Innate gut microbiota predisposes to high alcohol consumption

Area of Science:

• Neuroscience
• Microbiology
• Genetics

Background:

• The transfer of gut microbiota from mother to offspring is established.
• High alcohol-drinking rat models offer insights into alcohol consumption mechanisms.

Purpose of the Study:

• To investigate the role of innate gut microbiota in the high alcohol intake of selectively bred rats.
• To explore the microbiota-gut-brain axis in regulating alcohol consumption.

Main Methods:

• Administration of nonabsorbable oral antibiotics to Wistar-derived high-drinker UChB rats.
• Bilateral vagotomy to assess the vagus nerve's role.
• Measurement of voluntary ethanol and saccharin intake.
• Analysis of proinflammatory cytokine gene expression in the gut.

Main Results:

• Antibiotic treatment reduced voluntary ethanol intake by 70%, an effect that persisted after discontinuation.
• Bilateral vagotomy inhibited alcohol intake by 75%.
• Gut microbiota modulation and vagotomy significantly reduced saccharin intake, indicating effects beyond simple fluid consumption.
• Antibiotic administration reduced proinflammatory cytokine expression (TNF-α, IL-6, IL-1β) in the gut.

Conclusions:

• Gut microbiota plays a significant role in mediating alcohol intake in high-drinking rats.
• The vagus nerve acts as a key communication pathway in the microbiota-gut-brain axis influencing alcohol preference.
• Mechanisms normally limiting heavy drinking appear to be impaired in alcohol-preferring animals due to gut microbiota alterations.