Have you ever taken your child, or gone to the doctor yourself for a strep throat or ear infection, or pneumonia or urinary tract or intestinal infection? Probably so. Have you or your child ever been hospitalized with an even worse infection? Hopefully not.

In either case, your doctor no doubt recommended an antibiotic – a very specific antibiotic -- for whatever specific infection he or she thought would effectively combat that bacterial infection. My point is: that while all antibiotics treat infections, the decision of which antibiotic should be used depends on the type of infection and its probable bacterial cause.

So you are probably saying to yourself, “I got it Dr. Stan – specific bacteria and a specific situation warrants a specific antibiotic. That makes perfect sense.” Yet the way most of the public thinks about probiotics and the way they're advertised and sold on the shelves, it's as if they're all in the same barrel, and you can just scoop some up and shovel them into your kid’s or your own body. They'll all alter the intestinal bacteria and immune system in the same way and you'll feel much better, no matter your problem.

That's just not true. As described in What to Feed Your Baby in much more detail, probiotics differ dramatically.

Yes, they all contribute to the bacteria living in your intestines (intestinal microflora), but only to a small degree to your or your child's normal state of health. Most probiotics provide a few billion organisms (expressed as colony forming units or CFUs) per dose or serving. A few billion CFUs is actually a tiny amount (about a millionth) of the number of bacteria and organisms living in your lower intestine. But if you have taken an antibiotic which wipes out some of that number or you have diarrhea flushing them out of your system, a few billion probiotic CFUs ("good" bacteria) help to restore a "healthier" population in your intestine.

However, probiotics, like antibiotics, differ considerably in their effect. Some don't even make it past the stomach, where many are destroyed by the acid and enzymes. And others don't adhere well to the intestinal surface, so they pass right on through. Some have been tested and seem more effective in reversing diarrhea (Lactobacillus GG or Culturelle) while others seem better for constipation (Bifidobacterium infantis 35624 or Align) or colic (Lactobacillus reuteri or Biogaia). And many have not undergone rigorous testing at all.

Notice that Align refers to a specific strain (35624) of a common probiotic species (B. infantis). That emphasizes the point that even the strain of the probiotic can make a difference, yet most probiotics that are sold do not specify the strain on their label. Some provide the milligrams of probiotic provided in each dosage or serving, but that has little meaning.

WHAT YOU SHOULD KNOW WHEN SHOPPING

What you want to know is what probiotic(s) are included--down to the strain. You can then look up the scientific research on that strain if you want to. You want to know how many CFUs of each strain are present at the end of the product’s shelf life. Probiotics lose effectiveness over time, so you are much better buying probiotics that have just been stocked. And you are better too finding ones that have substantiated health claims regarding the condition you are trying to improve. That means that meaningful research has been done and you're not just depending on the manufacturer's promotional material or on testimonials of people who say they feel great taking them.

ARE THEY SAFE?

Generally, the answer is yes. Many probiotics have been around in yogurt and other fermented foods since those foods existed. But some of the probiotics never got past the stomach acid.

But sometimes the answer is no, definitely not--though you'd think the opposite. Infants, children and adults with immune deficiencies, auto-immune conditions or cancer being treated with immune-suppressing drugs may not be candidates for probiotics--though they're the ones you'd think would benefit the most. The problem is that such individuals are so susceptible, a probiotic can establish itself in the blood stream and cause a serious -- even fatal -- infection. A clinical trial with a probiotic used to treat Crohn's disease in children had to be stopped in fact because patients on the probiotic got sicker than those who weren't taking it.

And of course, the question is how long they are needed. Unfortunately, we don't know. Stop a probiotic and the intestine gradually reverts to its normal intestinal flora. But that doesn't mean you should use it forever. I usually recommend you treat during the infection or problem and then once that's resolved, continue for another 2-4 weeks, depending on the severity of the problem.

So bottom line, the right probiotics can be helpful in certain conditions, for a not-indefinite period of time, with much to be learned about when they are best used and how to keep a naturally healthy intestinal immune system. PREbiotics can help. But that's another post--or a quick reference to that section in What to Feed Your Baby.