Small amounts are then taken from the samples and grown in cultures. Once grown, the bacteria are freeze-dried and kept in cold storage until they're reactivated by increased temperature, moisture and an adequate supply of nutrients. If probiotics are stored on a warm shelf or transported in warm conditions, the viability of the bacteria decreases rapidly, says Anthony Almada, M.S., supplement researcher. For optimal effectiveness, he advises probiotics be kept at as cold a temperature as possible. Even freezing probiotic products won't damage them, he says.
Some experts disagree.
R.D. Certain enterococcus species of probiotics demonstrate improved temperature resistance, he adds. Once ingested, probiotics navigate stomach acid and nest in the intestines, where they can benefit the body. Almada says products should contain more than a billion of these good bacteria per dose to ensure a potent amount makes it through the stomach since many are destroyed en route. Once in the small intestine, they attach to the villi, tiny finger-like protrusions extending from the wall of the intestine. In doing so, they increase that organ's absorption area, where they aid digestion and fight infection, according to Almada.