Crazy to me that they are now finding out why an approved drug is helping people. Kind of backwards when you think about it.
I think you have it wrong. Possibly the science writer led you astray. The primary effect of the drug is to target a chemical messenger in the immune system. All of the biologics either block the upregulation of inflammation or the downregulation. While new details can always be uncovered, the effect of the drug on interleukins and immune cells is well understood.
Previously the effect on epithelial cells was not clear. I am still not sure it is clear. They do not demonstrate a direct effect such as byutrate fermentation has on epithelial healing, but rather that epithelial healing is clearly associated with the drug. This might be a secondary effect. The body's innate healing mechanisms get some traction once the inflammation is blocked.
Whatever the deficiencies of the science writer aside, it is a bit of a passive aggressive indictment to comment (incorrectly it turns out) how surprising they are only now figuring out how an approved drug is helping people.
And confusion about
the primary and secondary therapeutic targets aside, approved drugs that help for unknown reasons come to market all the time. Basic research discovers the why of how a drug help. Med approval research only seeks to establish that it is effective and safe.
Aspirin was approved for decades before we had any real inkling of how it actually suppressed pain and fever. Often drugs for one disease leads to the medical community noticing that people receiving the drug do better if they get another disease. So, a kidney drug become approved as a pancreas drug or some such.
Now I wish we lived in a society where there was so much funding for basic research, and where our youth were not lagging far behind youths in other countries in science and math. I wish that when a clinical study shows some benefit on a new target (e.g., epithelial cells) that basic research is so well staffed and funded that it can say in a matter of months exactly why it has that newly discovered benefit. But sadly, we live in this world where science is suspect, research funding starves while weapons are mass produced. The short of it is that is is not a problem or surprising if a clinical trial confirms an immune modulating drug has a demonstrable benefit on a non-immune target like epithelial cells.