Published in American Journal of Physiology – Endocrinology and Metabolism, researchers have discovered that flaxseed fibre has the potential to improve metabolic health.
Research in mice suggests that the fermentation of flaxseed fibre in the gut changes the microbiota to improve metabolic health and protect against diet-induced obesity.
What do you know about flaxseed fibre?
Flaxseed is a fibre-rich plant that has shown to improve cholesterol levels and inflammation in the colon. However, there is little research on the fermentability of flaxseed and how flaxseed fibre affects gut microbiota.
The organisms that live in the digestive tract, gut microbiota, play a vital role in regulating weight and the way the body processes glucose tolerance. The breakdown of dietary fibre in the gut, a process otherwise known as fermentation, can produce favourable changes in the digestive system.
Such breakdown includes changes such as an increase in beneficial fatty acids, which may reduce the development of fat tissue in the body and improve immune function.
Details of the study
The researchers measured the amount of oxygen the mice used, carbon dioxide produced, food and water consumed, and energy expended over the period of 12 weeks. Glucose tolerance was also measured near the end of the trial.
The subjects were split into four different diet groups, a standard diet (‘control’), a high-fat diet that contained no fibre (‘high-fat’), a high-fat diet that contained 10 % indigestible cellulose fibre (‘cellulose’), and a high-fat diet that contained 10% flaxseed fibre (‘flaxseed’).
At the end of 12 weeks, the researchers examined the animals’ cecal contents, bacteria and other biological materials in the pouch that forms the beginning of the large intestine (cecum).
The group with high-fat had fewer bacteria associated with improved metabolic health, lower levels of beneficial fatty acids and more of a bacterium linked to obesity when compared to the other groups.
Bacteria levels in both the cellulose and flaxseed groups returned to healthier levels when compared to the high-fat group.
The flaxseed group was more physically active and had less weight gain than the other high-fat diet groups.
The mice that received flaxseed supplements also had better glucose control and levels of beneficial fatty acids that were comparable to the healthy control group. When examining the cecal contents, the research team found evidence that the bacteria present ferment fibres from the thick, glue-like layer of the flaxseed shell. The bacteria that perform fermentation then produce more beneficial fatty acids.
So how did researchers conclude this would improve metabolic health?
The researchers added: “Our data suggest that flaxseed fibre supplementation affects host metabolism by increasing energy expenditure and reducing obesity as well as by improving glucose tolerance.
“Future research should be directed to understand relative contribution of the different microbes and delineate underlying mechanisms for how flaxseed fibres affect host metabolism.”