We as medical practitioners frequently prescribe enzymatic preparations like Trypsin-Chymotrypsin, which actually are proteins. Often I wonder how come a protein gets absorbed undigested, through our intestine, and reaches the site of its action (inflamed tissues)? After all we have been taught in biochemistry & physiology that protein, before getting absorbed, must be broken down into its constituent amino acids.

  • $\begingroup$ Is it actually absorbed, or does it act locally within the digestive tract? $\endgroup$ Mar 25, 2022 at 20:50
  • $\begingroup$ @DrMoishePippik. I think you are referring to enzymes like PANCREATIN which are used solely as digestive enzyme medicine.Yes pancreatin is intended and in fact does act locally inside the intestine. But TRYPSIN-CHYMOTRYPSIN type of preparations which , although may be used as digestive enzyme to act locally, are more commonly used with an intent to reduce inflammation at post surgical or traumatic wounds. I wonder how on earth an enzyme , taken orally , can bypass the digestive degradation to amino acids and reach the distant sites of inflammation, say in our limbs? $\endgroup$ Mar 26, 2022 at 1:17
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    $\begingroup$ This question is about physiology but with a healthy dose of biochemistry, so probably ok for the site although better suited for biology SE. However, it would be much improved with citations to sources. $\endgroup$
    – Buck Thorn
    Mar 26, 2022 at 7:09
  • $\begingroup$ I’m closing this question because it’s not about chemistry. $\endgroup$ Mar 26, 2022 at 11:39
  • $\begingroup$ There is no biochemistry involved in this question. It’s physiology and medicine. $\endgroup$ Mar 26, 2022 at 11:40

1 Answer 1


Too long for a comment:

In order for a protein to be absorbed, two things are required: (1) It needs to reach the absorption sites of the gut intact; and (2) It must be able to pass through the intestinal lining.

Gerhard Lorkowski [1] claims "Due to enteric coating, degradation of the protein structure to single amino acids or peptides in the acidic environment of the stomach is reduced." and "Research has confirmed that peptides and larger protein molecules pass through the mucosal barrier of the gastrointestinal tract."

The first claim is plausible to me. I don't know about the second. It's intriguing, but Lorkowski didn't provide any references to support it.

I'd recommend asking this question on Biology SE. You can relate what Lorkowski wrote as a starting point.

[1] Lorkowski, Gerhard. “Gastrointestinal absorption and biological activities of serine and cysteine proteases of animal and plant origin: review on absorption of serine and cysteine proteases.” International Journal of Physiology, Pathophysiology and Pharmacology, vol. 4,1 (2012): 10-27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3312459/


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