Probiotics and Nutraceuticals

The field of nutritional psychiatry seeks to expand our understanding of how diet and nutrition influences the risk for psychiatric disorders, including depression. Improved knowledge about these relationships will provide new insights to guide the prevention and treatment of depression. A number of different methodologies trying to quantify how diet, nutrition, and dietary elements may affect mood and the risk for developing depression are detailed in this chapter, including naturalistic studies of diet, specific analysis of dietary elements, and clinical trials using dietary elements as treatments. Dietary elements that are commonly taken used as supplements but are suggested to function in some ways like medication are referred to as nutraceuticals. Those with reasonable support for their use in depression are detailed here, including omega-3 fatty acids. Continued examination of the role of the gut microbiota provides new avenues for treatment development and a deeper understanding of the physiology that underlies depression. Importantly, the gut microbiota is responsive to diet, taking what we eat and turning it into other products, and these byproducts are thought to have an important role in mood regulation. Thus, cultivation or supplementation of important bacterial groups by dietary modulation or probiotics may be new tools for improving depressive symptoms. This chapter will provide a broad perspective on the knowledge of how nutrition influences depression and some emerging probiotic and nutraceutical treatment strategies.