Strawberries can boost gut health

Eating about a quarter cup of strawberries daily can prevent colon inflammation and improve gut health, say scientists.

"The sedentary lifestyle and dietary habits of many people -- high-sugar, high-animal-fat, but low-fiber diets -- may promote colonic inflammation and increase the risk of inflammatory bowel disease," said Hang Xiao, who led the study.

Inflammatory bowel disease (IBD) is a set of painful conditions that can cause severe diarrhea and fatigue. Treatments can include medications and surgery.

IBD includes both Crohn's disease, which can infect any part of the gastrointestinal tract, and ulcerative colitis, which is characterised by inflammation of the colon and rectum.

People with IBD also have a higher risk of colorectal cancer.

The dietary consumption of fruits and vegetables has been associated with a lowered risk of IBD.

To establish an effective and practical approach to decrease colonic inflammation in both IBD patients and the general population, researchers from the University of Massachusetts Amherst in the US focused on strawberries due to their wide consumption.

According to Yanhui Han, a PhD student who conducted the study, most of the previous reports focused on the effects of purified compounds and extracts from strawberries.

"But when you only test the purified compounds and extracts, you miss out on a lot of other important components in the berries, such as dietary fibre, as well as phenolic compounds bound to the fibres, that can't be extracted by solvents," he said.

In their experiment, researchers used four groups of mice -- a group of healthy mice consuming a regular diet, and three groups of mice with IBD consuming a regular diet, a diet with 2.5 per cent whole strawberry powder or a diet with 5 per cent whole strawberry powder.

Xiao said they tried to feed the mice doses of strawberries that would be in line with what a human could reasonably consume.

The researchers found that dietary consumption of whole strawberries at a dose equivalent to as low as three-quarters of a cup of strawberries per day in humans significantly suppressed symptoms like body weight loss and bloody diarrhea in mice with IBD.

Strawberry treatments also diminished inflammatory responses in the mice's colonic tissue.

Colonic inflammation adversely impacts the composition of microbiota in the gut. With IBD, the abundance of harmful bacteria increases, while levels of beneficial bacteria decrease in the colon.

Following the dietary treatments of whole strawberries, the researchers observed a reversal of that unhealthy microbiota composition in the IBD mice.

The team also obtained experimental data that indicated strawberries might impact abnormal metabolic pathways in the IBD mice, which in turn could lead to the decreased colonic inflammation they observed.

Next, the team will try to validate their findings in IBD patients.