Dr. Amy Nett: The main marker I’m going to focus on here is the indican, which was high. Again, just sort of reviewing the content from this week, we said that indican is an organic acid that’s derived from bacterial metabolism of tryptophan. So when you see elevated indican, this is one of the few markers that can actually be an indicator of bacterial overgrowth in the small bowel. We said that, in general, we really can’t use the organic acid markers to differentiate whether the problem is in the ascending colon or if it’s in the small bowel, but indican is one of the markers that does somewhat localize the pathology to the small bowel. The other thing you can use indican for—and it might not be in this seven-year-old patient we’re talking about—but again, if you see fat malabsorption or steatorrhea, indican can help differentiate between pancreatic insufficiency and biliary stasis. That’s the other role of indican. But we also have to remember that indican can be elevated in the setting of incomplete protein digestion. So if you have a seven-year-old boy with behavioral issues, indican could certainly be an indication of SIBO. Other things you would think about, a seven-year-old boy with behavior issues, if he has something like ADHD, if he’s not really sitting still for his meals, is he properly digesting food, or is there incomplete protein digestion that’s causing the elevation in indican? I very rarely use findings on the organic acids test alone to make a diagnosis. I think it can point you in the direction of saying that there probably is some microbial imbalance, and I think it’s worth following up with a SIBO breath test, and then you’ve already done the Doctor’s Data stool analysis, because, sure, the high indican can be a marker of SIBO, but it’s not a definitive marker and it’s not particularly specific.
Then the other markers you mentioned, again, these are markers that are involved in detoxification and peripheral neurotransmitter metabolism. Then the formiminoglutamic acid, which we sometimes just call FIGLU—much easier than saying formiminoglutamic acid every time—is an intermediate in the metabolism of histidine, so that can be used as a marker of methylation. That may indicate a folate deficiency. There is a lot of information, and remember for kids with behavioral issues, Chris mentioned, we tend to actually run the Great Plains organic acids test, both because they have more markers for clostridial species and because there are more markers for yeast overgrowth. If you’re working with kids, particularly on the spectrum or otherwise having behavioral issues, it might be worth considering the Great Plains organic acids test. Otherwise, we do generally run the Genova test. Based on those markers, I think it definitely points you in the direction of SIBO but doesn’t diagnose it and also points you in the direction of possible impaired methylation, so if you’re doing methylation testing, that could be a place to consider as well.