So-called ‘functional foods’ can promote health and/or reduce the risk of disease. Dr Jelena Vulevic, Medical Sciences Liaison, Clasado Research Services, University of Reading, UK examines pro- and prebiotics
Foods that exhibit properties over and above their basic nutritional value are known as ‘functional foods’ or nutraceuticals. These types of foods can beneficially affect the body by promoting health and well-being and/or reducing the risk of disease. Amongst functional foods that are currently on the market, one of the most interesting and researched are the so-called ‘colonic functional foods’.
To varying extents, such foods employ the trillions of bacteria that make up the complex gut microbiota to affect our bodies in a beneficial way. These gut bacteria exist in a symbiotic relationship with our body and have a variety of important roles, including being involved in the proper functioning of the immune system, displacement of pathogens in the gut, metabolism of dietary carcinogens and toxins and the synthesis of vitamins, to name just a few. For the body to be able to effectively fight off infections, as well as having a healthy and efficient digestion, the presence of the appropriate bacteria in the gut is essential.
The gut microbiota’s constant requirement for nutrition provides an opportunity to modulate it through the diet
The influence of these bacteria also extends well beyond the gut, including the production of pro/anti-inflammatory molecules that have far-reaching effects throughout the body. Furthermore, the gut microbiota is involved in lipid metabolism in the liver and fat tissue and the regulation of mood and cognition in the brain.
The gut microbiota’s constant requirement for nutrition provides an opportunity for us to modulate it through the diet. Modulation of the microbiota by dietary intervention provides an attractive, safe and non-invasive way by which the enhancement and optimisation of important physiological functions may be achieved. The most frequently used dietary method of beneficially influencing the microbiota composition is the consumption of probiotics (live micro-organisms), although the prebiotic approach (selectively fermented food ingredients) is increasing in popularity.
The introduction of prebiotics into the diet has provided evidence to suggest that the composition of the microbiota and their metabolic activities can be modified by relatively small changes in lifestyle and diet. In the case of probiotics, allochthonous micro-organisms are introduced into the gut where they have to compete against the established bacterial community. Prebiotics, on the other hand, modify gut function by targeting endogenous bacteria, making them, arguably, the most practical and efficient way to manipulate the gut microbiota.
For foods to have a prebiotic status, they must have proven scientific evidence that demonstrates their essential properties
All current prebiotics are non-digestible oligosaccharides (carbohydrates), and although some can occur naturally in certain types of fruits and vegetables (such as garlic, asparagus and leeks), they are generally present in insufficient quantities to exert a prebiotic effect. Consequently, prebiotics are produced commercially through the hydrolysis of polysaccharides or through catabolic enzymatic reactions from lower molecular weight sugars.
For foods to have a prebiotic status, they must have proven scientific evidence that demonstrates their essential properties; that is, the ability to escape enzymatic digestion in the upper gut, arrival into the lower gut without change to their structure and selective metabolism by beneficial bacteria (bifidobacteria and lactobacilli, for example). Although there are many commercially available foods and food ingredients that claim to be prebiotics, at present only lactulose, fructo-oligosaccharides and galacto-oligosaccharides (GOS) have proven prebiotic effect and status.
Technological advances have made it possible to tailor the chemical structure of prebiotics to enhance their functionality. One example of this is the prebiotic Bimuno (Clasado Biosciences Ltd), a GOS mixture produced from lactose using enzymes from the probiotic Bifidobacterium bifidum NCIMB 41171. The result is a unique second generation prebiotic with enhanced functionality, including a highly selective and powerful prebiotic effect (growth of beneficial bifidobacteria and improved colonisation resistance), anti-invasive function (increasing protection against bacterial pathogens), and the ability to interact directly with the immune system improving barrier function in the gut.
