Deakin University
Browse

File(s) not publicly available

Plasma measurements of the dual sugar test reveal carbohydrate immediately alleviates intestinal permeability caused by exertional heat stress

Version 2 2024-06-14, 16:53
Version 1 2023-10-06, 04:12
journal contribution
posted on 2024-06-14, 16:53 authored by MJ Houghton, Rhiannon SnipeRhiannon Snipe, G Williamson, RJS Costa
AbstractThe aim of this set of randomised cross‐over 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 l‐rhamnose is measured cumulatively in urine. This follow‐up study exploits our novel high‐performance anion exchange chromatography with pulsed amperometric detection (HPAEC‐PAD) protocol to accurately quantify the sugars in plasma. Endurance‐trained participants completed experimental trial A (ET‐A; n = 8), consisting of 2 h running at 60% in temperate, warm and hot ambient conditions, and/or experimental trial B (ET‐B; n = 9), consisting of 2 h running at 60% in the heat while consuming water, carbohydrate or protein. Blood samples were collected and plasma lactulose (L) and l‐rhamnose (R) appearance, after dual sugar solution ingestion at 90 min of exercise, was quantified by HPAEC‐PAD to measure plasma L/R and reveal new information about intestinal permeability immediately post‐exercise and during recovery. In ET‐A, plasma L/R increased immediately post‐exercise in hot compared with temperate and warm conditions, while, in ET‐B, 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‐PAD at intervals to maximise intestinal permeability data collection in exercise gastroenterology research, as this gives additional information compared to urinary measurements. imageKey points Intestinal permeability is typically assessed using a dual sugar test, by administering a drink containing non‐metabolisable sugars (e.g. lactulose (L) and l‐rhamnose (R)) that can enter the circulation by paracellular translocation when the epithelium is compromised, and are subsequently measured in urine. 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‐exercise recovery period reveals novel acute response information compared to measuring 5‐h cumulative urine L/R. 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. We recommend using our dual sugar absorption test protocol to maximise intestinal epithelial permeability data collection in exercise gastroenterology research and beyond.

History

Journal

Journal of Physiology

Volume

601

Pagination

4573-4589

Location

London, Eng.

ISSN

0022-3751

eISSN

1469-7793

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Issue

20

Publisher

Wiley