I'd read that people with low mood tend to be depleted in butyrate-producing bugs like Coprococcus and Dialister. A fermented drink is not a fix for anything, but it gave me something concrete to try alongside the rest of what I was already doing: feed the bugs that seem to go missing. I started counting plant varieties — aiming for 30+ a week — and added kefir most mornings. I tracked mood 1-5 every day. The first two weeks: nothing. Around week four my mornings stopped feeling like wading through wet sand, and my logged mood drifted from a flat 2 to a 3-4. Correlation, not proof. But watching my own line move kept me consistent when motivation didn't.