{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,13]],"date-time":"2026-04-13T14:16:34Z","timestamp":1776089794808,"version":"3.50.1"},"reference-count":10,"publisher":"BMJ","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gut"],"published-print":{"date-parts":[[1987,6]]},"abstract":"<jats:p>After ingestion of a non-absorbable carbohydrate breath hydrogen excretion increases early at about 10 minutes, and again later when the ingested carbohydrate enters the caecum. The late rise has been used as a marker of mouth to caecum transit time, but the source of the early rise has not been satisfactorily explained. We studied in 60 healthy volunteers the source and frequency of the early rise in breath hydrogen after ingestion of a non-absorbable carbohydrate. After ingestion of either lactulose solution (10 g in 150 ml water), lentil soup (46 g carbohydrate) or solid meal containing baked beans (15 g carbohydrate), breath hydrogen was significantly raised above basal concentrations within 10 minutes (81 +\/- 27, 395 +\/- 138 and 110 +\/- 52% above basal respectively). A significant rise in breath hydrogen (75 +\/- 21%) occurred 10 minutes after sham lactulose feeding (lactulose applied to oral cavity but not swallowed), but no early peak occurred after sham saccharin feeding (non-fermentable carbohydrate), intragastric or intraduodenal administration of lactulose. Ten of the 12 subjects given lactulose sham feeding were restudied after oral hygiene with chlorhexidine mouthwash. In these the early hydrogen peak was abolished. Oral hygiene also reduced the occurrence and magnitude of the early hydrogen rise after lactulose ingestion. These findings indicate that the early rise in breath hydrogen observed after ingestion of lactulose is produced by interaction with oral bacteria.<\/jats:p>","DOI":"10.1136\/gut.28.6.721","type":"journal-article","created":{"date-parts":[[2007,9,18]],"date-time":"2007-09-18T17:41:31Z","timestamp":1190137291000},"page":"721-725","source":"Crossref","is-referenced-by-count":36,"title":["Evaluation of the hydrogen breath test in man: definition and elimination of the early hydrogen peak."],"prefix":"10.1136","volume":"28","author":[{"given":"G","family":"Mastropaolo","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"W D","family":"Rees","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[1987,6,1]]},"reference":[{"key":"ref_1","first-page":"546","article-title":"Investigation of small bowel transit time in man utilising pulmonary hydrogen (H2) measurements","volume":"84","year":"1975","unstructured":"Bond JH, Levitt MD. Investigation of small bowel transit time in man utilising pulmonary hydrogen (H2) measurements. J Lab Cell Med 1975; 84: 546-55.","journal-title":"J Lab Cell Med"},{"key":"ref_2","first-page":"893","article-title":"Assessment of the reproducibility of the lactulose H2 breath test as a measure of mouth to caecum transit time","volume-title":"Gut","volume":"24","author":"SJ, La Brooy; MS, Male; BK, Beavis; JJ, Misiewicz","year":"1983","unstructured":"La Brooy SJ, Male MS, Beavis BK, Misiewicz JJ. Assessment of the reproducibility of the lactulose H2 breath test as a measure of mouth to caecum transit time. Gut 1983; 24: 893-6."},{"key":"ref_3","first-page":"668","article-title":"Breath hydrogen test for small intestine bacterial colonization","volume":"i:","author":"Metz, G.; Gassul, M.A.; Deason, B.S.; Senkings, D.S.A.; Blendis, L.M.","year":"1976","unstructured":"Metz G, Gassul MA, Deason BS, Senkings DSA, Blendis LM. Breath hydrogen test for small intestine bacterial colonization. Lancet 1976; i: 668-9.","journal-title":"Lancet"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"333","DOI":"10.3109\/00365527909179892","article-title":"The lactutose hydrogen breath test as a diagnostic test for small bowel overgrowth","volume":"14","year":"1979","unstructured":"Rhodes JM, Middleton 0, Jewell DP. The lactutose hydrogen breath test as a diagnostic test for small bowel overgrowth. ScandJ Gastroenterol 1979; 14: 333-6.","journal-title":"ScandJ Gastroenterol"},{"key":"ref_5","first-page":"1058","article-title":"Quantitative measurement of lactulose absorption","volume":"70","year":"1979","unstructured":"Bond JH, Levitt MD. Quantitative measurement of lactulose absorption. Gastroenterology 1979; 70: 1058-62.","journal-title":"Gastroenterology"},{"key":"ref_6","first-page":"119","article-title":"Breath hydrogen in hyposucrosia","volume":"i:","author":"Metz, G.; Jenkins, D.J.A.; Newman, A.; Blendis, L.M.","year":"1976","unstructured":"Metz G, Jenkins DJA, Newman A, Blendis LM. Breath hydrogen in hyposucrosia. Lancet 1976; i: 119-20.","journal-title":"Lancet"},{"key":"ref_7","first-page":"1276","article-title":"Transit of a meal through the stomach, small intestine and colon in normal subjects and its role","volume-title":"the pathogenesis of diarrhoea. Gastroenterology 1980; 79","author":"Read, N.W.; Miles, C.A.; Fisher, D.","unstructured":"Read NW, Miles CA, Fisher D, et al. Transit of a meal through the stomach, small intestine and colon in normal subjects and its role in the pathogenesis of diarrhoea. Gastroenterology 1980; 79: 1276-82."},{"key":"ref_8","first-page":"38","article-title":"Differential transit of liquids and solid residue through the human ileum","volume":"245","author":"Kerlin, P.; Phillips, S.","year":"1983","unstructured":"Kerlin P, Phillips S. Differential transit of liquids and solid residue through the human ileum. Am J Physiol 1983; 245: G38-G43.","journal-title":"Am J Physiol"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"834","DOI":"10.1136\/gut.26.8.834","article-title":"Read NW, Al-Janabi MN, BatesTE, etal. Interpretation of the breath hydrogen profile obtained after ingesting a solid meal containing unabsorbable carbohydrate","volume":"26","year":"1985","unstructured":"Read NW, Al-Janabi MN, BatesTE, etal. Interpretation of the breath hydrogen profile obtained after ingesting a solid meal containing unabsorbable carbohydrate. Gut 1985; 26: 834-42.","journal-title":"Gut"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1349","DOI":"10.1136\/gut.26.12.1349","article-title":"Extraintestinal influences on exhaled breath hydrogen measurements during the investigation of gastrointestinal disease","volume":"26","author":"Thompson, D.G.; Binfield, P.; De Belder, A.; O'Brien, J.; Warren, N.A.; Wilson, M.","year":"1985","unstructured":"Thompson DG, Binfield P, De Belder A, O'Brien J, Warren NA, Wilson M. Extraintestinal influences on exhaled breath hydrogen measurements during the investigation of gastrointestinal disease. Gut 1985; 26: 1349-52.","journal-title":"Gut"}],"container-title":["Gut"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/gut.28.6.721","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T07:04:07Z","timestamp":1765609447000},"score":1,"resource":{"primary":{"URL":"https:\/\/gut.bmj.com\/lookup\/doi\/10.1136\/gut.28.6.721"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1987,6]]},"references-count":10,"journal-issue":{"issue":"6","published-online":{"date-parts":[[1987,6,1]]},"published-print":{"date-parts":[[1987,6]]}},"alternative-id":["10.1136\/gut.28.6.721"],"URL":"https:\/\/doi.org\/10.1136\/gut.28.6.721","relation":{},"ISSN":["0017-5749","1468-3288"],"issn-type":[{"value":"0017-5749","type":"print"},{"value":"1468-3288","type":"electronic"}],"subject":[],"published":{"date-parts":[[1987,6]]}}}