Table 2.

Challenges in Nutritional Psychiatry.

Challenges
Poor translatability of preclinical findings into human psychiatric diseases due to heterogeneity of human study populations, confounding environmental factors and significant interspecies differences in brain structure and function.
Paucity of high quality RCT showing diet-induced normalization of disease-associated dysbiosis causally related to clinical improvements.
Detailed and standardized characterization of the gut microbiome down to the strain level, and functional characterization using shotgun metagenomics, meta-transcriptomics and metabolomics has only been used in a minority of recent studies.
Methodological limitations in assessing dietary habits using questionnaires and interviews
Implementation of and adherence to a standardized diet over long periods of time has been challenging.