Plantain and broccoli fibres may block a key stage in the development of the inflammatory bowel disorder, Crohn's disease, suggests preliminary research published online in Gut.
The causes of Crohn's disease are thought to be a mix of genetic and environmental factors, one of which is very likely to be diet.
The disease is significantly less common in developing countries, where fibrous fruit and vegetables are dietary staples, and its incidence has recently risen rapidly in Japan, in tandem with the increasing adoption of a more Westernised diet.
One of the key stages in the development of Crohn's is invasion of the cells lining the bowel (epithelial cells) by bacteria, particularly a "sticky" type of Escherichia coli, so the researchers looked at dietary agents that might influence this process.
They cultured M (microfold) cells, bowel lining cells that are the common entry point for invading bacteria that cause diarrhoea - a process known as translocation.
The researchers tested whether preparations of plant soluble fibres prepared from leeks, apples, broccoli, and plantains, and the fat emulsifiers polysorbate 60 and 80, commonly used in processed food manufacture, could alter E coli translocation across M cells.
Plantain and broccoli fibres (5 mg/ml) reduced translocation of E. coli by between 45% and 82%, while leek and apple fibres had no noticeable impact. By contrast, the emulsifier polysorbate 80 substantially increased translocation.
These results were then confirmed in tissue samples taken from patients undergoing surgery for other gut disorders.
The findings suggest that supplementing the diet with broccoli/plantain fibres might prevent relapse of Crohn's disease, say the authors.
They go on to add that the results could have further implications for the treatment of Crohn's disease as many enteral feeds contain emulsifiers, which may account for the variable response to this type of treatment.