{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T12:45:20Z","timestamp":1786711520815,"version":"build-2736575974"},"reference-count":43,"publisher":"Wiley","issue":"20","license":[{"start":{"date-parts":[[2023,9,11]],"date-time":"2023-09-11T00:00:00Z","timestamp":1694390400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["physoc.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["The Journal of Physiology"],"published-print":{"date-parts":[[2023,10]]},"abstract":"<jats:sec><jats:title>Abstract<\/jats:title><jats:p>The aim of this set of randomised cross\u2010over studies was to determine the impact of progressive heat exposure and carbohydrate or protein feeding during exertional stress on small intestine permeability using a dual sugar test. In our previous work, and typically in the field, recovery of lactulose and <jats:sc>l<\/jats:sc>\u2010rhamnose is measured cumulatively in urine. This follow\u2010up study exploits our novel high\u2010performance anion exchange chromatography with pulsed amperometric detection (HPAEC\u2010PAD) protocol to accurately quantify the sugars in plasma. Endurance\u2010trained participants completed experimental trial A (ET\u2010A; <jats:italic>n<\/jats:italic>\u00a0=\u00a08), consisting of 2\u00a0h running at 60%  in temperate, warm and hot ambient conditions, and\/or experimental trial B (ET\u2010B; <jats:italic>n<\/jats:italic>\u00a0=\u00a09), consisting of 2\u00a0h running at 60%  in the heat while consuming water, carbohydrate or protein. Blood samples were collected and plasma lactulose (L) and <jats:sc>l<\/jats:sc>\u2010rhamnose (R) appearance, after dual sugar solution ingestion at 90\u00a0min of exercise, was quantified by HPAEC\u2010PAD to measure plasma L\/R and reveal new information about intestinal permeability immediately post\u2010exercise and during recovery. In ET\u2010A, plasma L\/R increased immediately post\u2010exercise in hot compared with temperate and warm conditions, while, in ET\u2010B, carbohydrate alleviated this, and this information was otherwise missed when measuring urine L\/R. Consuming carbohydrate or protein before and during exercise attenuated small intestine permeability throughout recovery from exertional heat stress. We recommend using the dual sugar test with quantification of plasma sugars by HPAEC\u2010PAD at intervals to maximise intestinal permeability data collection in exercise gastroenterology research, as this gives additional information compared to urinary measurements.\n<jats:boxed-text content-type=\"graphic\" position=\"anchor\"><jats:graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mimetype=\"image\/png\" position=\"anchor\" specific-use=\"enlarged-web-image\" xlink:href=\"graphic\/tjp15721-gra-0001-m.png\"><jats:alt-text>image<\/jats:alt-text><\/jats:graphic><\/jats:boxed-text><\/jats:p><\/jats:sec><jats:sec><jats:title>Key points<\/jats:title><jats:p><jats:list list-type=\"bullet\">\n<jats:list-item><jats:p>Intestinal permeability is typically assessed using a dual sugar test, by administering a drink containing non\u2010metabolisable sugars (e.g. lactulose (L) and <jats:sc>l<\/jats:sc>\u2010rhamnose (R)) that can enter the circulation by paracellular translocation when the epithelium is compromised, and are subsequently measured in urine.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>We demonstrate that our recently developed ion chromatography protocol can be used to accurately quantify the L\/R ratio in plasma, and that measuring L\/R in plasma collected at intervals during the post\u2010exercise recovery period reveals novel acute response information compared to measuring 5\u2010h cumulative urine L\/R.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>We confirm that exercising in hot ambient conditions increases intestinal epithelial permeability immediately after exercise, while consuming carbohydrate or protein immediately before and during exercise attenuates this.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>We recommend using our dual sugar absorption test protocol to maximise intestinal epithelial permeability data collection in exercise gastroenterology research and beyond.<\/jats:p><\/jats:list-item>\n<\/jats:list><\/jats:p><\/jats:sec>","DOI":"10.1113\/jp284536","type":"journal-article","created":{"date-parts":[[2023,9,11]],"date-time":"2023-09-11T13:26:25Z","timestamp":1694438785000},"page":"4573-4589","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["Plasma measurements of the dual sugar test reveal carbohydrate immediately alleviates intestinal permeability caused by exertional heat stress"],"prefix":"10.1113","volume":"601","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6579-7995","authenticated-orcid":false,"given":"Michael J.","family":"Houghton","sequence":"first","affiliation":[{"name":"Department of Nutrition, Dietetics and Food, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences Monash University  Notting Hill Victoria Australia"},{"name":"Victorian Heart Institute Monash University  Clayton Victoria Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rhiannon M. J.","family":"Snipe","sequence":"additional","affiliation":[{"name":"Centre for Sport Research, School of Exercise and Nutrition Sciences Deakin University  Burwood Victoria Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gary","family":"Williamson","sequence":"additional","affiliation":[{"name":"Department