Researchers have found that the consumption of dietary fibre from oat and rye brans increased the growth of beneficial microbes in the intestines and reduced hepatic inflammation.
In addition, diets enriched with oat or rye bran were shown to attenuate weight gain. The effects of oat and rye were partly different, but both were beneficial for health.
For the study, published in the Molecular Nutrition & Food Research, the research team from the University of Eastern Finland, VTT Technical Research Centre of Finland collaborated with the University of Hong Kong.
The health benefits of oat, rye and other whole-grain products have been widely studied, and their use has been associated with decreased inflammation and improved glucose, lipid and adipose tissue metabolism in human and animal experimental research.
In addition, they have been linked to a decreased risk of obesity, metabolic syndrome, cardiovascular diseases and type-2 diabetes. Different dietary fibres are also known to have different health effects.
In the current study, the research team wanted to investigate differences in metabolites produced by gut microbiota and their interactions with host metabolism in response to supplementation with oat and rye bran fibres.
The study was an animal experiment during which mice were fed a high-fat Western diet for 17 weeks. Two groups were fed the same diet enriched with 10 per cent of either oat or rye bran.
Among the various gut microbial metabolites, this study focused on those especially relevant to the development of fatty liver disease, which is often associated with obesity. Thus, microbial metabolites were assessed by measuring cecal short-chain fatty acids (SCFAs), ileal and faecal bile acids, and the expression of genes related to tryptophan metabolism.
The findings suggest that both brans have the capacity to create a favourable environment in the gut by supporting the growth of beneficial microbes.
Both bran fibres enhanced the production of SCFAs, leading to improved gut integrity, reduced liver inflammation. “In addition, both oat and rye supplementation were shown to attenuate weight gain associated with a high-fat diet,” the authors noted.