The Western diet is implicated as a causative factor in the development of the metabolic syndrome. This likely relates to the overly processed and refined foods present in the diet. In particular, the processing of whole foods often removes much or all of the fibre content, and this is done to increase shelf life and to improve the taste for consumers. The removal of fibre from whole foods during processing is thought to be detrimental to the health because fibre confers beneficial glycaemic effects which improve insulin sensitivity, a reduction in the latter being associated with the metabolic syndrome. However, evidence also suggests that fibre is beneficial because it can supply a source of energy for beneficial Gram positive in the large intestine such as bifidobacteria, which can grow in numbers and subsequently outcompete pathological strains that may be associated with the development of disease. For example, certain Gram negative bacteria can produce lipopolysaccharides (LPS) (here) that can cause chronic low grade inflammation.
The ability of fibre to improve the health of the colon and host immunity, while reducing the factors associated with an increased risk of metabolic syndrome has been tested in obese but otherwise healthy human subjects1 For example, a mixture of galacto-oligosaccharides was fed to forty five obese subjects who were at increased risk of developing the metabolic syndrome. Galacto-oligosaccharides are a prebiotic non-digestible carbohydrate made of galactose units of various chain lengths that are known energy substrates for colonic bacteria such as lactobacilli and bifidobacteria. In this regard they are classified as a form of dietary fibre. Subjects consumed the galacto-oligosaccharides or a maltodextrin control of twelve weeks before switching to the alternative treatment. The results showed that consumption of the galacto-oligosaccharides increased the number of beneficial bifidobacteria at the expense of the less desirable Bacteroides spp. and C. histolyticum. This supports previous studies showing beneficial effects for galacto-oligosaccharides on gut health.
As well as the improvements in gut microbiota ratios, the galacto-oligosaccharides also had beneficial effects on a number of markers of the metabolic syndrome. In particular consumption of the galacto-oligosaccharides was associated with an increase in faecal excretion of immunoglobulin A suggesting that immunity had improved, and a decrease in the faecal excretion of calprotectin suggested that gut inflammation had been reduced. Plasma levels of insulin, triglycerides, total cholesterol and the total to high density lipoprotein (HDL) cholesterol were also reduced. These reductions are important, because as plasma levels of these markers increase the risk of chronic and serious disease increases. Reductions in the plasma levels of C-reactive protein also suggested that the subjects had experienced reduction in the levels of systemic chronic inflammation. Inflammation is now associated with the development of the metabolic syndrome, and so this is further evidence that the fibre was beneficially affecting metabolic regulation and health.
Dr Robert Barrington’s Nutritional Recommendation: If you are not on a high fibre diet then you should be. But this does not mean fibre supplements such as the one in their study need to be consumed. Plant foods in their natural whole food state contain high amounts of dietary fibre that may explain the health benefits of fruits and vegetables. Generally those with more fibre in their diets are thinner, healthier and happier. What is not to like?
RdB
