Duke Scientists Discover Gut-Brain Neural ‘Sixth Sense’ Influencing Appetite

Scientists at Duke University have discovered a new 'sixth sense' called the neurobiotic sense, which allows the brain to receive real-time signals from gut microbes to regulate appetite and potentially influence behavior and emotional states. This system involves specialized gut cells called neuropods that detect a bacterial protein called flagellin using the TLR5 receptor and immediately send signals to the brain via the vagus nerve. Experiments showed that mice receiving flagellin ate less, while mice lacking the TLR5 receptor failed to respond and gained weight, highlighting the gut’s direct role in controlling food intake. Researchers suggest this gut-brain communication could also impact mood, anxiety, and depression, indicating a broader influence of the microbiome on mental health. The findings open new avenues for understanding how microbial activity in the gut affects not only eating behavior but also overall well-being. This discovery challenges traditional views of the gut as solely a digestive organ and positions it as an active participant in brain function and behavior regulation.