Harmful bacteria such as Clostridia and Veillonella are those that possess pathogenicity or transform food components into harmful substances.

Intermediate group bacteria such as Bacteroides and Eubacteria do not show virulence under normal conditions, but they may cause opportunistic infections when our body's immunity or resistance is low.

Beneficial bacteria represented by Bifidobacteria and Lactobacilli suppress the harmful bacteria and exert many beneficial properties as described below.

A healthy intestinal flora is where the beneficial bacteria keep the harmful bacteria under control. When they take up most of the available space in your intestines, the harmful bacteria have less opportunity to grow to form a thriving colony that will make you ill.

If the number of beneficial bacteria drop, the harmful bacteria will grab the opportunity to take over. So as you can see, the balance is very crucial.

What can upset our bacteria balance: -

• Diet that are too oily, fatty, fiber lacking and too much alcohol consumption
• Stress. Research shows that continued stress can upset your intestines
• Drugs including antibiotics. Antibiotics kill both harmful and beneficial bacteria
• Use of steroids such as hormonal drugs and 'the Pill'
• Ageing
• Infection by yeast and food-poisoning bacteria such as E. coli and Salmonella