The contribution of the large intestine to energy supplies in man.
Level 5 - mechanism / opinion, no new human data
Narrative review and theoretical estimation based on physiological mechanisms
PubMed 6320630 · doi:10.1093/ajcn/39.2.338
What was done
The author reviewed existing evidence regarding anaerobic carbohydrate fermentation into short-chain fatty acids, their absorption, and subsequent metabolism in the human large intestine, drawing comparisons with herbivore physiology.
What was found
Anaerobic fermentation of carbohydrates in the human colon was estimated to yield short-chain fatty acids providing 5% to 10% of human energy requirements. Additional minor energy contributions were attributed to large intestinal absorption of fat and bacterial breakdown products of protein. No primary trial metrics or exact numbers from clinical cohorts were reported in the abstract.
Why it matters
This review provides an early quantitative framework estimating how colonic bacterial fermentation contributes to human dietary energy supply.
Limits
The abstract describes a narrative review and theoretical estimation rather than a systematic review or primary empirical trial. Sample sizes, dietary intake variables, inter-individual microbiome differences, and estimation methodologies are not provided in the abstract.
Cited by
- supports Short-chain fatty acids produced from fiber fermentation by the gut microbiome can account for around 10% of total dietary energy uptake in some people.