Researchers from Joslin Diabetes Center of Harvard Medical School in Boston have revealed that a high-fat diet accompanied by changes in gut bacteria might alter brain chemistry to promote anxiety and depression.
According to National Center for Health Statistics (NCHS), around 650 million suffer from obesity and diabetes. The major factors for this epidemic are high fat diet and reduced physical activities. Obesity leads to cardiovascular diseases, heart attack, and kidney failure. Researchers from Joslin Diabetes Center of Harvard Medical School in Boston established a link between obesity and anxiety and depression.
In an experiment, mice were fed a high fat diet. The mice subsequently developed obesity and diabetes and were subjected to behavioral test for anxiety and depression. The mice replicated mood disorders. However, the mice fed with normal diet depicted no reflective behavior of anxiety and depression. To conclude the results, the mice were given antibiotics in drinking water. The levels of anxiety and depression decreased as gut bacteria was eliminated by the antibiotics. The mice depicted normal behavior in following tests. The researchers transferred fecal samples from the obsessed and diabetic mice to guts of germ free mice. The mice developed similar behavior as the obsessed mice.
The MRI scan of the brain revealed that the mice had developed insulin resistance, which affects their ability to convert glucose into energy. The excessive glucose in the cells result to type 2 diabetes. This insulin resistance was not evident in germ free mice that had no gut bacteria. The mice that were induced with fecal samples had no insulin resistance after treating them with antibiotics. The experiments prove that gut microbes play pivotal role in causing anxiety and depression. The study was published in the journal Molecular Psychiatry on June 18, 2018. The researchers are further working on identifying the microbes that exert the most influence on the gut.