You are not entirely human — from a biological perspective. According to the National Human Genome Research Institute, your body is comprised of around 10 times as many microbial cells versus human cells.
In a breakthrough study released in Molecular Psychiatry, researchers from MIT and Harvard found that “changes in your gut microbiota can affect your brain insulin signaling and your body’s metabolite levels,” which then affect your neurobehaviors.
The researches found that mice given a diet high in fat had increased anxiety, depression and obsessive behaviors.
The mice with induced overweightness had insulin resistance in their brain. The researchers linked the behaviors of depression and anxiety to “increased inflammation and decreased insulin signaling in the nucleus accumbens.”
The scientists then changed the microbiome of the overweight mice with antibiotic treatment.
The results were improved insulin sensitivity and the complete reversing of the anxiety and depression.
The researchers then switched the microbiota from the overweight mice that got antibiotics with those that did not, to mice that lacked a natural microbiome.
Only the mice that got the microbiota from the obese mice but did not get antibiotics started to show signs of anxiety — leading the scientists to conclude that the microbiome was the primary factor.
The researchers now say that studying the gut-brain relationship “may open new ways to treatment mood disorders” in the future.