Prolonged consumption of food high in saturated fat, such as butter and animal fat, can lead to inflammatory gut disease and subsequently increase the risk of colon tumours.

Researchers from Nanyang Technological University (NTU) found that eating a lot of saturated fat keeps the amount of a naturally occurring protein, angiopoietin-like 4 (ANGPLT4) low, triggering immune cells to act, which results in gut inflammation over time.

ANGPLT4 regulates inflammatory responses, and the study was conducted to find out its effects on gut health.

Researchers found that, in mice, high levels of ANGPLT4 in the gut led to less severe inflammation in the area, and that high levels of saturated fat eaten over a long period also decreased the amount of ANGPLT4 present in the body.

The study is a joint project between the Karolinska Institutet (KI) in Sweden and Ms Terri Phua, a doctoral student at NTU.

According to a 2015 study, 10 in every 100,000 Singaporeans today have Crohn's disease, a type of inflammatory bowel disorder (IBD), up from two per 100,000 20 years ago. IBD primarily includes ulcerative colitis and Crohn's disease, of which the former is more common in Singapore. Both cause diarrhoea, abdominal pain, weight loss, blood in the stool and fatigue.

"A high intake of saturated fat could increase the prevalence and replication of harmful pathogens, suppressing ANGPLT4 and causing severe inflammation," said Associate Professor Andrew Tan, the associate chair for students at NTU's School of Biological Sciences, who was also part of the study.

He said the findings affirmed the conventional wisdom of eating more food with unsaturated fats, such as nuts, fish and vegetables, and less food with saturated fat, such as butter and lard.

In related research, NTU partnered Wageningen University in the Netherlands to study the effects of trans fat on gut health.

The recently published study, which also conducted experiments on animal subjects, showed that trans fat also lowered ANGPLT4 levels, without resulting in gut inflammation.

However, prolonged consumption of high amounts of trans fat may lead to the hardening and narrowing of arteries, which increases the risk of cardiovascular diseases such as high blood pressure and stroke.

Moving forward, the team is expanding its research to find methods for early detection of cardiovascular disease and the reduction of gut inflammation.

The studies are funded by the NTU iFood Research Grant and Singapore's Ministry of Education, and supported by NTU-KI and the Nanyang President's Graduate Scholarship.