Dendritic cells play a key role in the mammalian immune system. These cells are present throughout the human body and are known to capture foreign bodies, or antigens, using extendable "arms" called dendrites. Once captured, dendritic cells present these substances to immune T cells, thereby initiating an immune response. Dendritic cells are responsive to their environment. For instance, dendritic cells in the intestine's mucosa (inner layer) capture harmful bacteria by extending their dendrites through the epithelium (outermost layer) and into the intestinal lumen (inner space). Researchers found short-chain fatty acids (SCFAs) produced by intestinal bacteria are responsible for initiating the...