Enterogenic metabolomics signatures of depression: what are the possibilities for the future.

Introduction: An increasing number of studies indicate that the microbiota-gut-brain axis is an important pathway involved in the onset and progression of depression. The responses of the organism (or its microorganisms) to external cues cannot be separated from a key intermediate element: their metabolites.

Areas covered: In recent years, with the rapid development of metabolomics, an increasing amount of metabolites has been detected and studied, especially the gut metabolites. Nevertheless, the increasing amount of metabolites described has not been reflected in a better understanding of their functions and metabolic pathways. Moreover, our knowledge of the biological interactions among metabolites is also incomplete, which limits further studies on the connections between the microbial-entero-brain axis and depression.

Expert opinion: This paper summarizes the current knowledge on depression-related metabolites and their involvement in the onset and progression of this disease. More importantly, this paper summarized metabolites from the intestine, and defined them as enterogenic metabolites, to further clarify the function of intestinal metabolites and their biochemical cross-talk, providing theoretical support and new research directions for the prevention and treatment of depression.