Trying to figure if I have leaky gut and to what degree. I have taken the following tests: 1. Lactulose/Mannitol Test: 2011: Lactulose .82 (ref <1.50), Mannitol 25 (ref 4 - 27) L/M Ratio: .03 (ref <=0.10) and then in 2014: Lactulose .90 (ref <1.50), Mannitol 28 (ref 4 - 27) L/M Ratio: .03 (ref <=0.10) 2. C-Sucrose Breath Test (Metabolic Solutions): 1.44% Low (ref > 3.91%) repeated at 1.14% 2 weeks later 3. DD Comp Stool Test: Secretary IgA: 11.6 (ref 51-204) 4. Cyrex Antibody Array 2: Occludin/Aonulin IgG 1.87 High (ref .2-1.5), Actomyosin IgA, Zonulin IgA/IgM, and all LPS's normal So the Lactulose/Mannitol and Cyrex test seem to be slight positives, but the C-Sucrose test and low Sec IgA seem to be stronger positives. One of my doctors is Dr. Leo Galland in NYC who is a gut specialist but he is new to both the C-Sucrose and Cyrex tests and doesn't quite know what to make of them. Limited papers on both of these, but the science seems to be there. Are there any other tests that could be useful? Quite a few tests I have taken have shown that there is an autoimmune component to my illness, so this is why I really suspect leaky gut. With the C-Sucrose breath test you ingest 20 grams of sucrose and the look to see how well the enzyme sucrase splits/digests the sucrose and check for the resulting CO2 in the breath. They make the assumption it seems that low sucrase production by the intestinal villi is a result of damage to the lining, and not a genetic defect, which is quite rare (1 in 5000 I believe). My low CO2 seems to be result of very limited sucrase activity. I also just read that low levels of Invertase/Sucrase enzymes can be the result of toxicity such has heavy metals (mercury) and that low activity of these enzymes can result in sugar not being broken down leading to fermentation in the GI tract causing overgrowth of bacteria and/or yeast. Any thoughts on the above? Hard to find information on this from either my doctors or online. Thanks!