Prebiotic effect: Plant-based and Mediterranean diets could boost gut health

Foods including legumes, bread, fish, nuts and wine are associated with high levels of friendly gut bacteria that aids the biosynthesis of essential nutrients and the production of short-chain fatty acids (SCFAs), the main source of energy for cells lining the colon, say Dutch scientists presenting at UEG Week 2019​.

The team, led by Laura Bolte from the University Medical Center Groningen, found that specific foods could provide protection for the gut by helping bacteria with anti-inflammatory properties to thrive.

The findings support the idea that the Mediterranean of plant-based diets could be an effective management strategy for digestive disorders, through the modulation of the gut bacteria, say those behind the work.

"We looked in depth at the association between dietary patterns or individual foods and gut microbiota,”​ said Bolte. “Connecting the diet to the gut microbiome gives us more insight into the relation between diet and intestinal disease. The results indicate that diet is likely to become a significant and serious line of treatment or disease management for diseases of the gut - by modulating the gut microbiome.”​

Digestive health​

Gut conditions and intestinal diseases represent a significant cost burden to the European economy, population and healthcare systems, said the team – noting that approximately 3 million people in Europe are affected by IBD and it has an estimated direct healthcare cost of up to €5.6 billion.

Obesity presents an even bigger public health concern, with over 50% of the European population considered overweight or obese and associated costs of €81 billion each year.

Study details​

The team followed four study groups, the general population, patients with Crohn's disease, ulcerative colitis and those with irritable bowel syndrome (IBS). They analysed a stool sample provided by each participant to reconstruct the host's microbiota and compared this with the results of a food frequency survey.

The results identified 61 individual food items associated with microbial populations and 49 correlations between food patterns and microbial groups.

Dietary patterns rich in bread, legumes, fish and nuts, were associated with a decrease in potentially harmful, aerobic bacteria, said the authors – adding that higher consumption of these foods was also associated with lower levels of inflammatory markers in stool that are known to rise during intestinal inflammation

A higher intake of meat, fast foods or refined sugar was associated with a decrease in beneficial bacterial functions and an increase in inflammatory markers, they added.

Bolte and colleagues said red wine, legumes, vegetables, fruit, cereals, fish and nuts were associated with a higher abundance of bacteria with anti-inflammatory functions, while plant-based diets were found to be associated with high levels of bacterial SCFA production.

Plant protein was also found to help the biosynthesis of vitamins and amino acids as well as the breaking down of sugar alcohols and ammonium excretion.

Animal-derived and plant-derived protein showed opposite associations on the gut microbiota, they said.

"A diet characterised by nuts, fruits, greater vegetable and legume intake than animal protein, combined with moderate consumption of animal derived foods like fish, lean meat, poultry, fermented low fat dairy, and red wine, and a lower intake of red meat, processed meat and sweets, is beneficially associated with the gut ecosystem in our study,”​ concluded Bolte.