Researchers have known that a high-fat diet is linked to a variety of medical problems such as heart disease, stroke, and even cancer.
Emerging research suggests a high-fat diet may also increase the risk for depression and other psychiatric disorders.
As discussed in a new study, researchers theorize that a high-fat diet produces changes in health and behavior, in part, by changing the mix of bacteria in the gut, also known as the gut microbiome.
The study is found in the journal Biological Psychiatry.
The human microbiome consists of trillions of microorganisms, many of which reside in the intestinal tract. These microbiota are essential for normal physiological functioning.
However, research has suggested that alterations in the microbiome may underlie the host’s susceptibility to illness, including neuropsychiatric impairment.
As a result, researchers at Louisiana State University decided to test whether an obesity-related microbiome alters behavior and cognition even in the absence of obesity.
For the study, non-obese adult mice were conventionally housed and maintained on a normal diet, but received a transplant of gut microbiota from donor mice that had been fed either a high-fat diet or control diet. The recipient mice were then evaluated for changes in behavior and cognition.
The animals who received the microbiota shaped by a high-fat diet showed multiple disruptions in behavior, including increased anxiety, impaired memory, and repetitive behaviors.
They also showed many detrimental effects in the body, including increased intestinal permeability and markers of inflammation. Signs of inflammation in the brain were also evident and may have contributed to the behavioral changes.
“This paper suggests that high-fat diets impair brain health, in part, by disrupting the symbiotic relationship between humans and the microorganisms that occupy our gastrointestinal tracks,” commented Dr. John Krystal, Editor of Biological Psychiatry.
Experts believe the findings provide evidence that diet-induced changes to the gut microbiome are sufficient to alter brain function even in the absence of obesity.
This is consistent with prior research, which has established an association between numerous psychiatric conditions and gastrointestinal symptoms. However, the mechanisms by which gut microbiota affect behavior are still not well understood.
Researchers believe additional studies are necessary, but the current findings do suggest that the gut microbiome has the eventual potential to serve as a therapeutic target for neuropsychiatric disorders.