Culture club: probiotics, the latest in functional food ingredients, are popping up everywhere--in yogurt, kefir, energy bars, powders, milk and more. So now there's no excuse for missing a dally dose of the "good guys".

When it comes to intestinal flora, there is no room for weeds, says Jonny Bowden, PhD, CNS, author of The 150 Healthiest Foods on Earth. "The gut is like a garden," says Bowden. "There are flowers (good Bacteria, aka probiotics, such as Lactobacillus acidophilus and Bifidobacterium bifidum) and there are weeds (harmful bacteria)." In a healthy person, the two are kept in check. But unfortunately, due to poor diet, and good guys, harmful bacteria have the competitive edge for space in the gut. The resulting imbalance could lead to digestive problems, poor immunity, reduced nutrient absorption, allergies, bloat, brain fog, yeast infections and even bad breath. And no wonder--the digestive system plays the starring role in your immune system. "The 'bad guys' feed on most of the things we eat in the American diet, such as sugar, bread and pasta," says Bowden. "Giving your body probiotics is like feeding the flowers."

Fortunately, there is no shortage of food and supplements containing probiotics these days. Take a look:

Yogurt and "Mini-Yogurts"

Yogurt is probably the most popular source of good bacteria, including L. acidophilus and L. casei. But be aware that not all yogurt contains these healthful bacteria, even if they're listed on the labels. Look for brands that contain live cultures added after pasteurization. "Some products could have started life with active cultures, but pasteurization kills them because it's a high-heat process," warns Bowden. And because sugar feeds the bad bacteria in your system, plain yogurt is best. "If sugar is added, you're just trading off benefits, " says Bowden. The same goes for sweet treats masquerading as health foods, such as yogurt-covered peanuts and raisins. "These products have no probiotic benefits," he says.

Individual "mini-yogurts" are an easy way to get an enormous amount of healthful bacteria (up to 50 billion live organisms) in one probiotic-packed shot. Bio-K+, for example, is sold in small individual containers and available in the refrigerated section of health food stores.

If you are lactose intolerant, you can still enjoy yogurt with no worries, because live yogurt culture contains enzymes that break down lactose.

Product examples: Nancy's Honey Yogurt in Plain; Bio-K+ Dairy Culture in Fruity.