[simplotek]

> It's a breakthrough but this research doesn't establish the claim in the title of the article.

What claim would that be? The only claims made in the article was that a) it's a breakthrough, and b) "Researchers say certain strains of gut bacteria are the likely cause of Parkinson's disease."

The article also refers to the bacterias as "probable causes".

Everything you pointed out supports these observations.

[brookst]

“Associated with” would have been a stronger claim than “probable cause of”.

[fsckboy]

> “Associated with” would have been a stronger claim

in English, "stronger claim" has a meaning ambiguous between "the claim is strongly defendable, i.e. more likely to be true", and "what is being claimed is of more powerful effect". I think here the claim they are trying to point out is the powerful effect, to say "this should be pursued, its importance is elevated by its potential strong causal/explanatory effect"

[simplotek]

"probable cause" means the same thing as "associated with", but establishes a specific hypothesis and stresses the fact that it is yet to be verified.

[byyyy]

No. Causation is different from correlation. "Associated with" means correlation, "probable cause" means causation. Causation is the stronger statement here.

While technically association is a prerequisite for causation (correlation doesn't imply causation but causation implies correlation) probable "cause" is too strong of a term here because the experiment didn't actually do a causative test. "Possible cause" might be better here because the title heavily implies a causative study was done.

Do note that in science nothing can be proven so in actuality probable cause is really the highest form of verification that can be made. That is the claim in the title.