Wild About Superfoods!

You’re probably familiar with blueberries being termed a ‘superfood’. This term that is sometimes given to certain foods that are particularly rich in beneficial nutrients including vitamins, minerals and phytonutrients. Blueberries were perhaps one of the first foods to be termed a ‘superfood’, as these little berries are packed with many different nutrients, in particular antioxidants, which can help support healthy cell function. Blueberry antioxidants include anthocyanins and polyphenols that are known to help maintain a healthy circulation and offer immune support.[1],[2],[3] 

But did you know it’s not just the antioxidant capacity of these little berries that mean they pack a powerful nutritional punch in terms of health?

A study has shown that blueberries also support the growth and activity of Bifidobacteria, one of the resident strains of gut microbiota that modulate our immune systems.[4] Researchers from Italy and America demonstrated how daily consumption of a powdered blueberry drink led to greater numbers of beneficial gut bacteria that have immunomodulatory effects.  In this respect, the blueberries are acting as a prebiotic, feeding and supporting the probiotic microbiota.

Prebiotics and a healthy gut, immune system and brain

Prebiotics include unique plant fibres like fructooligosaccharides (FOS) that nourish the beneficial bacteria in your gut. First identified twenty years ago by Marcel Roberfroid of the University of Louvain in Belgium[5], prebiotics have already attracted and stimulated wide-ranging research in nutrition and medicine. New developments in molecular microbiology are allowing scientists to accurately measure the impact of prebiotics on our health, and have led to novel insights about how to protect and nourish a healthy gut.[6] In fact, prebiotics are often considered as potent as probiotics, administered either in fermented dietary sources or as a supplement, in terms of shifting the microbial composition.[7]

Prebiotics offer remarkable benefits when we consume them: selective stimulation of health supporting gut microbiota, improvement in bowel function, protection from infection, relief from constipation, reduced risk of colon cancer, diabetes, obesity, and depression.[8],[9],[10]

Prebiotics also protect the intestinal barrier and maintain the ‘tight junctions’ between the digestive system epithelial cells, helping lower inflammatory responses to certain food antigens and to mycotoxins commonly found in grains and nuts.[11]  The integrity of the intestinal lining is crucial for overall health as this intestinal barrier acts as a shield, which can be modified by the gut microbiota and is itself part of the immune system of the gut.[12] Increased intestinal permeability has been linked to Irritable Bowel Syndrome (IBS), inflammatory bowel disease, coeliac disease, gluten sensitivity, and neurological and autoimmune disease.[13],[14],[15],[16]  

Changes to the gut microbiome are also now known to affect emotions, mood and cognition. Consumption of prebiotic fibres can therefore potentially enhance brain function by modulating gut bacteria.[17]

Please read our blogs on ‘How Healthy is Your Brain’ and ‘Heal Your Gut – A Crucial Link for Successful IBS Management’ for more information about nutritional support brain and gut health.

Blueberries as Prebiotics

So what do blueberries contain that has been shown to have this prebiotic effect?

Prebiotics are characterised as plant fibres that are not digested and absorbed but rather pass through the digestive tract positively influencing including gut microbiota and in turn the immune system.[18] It’s now known that whilst some polyphenols in our diet are absorbed and act as antioxidants within the body, others pass through the small intestine without being absorbed, thus encountering the Bifidobacteria gut microbiota that mainly colonise the colon. The suggested mechanism of action of the unabsorbed polyphenols is the development of a two-way mutual reaction between polyphenolic compounds and gut microbiota[19]:

1. Polyphenols modulate the composition of the gut microbial community mostly through the inhibition of pathogenic bacteria and the stimulation of beneficial bacteria.
2. The polyphenols are bio-transformed into their metabolites by gut microbiota that results in the increased bioavailability of polyphenols that are absorbed into the body for antioxidant action.

Therefore, the interactions of dietary polyphenols and gut microbiota may result in a very positive impact on human health.

Getting The Best From Superfoods

Blue berries are a rich source of polyphenols, which can also be found in bilberries, flaxseeds, apples, plums and cocoa, as well as other foods. Frozen or fresh berries taste great with porridge, as a snack or blended into fresh juices and smoothies making a tasty and easy to digest meal.

