![The Discovery Files show](https://d3dthqtvwic6y7.cloudfront.net/podcast-covers/000/014/590/small/the-discovery-files.jpg)
Summary: A study at Oregon State University indicates that both a high-fat and a high-sugar diet, compared to a normal diet, cause changes in gut bacteria that appear related to a significant loss of "cognitive flexibility," or the power to adapt and adjust to changing situations. This effect was most serious on the high-sugar diet, which also showed an impairment of early learning for both long-term and short-term memory.