Newly discovered ‘sixth sense’ links gut microbes to the brain in real time (Medical Xpress)

In a landmark study published in Nature, Duke University researchers unveiled a “sixth sense” that allows the brain to respond instantly to gut microbes. This neurobiotic sense operates via neuropods—specialized gut cells that detect flagellin, a microbial protein, and relay appetite-suppressing signals to the brain via the vagus nerve.

Key findings:

• Gut bacteria release flagellin during digestion, which is detected by neuropods using the TLR5 receptor.
  
• This signal rapidly tells the brain to stop eating—a direct microbial influence on behavior.
  
• Mice without the TLR5 receptor did not respond to the flagellin and gained more weight.
  
• The study opens new paths to understand how microbes affect eating, mood, and possibly psychiatric conditions.
  

🧠💡 This discovery adds a new dimension to the gut-brain axis, suggesting behavior can be modulated by microbial signals in real time—not just through immune or hormonal responses.