{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T22:20:19Z","timestamp":1790806819936,"version":"4.1.0"},"reference-count":16,"publisher":"BMJ","issue":"1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gut"],"published-print":{"date-parts":[[1988,1]]},"abstract":"<jats:p>About 5% of normal subjects fail to produce increased hydrogen breath concentration after ingestion of the non-digestible carbohydrate lactulose (low hydrogen producers). The existence of low hydrogen producers limits the diagnostic use of hydrogen (H2) breath tests. We studied the effects of lactulose and of magnesium sulphate (MgSO4) pretreatment on stool-pH and on hydrogen exhalation after oral loading with lactulose or lactose in 17 hydrogen producers and 12 low hydrogen producers. In seven hydrogen producers acidification of stool pH by lactulose pretreatment (20 g tid) decreased hydrogen exhalation and three of seven (43%) became low hydrogen producers. In contrast, after pretreatment of eight low hydrogen producers with magnesium sulphate (5 g twice daily) all eight produced hydrogen after a lactulose load. Similarly four lactose intolerant low hydrogen producers had abnormal lactose hydrogen breath tests after MgSO4 pretreatment. MgSO4 pretreatment neither resulted in false positive lactose hydrogen breath tests in five lactose tolerant hydrogen producers, nor increased the hydrogen exhalation in five additional hydrogen producing controls after ingestion of lactulose. The results of these studies confirm that hydrogen production from lactulose decreases when the colonic pH is lower (lactulose pretreatment), and increases when colonic pH is higher (MgSO4 pretreatment). In low hydrogen producers the lacking increase of H2 exhalation after ingestion of non-digestible carbohydrates can be overcome by MgSO4 pretreatment, thus increasing the sensitivity of the test by avoiding false negative hydrogen breath tests in low hydrogen producers with disaccharide malabsorption or maldigestion. The underlying mechanism of this remarkable effect of MgSO4 pretreatment warrants further investigation.<\/jats:p>","DOI":"10.1136\/gut.29.1.21","type":"journal-article","created":{"date-parts":[[2007,9,18]],"date-time":"2007-09-18T17:41:31Z","timestamp":1190137291000},"page":"21-26","source":"Crossref","is-referenced-by-count":37,"title":["Acidic colonic microclimate--possible reason for false negative hydrogen breath tests."],"prefix":"10.1136","volume":"29","author":[{"given":"H","family":"Vogelsang","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P","family":"Ferenci","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S","family":"Frotz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S","family":"Meryn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A","family":"Gangl","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[1988,1,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1016\/0009-8981(80)90004-2","article-title":"A new method for the detection of hydrogen in breath and its application to acquired and ipborn sugar malabsorption","volume":"108","author":"Bartlett, K.; Dobson, J.V.; Eastham, E.","year":"1980","unstructured":"Bartlett K, Dobson JV, Eastham E. A new method for the detection of hydrogen in breath and its application to acquired and ipborn sugar malabsorption. Clin Chim Acta 1980; 108: 189-94.","journal-title":"Clin Chim Acta"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/S0140-6736(77)90098-8","article-title":"Breath-hydrogen test and smoking","volume":"ii:","author":"Tadesse, K.; Eastwood, M.","year":"1977","unstructured":"Tadesse K, Eastwood M. Breath-hydrogen test and smoking. Lancet 1977; ii: 91.","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1016\/S0016-5085(19)34395-1","article-title":"Respiratory hydrogen and methane as affected by consumption of gas-forming goods","volume":"51","author":"Calloway, D.H.","year":"1966","unstructured":"Calloway DH. Respiratory hydrogen and methane as affected by consumption of gas-forming