Low trehalase activity is associated with abdominal symptoms caused by edible mushrooms

Background: The purpose of the study was to evaluate whether maldigestion o f trehalose causes abdominal symptoms and which available diagnostic method best distinguishes intolerant from tolerant subjects, Methods: A 25-g oral trehalose load test was performed in 64 subjects. The 19 experiencing clea r symptoms constituted the trehalose-intolerant subjects. Changes from base -line levels of blood glucose, breath hydrogen, and methane and symptoms we re recorded after the test. Trehalase activity was determined in serum and on a duodenal biopsy specimen obtained by endoscopy. Results: Intolerant su bjects were best differentiated from tolerant subjects by changes in breath gases (hydrogen and methane) and duodenal trehalase to sucrase ratio. The change in breath gases correlated inversely with duodenal trehalase activit y, duodenal trehalase to sucrase ratio, and plasma trehalase activity. The correlation between serum and duodenal trehalase activities was on the orde r of 0.6. Two subjects were found to have trehalase deficiency. Conclusions : It is obvious that trehalose maldigestion can cause symptoms similar to t hose of lactose maldigestion and intolerance. Three factors control the gen esis of symptoms: 1) the activity of small-bowel trehalase: if it is low, t rehalose is maldigested and more trehalose is passed into the colon; 2) the maldigested trehalose, which causes osmotic water flow into the colon, res ulting in loose stools and diarrhea; and 3) most importantly, the microflor a of the colon, from which symptoms will arise if there are bacteria capabl e of producing gases from maldigested trehalose. If colonic bacteria cannot produce gases, then distention of the abdomen and intestinal gas expulsion as eructations and flatus will not occur.