adam_scholl's Shortform

I was surprised to find a literature review about probiotics which suggested they may have significant CNS effects. The tl;dr of the review seems to be: 1) You want doses of at least or CFU, and 2) You want, in particular, the strains B. longum, B. breve, B. infantis, L. helveticus, L. rhamnosus, L. plantarum, and L. casei.

I then sorted the top 15 results on Amazon for "probiotic" by these desiderata, and found that this one seems to be best.

Some points of uncertainty:

  • Probiotic manufacturers generally don't disclose the strain prop
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Turns out there's an app (Apple, Android) which compiles evidence from 179 studies on probiotics, ranks them by strength of evidence (study design, etc.) then suggests the most evidence-supported probiotic for a given "indication" (allergies, IBS, etc.). The only available CNS-related indication is "Mood/Affect", though, and the review described in the OP isn't included in the study database, nor were any of the three studies included in that review that I spot-checked. But the two strains it recommends for mood/affect (b. lon... (read more)

4Connor_Flexman5moI was initially very concerned about this but then noticed that almost all the tested secondary endpoints were positive in the mice studies too. The human studies could plausibly still be meaningless though. Has anyone (esp you Jim) looked into fecal transplants for this instead, in case our much longer digestive system is a problem?
5Adam Scholl5moI agree the effect is consistent enough that we should be suspicious of file drawer/p-hacking—although of course that's also what you'd expect to see if the effect were in fact large—but note that they were different studies, i.e. the human studies mostly weren't based on the non-human ones.

adam_scholl's Shortform

by Adam Scholl 12th Aug 20199 comments