Scientists analyzed an ancient protein called flagellin, released from the tail of bacteria (known as the flagella), and found that the gut’s neuropods could sense this protein, triggering an appetite-suppressing response. Related Story Your Microbiome Shapes Your Psychedelic TripAnd now, a new study led by scientists at Duke University suggests that there’s yet another sense lurking in our gut. When the same experiment was conducted with mice that lacked the TLR5 receptor, the mice ate their fill and quickly gained weight. This is what the researchers call our “neurobiotic sense,” and it very well could be our sixth sense. The next step for the scientists is to figure out what diets change the microbiome and in what ways.