Probiotics

What are probiotics?

Probiotics are replacement so-called ‘good’ bacteria that help keep the gut healthy. These will improve digestive disorders but there are other, less obvious but equally important health benefits.

It is well known that the human gastrointestinal system contains an immeasurable amount of ‘friendly’ bacteria. Most of the bacteria found in the large intestine are anaerobes including bacteroides, eubacterium and bifidobacterium. Imbalance and/ or overproliferation of the wrong types of bacteria in the gastrointestinal tract is a well established phenomenon and healthcare practitioners often use oral probiotic supplementation to re-balance this microflora environment.

There have now been over 50 clinical trials involving some 6,000 patients and all asking “Do Probiotics really work?” Some scientists have looked at how they can help relieve and even prevent digestive disorders, including irritable bowel syndrome (IBS). Some have examined how Probiotics can help prevent recurrent thrush; others investigated how they could help control different types of diarrhoea.

In 100 patients with severe IBS, for example, of the 20 who took a Lactobacillus probiotic, 70% reported a dramatic improvement in symptoms. Of those who took conventional anti-spasmodic treatments, less than a third reported any kind of relief and of those who took an inactivated placebo pill, nobody said they felt any better.

Who Is Going To Benefit from taking Probiotics?

Since prevention of sickness, including digestive problems, is so much better than cure, we can all benefit from taking a daily Probiotic. Among those who will see the most dramatic difference to their health and well-being are:

• Anyone who has a hectic and stressful lifestyle
• Anyone who is prone to infections; including colds
• Anyone who has a history of Digestive Stress - especially IBS
• Women who are prone to thrush
• Anyone who is or who has been taking antibiotics
• Anyone travelling abroad

The health benefits of oral probiotic supplements are subsequently now well known and accepted amongst the health care profession. Probiotics exert benefits through the prevention of colonisation, cellular adhesion and invasion by pathogenic organisms; antimicrobial activity and immune modulation. Evidence suggests that providing beneficial bacteria may reduce cancer risk and decrease inflammation. Probiotics may therefore be beneficial for inflammatory bowel disease, irritable bowel syndrome, intestinal inflammation and diarrhoea.

Emphasis has been placed on the development of high strength probiotic supplements. However recent evidence suggests that such high numbers of bacteria may not be necessary for the beneficial colonisation and beneficial effects of probiotics in the gastrointestinal system.

Environment for colonisation

An environment conducive to the growth and metabolism of beneficial bacteria involves a supply of essential nutrients. Prebiotics including dietary fibres can aid in establishing this environment by providing substrates for bacterial fermentation and proliferation. A "prebiotic" is a nondigestible food ingredient whose beneficial effects on the host result from the selective stimulation of growth and/or activity of members of the bacterial community that inhabit the human bowel (the gut microbiota).

In human cells, inulin-derived fermentation products inhibit cell growth, modulate differentiation and reduce metastasis activities. Evidence has accumulated that shows inulin-type fructans and corresponding fermentation products reduce the risks for colon cancer.4Compared with transitory effects of probiotics, the prebiotic action of fermentable carbohydrates potentially provide the opportunity for sustainable modulation of activity of the gut microbiota.5

Do probiotics need to be enteric coated?

Enteric coating is often used in the encapsulation processes to allow passage of the supplement/medicine in question through the stomach without being broken down by gastric acid. The benefit of this is thought to be release of the product in the small intestine rather than the stomach. However, it may be queried whether this process is really necessary for the body to receive the benefits of probiotic supplementation? When formulating probiotic supplements, careful consideration of specific species and strains are taken into consideration;

• firstly for their specific areas of colonisation (e.g. small intestine, large intestine)
• secondly for their specific activity and benefits in particular conditions (e.g. anti-inflammatory, immune modulating, anti-diarrhoeal, suppression of specific detrimental bacteria)
• thirdly for their resistance to both gastric and bile acid

This third point takes into consideration whether the specific strains of bacteria will potentially be killed by gastric and bile acid on their passage through to the intestines.
Significant information is available on the acid resistance of bacteria species and strains. Lactobacillus plantarum, Bifidobacterium longum, Lactobacillus casei and Lactobacillus rhamnosus being extremely acid resistant .

Friendly bacteria may be useful – alive or dead!

Common sense tells us that even though these bacteria are considerably acid tolerant/ resistant, not every single one will remain alive and “viable” upon reaching the intestines. However, recent data from animal models indicate that the protective effects of probiotics are at least partially mediated by their own DNA rather than their metabolites or their ability to colonise in the colon. This implies that the therapeutic benefits of probiotics not only mediated from live viable bacteria but also from dead ‘non-viable’ bacteria. One study evident of the beneficial effects of dead bacteria showed that both live and heat killed Lactobacillus rhamnosus GG can modulate inflammatory cytokine activity. Both live and dead LGG down-regulated activities of TNF-α, though the dead bacteria had a slightly lower potential to do this than the live bacteria.

Live bacteria produce essential organic acids, but dead bacteria may also release organic acids that can be beneficial to the human gastrointestinal tract. Dead bacteria can transfer DNA to surrounding bacteria to enhance their proliferation and colonisation.

This information provokes the question once again, whether enteric coating is indeed beneficial or simply adding unnecessary cost to probiotic supplements.

>Prebiotics

Research illustrates that ensuring the correct environment and ‘food’ for the bacteria are just as important to ensure their activity, and providing prebiotic supplementation With a prebiotic, you go back a nutritional step and simply feed up the good bacteria that already exist in the digestive tract), alongside probiotics may enhance probiotic activity and benefits moreso than providing simply a super strength probiotic. Increasing evidence also suggests that combining several probiotic bacteria into multistrain probiotics will achieve stronger effects than single-strain probiotics. Therefore a modest strength, multi-strain probiotic formula together with prebiotics and fibre may provide more benefit than a super strength probiotic formula.

The term prebiotics was first coined in 1995 when it was used to define “a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon that can improve the host health.”

Clinical trials on humans have already shown this works, using substances called oligosaccharides as prebiotics. The best-known of these is fructo-oligosaccharide, usually shortened to FOS. Oligosaccharides are sugars that occur naturally in foods such as leeks, asparagus, Jerusalem artichokes, garlic, onions, wheat, oats, and soybeans.

FOS are not degraded or absorbed in the upper intestinal tract, and so can survive the normally hazardous passage through the digestive system to reach the colon. However, you cannot eat enough of these foods in a normal diet to provide a significant prebiotic effect, which is why you will need to take a supplement.

FOS is the current leader in prebiotics, not least because we know it works. In trials with human volunteers, for example, those whose diets were supplemented with 15g per day of FOS developed far more of the beneficial bifidobacteria than those in the control group who were given sucrose. FOS supplementation was also shown to significantly reduce the populations of less beneficial gut bacteria, and these effects were recorded for as long as the FOS was being taken.

It is true that both groups had higher levels of more beneficial bacteria at the end of the two-week trial, but the improvements with the FOS were more impressive. The reason FOS are so effective is that they only promote levels of the good bifidobacteria strain. This is able to thrive, when other micro-organisms show no change, because it has a potent enzyme called Beta-fructosidase that can easily breakdown the FOS molecules for digestion by the bacteria.