Looking for better digestion in a bottle? Here are some important tips to keep in mind when shopping for probiotic supplements.

Everyone’s gut is populated with bacteria. Some of these microorganisms have the potential to be harmful, but many of them are beneficial and help protect the digestive tract. The benefits of these “bugs” extend beyond digestion, contributing to healthy skin, blood and immunity as well. Probiotics can be found in supplement form as well as naturally existing in cultured and fermented foods. Common food sources of probiotics include yogurt, kefir, sauerkraut, kimchi, miso and other fermented items. Probiotic supplements are most often available in capsule form but can also be found in liquid tinctures. More and more foods are being fortified with probiotics, including chocolate bars, beverages and breakfast cereals.

The supplement industry remains poorly regulated, so it’s up to consumers to choose wisely. Since you can’t rely simply on what’s on the label, here are some tips.

Many supplements contain more than just probiotics, and consumers should be mindful of other ingredients in case of allergies and to avoid experiencing interactions with medications or taking in toxic doses of nutrients they are already getting enough of.

Some require refrigeration, and those that can be stored at room temp must be kept clear of heat, as it can destroy the bacteria.

Many products will be less effective past a certain date.

When first taken, probiotics can cause gas and bloating … which may be the symptoms some folks are trying to alleviate by taking a probiotic.

5) Get your doctor’s advice if you have a weakened immune system.

Probiotics may be harmful to those with weakened immune systems; consult your doctor before taking a probiotic supplement.

Dana Angelo White, MS, RD, ATC, is a registered dietitian, certified athletic trainer and owner of  Dana White Nutrition, Inc. , which specializes in culinary and sports nutrition.