Intraluminal pH of the human gastrointestinal tract.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic methodology
What was done
This narrative review synthesized methodologies for measuring human gastrointestinal pH (intubation vs. radiotransmitting capsules), established regional luminal pH profiles in healthy adults and children, and evaluated alterations caused by intestinal resection, gastrointestinal diseases (chronic pancreatitis, cystic fibrosis, inflammatory bowel disease), diet, and medications.
What was found
In healthy subjects, intraluminal pH transitions from highly acidic in the stomach to approximately pH 6 in the duodenum, progressively increasing to about pH 7.4 in the terminal ileum. Colonic pH sharply drops to 5.7 in the caecum and gradually rises to 6.7 in the rectum. Children demonstrate an identical pH profile. Ileocaecal resection increases proximal colonic pH and shortens small intestinal transit time, while colon resection with ileostomy does not alter remaining gut pH. Chronic pancreatitis and cystic fibrosis lower proximal small intestinal pH, and severe active ulcerative colitis and Crohn's disease are associated with very low colonic pH.
Why it matters
Understanding baseline gastrointestinal pH and disease-specific deviations is critical for formulating pH-dependent oral controlled-release drug delivery systems and predicting drug absorption.
Limits
The abstract describes a narrative review with no systematic search criteria, quality appraisal of included studies, total participant counts, or statistical variance (e.g., standard deviations or ranges) reported for the cited pH values.
Cited by
- context Blood pH is slightly alkaline, the stomach is highly acidic, the large intestine is acidic, and the small intestine is alkaline.