Foods available at the grocery store that claim to boost immunity are a simple matter of eating good bacteria to fight bad bacteria and viruses. Foods with pro-biotics can improve immunity and perhaps digestion, Dr. Dave Hnida reports.

Several studies show people who eat yogurt every day producer more infection fighting cells and have stronger immune systems than those who don’t eat yogurt.

As long as it says live and active cultures on the label, any yogurt should do the trick, Hnida says.

There are some products and special yogurts that have concentrated amounts of a special good bacteria that can also really improve the immune system. Lab studies seem to prove that those claims hold water.

Hnida said people should still get flu shots, on top of eating immune boosting foods.

There have been no comparison studies to compare yogurt use with vitamin C or Echinacea.

Research about the good bacteria and improved intestinal health isn’t as good. The good stuff in yogurt could help if people have diarrhea from an antibiotic or travel. It could also help lessen lactose intolerance. But it might not help cure irritable bowel syndrome.

Dr. Dave said the bottom line is the products are safe and really do help some people. But they’re not miracle products.

Dr. Dave’s List of Functional Foods:

For lowering cholesterol: Promise Activ Yogurt Shot, Minute Maid Heart Wise Orange Juice.

For boosting immunity: Dan Active, Horizon Organic Yogurts.

For regulating digestion: Dannon Activia, Stonyfield Products, Yo Plait Yo-Plus.

Dr. Dave said there are many more available. Read the labels to make sure the products contain live and active cultures.

Dr. Dave Hnida - MMVII CBS Television Stations