Lipid A is a component of the outer membrane of Gram-negative bacteria. It is a type of lipid that forms part of the lipopolysaccharide (LPS) structure, which is crucial for the bacteria's integrity and protection. Lipid A anchors the LPS to the bacterial membrane and plays a significant role in the immune response of the host. When Lipid A is released into the body, it can trigger strong immune reactions, leading to inflammation. This can be beneficial in fighting infections but may also contribute to severe conditions like septic shock if the response is excessive. Understanding Lipid A is important for developing treatments against bacterial infections.