Use and abuse of hydrogen breath tests

Studies on absorption and metabolism of palatinose (isomaltulose) in rats

“…5, the administration of lactulose, a disaccharide indigestible in the small intestine, produced a significant amount of H 2 in the expired air. Contrarily, when rats were administered palatinose or sucrose, levels of H 2 in the expired air stayed well below 10 parts per million, the level of H 2 above which carbohydrate malabsorption in the small intestine is diagnosed (5) , for 7 h, a period that is long enough for unabsorbed carbohydrates to pass through into the colon. These results indicate that palatinose is fully hydrolysed and absorbed in the small intestine as well as sucrose is, even if their metabolic pathways are different.…”

“…H 2 concentration increased gradually in the lactulose group. In the case of lactose intolerance, the definition of a positive test has varied but a rise of 10 -20 parts per million over basal values is usually considered to indicate malabsorption (5) . According to this definition, the H 2 concentration was significantly greater in the lactulose group compared with the concentration at baseline from 4 h and extending to the end of the experiment.…”

“…The rats were placed in the chamber immediately after the oral administration of [1-13 C]sucrose or [1][2][3][4][5][6][7][8][9][10][11][12][13] C]palatinose at a dose of 2 g/kg (mixture of 0·175 g of [1- Schematic illustration of the system used to collect expired air from rats. Briefly, this system composed of a desiccator that was used as an animal chamber, a pump and breath sampling bags.…”

Genetic testing improves the diagnosis of adult type hypolactasia in the Mediterranean population of Sardinia

“…The L-BHT and its different modifications are indirect tests and although a series of precautions are usually taken before performing the test, it bears a reasonably high risk for wrong positive and negative results (Simren and Stotzer, 2006). However, it is considered the most reliable, non-invasive and economical technique by several authors (Bond and Levitt, 1972;Montes and Perman, 1991) and the strategy of improved L-BHT test was preferred in this work because, although jejunal biopsy is considered one of the most reliable methods to detect lactose malabsorbers and many researchers use it as gold standard in comparison studies, it seemed to us too invasive for the diagnosis of such a mild condition as adult type hypolactasia.…”

Monitoring technologies in the neonatal intensive care unit: implications for the detection of necrotizing enterocolitis

“…Breath hydrogen is currently being investigated in the areas of small intestinal bacterial overgrowth and lactose/fructose malabsorption. 26,27 Bacterial overgrowth in the intestines of neonates is a risk factor for the development of NEC. A significant increase in breath hydrogen concentration derived from these bacteria was found in the infants who were later confirmed to have developed NEC.…”