Your intestines are an important part of your immune system. Inside, nutrients from the foods you eat are absorbed and shuttled to cells throughout your body to keep them nourished and healthy.

Inside your intestines hundreds of different bacteria live — some good for your health, others not so good. It is important to have a healthy dose of good bacteria living in your intestines because they help your immune system get rid of bad bugs.

Being ill, chronically stressed, overtired or on antibiotics diminishes the number of good bacteria in your gut. To get and keep good bacteria growing inside your intestinal tract eat foods containing pro- and pre-biotics.

Probiotics

There are dozens of different types of probiotics (good bacteria) that take up residence in your intestines. They can:

• Help you absorb as many nutrients as possible from the foods you eat and actually make a couple of nutrients — vitamin B12 and vitamin K.
• Crowd out room in your intestine for not-so-good bacteria.
• Block harmful bacteria in your intestine from moving out into your bloodstream.
• Produce acids that lower the pH of the intestine which then kills disease-causing bacteria.
• Boost immune activity by sending signals to immune cells to stay on task and on patrol.
• Help create infection-fighting substances.

Note: The number of probiotics in a product can vary significantly. Look at the label. Ideally, it will list the type of bacteria in the food and the amount of bacteria present. If not, look for a seal that notes the product contains "live active cultures." Research says a daily intake of 3 to 5 billion "units" helps health. Wade in slowly when using probiotics-jumping in could lead to unpleasant intestinal side effects.)

Prebiotics

These are proteins and undigestible parts of certain foods (fiber) that when eaten feed the healthy bacteria in your intestine and promote their growth and activity.

Barley, oats, beans, pears, apples, citrus fruits, artichokes and Brussels sprouts plus nuts and seeds contain a type fiber that encouages healthy bacteria to grow.

Once you stop including probiotics and prebiotics in your diet, their beneficial activity disappears.