Table 3.

Future directions in Nutritional Psychiatry.

Clinical implications/future directions
Until an objective’s therapeutic benefits of specific dietary interventions have clearly been established, effective treatments are limited to the general recommendation of a healthy, largely plant-based diet with high variety of fruit and vegetables, or a ketogenic diet in some instances.
Results from high quality RCTs demonstrating benefits beyond adherence to a largely plant based (“microbiome-friendly”) diet by the intake of supplementary pre-, pro- or postbiotics are currently not available.
Potential therapeutic benefits of fecal microbial transplants in brain disorders, mimicking such effects previously reported in animal models, and in human C difficile colitis has generally not been successful, with the exception of an uncontrolled study in ASD (Kang et al., 2017; Kang et al; 2019). Confirmation of these findings in an RCT is essential before recommending in as an effective treatment for ASD. Reported studies about therapeutic benefits of fecal microbial transfer in patient populations for other psychiatric conditions have recently been reviewed with mixed results (Chinna Meyyappan et al., 2020).