Gut & microbiome
Only a small fraction becomes serotonin; most runs down the kynurenine pathway.
Not yet investigated
Only a small fraction becomes serotonin; most runs down the kynurenine pathway.
This star is on the map because the show intends to take the question apart properly — the trials, how it is actually tested, whether the thing sold is the thing studied. That work is not done yet, and nothing here should be read as a conclusion. When the investigation is published it will appear on this page.
What we are reading
Gathered for the investigation and not yet written up. Each note says what the paper does and does not show.
Narrative review — the weakest review type, so treat as a map rather than evidence. The map itself is the point: one amino acid feeds two pathways that pull in opposite directions, and inflammation shifts the traffic from the serotonin branch toward kynurenine. That is the mechanistic bridge between 'inflammation' and 'low mood' that most popular accounts skip.
Connected on the map
Also in Gut & microbiome
The letter
The full citation list for each investigation, the studies that didn't make the episode, and any corrections — sent the morning it publishes.
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