Common dietary fibres may alter gut bacteria composition

The study – published in The Journal of Nutrition – investigated the effects of the common dietary f…

The study – published in The Journal of Nutrition – investigated the effects of the common dietary fibres polydextrose and soluble corn fibre (SCF) on the composition of the human gut microbiota.

Led by Professor Kelly Swanson of the University of Illinois, USA, the research team found consumption of the fibres significantly affected the relative abundance of bacteria at the class, genus, and species level.

"When we understand what kinds of fibres best nurture these health-promoting bacteria, we should be able to modify imbalances to support and improve gastrointestinal health,"said Swanson.

 “Our data demonstrate a beneficial shift in the gut microbiome of adults consuming polydextrose and SCF, with potential application as prebiotics,” he revealed.

According to Swanson, shifts in bacteria such as those seen in his study—which occurred when more and differing types of fiber were consumed— are the opposite of what you would find in a person who has poor gastrointestinal health.

Such findings lead him to believe that there are new possibilities for using pre- and probiotics to promote intestinal health.

"For example, one type of bacteria that thrived as a result of the types of fibre fed in this study is inherently anti-inflammatory, and their growth could be stimulated by using prebiotics, foods that promote the bacteria's growth, or probiotics, foods that contain the live microorganism," he said.

Gut health

As the fibres ferment in the gut, they produce short-chain fatty acids and other metabolites that can encourage the growth of strains of ‘friendly’ bacteria, noted Swanson, who added that the changes could result in many health benefits.

Previous research has suggested changes to the gut ecosystem by modifying beneficial bacteria in the gut could help to support a healthy gastrointestinal tract, in addition to modifying the risk of developing several conditions such as type 2 diabetes, obesity, inflammatory bowel disease, colon cancer, and autoimmune disorders such as rheumatoid arthritis.

However, the team noted that the relative contribution of novel fibres – such as polydextrose and SCF – to the human gut microbiome and its association with host physiology has not been well studied.