Eating a diet that's high in healthy fats can undoubtedly change the composition of your microbiota. Additionally, eating unhealthy fats, such as vegetable oils that are high in omega-6 fatty acids, can negatively impact your gut and your overall health by causing inflammation and intestinal permeability.If you decide to follow a high-fat diet, such as the ketogenic diet, it's particularly important to pay attention to the health of your microbiome because recent research has shown that gut bacteria play a key role in the absorption and metabolism of dietary fat, allowing you to get "get more calories for the same foods," according to the Carnegie Institution for Science.