While studying the brain-gut axis, scientists focused on neuropods—sensory cells lining the colonic epithelium. It turned out that these cells detect the bacterial protein flagellin and quickly transmit a signal to the brain indicating sufficient food, according to Science Daily. This mechanism, known as the neurobiotic sense, controls appetite.
Further experiments demonstrated that neuropods recognize the protein via the TLR5 receptor, transmitting a signal through the vagus nerve. Without TLR5, communication is disrupted and the satiety signal fails.
"Blocking this signaling pathway altered the eating habits of mice. Thus, we see a deeper connection between the gut microbiota and behavior," the authors stated. They now want to understand how certain diets alter the microbiota and what impact this has on the risk of developing mental disorders and obesity.
Investigating the signaling properties of the brain-gut axis is crucial for better understanding human physiology. For example, scientists recently discovered how the brain monitors the gut. This discovery also makes an important contribution to the study of eating behavior and the treatment of disorders.