goods. Gastroenterology 1966; 51: 383-9.","journal-title":"Gastroenterology"},{"key":"ref_4","first-page":"163","article-title":"Hydrogen catabolism in the colon of the rat","volume":"84","author":"Levitt, M.D.; Berggren, T.; Hastings, J.; Bond, J.H.","year":"1974","unstructured":"Levitt MD, Berggren T, Hastings J, Bond JH. Hydrogen catabolism in the colon of the rat. J Lab Clin Med 1974; 84: 163-7.","journal-title":"J Lab Clin Med"},{"key":"ref_5","first-page":"602","article-title":"Alterations of the colonic flora and their effect on the hydrogen breath test","volume-title":"Gut","volume":"19","author":"Gilat, T.; Ben Hur, H.; Gelmann-Malachi, E.; Terdiman, R.; Peled, Y.","year":"1978","unstructured":"Gilat T, Ben Hur H, Gelmann-Malachi E, Terdiman R, Peled Y. Alterations of the colonic flora and their effect on the hydrogen breath test. Gut 1978; 19: 602-5."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"608","DOI":"10.1172\/JCI111738","article-title":"Influence of chronic lactulose ingestion on the colonic metabolism in man (an in vivo study)","volume":"75","author":"Florent, C.; Flourie, B.; Leblond, A.; Bautureau, M.; Bernier, J.; Rambaud, J.","year":"1985","unstructured":"Florent C, Flourie B, Leblond A, Bautureau M, Bernier J, Rambaud J. Influence of chronic lactulose ingestion on the colonic metabolism in man (an in vivo study). J Clin Invest 1985; 75: 608-13.","journal-title":"J Clin Invest"},{"key":"ref_7","first-page":"397","article-title":"Lactulosehydrogen (H2) breath test in health and disease","volume":"17","author":"Metz, G.L.; Jenkins, D.J.A.; Blendis, L.M.","year":"1976","unstructured":"Metz GL, Jenkins DJA, Blendis LM. Lactulosehydrogen (H2) breath test in health and disease. Gut 1976; 17: 397-8.","journal-title":"Gut"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1172\/JCI110079","article-title":"Role of pH in production of hydrogen from carbohydrates by colonic bacterial flora","volume":"76","author":"Perman, J.A.; Modler, S.; Olson, A.C.","year":"1981","unstructured":"Perman JA, Modler S, Olson AC. Role of pH in production of hydrogen from carbohydrates by colonic bacterial flora. J Clin Invest 1981; 76: 643-50.","journal-title":"J Clin Invest"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"999","DOI":"10.1136\/gut.15.12.999","article-title":"Effects of lactulose and other laxatives on ileal and colonic pH as measured by a radiotelemetry device","volume":"15","author":"Bown, R.L.; Gibson, J.A.; Sladen, G.E.; Hicks, B.; Dawson, A.M.","year":"1974","unstructured":"Bown RL, Gibson JA, Sladen GE, Hicks B, Dawson AM. Effects of lactulose and other laxatives on ileal and colonic pH as measured by a radiotelemetry device. Gut 1974; 15: 999-1004.","journal-title":"Gut"},{"key":"ref_10","first-page":"237","article-title":"Blendis LM. A simple method of measuring breath hydrogen in carbohydrate malabsorption by endexpiratory sampling","volume":"50","author":"Metz, G.L.; Gassul, M.A.; Drasar, B.S.; Jenkins, D.J.A.","year":"1976","unstructured":"Metz GL, Gassul MA, Drasar BS, Jenkins DJA, Blendis LM. A simple method of measuring breath hydrogen in carbohydrate malabsorption by endexpiratory sampling. Clin Sci Molec Med 1976; 50: 237-40.","journal-title":"Clin Sci Molec Med"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1232","DOI":"10.1056\/NEJM197512112932405","article-title":"Prospective comparison of indirect methods for detecting lactase deficiency","volume":"293","author":"Newcomer, A.D.; McGill, D.B.; Thomas, P.J.; Hofmann, A.F.","year":"1975","unstructured":"Newcomer AD, McGill DB, Thomas PJ, Hofmann AF. Prospective comparison of indirect methods for detecting lactase deficiency. N Engl J Med 1975; 293: 1232-6.","journal-title":"N Engl J Med"},{"key":"ref_12","first-page":"278","article-title":"The hepatic coma syndrome and lactulose","author":"Conn, H.O.; Lieberthal, M.M.","year":"1983","unstructured":"Conn HO, Lieberthal MM. The hepatic coma syndrome and lactulose. 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