A 6-month randomized controlled trial investigated various dietary fat levels and their impacts on the gut microbiome. The study included 217 young, healthy adults, aged 18 to 35, and provided all of the food participants ate during the 6-month period. Fat consumption was split up among three groups – a low-fat diet (calories from fat 20% of energy consumed), a medium-fat diet (calories from fat 30% of energy consumed), and a high fat diet (calories from fat 40% of energy consumed). Effects of dietary fats on the gut microbiome were assessed using stool samples and plasma inflammatory markers.

Study results showed that short chain fatty acid production was significantly lower in the higher fat group, while plasma inflammatory markers were elevated. The lower fat diet was associated with increased microbial diversity and other positive microbial markers. BMJ

Takeaway: Researchers who conducted the study conclude that a high fat diet in healthy, young adults may result in negative changes to the gut microbiome that could be a marker for declining health in the long-term. Keeping dietary fat in check is an important part of achieving gut and overall health, and the source of fat is also important. When consuming fat in your diet, focus more on fats from plant sources like nuts, seeds, and avocados, and try to limit fats from oils and animal products, such as dairy and animal meats.