Probiotics vs Omega-3
for mood
Stronger evidence: tie
Stronger effect: Omega-3
Safety: Omega-3 carries a serious interaction; Probiotics has none recorded.
For mood, the two are evidence-matched; the difference is in effect and safety.
Probiotics
grade C low certainty
small effects on mood/anxiety in some "psychobiotic" trials; strain-specific, heterogeneous
strain-dependent, adults
Omega-3
grade C moderate certainty
small benefit for depressive symptoms, clearest with higher-EPA formulations
1–2 g EPA, adults with depression
sources: PMID:42221774 · PMID:20000102