The role of bacteria in stress
Disruptions to the gut flora can affect our mental health. How could this connection be used to prevent stress-related disorders? This is what psychologist Laura Steenbergen will investigate with the aid of a project grant from the LUF and, on the basis of a partnership between the two funds, the Gratama Foundation.
It was 2,500 years ago that Greek physician Hippocrates said all disease begins in the gut. The gut also figures in the language we use to express our feelings: gut feeling, butterflies in your stomach, unable to stomach something, to name but a few examples. It has been assumed that there is a connection between the stomach and our health for a long time already, therefore. Scientists began to pay more attention to this in 2004, and Japanese researchers discovered that mice without gut flora – gut bacteria populations – exhibit a much stronger response to stress, but that this response could be reversed with probiotics, good bacteria.
Dr Steenbergen researches the development of stress-related disorders such as anxiety and depression. The connection between the gut and the brain has potential for this research field. ‘In previous research, I showed how probiotics can reduce the tendency to worry. Perhaps the gut flora could be used to prevent stress-related disorders. But if we want to know which probiotics are most promising, we have to know the exact link between disrupted gut flora and responses to emotional events. That link may be influenced by the immune system, particularly the production of proinflammatory molecules. One way in which the gut flora communicates with the brain is via these molecules.’
‘Until the individual academic disciplines venture beyond their comfortable islands of expertise, we will be left with many unanswered questions’
What is new about this research is that it combines analysis of the immune system and gut flora with methods from psychological research. ‘If you want to promote mental health, you will only achieve progress with truly interdisciplinary insights. That’s what I believe. Until the individual academic disciplines venture beyond their comfortable islands of expertise, we will be left with many unanswered questions.’
This interdisciplinarity means that Dr Steenbergen is not conducting the research alone. ‘Many research grants are aimed at deepening knowledge rather than integrating existing knowledge. This is also possible with a LUF grant, but you can look wider too. I am not creating anything new but am using methods that have existed for longer. The difference is that I’m going to integrate them. And it is not one person who is going to do all this. We have created a network of expertises that will make new insights possible.’
Leiden University Medical Center will provide expertise about and measure the activity of the immune system, and My Microzoo, a company that specialises in analysing gut flora in faecal samples, will offer its expertise. In collaboration with these two partners, Dr Steenbergen hopes to map the relationships between disruptions to the gut flora, the immune system and responses to emotional events.
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Header photo: within the scope of outreach and knowledge sharing, Laura Steenbergen regularly gives presentations at public events, speaking at TEDxAlkmaar in 2019, for instance.