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Intestinal gas homeostasis: disposal pathways.
M Mego1, A Bendezú1, A Accarino1
1Digestive System Research Unit, University Hospital Vall d'Hebron, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.
Neurogastroenterology and Motility
|January 13, 2015
Summary
Most intestinal gas is absorbed or metabolized, not expelled. Only 23% of gas produced by gut fermentation is eliminated via the anus, impacting functional gut disorder symptoms.
Area of Science:
- Gastroenterology
- Human Physiology
- Microbiology
Background:
- Functional gut disorders often involve gas-related symptoms, but intestinal gas homeostasis is poorly understood.
- The pathways for intestinal gas elimination are not fully elucidated.
- Understanding gas dynamics is crucial for interpreting symptoms in gastrointestinal conditions.
Purpose of the Study:
- To quantify the proportion of endogenously produced intestinal gas eliminated via the anus versus alternative pathways.
- To investigate the role of exogenous gas infusion in measuring endogenous gas production and elimination.
- To clarify intestinal gas homeostasis in healthy individuals.
Main Methods:
- Healthy subjects underwent a flatulogenic meal test.
- Exogenous gas (5% SF6) was infused into the jejunum at a high rate (24 mL/min) in paired studies to 'wash-out' endogenous gas.
- Gas evacuated per anus was collected over 4 hours to calculate the proportion of endogenous gas eliminated.
Main Results:
- Over 1800 mL of endogenous gas was produced in 4 hours during wash-out experiments.
- Under basal conditions, only 376 mL of gas was evacuated per anus.
- This indicates that only 23% of produced gas is eliminated anally, with 77% utilizing alternative pathways.
Conclusions:
- Intestinal gas homeostasis is dynamic, involving rapid absorption and microbial metabolism.
- A significant majority of gas produced by colonic fermentation is not eliminated rectally.
- These findings help explain the pathophysiology of gas-related symptoms in functional gut disorders.
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