Gut bacteria linked to mental health
Specific bacterial strains that reside in the gut can produce compounds that interact with the brain causing mental health issues, such as depression, and impact quality of life, according to data published in Nature Microbiology.
Jeroen Raes, PhD, of KU Leuven-University of Leuven and the VIB Center for Microbiology in Belgium, said in a press release that the link between microbial metabolism and mental health has been a controversial topic in the realm of microbiome research.
“The notion that microbial metabolites can interact with our brain – and thus behavior and feelings – is intriguing, but gut microbiome-brain communication has mostly been explored in animal models, with human research lagging behind,” he said. “In our population-level study we identified several groups of bacteria that co-varied with human depression and quality of life across populations.”
Raes and colleagues analyzed fecal microbiota data collected from 1,054 patients enrolled in the Flemish Gut Flora Project to explore the relationship between the microbiome and quality of life and depression. The patients in the study also had a general practitioner diagnosis of depression.
Researchers identified two bacterial genera — Coprococcus and Dialister — were depleted in patients with depression whether or not they were taking antidepressants. They validated their findings in an independent cohort of 1,063 individuals from the Dutch LifeLinesDeep cohort and in a group of patients diagnosed as clinically depressed at University Hospitals Leuven in Belgium.
Raes said that the community of bacteria associated with mental health was similar to a group they previously identified in patients with Crohn’s disease.
“This finding adds more evidence pointing to the potentially dysbiotic nature of the Bacteroides2 enterotype we identified earlier,” he said in the release. “Apparently, microbial communities that can be linked to intestinal inflammation and reduced wellbeing share a set of common features.”
Investigators also sought to develop a model that would aid in the identification of bacteria that can interact with the nervous system. They explored the genomes of more than 500 gut-isolated bacteria and studied their ability to produce neuroactive compounds.
Mireia Valles-Colomer, a PhD student at KU Leuven-University of Leuven and the VIB Center for Microbiology, said they took a broad look at the many compounds present in the gut that interact with the nervous system.
“Our toolbox not only allows to identify the different bacteria that could play a role in mental health conditions, but also the mechanisms potentially involved in this interaction with the host,” she said in the release. “For example, we found that the ability of microorganisms to produce DOPAC, a metabolite of the human neurotransmitter dopamine, was associated with better mental quality of life.”
Researchers said their findings will need to be confirmed but could help guide future research on the microbiome-gut-brain axis. – by Alex Young