Cooked food alters gut bacteria population

Eating cooked food alters the microbiomes of both mice and humans, according to a study with implications for understanding how cooking may have prehistorically altered the evolution of the microbes in our gut.

The study noted that many aspects of human health, including chronic inflammation and weight gain, are strongly influenced by ecological health of microbes present in and on us – collectively called our microbiome.

"Our lab and others have studied how different kinds of diet – such as vegetarian versus meat-based diets – impact the microbiome," said a researcher.

The researchers, including those from UCSF, examined how cooking impacted the microbiomes of mice by feeding diets of raw meat, cooked meat, raw sweet potatoes, or cooked sweet potatoes to groups of animals.

The research team found that raw meat had no discernible effect on the animals' gut microbes compared to the cooked ones. However, study noted that raw and cooked sweet potatoes significantly differed in their impact on animals' microbiomes.

The researchers added that microbes' patterns of gene activity, and biologically crucial metabolic products they produced differed between mice that ate cooked and those that fed on raw food. They then used a more diverse array of vegetables, and fed the mice an assortment of raw and cooked sweet potato, white potato, corn, peas, carrots, and beets.

The researchers said that as the host soaked up calories in the small intestine, it left less for hungry microbes further down the gut. They added that many raw foods contained potent antimicrobial compounds that appeared to damage certain microbes.