The human digestive system breaks down and absorbs large-scale protein structures intact
the verdict
REFUTED
the evidence says no
confidence 9/100
Proteins and large-scale structures are broken down into smaller constituent amino acids and peptides by digestive enzymes rather than being absorbed intact, a process requiring specialized delivery systems if intact macromolecules are to cross the intestinal barrier.
Evidence against · 3
Intestinal Absorption of FITC-Dextrans and Macromolecular Model Drugs in the Rat Intestinal Instillation Model
2022 · cited by 23
Highlights that large macromolecules and proteins are susceptible to enzymatic degradation in the intestinal lumen and face strict size exclusion, requiring special permeation enhancers or techniques to achieve limited absorption.
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More against · 2
Development of an in situ small intestinal injection technique for targeted macromolecule delivery and in vivo functional studies in mice.
2026 · cited by 1
Notes that biological macromolecules are highly susceptible to degradation in the gastrointestinal tract and cannot typically survive oral delivery without specialized, invasive delivery techniques.
Oral delivery of biologics: from barrier-limited formulation to active convective transport.
2026 · cited by 0
Explains that the gastrointestinal tract blocks the absorption of proteins and peptides through size exclusion, enzymatic degradation, and barriers that keep oral bioavailability below 1% unless specialized active delivery devices are used.