Can a gut antibiotic ease stress depression in adolescent rats?
In 56 adolescent rats, 150 mg/kg rifaximin during 4 weeks of CUMS restored sucrose preference, open-field and water-maze performance, raised Ruminococcaceae/Lachnospiraceae and brain butyrate, and shifted microglia toward anti-inflammatory functions.
Source
Rifaximin-mediated gut microbiota regulation modulates the function of microglia and protects against CUMS-induced depression-like behaviors in adolescent rat
Study at a glance
- Design
- Animal / in-vitro — Adolescent rats: 4-week CUMS ± 150 mg/kg oral rifaximin; 16S microbiota, SCFAs, microglia, hippocampal neurogenesis, and depression-like tests
- N
- N=56 · 56 three-week-old rats; n = 14 in CON, CON+R, CUMS, and CUMS+R
- Population
- Adolescent rats (started at 3 weeks) under chronic unpredictable mild stress
- Outcome
- Depression-like and cognitive behavior, fecal microbiome, brain/serum SCFAs, microglial phenotype, hippocampal neurogenesis
Structured fields used in claim comparison tables when every cited study has a complete layer.
What they did
Randomized 3-week-old rats (n = 14/group) to control ± rifaximin or CUMS ± rifaximin for 4 weeks (150 mg/kg i.g.), then ran SPT, open field, and Morris water maze plus 16S, SCFAs, and hippocampal microglia/neurogenesis assays.
What they found
Rifaximin improved CUMS depression-like and maze behavior, increased Ruminococcaceae and Lachnospiraceae (positively correlated with brain butyrate), raised anti-inflammatory microglial factors, and prevented CUMS neurogenic abnormalities.
The limits
What it doesn't show
Rat CUMS plus a poorly absorbed antibiotic is not a clinical depression trial; rifaximin is not shown to treat human adolescent MDD, and n = 14/group is modest.
Key terms
- Rifaximin
- Poorly absorbed antibiotic given here at 150 mg/kg to remodel gut microbiota.
- CUMS
- Chronic unpredictable mild stress used to induce depression-like behavior.
- Ruminococcaceae / Lachnospiraceae
- Butyrate-associated gut families that rose with rifaximin.
- SCFA / butyrate
- Short-chain fatty acids; brain butyrate tracked the enriched taxa.
- Microglia
- CNS immune cells whose anti-inflammatory output increased with rifaximin.
- Morris water maze
- Spatial memory task improved alongside SPT and open field.
Flashcards
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Total rats numbered:
Common questions
How many rats?
56 (n = 14 in each of four groups).
Rifaximin dose/duration?
150 mg/kg intragastric during 4 weeks of CUMS.
Which taxa increased?
Ruminococcaceae and Lachnospiraceae.
Which SCFA tracked those taxa?
Brain butyrate.
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