Key Findings

A beloved snack might not be so kind to your digestive system — cheese on toast could harm gut health, according to new research.

Scientists discovered that consuming unmelted cheddar had a beneficial influence on the gut microbiome — the complex community of bacteria and other microorganisms that play a role in everything from mood regulation to immune function.

Solid cheddar helped boost microbial diversity, keeping the microbiome well-balanced. However, when the cheese was heated until melted, this diversity dropped, which negatively impacted gut health.

Study Details

A team at University College Dublin set out to examine how cheddar cheese affects this delicate ecosystem.

Over six weeks, they monitored 69 participants. One group consumed 120 grams of solid cheddar daily; another ate the identical amount, but in melted form.

At the conclusion of the trial, researchers measured alterations in the gut bacteria of the volunteers.

They concluded that cheddar was advantageous for the microbiome, yet when it was melted for cheese on toast, the positive effects largely disappeared.

Heating hard cheese alters its structure, making it more difficult for the body to absorb beneficial nutrients, the scientists explained.

Cheese on toast is bad for your gut health, a study has found

Scientific Explanation

In a paper released in Frontiers In Microbiology, the researchers noted: ‘Once cheddar cheese is melted, the dense semi-solid matrix is disrupted and forms a looser structure.

‘This may partially account for the lack of an increase in bacterial diversity observed with melted cheese.’

Popularity of the Snack

Surveys indicate that cheese on toast is the United Kingdom’s preferred snack, with nearly one in four people saying it’s their top choice when hunger strikes.