The paper is about the gut-first hypothesis of Parkinson disease (PD), I don’t think the Washington Post sensationalized it that much. And the p-values they find are pretty amazing. P<.001 and still P=.01 after covariate adjustment.
I agree. They know dopamine makes things worse for PD pateints.
My Theory: The reason that Dopamine fails is because they do not have low dopamine, but low energy for the dopamine receptor. The dopamine receptors are G Coupled Protein receptors that need GTP to function. So if you are low in the purine GTP then it does not matter how much dopamine you make.
Giving these patients dopamine works, but then fails, because it depletes the cells of GTP.
Sure. Interesting hypothesis. More research needed.
*edit, for the record, for me, as a postdoc, a hypothesis, while more structured than mere speculation, is still an unproven explanation that requires rigorous testing and peer review before it can be considered established scientific knowledge, and thus remains speculative.
The p-values don't say anything about the size of the effect. With a large sample size, they are almost guaranteed to be small. In fact, the confidence interval after covariate adjustment comes very closing to containing the value 1, which suggests no substantive change between the groups.