Researchers at WEHI in Melbourne, previously known as the Walter and Eliza Hall Institute, discovered these concealed changes might accumulate over time, possibly contributing to the development of chronic inflammatory diseases that appear later in life.

Eating only two days of high-fat food depleted a key protein that protects the gut, known as  IL-22, the study revealed.

The hope is that these findings will bring about revisions to dietary recommendations, enhancing natural gut protection and supporting individuals dealing with chronic inflammatory illnesses like bowel disease.

Dr Cyril Seillet, a senior author on the paper, said the findings show that every meal we consume impacts our gut health.

“The more saturated fats we eat, the more inflammation that builds up – gradually weakening our gut defences and increasing our susceptibility to chronic inflammation.

“But this inflammation build-up is initially silent, remaining hidden in our bodies until years later, where it can present as chronic inflammation.”

About one-third of Australians live with chronic inflammatory disease, such as coeliac disease and rheumatoid arthritis.

But how this inflammation is triggered and causes disease remains largely unknown.

The new study, published in the journal Immunity, highlighted short-term exposure to high-fat diets sparked inflammation in mice as well as limiting their bodies’ capacity to resist it.

First author on the paper, Le Xiong, said high-fat diets were a “double hit” to our gut barrier because they not only promoted inflammation, but also disabled the body’s ability to fight it.

“IL-22 is a critically important protein for gut health and protection. Without it, the gut loses its ability to prevent inflammation,” he said.

Encouragingly, the researchers found consuming food high in unsaturated fat – such as nuts and avocadoes – improved the protein’s production, strengthening the gut’s resistance to disease.