7 December 2022 – 08:09
Our microbiome, the billions of microorganisms that live in and on our bodies, control many important body functions, including the functions of the brain. Joint research from Amsterdam UMC, UvA and Erasmus MC shows a connection between the composition of the microbiome and depression. This composition is also related to ethnic differences in having a depression. The studies, which are partly based on data from the HELIUS study, are published today as a double publication in Nature Communications
A wide variety of microorganisms, such as bacteria, viruses and yeasts, live on and in the human body. All these microorganisms together are called the microbiome. The microbiome is necessary for optimal physical function; for example, through the production of essential nutrients and protection against pathogens. Disturbances in the microbiome increase the risk of several diseases. For example, there is increasing evidence that brain diseases are also related to disturbances in the microbiome.
Role of microbiome
The largest study to date of the relationship between the microbiome and depression involved 3,211 subjects from the HELIUS study (see box). This research shows a clear connection between the composition of the microbiome and depression. A microbiome with a lower diversity of bacteria, or one in which certain bacterial species are underrepresented, was associated with depression or with more depressive symptoms in this study. This association was as strong as that of known risk factors for depression – such as smoking, alcohol consumption, little exercise and obesity. Influence of the microbiome can therefore be very relevant for the treatment of depression. “Knowing which disturbances in the microbiome are essential for depression opens up new possibilities for treatment and prevention. They are badly needed,” says Anja Lok, psychiatrist and researcher at the Department of Psychiatry at Amsterdam UMC.
Previous HELIUS research has already shown ethnic differences in terms of the composition of the microbiome on the one hand and the prevalence of depression on the other. But is there a connection between these differences? Researcher Jos Bosch from the Department of Psychology, UvA: “The ethnic differences in depression actually seem to be linked to ethnic differences in the microbiome. We don’t know exactly why that is yet. This association was not due to lifestyle differences such as smoking, drinking, weight or exercise, and deserves further investigation. For example, diet can play a role.” This is the first study to show that the difference in depression between population groups is related to the composition of the microbiome.
Confirmation of the Rotterdam study
It is important to determine whether the associations found between the microbiome and depression can be confirmed by other studies. In the second article in Nature Communications, by researchers from Erasmus MC, data from the HELIUS study were compared with data from the ERGO study, also known as the Rotterdam study (see box). This shows that both studies confirm a consistent relationship between twelve groups of bacteria and the occurrence of depression. This comparative study also provides an explanation: the twelve bacterial groups produce ‘neurotransmitters’, substances that play an important role in depression. “These results therefore provide clear direction for future research into possible treatments, such as probiotics, prebiotics, synbiotics, faecal transplantation, lifestyle and diet,” says Anja Lok. At the Department of Psychiatry at Amsterdam UMC, she is conducting various studies on ways to influence the microbiome to treat depression more effectively and in a personalized way.
About the HELIUS study
Amsterdam UMC and GGD Amsterdam started the HELIUS study (Healthy Living in Cities) in 2010: a study in which 23,000 people are followed over a long period of time. The purpose of the research is to gain insight into health differences between Amsterdammers with a multi-ethnic background in an urban environment. The HELIUS study focuses on the common chronic conditions: cardiovascular diseases, infectious diseases and mental disorders. Prof. Max Nieuwdorp leads the microbiome cohort and collected all microbiome data. The knowledge generated by HELIUS research helps to better tackle health problems and improve medical care.
About the ERGO survey
ERGO (Erasmus Rotterdam Health Research) is a long-term population study conducted by Erasmus MC among almost 20,000 people aged 40 and older in the Ommoord district of Rotterdam. The study examines health problems common in old age. Thanks to this extensive research, more and more knowledge is becoming available about the onset and course of disease in the elderly.
Source: Amsterdam UMC, UvA and Erasmus MC