The yeast species called candida albicans lives in your gut. That's normal and not a problem — until there's too much of it, which then becomes a condition called "yeast overgrowth."

When there is an overgrowth of billions of unnecessary yeast, your gut turns into a churning fermentation tank. (Yeast, remember, is the organism that ferments beer and wine.)

Needless to say, they generate plenty of excess gas and the bloating that goes along with it. They also play havoc with the production of normal stool, while pumping out toxins, weakening the immune system and generally causing problems.

One little-known sign of yeast overgrowth: chronic nasal congestion and sinus issues.

Yeast overgrowth is typically triggered by one or more of the following factors:

• Taking antibiotics. They kill the friendly bacteria in the gut that keep candida in check.

• Taking high-dose anti-inflammatory corticosteroids, like prednisone, which suppress immune function.

• Eating a high-sugar diet. Sugar is yeast's favorite food.