The keto diet could have a positive effect on the gut in more ways than one, according to a new study published in the May 20 issue of the journal Cell and showed that it can significantly alter the microbes in our gut.
The two-month study first tracked microbiome changes in 17 obese or overweight men according to their diet, followed by further testing in mice.
Study author Peter Turnbaugh, an associate professor of microbiology and immunology at the University of California, San Francisco, together with some researchers placed half of the men on a one-month “standard” Western diet based on 50 percent carbohydrates, 15 percent protein and 35 percent fat.
Meanwhile the other half started a keto diet made up of five percent carbs, 15 percent protein and 80 percent fat.
After the first month the two groups switched diet plans.
When the men switched to the keto diet of low carbs and high fat, stool sample analyses revealed “significant shifts” in levels of 19 bacterial “families.”
In order to see the potential effects of the change, the researchers extracted microbial samples from the guts of the keto group and inserted them into the guts of mice.
They saw a drop in the levels of a critical infection-fighting cell, which is known to cause inflammation in autoimmune diseases.
However, the researchers didn’t stop there – the promising results could also be varied by changing the diet of the mice.
Exposing the mice to either a low fat, high fat or keto diet changed the gut microbe levels, with a low-carb keto diet driving them back down.
The researchers said this suggested the microbiome responds in different ways as dietary fat is introduced and increased to the high levels that are seen in a ketogenic diet, causing ketones. Most significantly, Turnbaugh discovered that a gradual rise in ketone levels, caused by being on a keto diet, caused a gradual change in gut composition.
The keto diet causes “ketone bodies” to be produced due to the way it restricts carbohydrates, forcing the body to use its fat reserves for energy.
Though it was a small study and more research is needed, Turnbaugh suggested that the findings could mean that it’s possible to alter the gut simply by targeting ketones.
“Ketone bodies can directly affect gut bacteria even in the absence of the full diet,” he said of the study.