Some people suggest that the term ‘superfoods’ is used solely for marketing purposes. There is certainly no legal definition of which foods can be labelled a superfood but we think that there are definitely foods that are entitled to this term due to their exceptional nutritional content. This includes blueberries, as well as spirulina, broccoli, green leafy vegetables like spinach, and their derivative powders, which can all be enjoyed as salads or blended into juices and smoothies to make a tasty and healthy immune, brain and gut-boosting drink.

So stock up today with the ultimate antioxidant and prebiotic super fruit – your gut, brain and immune health will thank you for it!

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References

1. Wallace (2011) Anthocyanins in Cardiovascular Disease. Adv Nutr 2:1–7
2. Mazza (2007) Anthocyanins and heart health. Ann Ist Super Sanita 43(4):369-74
3. Cuevas (2013) Modulation of Immune Function by Polyphenols: Possible Contribution of Epigenetic Factors. Nutrients 5(7): 2314–2332
4. Guglielmetti S et al (2013) Differential Modulation of Human Intestinal Bifidobacterium Populations after Consumption of a Wild Blueberry (Vaccinium angustifolium) Drink. J Agri Food Chem 61:34 8134-140
5. Gibson GR, Roberfroid MB. (1995) Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. J Nutr 125(6):1401-12
6. Roberfroid M. Prebiotics: the concept revisited. J Nutr. 2007 Mar, 137 (3 Suppl 2): 830S-7S
7. Khamsi R, A (2015) Gut Feeling About Immunity. Nat Med 21:674-677
8. Swennen K, Courtin CM, Delcour JA. Non-digestible oligosaccharides with prebiotic properties. Crit Rev Food Nutr, 46 (2006) 459.
9. Cheu  et al (2008) Effects of xylooligosaccharides in type 2 diabetes mellitus. J Nutr Sci Vitaminol (Tokyo), 54:396
10. Chung, YC, Hsu CK & Ko CY. Dietary intake of xylooligosaccharides improves the intestinal microbiota, fecal moisture, and pH value in the elderly Nutr Res, 27 (2007) 756
11. Akbari P, Braber S2, Alizadeh A, Verheijden KA, Schoterman MH, Kraneveld AD, Garssen J, Fink-Gremmels J. Galacto-oligosaccharides Protect the Intestinal Barrier by Maintaining the Tight Junction Network and Modulating the Inflammatory Responses after a Challenge with the Mycotoxin Deoxynivalenol in Human Caco-2 Cell Monolayers and B6C3F1 Mice. J Nutr. 2015 Jul;145(7):1604-13. PMID: 26019243
12. Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci. 2015; 9: 392
13. Hollon J, Puppa EL, Greenwald B, Goldberg E, Guerrerio A, Fasano A. Effect of gliadin on permeability of intestinal biopsy explants from celiac disease patients and patients with non-celiac gluten sensitivity.Nutrients. 2015 Feb 27;7(3):1565-76
14. de Magistris L, Picardi A, Siniscalco D, Riccio MP, Sapone A, Cariello R, Abbadessa S, Medici N, Lammers KM, Schiraldi C, Iardino P, Marotta R, Tolone C, Fasano A, Pascotto A, Bravaccio C. Antibodies against food antigens in patients with autistic spectrum disorders. Biomed Res Int. 2013;2013:729349
15. Fasano A. Zonulin and its regulation of intestinal barrier function: the biological door to inflammation, autoimmunity, and cancer. Physiol Rev. 2011 Jan;91(1):151-75
16. John LJ, Fromm M, Schulzke JD: Epithelial barriers in intestinal inflammation. Antioxid Redox Signal 2011, 15:1255–1270
17. Mayer EA, Knight R, Mazmanian SK, Cryan JF, Tillisch K Gut microbes and the brain: paradigm shift in neuroscience. J Neurosci. 2014 Nov 12;34(46):15490-6
18. Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci. 2015; 9: 392
19. Ozdal (2016) The Reciprocal Interactions between Polyphenols and Gut Microbiota and Effects on Bioaccessibility. Nutrients 8(2): 78