I know that eating helpful gut bacteria (acidophilus, for example, found in active yogurt cultures) helps our digestion work at its best, and can improve our immune function, but little did I know that scientists are studying the effect of healthy gut bacteria on emotional resilience and mood. It turns out that good gut bacteria seem to work with the function of the Vagas Nerve, the nerve that links the brain to the digestive tract, to stimulate positive emotional function. (Check out a brief intro to this amazing nervous system giant here: Vagas Nerve.)
In mice, this connection made mice more resilient in the face of stress and able to persist in difficult circumstances far beyond their "normal" peers. There is more than some suggestion that human emotions and mental health could be lifted by additions of pro-biotics into the daily diet. Jamie Lee Curtis (Activia!) may be absolutely right: adding yogurt or other pro-biotic supplements can make you a happier, healthier person overall.
If you struggle with mood, energy, and lethargy, it may be worth your while to give daily yogurt or a pro-biotic supplement a try.
If you'd like to hear more about this research, listen to this episode of the science radio program, RadioLab, entitled, "Guts." (The research about the mice is around the halfway mark if you'd like to cut to the chase.) The whole program is amazing.