Lactobacillus fermentum helps balance the immune system by changing gut bacteria in stressed mice through a specific metabolic pathway

Lactobacillus fermentum (LF) supplementation may decrease proinflammatory cytokines and IDO expression in multiple brain regions.

• Chronic unpredictable mild stress (CUMS) was used to model depression in this study.
• 1-methyl-D-tryptophan (1-MT) and LF were found to modulate the expression of immune-related factors in the brain.
• LF administration restored gut microbial diversity and increased overall community richness.
• Alterations in gut microbiota may influence behavior and neurochemistry related to depression.
• The findings suggest a potential role for LF in mitigating neuroinflammatory changes associated with mood disorders.

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