Probiotics are emerging as a way for companies to market their products now that the consumer is becoming more familiar with their role. Some of these products such as kefir and some yogurts have had probiotics in them naturally, however other products are adding them in an effort to differentiate themselves in the market place.

Fermentation is when carbohydrates in a food or beverage break down to form alcohol, as in wine and beer, or lactic acid in preserved food. In lacto-fermentation, the ‘good’ bacteria, or probiotics, drive the transformation. Fermentation is manipulating environmental conditions to encourage the growth of some micro-organisms and not others.

So, how does it all work? Fermented raw vegetables as well as cultured foods such as yogurt and kefir infuse the gut with healthy bacteria. The fermentation increases the bioavailability of minerals and vitamins, which lead directly to health benefits. Fermentation also creates lactic acid, making minerals more soluble. It also produces enyzmes that help break down proteins and fatty acids, helping digestion, and yielding the benefits we associate with probiotics.

While more research is needed, some evidence suggests that taking probiotic supplements can reduce the fever incidence due to colds and flu by 73 percent in children. A small study also found that by eating yogurt fortified with probiotics did increase T-cells, the body’s key players in the defense against viruses and other pathogens. There isn’t enough research to show that probiotics would fight off major illness.

Probiotics and digestion have a more clear relationship. Fermented milk or kefir is easier to digest due to the removal of most of the lactose. These may be better options than milk for those who are lactose deficient. Some evidence also suggests probiotics to be beneficial in treating diarrhea, treating the symptoms associated with irritable bowel syndrome and speeding the treatment of certain intestinal infections.

The bottom line? If you are taking an antibiotic, I believe it to be beneficial to double up on your yogurt or kefir; my primary recommendation is to get necessary nutrients through food rather than through supplements. If eating those foods isn’t an option for you, then invest in a probiotic supplement.

Melissa Gerharter MS, RD is co-owner of Joust Strength and Fitness of Ann Arbor, joustfitness.com. She is also a personal trainer and an adjunct lecturer at Eastern Michigan University. She can be reached at Melissa@joustfitness.com.