The findings published in the journal Biological Psychiatry suggest that even those who are not obese should avoid fatty foods to stave of diet-induced psychiatric disorders.
High-fat diet produces changes in health and behaviour, in part, by changing the mix of bacteria in the gut, also known as the gut microbiome, the researchers noted.
“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 John Krystal, editor of Biological Psychiatry.
The human microbiome consists of trillions of microorganisms, many of which reside in the intestinal tract.
The researchers at the Louisiana State University in the US tested whether an obesity-related microbiome alters behaviour 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 behaviour and cognition.
The animals who received the microbiota shaped by a high-fat diet showed multiple disruptions in behaviour, including increased anxiety, impaired memory, and repetitive behaviours.
Further, they 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 behavioural changes, the researchers noted.
These findings provide evidence that diet-induced changes to the gut microbiome are sufficient to alter brain function even in the absence of obesity.