Condition of chronic stress {51111182}

Shared Reference Notes

• [1.1] 
  - A condition of chronic stress induced in mice reduced Lactobacillus, Eubacterium rectale, Lachnospira, Butyricicoccus, Sutterella, and Faecalibacteria and increased the number of pathogenic species Clostridium, Proteobacteria, Actinobacteria, and Enterobacteriaceae.
• [1.2] [#Crohn’s disease] 
  - Stress-exposed mice > develop ileal dysbiosis, dominated by the expansion of #Enterobacteriaceae. - Stress-induced glucocorticoids promote > apoptosis of CD45+CD90+ cells that normally produce #IL-22, a cytokine that is essential for the maintenance of ileal mucosal barrier integrity. - Blockade of glucocorticoid signaling or administration of recombinant #IL-22 > restores mucosal immunity, prevents ileal dysbiosis.
• [1.3] [#Lipopolysaccharide] [#Antibiotic Therapy] 
  - stressor exposed mice had significantly altered community structure of their gut microbiota, with decreased abundance of the genus #Bacteroides and increased abundance of the genus #Clostridium. This was accompanied by increased circulating levels of IL-6 and monocyte chemoattractant protein 1 (MCP-1). - In a follow-up experiment, animals were fed an antibiotic cocktail in the morning and evening by oral gavage, beginning three days before the stressor and continuing to the end of the experiment. Antibiotic treatment prevented the increases in IL-6 and MCP-1. - mice receiving the stressor had elevated hepatic portal blood levels of LPS (from the gastrointestinal draining vein) and elevated mRNA expression of IL-1β, IL-6, and TNF in the hypothalamus, though no changes in circulating cytokines. Pretreatment with L. farciminis, antibiotics, and ML-7 all prevented these increases.
• [#Limosilactobacillus (Lactobacillus) reuteri] - chronic stress was connected with increased #Depression-like behavior (as measured by the forced swim test), reduced Lactobacillus spp. in the fecal microbiome, as well as increased circulating levels of #kynurenine, a direct metabolite of #Tryptophan via the enzyme IDO1. - supplemented the diet of the mice with L. reuteri ATCC 23272 for an additional 4 weeks, which was sufficient to reverse behavior and #kynurenine concentrations. - The reversal of #Depression-like behaviors was diminished if #kynurenine levels were artificially elevated during probiotic supplementation, suggesting a link between #kynurenine signaling and #Depression-like behavior.
• [1.4] 
  - in a model of chronic unpredictable mild stress, #Ferulic acid ameliorated depressive-like behaviors possibly through the upregulation of #BDNF, postsynaptic protein PSD95 levels, and synapsin I in the prefrontal cortex and hippocampus
• [1.5] [#Western-style diet] 
  - the relative abundance of the parabiont genus #Eisenbergiella has been reported to be decreased by a Western style diet and increased in a model of stress in rats as well as in #Adult male #Athletes
• [1.6] 
  - stressed animals had a decrease in the abundance of #Lactobacillus after stress and continued with many groups showing that oral administration of a #Lactobacillus #Probiotic can alleviate the #Anxiety- and #Depression-like behavior in a multitude of models
• [#Anxiety] - increased #Secondary bile acids and reduced #Cholic acid in the serum of ex-germ free mice exposed to fecal material from stressed mice
• [#Lactobacillus intestinalis, #Lactobacillus murinus] - L. intestinalis and L. murinus are indeed driving IFNγ production - likely via antigen presentation and not due to direct pattern recognition receptor activation. - IFNγ produced in response to Lactobacillus is sufficient to provide resilience in response to environmental stressors. - astrocytes and premyelinating oligodendrocytes also have IFNγ receptors, indicating that there may be several responding cell types in the brain - meningeal sources of IFNγ can act directly on neuronal IFNγ receptors to promote the normal development of social behavior

References Notes