By JANE E. BRODY
JULY 21, 2014 10:27 AM The label on my bottle of Nature’s Bounty Advanced Probiotic 10 says it contains 10 probiotic strains and 20 billion live cultures in each two-capsule dose. The supplement provides “advanced support for digestive and intestinal health” and “healthy immune function.”
I have no way to know if any of this is true. Like all over-the-counter dietary supplements, probiotics undergo no premarket screening for safety, effectiveness or even truth in packaging. Can there really be 20 billion micro-organisms “guaranteed at the time of manufacture” in those dry capsules that will spring into action in my digestive tract?
I’m not sure what prompted me to try probiotics. Perhaps it was to stimulate a sluggish gut or to counter lactose intolerance or, as some enthusiasts have suggested, to enhance a healthy old age. Japan, where a woman’s life expectancy far exceeds ours, accounts for half the world’s consumption of probiotics.
Maybe it was the invitation I received to a coming symposium, “Gut Microbiota, Probiotics and Their Impact Throughout the Lifespan,” convened by Dr. W. Allan Walker at Harvard Medical School.To be sure, lay and scientific literature are filled with probiotic promise, and I am hardly the only consumer who has opted to hedge her bets. The global market for probiotic supplements and foods is expected to reach $32.6 billion this year, with a projected annual growth of 20 percent or more.