 Hi, this is Dr. Ruscio and let's talk about SIBO, small intestinal bacterial overgrowth, to know when you have it and more importantly when you don't have it. SIBO, or small intestinal bacterial overgrowth, is a condition of bacterial overgrowth that may cause many of the cases of irritable bowel syndrome and or IBS and this can include things like abdominal pain or gas, altered stool, frequency or consistency so constipation, diarrhea and oscillation between the two and also altered formation of the stool, loose stools, hard stools, compact stools. This is a common condition. IBS affects about 10% of the population and SIBO, small intestinal bacterial overgrowth, can underlie many of those cases. So because of this, SIBO is often tested for and there are two different types of tests that can be used. They're both breath test, one uses lactulose, one uses glucose and they both have merit and they can both be very successfully but there's some intricacies to especially the lactulose test that's important to understand to prevent you from having what's called a false positive and this is where the lab says you have SIBO but you actually don't have SIBO and what I've been noticing over the past year or so is many patients come in with quite a bit of fear surrounding SIBO. They've heard that you could never get rid of it. They've heard of people that keep treating it and retesting and are still positive and I have not found that to be true for most cases. There are certainly a smaller subset of patients that have a very hard hand that they've been dealt and they have to work very hard to gain symptomatic improvement and they're much harder cases but for the majority of people, SIBO is something that can be overcome but if you don't understand how to treat SIBO the right way A and also B understand how to interpret the tests, you can fall into the syndrome of thinking that you've never been able to clear SIBO. Now recently in one of our podcasts we went into great detail comparing the lactulose and the glucose tests and I'll try to find that link and put that in here if you wanted to go to that episode and get all the science behind these different tests but the main thing to understand is that with lactulose testing there's a higher chance of having a false positive meaning you're falsely positive meaning the test shows you have the condition but you don't actually have the condition and one of the keynote things that can suggest this is if someone first has SIBO and this is again all this will be on the lactulose test I'm referring to someone test positive for SIBO they treat it and they respond very well to treatment but their retesting shows they still have SIBO and especially if that retesting is done once and then maybe you do it again a month later or if you finish SIBO treatment and then your retest was several weeks later and you retested and your symptoms were gone at that point and your symptoms were still gone at that point as long as there's been a few weeks where you've been symptom-free and the retest show is that you actually have SIBO that can denote a false negative and so I'll put up on the screen a minute here a patient's lab results just from today that perfectly encapsulated this but essentially this gentleman came in with quite a bit of symptoms he was also positive for SIBO we treated him he responded marvelously symptoms were pretty much completely gone was feeling great and we retested his SIBO was positive we decided since it looked fishy to wait a few weeks and retest again to see if that positive result was still found and it was still found again so this gentleman still feeling great and exhibiting none of the signs of symptoms of SIBO came in feeling like he was a failure he was doing something wrong and he had this underlying problem and he was actually very upset excuse me until I simply explained to him the issue of false positives and this is important because understanding the issue of false positives and explain that to a patient can prevent them from thinking that something is wrong with them or they failed or they've done something wrong or they've eaten the wrong way and it can take a lot of stress off of them and it can also prevent the clinician for meeting to treat the patient again and more importantly to the patient unnecessarily so to put this patient's lab results up on the screen here's what you see you see their sample one two three four five six seven and so on and they coincide with a time interval of baseline 20 minutes 40 minutes 60 minutes 80 minutes 100 minutes and so on and then next to that you see the PPM H2 which is just parts per million of hydrogen and you also see PPM CH4 which is parts per million of methane I'll be referencing just the hydrogen for our conversation the H2 because they both coincide with each other so when you when you drink the lactulose as part of this breath test after you drink it the lactulose works its way down your small intestine and very little gas should be released there but eventually when it gets into the large intestine that's where there's a lot of bacteria and a lot of gas should be released and we should see that levels elevate so around 100 to 120 minutes is when this transition to occur this is why you see that black line between 7 and 8 that's probably the latest point at which we'd expect this transition to occur now that's when we normally would see the gas levels elevate but in this patient they're elevated before that black line which shows a positive however they're only elevated kind of toward the end of this test which could mean that that person has either a short small intestine or the lactulose is making its way through their small intestine too quickly maybe because the lactulose is somewhat irritating to this individual small intestine so the small intestine rushes it through it gets to the large intestine earlier than we think it should from a timing perspective and we see this elevation of gas so that's what we're seeing here at 80 minutes in 100 minutes we're seeing the score of 109 and 119 but because this has happened in a patient who has for several weeks been symptom free this is almost certainly a false positive so why this is important to understand is that again this prevents the patient from feeling like they did something wrong or there's something wrong with them prevents the doctor from doing more or an unnecessary treatment this doesn't happen with the glucose as a testing agent so if you really wanted to verify this you can repeat the test using glucose instead of lactulose the patient and I today decided not to do that because really we had gotten to the clinical endpoint we were trying to get to he was feeling much better there wasn't need to do any more testing this is not to say that lactulose is a bad test and can't be used it definitely has utility it's just important to understand this presentation if someone has been treated and responded really well and their labs look like this with lactulose meaning they're positive but they're only positive toward the end of the test that's very suggestive of a false positive so something very important to keep in mind and I think this may prevent some people out there that I hear by indirectly in the clinic who claim they can never get rid of SIBO it may because you're not working with a good clinician it may be because you're using a unvalidated test like potentially a urine test or maybe because you're using a test like the lactulose breath test that has a high incidence of false positives at the end of the day it's important to be practical and think through these issues if you've seen a great improvement in your symptoms but your labs haven't improved I would always trust the symptoms ahead of the labs in most cases it's not an absolute rule but certainly this case supports that so lactulose and glucose can both be used for SIBO breath testing but lactulose has a higher incidence a much higher incidence of false positives be on the lookout if you're a patient or if your clinician for this type of presentation the the short takeaway is if you see elevations of the gas levels only toward the very end of the test in a patient that has no symptoms or their symptoms have responded very nicely then it's most likely a false positive a little deeper of a concept than we usually discuss but I think this hopefully will help a lot of people so this is Dr. Ruscio I hope this information helps you get healthy and get back to your life thanks