Annika Zhang

The association between the gut microbiome and depression

Started June 6, 2025

Abstract or project description

280 million people suffer from depression worldwide. Many people who suffer from depression experience digestive problems that are associated with alterations in the gut microbiome, such as less diversity and more harmful species within the gut microbiome. However, there have been mixed findings regarding the link between depression and the gut microbiome, which make it difficult to understand the precise nature of this association. The purpose of this review is to synthesize current knowledge regarding the relationship between gut microbiota and depression. Specifically, this review discusses studies examining the relationship between the gut microbiome and depression in terms of specific taxa (e.g., Bifidobacterium, Lactobacillus), the mechanisms and processes that take place along the microbiota-gut-brain-axis, the role of stress on the gut microbiome and depression, as well as treatment options (e.g., antidepressants, probiotics) for individuals suffering from depression with gut-related symptoms. Finally, this review discusses limitations of current work and recommendations for future research. This review found that there was a large amount of evidence that gut microbiota was related to depression, but additional research is needed to elucidate causal mechanisms. Disentangling the complex relationship between the gut microbiome and depression is critical for enhancing risk identification, tailored interventions, and treatment development.