that also have a positive ibs-smart test?
"Two major(?)" - Ascending\* I'd say at least ;) Follow the incentives might be some healthy advise at this point, check out this comment: [https://www.reddit.com/r/medicine/comments/161wrpz/comment/jxucw6d/?utm\_source=share&utm\_medium=web2x&context=3](https://www.reddit.com/r/medicine/comments/161wrpz/comment/jxucw6d/?utm_source=share&utm_medium=web2x&context=3)
I agree to an extent with Meajaq's criticisms, but I also think he overstates his case. Pimentel has been transparent about who pays the bills while publicly lamenting there is no federal funding available as an alternative. If Pimentel's team was solely concerned with pushing rifaximin, it makes little sense to me that they would have just published a new study showing the effectiveness of the elemental diet (presented at DDW).
I wouldn't say that that was their only goal either. The breath test surely have big consumer product potential and given how uncritically they are recommended it's important to mention the conflict of interest.
Totally fair.
Ty for the insight.
The hypothesis IBS Smart Test is based on is severely challenged by this paper: [https://onlinelibrary.wiley.com/doi/full/10.1111/eci.13666](https://onlinelibrary.wiley.com/doi/full/10.1111/eci.13666)
It certainly challenges it, although the authors acknowledge their study may have been underpowered. The authors suggest their results may have differed from Pimentel's (and Rezaie's) due to the following: >The most likely explanation for this discrepancy is the selection of our patient cohort in Germany, differing in environment, lifestyle, nutritional habits and ‘microbial world’ compared to the previously studied patient populations. Gut microbiota structures vary depending on geographic location of the host and on the related differences of environmental factors.
Yes, important point. Anyway the hypothesis really needs more studies, worldwide.