I think when people see a difference in modern life versus traditional, and that difference was unexpected and unintended, that in itself is cause for concern. I don't need to believe claims about how important the gut biome is to the brain etc. But I would be surprised if the there weren't some consequence of the difference, and it seems like wishful thinking to suppose, as you do, that the consequences are benign.
I didn’t conclude that the effects are benign. I claimed that this article does nothing to assist me in deciding if they are.
Similarly, global warning is rising temperature, and we are trying hard to model the effects, but it's really all it is: models and guesses. We would much prefer if we could go back to the climate we were familiar with for the past 20,000 years. That one we were starting to understand to some extent. Now all bets are off
Whilst microbiome is a fascinating topic people are quick to lend unsubstantiated pet theories new credence, harboured by the topics nasence and complexity.
Anecdotally, logical fallacy bingo is a great actual game and I recommend everyone play