The unique final composition and heightened functionality of Bimuno stem from the probiotic source of the enzyme used during its manufacture. Other types of GOS currently available are produced using widely available commercial enzymes present in a number of different bacteria (both beneficial and detrimental), resulting in a product that is less selective towards beneficial bifidobacteria in the gut.1,2
In the last few years, numerous studies have demonstrated the various functional properties of Bimuno. It has been demonstrated in humans to be the most selective prebiotic currently on the market, targeting very specific species of beneficial gut bacteria.2 As a result, it also has the most potent bifidogenic effect amongst prebiotics, requiring the lowest effective dose (1.37g GOS). Its prebiotic properties, namely significant increases in bifidobacteria at the expense of less desirable groups of bacteria in the gut, have been confirmed in healthy adults, healthy elderly adults, irritable bowel syndrome (IBS) sufferers and overweight adults.2–5
In terms of its protection against pathogens, Bimuno was shown to significantly reduce pathology and colonization associated with food-borne salmonellosis and to significantly reduce the incidence, severity and duration of traveller’s diarrhoea.6–8 In elderly adults, Bimuno significantly increased the activity of cells involved in the killing of pathogens and tumours, and positively regulated production of anti- and pro-inflammatory molecules, thus demonstrating its positive effect upon the immune system.3
Its positive immunomodulatory effect was further demonstrated in overweight adults with metabolic syndrome (MS), where it significantly increased gut immune parameters involved in the protection against pathogens, as well as reducing blood and faecal inflammatory markers.5 In this study, Bimuno was also shown to significantly reduce markers associated with MS that are known to increase the risk of developing cardiovascular disease, namely insulin and lipids, thus demonstrating further its positive interaction with the host independently of other lifestyle changes. Finally, by significantly reducing symptoms such as bloating and abdominal pain in IBS sufferers, Bimuno’s ability to benefit overall digestive wellness has also been demonstrated.4
In conclusion, dietary intervention using Bimuno is not only an attractive option for the enhancement of gut health, but it also has potent immunomodulatory and systemic effects. It’s reasonable to suggest that Bimuno could provide beneficial effects in a number of different situations, such as ageing, infection, poor diet associated with being overweight, stress, long-term medication and when travelling abroad.
Bimuno is an excellent example of how technological advances can be used to further modulate the gut microbiota and to positively affect overall health. The research conducted to date is part of an extensive and ongoing programme, examining the central role the gut plays in various aspects of human health. This work is set to reveal further exciting benefits of the unique Bimuno technology in the very near future.
1. G. Tzortzis, et al., “A Novel Galactooligosaccharide Mixture Increases the Bifidobacterial Population Numbers in a Continuous In Vitro Fermentation System and in the Proximal Colonic Contents of Pigs In Vivo,” J. Nutr. 135, 1726–1731 (2005).
2. F. Depeint, et al., “Prebiotic Evaluation of a Novel Galactooligosaccharide Mixture Produced by the Enzymatic Activity of Bifidobacterium bifidum NCIMB 41171 in Healthy Humans: A Randomized, Double-Blind, Crossover, Placebo-Controlled Intervention Study,” Am. J. Clin. Nutr. 87, 785–791 (2008).
3. J. Vulevic, et al., “Modulation of the Faecal Microflora Profile and Immune Function by a Novel Trans-Galactooligosaccharide Mixture (B-GOS) in Healthy Elderly Volunteers,” Am. J. Clin. Nutr. 88, 1438–1446 (2008).
4. D.B.A. Silk, et al., “Clinical Trial: The Effects of a Trans-Galactooligosaccharide Prebiotic on Faecal Microbiota and Symptoms in Irritable Bowel Syndrome,” Aliment. Pharmacol. Ther. 29, 508–518 (2009).
5. J. Vulevic, et al., “A Mixture of Trans-Galactooligosaccharides Reduces Markers of Metabolic Syndrome and Modulates the Fecal Microbiota and Immune Function of Overweight Adults,” J. Nutr. 143, 324–331 (2013).
6. L.E.J. Searle, et al., “A Mixture Containing Galactooligosaccharide, Produced by the Enzymic Activity of Bifidobacterium bifidum, Reduces Salmonella enterica Serovar Typhimurium Infection in Mice,” J. Med. Microbiol. 58, 37–48 (2009).
7. L.E.J. Searle, W.A. Cooley and G. Jones, “Purified Galactooligosaccharide, Derived from a Mixture Produced by the Enzymic Activity of Bifidobacterium bifidum, Reduces Salmonella enterica Serovar Typhimurium Adhesion and Invasion In Vitro and In Vivo,” J. Med. Microbiol. 59, 1428–1439 (2010).
8. A. Drakoularakou, et al., “A Double-Blind, Placebo-Controlled, Randomized Human Study Assessing the Capacity of a Novel Galacto-Oligosaccharide Mixture in Reducing Travellers’ Diarrhoea,” Eur. J. Clin. Nutr. 64, 146–152 (2009).