The Role of the Microbiome and Diet in Depression by Prof Michael Berk
Prof Michael Berk is the Alfred Deakin Chair of Psychiatry at Deakin University. He is a past President of the International Society of Bipolar Disorders and the Australasian Society of Bipolar and Depressive Disorders. In addition, he holds several honorary professorial research fellowships. Prof Berk has published over 800 papers and has received several national and international awards, including the Brain and Behaviour Foundation Colvin prize.
A very important question is, ‘does reverse causality explain the relationship between diet and depression?’. And the answer appears to be ‘no’.
We are now beginning to understand that one of the important mediators of the relationship between diet quality and the brain is the microbiome, and the gut is now a critical area of feverish interest in the whole field.
The most important factor influencing the gut microbiome is diet.
Summary and slides
Professor Berk begins this segment by stating that most longitudinal studies appear to show diet quality predicts mental health outcomes. However, mental health at baseline does not have a predictive capacity in terms of subsequent diet.
The link between diet and inflammation is described; increasing diet quality proportionally decreased levels of C-reactive protein. The opposite effect was seen with worsening diet quality.
The effect of diet quality on brain structure over time is then described, with age-related progressive brain changes being ameliorated to an extent by a good quality diet.
Professor Berk then describes the link between biological systems which are dysregulated in depression and gut microbiota, highlighting that diet is the most important factor which influences gut microbiota.
Finally, he talks about up-coming trials which will investigate the effect of faecal microbial transplants in treating depression.
Take Home Points
- Depression is an inflammatory disease, and inflammation is significantly impacted by diet.
- Diet is the single most important factor that influences the gut microbiome.
- Trials investigating the impact of altering the microbiome in depression are ongoing.