of Nutrition, Dietetics and Food, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences Monash University  Notting Hill Victoria Australia"},{"name":"Victorian Heart Institute Monash University  Clayton Victoria Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3069-486X","authenticated-orcid":false,"given":"Ricardo J. S.","family":"Costa","sequence":"additional","affiliation":[{"name":"Department of Nutrition, Dietetics and Food, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences Monash University  Notting Hill Victoria Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2023,9,11]]},"reference":[{"key":"e_1_2_5_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.wem.2018.06.004"},{"key":"e_1_2_5_3_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41596-022-00736-0"},{"key":"e_1_2_5_4_1","doi-asserted-by":"publisher","DOI":"10.3390\/foods10081939"},{"key":"e_1_2_5_5_1","doi-asserted-by":"publisher","DOI":"10.1152\/ajpgi.00266.2018"},{"key":"e_1_2_5_6_1","doi-asserted-by":"publisher","DOI":"10.1186\/s12876-014-0189-7"},{"key":"e_1_2_5_7_1","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.01032.2018"},{"key":"e_1_2_5_8_1","doi-asserted-by":"publisher","DOI":"10.1080\/23328940.2019.1597676"},{"key":"e_1_2_5_9_1","doi-asserted-by":"publisher","DOI":"10.1139\/apnm-2016-0453"},{"key":"e_1_2_5_10_1","doi-asserted-by":"publisher","DOI":"10.1111\/apt.14157"},{"key":"e_1_2_5_11_1","doi-asserted-by":"publisher","DOI":"10.1123\/ijsnem.2022-0048"},{"key":"e_1_2_5_12_1","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1974.37.2.247"},{"key":"e_1_2_5_13_1","doi-asserted-by":"publisher","DOI":"10.3758\/BRM.41.4.1149"},{"key":"e_1_2_5_14_1","doi-asserted-by":"publisher","DOI":"10.1093\/clinchem\/42.3.445"},{"key":"e_1_2_5_15_1","doi-asserted-by":"publisher","DOI":"10.1139\/apnm-2020-0118"},{"key":"e_1_2_5_16_1","doi-asserted-by":"publisher","DOI":"10.3389\/fphys.2021.719142"},{"key":"e_1_2_5_17_1","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0000000000002546"},{"key":"e_1_2_5_18_1","doi-asserted-by":"publisher","DOI":"10.1139\/apnm-2019-0187"},{"key":"e_1_2_5_19_1","first-page":"114","article-title":"Circulatory endotoxin concentration and cytokine profile in response to exertional\u2010heat stress during a multi\u2010stage ultra\u2010marathon competition","volume":"21","author":"Gill S. K.","year":"2015","journal-title":"Exercise Immunology Review"},{"key":"e_1_2_5_20_1","doi-asserted-by":"publisher","DOI":"10.1155\/2012\/356895"},{"key":"e_1_2_5_21_1","doi-asserted-by":"publisher","DOI":"10.2174\/187221310791163080"},{"key":"e_1_2_5_22_1","doi-asserted-by":"publisher","DOI":"10.1111\/pedi.12865"},{"key":"e_1_2_5_23_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00421-018-3996-7"},{"key":"e_1_2_5_24_1","doi-asserted-by":"publisher","DOI":"10.3389\/fped.2022.874116"},{"key":"e_1_2_5_25_1","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0000000000001800"},{"key":"e_1_2_5_26_1","doi-asserted-by":"publisher","DOI":"10.1053\/j.gastro.2021.04.020"},{"key":"e_1_2_5_27_1","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00452.2019"},{"key":"e_1_2_5_28_1","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.2001.90.6.2075"},{"key":"e_1_2_5_29_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.PCC.0000175990.72753.97"},{"key":"e_1_2_5_30_1","doi-asserted-by":"publisher","DOI":"10.1006\/jsre.2000.5862"},{"key":"e_1_2_5_31_1","doi-asserted-by":"publisher","DOI":"10.1111\/nmo.14382"},{"key":"e_1_2_5_32_1","doi-asserted-by":"publisher","DOI":"10.1139\/apnm-2016-0646"},{"key":"e_1_2_5_33_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00421-017-3744-4"},{"key":"e_1_2_5_34_1","doi-asserted-by":"publisher","DOI":"10.3389\/fphys.2021.773054"},{"key":"e_1_2_5_35_1","doi-asserted-by":"publisher","DOI":"10.1055\/s-2004-820957"},{"key":"e_1_2_5_36_1","doi-asserted-by":"publisher","DOI":"10.3748\/wjg.v23.i48.8452"},{"key":"e_1_2_5_37_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0099256"},{"key":"e_1_2_5_38_1","doi-asserted-by":"publisher","DOI":"10.3390\/metabo12040302"},{"key":"e_1_2_5_39_1","doi-asserted-by":"publisher","DOI":"10.1139\/apnm-2017-0361"},{"key":"e_1_2_5_40_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00421-017-3781-z"},{"key":"e_1_2_5_41_1","doi-asserted-by":"publisher","DOI":"10.1055\/s-0043-122742"},{"key":"e_1_2_5_42_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.clnu.2012.06.014"},{"key":"e_1_2_5_43_1","doi-asserted-by":"publisher","DOI":"10.14814\/phy2.14945"},{"key":"e_1_2_5_44_1","doi-asserted-by":"publisher","DOI":"10.1042\/BSR20181704"}],"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/JP284536","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,13]],"date-time":"2023-10-13T09:24:18Z","timestamp":1697189058000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/JP284536"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,9,11]]},"references-count":43,"journal-issue":{"issue":"20","published-print":{"date-parts":[[2023,10]]}},"alternative-id":["10.1113\/JP284536"],"URL":"https:\/\/doi.org\/10.1113\/jp284536","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,9,11]]},"assertion":[{"value":"2023-02-15","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-08-18","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-09-11","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}