By James Collier BSc (Hons) – Nutrition Consultant
One area of nutrition which has attracted much interest from clinicians, health enthusiasts and sports nutritionists alike is the topic of intestinal microflora: there are claims that including probiotics and prebiotics in your diet can have health and performance boosting effects. Let’s look at what probiotics and prebiotics actually are and if there’s any truth to these claims.
What are Probiotics and Prebiotics?
Probiotics have a favourable effect on the population of the ‘good’ bacteria that reside in our digestive systems. A probiotic may be defined as: ‘A preparation or product containing viable, defined micro-organisms in sufficient numbers, which alter the microflora of the host intestine and, by that, exert beneficial health effects on the host’ (Schrezenmeier & De Vrese 2001).
In our intestine we have microflora which live in a natural symbiotic relationship with us in our intestines and are essential to good health having a number of positive effects: primarily helping our digestive systems work efficiently. We traditionally view bacteria as being ‘bad’, whereas in reality there are only a relatively small number of strains which are pathogenic and most microbes are harmless and contribute to good health and well-being (Gibson 2003).
Examples of probiotics include bifidus and acidophilus. They are found in live yoghurts, powders, specially formulated probiotic drinks or supplement capsules which contain one or more of the strains of these good bacteria.
With food processing, pollution and antibiotic therapy, numbers of our gut microflora can be diminished and studies have shown by actively consuming the bacteria the size of the colonies in the gut can be increased, which improves digestion.
Moreover, the numerous studies have also shown that with optimal numbers the immune system is improved, increasing our ability to fight disease. Probiotics may also have a role in reducing the severity of allergies.
Prebiotics are certain nutrients and constituents of food which our own gut flora feed on, thus increasing their numbers. Prebiotics include fructo-oligosaccharides (FOS), which are found naturally in many plants including leeks, onions, wheat, garlic, chicory root and artichokes where they function as storage carbohydrates, and some other soluble fibres found in pulses, fruit and some cereal products.
FOS are low molecular weight carbohydrates, and since they are not broken down significantly by the digestive processes in the stomach and small intestine, they are classified as dietary fibre. FOS are water soluble, being non viscous fructans, and have a low water retention capacity. Thus prebiotics also help digestion and the immune system by increasing microflora levels.
Both probiotics and prebiotics work to increase the colony size of the gut’s natural microflora. More and more people are including them in their diet to promote good health. The bodybuilder can also benefit, as he/she can digest their (large quantity) of food more easily helping to provide a more efficient influx of energy and protein.
Pro- and prebiotics may also help the immune system keep diseases at bay, so the bodybuilder can train harder and recuperate more quickly.
You can obtain probiotics from eating probiotic yoghurts like Muller Vitality and Danone Activia, probiotic drink products like Yakult, Actimel or LC1, or special powders or probiotic capsules. More recently bodybuilding supplement companies have recognised the benefits, and are adding probiotics and FOS to supplement formulas like meal replacement powders.
With food processing, pollution and antibiotic therapy, the numbers of bacteria living naturally in our gut are reduced, and research has shown that active consumption of bacteria increases the size of intestinal colonies thereby improving digestion of food.
Moreover, numerous studies have also shown that with optimal numbers of ‘good’ bacteria, the immune system is improved, increasing our ability to fight disease (Gibson & Roberfroid 1995). Probiotics may also have a role in reducing the severity of food allergies and intolerances, and may help reduce severity of symptoms in both osteo- and rheumatoid arthritis.
Pre- and probiotics have been incorporated into nutrition and sports supplements, nutraceuticals and functional foods in order to exert positive effects on the digestion, the immune system and possibly some degenerative diseases.
Orrhage et al, 2000 studied the effects on the intestinal microflora of oral supplementation with probiotics (Bifidobacterium longum, Lactobacillus acidophilus) and the prebiotic oligofructose in thirty individuals during the oral administration of an antibiotic for seven days.
All individuals showed a marked decrease in populations of microorganisms, notably a rapid and almost complete disappearance of Escherichia coli and bifidobacteria during antibiotic administration, which was accompanied by an overgrowth of enterococci and intestinal yeasts.
Although the number of lactobacilli also decreased, the population was higher in those individuals who received both daily prebiotic and probiotic supplements. This study demonstrates not only the susceptibility of healthy gut flora to antibiotics, but also the viability of prebiotic and probiotic supplementation.
Simply put: probiotics are foods which provide the actual ‘good’ bacteria, and prebiotics are those nutrients which the bacteria feed on to increase their numbers. The effect of a probiotic may be enhanced by having a prebiotic as the support medium; for example milk contains nutrients for lactobacillus, and so many probiotic drinks are milk or yoghurt-based.
Probiotic Yoghurts, Drinks or Supplements?
‘Which is the best way to obtain your probiotics?‘ is a common question on the MuscleTalk forums, understandably, as the TV ads by the yoghurt companies will have us believe that their yoghurts or drinks are best, and the nutritional supplement companies will have you believe that their powder or capsule is the best. This is marketing, obviously, and there are advantages for each.
With the yoghurts and yoghurt drinks one plus point is that the bacteria species are contained in a prebiotic medium, keeping them more active, plus you’re actively consuming prebiotics too. But the colony size is considerably smaller than what’s contained in a good quality capsule.
Indeed, in the drinks there may only be one species, whereas in the capsules (a good quality brand) there may be several. However, studies which have indicated benefits have only required amounts which can be obtained from the drinks – do we need the quantities in the capsules?
More may well be better especially considering there are different species, and bodybuilders do typically eat more food.
Let’s take a practical view: bodybuilders do eat yoghurts, so it may simply be convenient and cheaper to include a normal probiotic yoghurt – if you’re going to be eating a yoghurt anyway.
Should Bodybuilders and Hard Training Athletes Include Probiotics and Prebiotics?
Probiotics has been a nutrition buzz-word for a fair few years now, and unlike many nutrition trends, the interest in them has not fallen off. Why is this? The evidence that they promote good health is strong (Gibson 2003); not only do they help us digest our food, but they may also help reduce the severity of food poisoning and reduce effects of food intolerance.
Obviously the authenticity of anecdotal reports is very limited, but nevertheless, people who use probiotic formals do report improvements in general well-being and improvement in sports performance: this could be due to some direct effect, or, more likely, due to improved digestion of food and therefore increased availability of nutrients. Also improved immunity and reduction in illness means fewer interruptions in training.
I would certainly recommend every keen trainer includes probiotics and prebiotics in their diet for good health, which is of doubtless benefit to any keen bodybuilder.
- Gibson GR (2003). Probiotics & Prebiotics and their Function. Functional Nutrition 2 (2): 11-13
- Gibson GR, Roberfroid MB (1995). Dietary modulation of the human colonic microbiotica: introducing the concept of prebiotics. J of Nutr 125: 1401-1412
- Orrhage K, Sjostedt S, Nord CE (2000). Effect of supplements with lactic acid bacteria and oligofructose on the intestinal microflora during administration of cefpodoxime proxetil. J Antimicrob Chemother. 2000 Oct;46(4):603-12.
- Schrezenmeier J, De Vrese M (2001). Probiotics, prebiotics and symbiotics – approaching a definition. Am J Clin Nutr 73 (Suppl) 361s-364s