Trim the fat for happiness, says latest diet research

These changes come about due to the high-fat diet's affect on the gut microbiome, according to the study.

The microbiome is a term used to describe the overall composition of microorganisms that reside in the intestinal tract, most of which are necessary for normal physiological functioning, although poor diversification can lead to health problems.

Working with mice, the research team set out to test whether an obesity-related microbiome could also affect behavior and mood.

They transferred the gut microbiota from mice that had been fed either a high-fat diet or a control diet into adult mice of normal weight that had been kept on a normal diet.

Recipient mice were kept under observation and researchers evaluated them for behavior and cognitive change.

Those who had received microbiota shaped by a high-fat diet underwent behavioral changes indicating increased anxiety and impaired memory.

They also engaged in repetitive behaviors and exhibited signs of physiological malaise such as inflammation.

"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," says Dr. John Krystal, Editor of Biological Psychiatry, in which the study was recently published.

Even in the absence of obesity, changes to the microbiota brought upon by a high-fat diet could alter brain function, according to the study, whose findings support prior research.