ASDA Health Matters

What are probiotics?

Probiotics are live micro-organisms, which are mostly bacteria. These are added to certain foods we eat and stay alive until they reach our digestive tract (gut). You might usually think of bacteria as something which makes you poorly, through food poisoning, infection or the common cold, for example. However, most bacteria are actually harmless and there are many, such as probiotics, which are believed to be beneficial, or helpful, to our health - these are often referred to as ‘good' bacteria.

What are prebiotics?

Prebiotics are a functional part of some foods which are high in fibre (fibrous), particularly fruit and vegetables. They occur naturally in these foods but can also be synthesized and added to foods. Prebiotics remain undigested until they reach your large intestine. Here, they encourage the growth of helpful bacteria by acting as a "food" for them to eat.

Collectively, all the bacteria in our digestive tract are called microflora and to remain healthy, we need to have a balance between helpful and harmful. Eating a balanced diet should naturally provide us with this balance.

Where are they found?

Probiotics can be found in certain cultured yoghurts and dairy products. ‘Cultured' means they contain bacteria. In these products, fermentation occurs, which means the bacteria produce an acid which improves flavour and texture. Lactobacillus and Bifidobacterium are two bacteria commonly found in these yoghurts and drinks. You may have noticed these names on product packaging.

It's worth remembering, that specific bacteria have specific probiotic effects - known as ‘strain-specific' probiotics. This means that, for example, if you suffer from constipation, Lactobacillus may relieve symptoms but Bifidobacterium may not. Also, we are all humans and all unique, so if a friend has similar symptoms to yours and recommends a product, you may not find it works for you.

Prebiotics can be found in lots fruit and vegetables - especially the fibrous ones such as those with skins on, for example, apples or brussels sprouts. They can also be contained in wholegrain carbohydrates, such as granary bread.

Below are some examples of probiotcs and prebiotics and their potential benefits which you may notice on food labelling.

PROBIOTICS

• Name (strain):Lactobacilli and Bifidobacteria
• Sources: certain yoghurts, other cultured dairy products and some non-dairy products
• Potential benefits: may improve gut health and immunity

PREBIOTICS

• Name:Inulin, fructo-oligosaccharides (FOS), polydextrose, arabinogalactan, Polyols:lactulose, lactitol
• Sources:wholegrains, onions, bananas, garlic, honey, leeks, artichokes, fortified foods/drinks, dietary supplements
• Potential benefits:may improve gut health; may improve calcium absorption

How are they helpful to our health?

To understand how probiotics and prebiotics work, you need to know what happens in your digestive tract when you have a drink, snack or meal. Food and drink passes from your mouth into your stomach, into your small intestine and eventually into your large intestine (colon). Along the way, it's broken down into smaller and smaller components, called nutrients, which are absorbed. But with some foods, this doesn't happen and food reaches the colon undigested - this is where pro and prebiotics come in.

When we eat such foods, fermentation occurs in our colon and this gives off gases that can cause embarrassing 'wind'! However, this is not a reason to avoid prebiotic foods as they also produce fatty acids - these may not sound very nice but they're good, because they slow down the growth of harmful bacteria and help gut regularity. Into the bargain, they help us absorb important nutrients such as calcium and iron, which we need for healthy bones and blood.

There is some evidence that having a balance of microflora in our digestive tract may also improve our immune system, reduce the risk of cancer and provide relief of symptoms associated with the following conditions. Bear in mind though, that more studies need to be done before experts agree on these benefits.

• Antibiotic-associated diarrhoea (ABD)
• Irritable Bowel Syndrome (IBS)
• Inflammatory Bowel Disease (IBD)
• Lactose intolerance
• Allergies

Probiotics, prebiotics and allergy

Allergic conditions, such as eczema and asthma, together with food intolerances, are on the increase and usually occur in young children. When we're born, we have no bacteria at all and have no protection from disease, which is why young babies and children easily develop coughs and colds. The good news is that as we grow, we very quickly build up bacteria in our bodies, which are either passed from our mother, through breast milk, ingested from food or picked up from our environment. These give us a strong immune system and protect us from infection and feeling poorly.

So why are allergic conditions on the increase? One theory is that over the last ten years or so, bacteria seems to have become a bad word - we only need to look at a cleaning product or hand wash which advertises its ‘anti-bacterial' power! A generation or two ago, these products weren't available, which means we were less protected from bacteria and allergies were less common.

In order to manage this increase, research into probiotics, prebiotics and allergy disease is a fast-growing area amongst scientists.

How to keep your bacteria balanced!

For most of us, the answer is simple - stick to a balanced diet that contains plenty of carbohydrate, especially wholegrains and fruit and vegetables, and don't eat more than the recommended amount of protein, fat and sugar. Generally speaking, this means that one-third of your plate should consist of carbohydrate, one-third fruit and vegetables and the remaining third mainly protein and dairy. It's important too, to have plenty of fluid to keep your gut moving and flush out bacteria.

Unless you're concerned about problems with your digestive tract, it's not necessary to buy ‘specialist' products in the form of cultured yoghurts and drinks. As you can see, pro and prebiotics can be found in many foods we eat every day - and which are less costly! If you decide to try specialist products, evidence suggests that the product should be consumed daily for at least one month before any benefits are experienced. After that, you should continue to take the product daily, otherwise there will be no long-term benefit.

If, however, you're not feeling better at the end of a month, it may be that your body is taking a little longer to adjust, or that you may be more suited to a different product.

You may also want to consider whether you are under any particular stress at the moment, have recently been poorly or taking any medication - all these things can upset our gut.

And finally, if you are at all concerned about any aspect of the above, please seek advice from your GP.