SIBO Tips; Low FODMAP Diet and Not Responding to SIBO Treatments – Audience Questions.

SIBO Tips; Low FODMAP Diet and Not Responding to SIBO Treatments – Audience Questions.

Dr. Michael Ruscio: Hi, everyone. This is Dr. Ruscio, and let’s discuss a few audience questions, one regarding if a low FODMAP diet can be used to predict if someone has SIBO, small intestinal bacterial overgrowth. And the other: what to do or what does it mean if you have SIBO and you’ve diagnosed it via a breath test, you treat for SIBO, your symptoms respond, but your lab tests don’t?

So let’s start with the first of these questions from Jeff Rothschild.

“Hey, Michael. How are you? I’ve been enjoying the listener Q&A podcasts that you’ve added. It’s a nice complement to the interviews. On that note, I had a question. Please forgive me if you’ve already answered this on a podcast or video, and I’d be happy to be directed somewhere. What I’ve been wondering is if a low FODMAP diet could be used somewhat diagnostically for SIBO? For example, they complain of bloating when eating certain foods, and they go on a low FODMAP diet. And all of their symptoms resolve. Is there anything else that could mean? I understand you would want to know if it was SIBO or what type for treatment purposes. But if someone can’t do a breath test for whatever reasons, does the dietary intervention have any predictive use?”

Now, unofficially, no. Officially, to be able to diagnose SIBO, you need to perform a breath test in order to diagnose it. In my opinion, a low FODMAP diet can be one tool that could suggest someone may have small intestinal bacterial overgrowth. So if someone responds favorably to a low FODMAP diet, that is suggestive that they may have small intestinal bacterial overgrowth, because small intestinal bacterial overgrowth and irritable bowel syndrome, IBS, there’s definitely a degree of overlap. It might be minimal. It might be fairly large, depending on what study that you read. But there is an association there. And the low FODMAP diet has been shown to be very effective, and there’s some pretty compelling research for the low FODMAP diet in IBS.

So because of those connections, yes, in my opinion unofficially if someone responds favorably to a low FODMAP diet, that may be indicative that there is SIBO present and it may indicate that there is a mild case of SIBO. What I suspect is that we’ll eventually learn that for mild cases of SIBO, people who go on a low FODMAP diet essentially balance out or eradicate their SIBO because the low FODMAP diet will starve the microbiota, starve the bacteria of substrates that are highly effective at feeding them, which is not a bad thing in my opinion.

For example, some studies have shown that a low FODMAP diet can lower inflammation, lower leaky gut, and lower immune activation. So the low FODMAP diet is low in compounds that feed bacteria; therefore, it starves bacteria. Therefore, my opinion is that the low FODMAP diet will likely address mild cases of SIBO.

But also remember that those with IBS—not everyone with IBS is going to have SIBO. But some studies have shown that those with IBS are hypersensitive to gas pressure, even though some studies have shown equivalent levels of gas pressure—because some gas pressure is normal—between those that are healthy and those that have IBS. So they both have comparable levels of gas, but those with IBS are hypersensitive to that gas. So normal gas levels in those with IBS may be enough to cause symptoms.

What likely happens is the low FODMAP diet decreases that gas pressure and it goes from normal to subnormal. And that may be one of the reasons why we see improvements, especially with things like abdominal pain and bloating in the IBS trials using a low FODMAP diet.

So, Jeff, I think that answers your question, and now we’ll transition to the next.

Ok. So the next question, Sandra asks,

“I’m curious what you have to say about someone who tests in the severe category of both methane and hydrogen. Gets treatment, Rifaximin, Flagyl, Alimed, Neem”—these are pharmaceutical and herbal treatments for SIBO—“and feels a lot better. Then retests and the test score is still the same, as in no change. What is that supposed to mean? By the way, the testing was done at your SIBO clinic in Oregon, Dr. Siebecker, so it was done per the proper protocol.”

So I’m assuming she’s directing this to a post that was both between Dr. Siebecker and myself.

So a few thoughts there. The utility of SIBO breath test in retesting after treatment has not been fully established. And this was outlined in the most up-to-date consensus report, which was the North American Consensus paper on SIBO breath testing. So we don’t exactly know how to use a SIBO breath test after someone has been treated.

And why this is relevant is because you may, or as you’re describing, have elevated gas levels but be symptom-free. And that might be ok. It’s not to say that everyone who has SIBO via the breath test is going to have a problem. And we’ve reviewed a few cases wherein people have become completely symptom-free, yet they still have elevated gas levels.

Now, that might be disconcerting to you, but keep in mind that SIBO is not tied to any mortality, meaning it won’t shorten your life. It won’t increase your risk of heart disease, of neurodegenerative disease, of what have you. It does have morbidities associated with it, meaning it’s inconvenient. And the symptoms may cause morbidities, meaning you may not go to work one day if you have a flare of diarrhea. You may withdraw from some social engagements due to food reactivity or due to abdominal cramping or pain. But it doesn’t seem to have any mortality associated with it.

Now, that may change in the future as we learn more. But because SIBO, at least according to the evidence to date, is only associated with inconvenience in terms of symptoms, then if you have SIBO but you have none of those symptoms, I’m not highly concerned about it.

Now, finally, you may also have a number of factors present that may be skewing the results of the test. You may have rapid small intestinal transit which is giving you a false positive. You may have an anatomically short small intestine, and actually some Asian populations have shown this, that SIBO breath testing may suffer from higher degrees of false positives because anatomically Asians apparently have shorter small intestines than what I’m assuming they’re comparing to predominantly being a European population.

And you may also have colonic overgrowth that may be skewing the test. And this may be more so responsible for a prolonged or a flat-line type methane presentation. But at the end of the day, I would not be overly concerned because it seems that the SIBO test has the most utility for establishing if someone may be a candidate for SIBO treatments: probiotics, low FODMAP diet, antibacterial treatments, and not necessarily something that can be highly utilized in terms of follow up retesting. And also, because, if you have SIBO, that doesn’t mean you’re going to have other factors.

For example, if someone has chronically-elevated high C-reactive protein, that has been correlated as an independent risk factor for heart disease. This type of information we do not have for SIBO. Now, we may have that in the future, but at least, to date, we don’t have that. So for all those reasons, I would focus predominantly on your symptoms and how you feel, make that the primary barometer. And as long as your symptoms are faring well, I wouldn’t be overly concerned about a breath test that is remaining positive.

Okay, that’s it. A few thoughts on the low FODMAP diet, SIBO, SIBO testing, retesting, and lack of responsiveness of the test to treatment. And this is Dr. Ruscio and hopefully this information helps you get healthy and get back to your life. Thanks.

What do you think? I would like to hear your thoughts or experience with this.

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Dr. Ruscio is your leading functional and integrative doctor specializing in gut related disorders such as SIBO, leaky gut, Celiac, IBS and in thyroid disorders such as hypothyroid and hyperthyroid. For more information on how to become a patient, please contact our office. Serving the San Francisco bay area and distance patients via phone and Skype.