Two
Studies in Europe have concluded that gut microbes can affect mood and/or
depression. One , a study led by Jeroen Raes, a microbiologist at the Catholic
University of Leuven in Belgium, studied 1054 people. Within this group 173
people either had been diagnosed with depression or had done poorly on a
quality of life survey. The microbiomes
of these people were compared to those of the other participants. Two kinds of
microbes Coprococcus and Dialister were missing from the microbiomes of the
depressed subjects but not from the others.
The team then looked at data from a study
done in the Netherlands in which the microbiomes of 1064 Dutch people were
assessed. They found the same two
microbes missing from those participants diagnosed with depression. While it is
not completely known how the two microbes influence depression, Coprococcus
seems to have a biochemical pathway resulting in formation of a dopamine
metabolite 3,4-dihydroxyacetic acid. Dopamine is an essential neurotransmitter
in the brain. This same microbe also makes an anti inflammatory substance gamma
amino butyric acid which is significant since increased inflammation is
implicated in depression.
Resolving
this microbiome-brain biochemical relationship might lead to novel therapies in
the future. In the meantime clinical neuroscientist Andre Schmidt of the
University of Basal has started a clinical trial in which his team is assessing
the mental health and microbiota of 40 depressed people before and after they
received a single fecal transplant. This transplant results in replacement of
the gut microbiome with that from a
donor.
