The hippocampus is to your brain just as the keyboard is to the computer's hard drive. The hippocampus is not where your memories are stored. But you depend on it to store memories.
Recently I read that our digestive tract have more neurons than a domestic cat has in its whole brain. So when I read that microbes in our guts may be controlling the moods we experience in our brains, it came as not such a surprise. The particular strain of microbes in your gut may be responsible for emotional health as well as your physical health. They may determine your sense of fear or anxiety or relaxation and calm. Stephen Collins, McMaster University, Canada, was the first to make this connection, in his studies on rats. Research is being done on humans now, by UCLA's Center for Neurobiology of Stress, Emeran Mayer, M.D.