Recent research has been pointing to the gut as ground zero for mental and physical wellness. Local health professionals weigh in. MOST OF US KNOW that a healthy diet, exercise and adequate sleep are essential for optimal health. Recently, however, more and more research has been pointing to the gut itself as ground zero for wellness, both physical and mental. But what, exactly, is a healthy gut? Why does it matter, and what does it have to do with our mental well-being?