Heard of probiotics, right? Then it's time to also jack up your knowledge on prebiotics – certain foods that can boost the growth of the good bacteria in your colon.

By now, you know that it's good for you to include yoghurt with live cultures, or other foods or supplements that contain so-called probiotics, in your diet.

Research has shown that probiotics – microbial foods or supplements that can be used to change or improve your intestinal bacterial balance – could boost immunity, treat diarrhoea, help for lactose intolerance and possibly prevent allergies and inflammatory bowel disease.

But what if you don't like yoghurt? Or you're not interested in taking supplements? Is there a way in which you can ensure a healthy gut flora simply by looking after the good bacteria that are already present in your gastrointestinal tract?

Yes, there is. And the answer could be as simple as eating more fruits, veggies, wholewheat foods and commercially-produced products that contain the right kind of fibre.

By including these foods in your diet, you can make sure that the probiotics you’re ingesting (if you do eat yoghurt or take supplements, for example), work more effectively towards protecting you from disease. At the same time, you'll also be boosting the good guys that are already present in your colon.

How does it work?
Foods that contain the above-mentioned "right type of fibre" are known as "prebiotics". Simply put, prebiotics are non-digestible food products that stimulate the growth of "good" bacteria already present in the colon. In other words, prebiotics act as food for probiotics.

While more research is being done, two fructo-oligosaccharide compounds have, in recent years, emerged as having very important prebiotic properties. These compounds, called inulin and oligofructose, contain substrates that nourish the beneficial microorganisms in the gut.

Both inulin and oligofructose are generally classified as dietary fibre. This is because of the fact that both simply pass through the GI tract without being absorbed (like other types of dietary fibre). Both also have definite health benefits.

These two fructo-oligosaccharides occur naturally in over 36,000 plants and vegetables, including chicory, artichokes, asparagus, salsify, leeks, onions and garlic. Chicory is a particularly good source of priobiotics.

What are the health benefits?
Unlike most other dietary fibres, inulin and oligofructose are selectively fermented by the intestinal flora, i.e. it benefits very specific bacteria in the colon.

Research has shown that these two fructo-oligosaccharides are selective growth media and energy substrates for the Bifidobacteria, which act as "good" bacteria (probiotics) in terms of human health.

By boosting the growth of these good bacteria, the prebiotics help to increase the bacteria's efficiency. And it has been shown that the Bifidobacteria group:

• Has an antibacterial effect on pathogens ("harmful" bacteria).

• Helps with the production of the B-vitamins.

• Promotes immunological attack against malignant cells, which cuts the risk for colon cancer.

Interestingly, preliminary studies are also showing that inulin and oligofructose could have a positive effect on calcium absorption, thereby increasing bone mineral density.

The fact that the fructo-oligosaccharides have a very low energy value is an added bonus.

How is it applied?
More and more manufacturers of food products and probiotic supplements are starting to recognise the potential of prebiotics. As a result, a trend is starting to emerge in which food and supplement manufacturers are making a point of adding inulin and/or oligofructose to their probiotic products.

Even companies that aren't specialising in probiotic foods or supplements are recognising the need for more products that have prebiotic qualities. Examples of other types of food to which the addition of prebiotics have been successfully applied include fruit juice, cereals, baby foods, ice cream, biscuits and even chocolate.

Making the most of prebiotics
While more research needs to be done before definite recommendations can be made, experts say that it couldn't harm to include more fibre in your diet.

Fruits, veggies and wholegrain foods are good sources of dietary fibre. Make a point of combining these foods with probiotic-rich foods, like yoghurt, sauerkraut and tempeh (a dish made from split soybeans and water), to make the most of their beneficial properties.

Read more about digestive health:

>> Pre and probiotics boost immunity

>> A healthy digestive tract

>> Good bacteria vs bad bacteria

You will find a comprehensive range of probiotics for the whole family in the Health365 shop


Image via Thinkstock.