High-fat diets have long been known to increase the risk for heart disease and stroke, but there is new evidence to link diets high in fat with a range of psychiatric disorders. Central to this newly recognized mind-gut relationship are the microorganisms that inhabit our intestines – the gut microbiome.
Increasingly, scientists are finding the population of microbes in our gut is linked intimately with brain function. Now, a new study in Biological Psychiatry raises the possibility that a high-fat diet produces changes in behaviors by changing this mix of bacteria.
The researchers, from Louisiana State University, were testing whether an obesity-related gut microbiome alters behavior and cognition – even in the absence of obesity. 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 study reveals that 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.
Further, it recorded many detrimental effects in the body, including increased intestinal permeability and markers of inflammation. Signs of inflammation in the brain were also evident, which the researchers believe may have contributed to the behavioral changes.
The findings provide evidence that diet-induced changes to the gut microbiome are sufficient to alter brain function, even in the absence of obesity. And while the mechanisms by which gut microbiota affect behavior are still not well understood, the researchers findings suggest that the gut microbiome has the potential to serve as a therapeutic target for neuropsychiatric disorders.
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