Probiotics are supplements that contain "good" bacteria, such as Lactobacillus acidophilus and Bifidobacterium infantis, which can help improve digestion and protect you from harmful bacteria. Probiotics have a short shelf life and require refrigeration to retain potency. Heat, moisture and direct sunlight can destroy the "good" bacteria in probiotic supplements. However, according to Jordan Rubin and Joseph Brasco, authors of "Restoring Your Digestive Health," you can test the viability of any probiotic supplement at home before risking the chance of taking a supplement that might not be effective.
Pour 4 oz. of cold milk into a glass. Add two to four capsules or caplets of any probiotic supplement to the milk.
Place the glass in a room temperature location. Leave the glass untouched for 24 to 48 hours.
Check the glass after the time has elapsed. If the milk has not curdled or thickened into a yogurt consistency, the probiotic is most likely not viable. The test works by measuring the ability of the probiotic to produce enzymes. If the probiotic can't produce enzymes in the milk, it probably won't be able to produce enzymes in the stomach.