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Dr. Claudio Fiocchi on beneficial live bacteria
What role do bacteria normally play in the gastrointestinal tract?
The bacteria that we have in the gastrointestinal tract are essential, and without them, we can't live. In very simple terms, they break down the food, and allow us to absorb nutrients that are beneficial to us. Many vitamins, for instance, or essential amino acids, can only be absorbed by the body after a bacteria has broken them down. So they're absolutely essential in that respect.
How do probiotics function in the body?
Most of the information about how they work is not particularly solid from a scientific standpoint. But when probiotics are introduced into the body, they establish a rapport with other bacteria that naturally reside in the body. The probiotics live together with the preexisting bacteria in our bodies, and counteract the negative effects of other bacteria. But probiotics only persist as long as they are continually ingested. So if you don't eat any foods or supplements containing probiotics, after about a month, they will be all gone.
How do we get probiotics into the gastrointestinal tract?
Probiotics don't normally exist in the intestine in great quantities. To keep them at high levels, which is necessary for beneficial effects, they have to be continually ingested. We don't actually know how much you need to take. But bacteria that we normally have in the body —especially in the GI tract — are present in very large amounts. So common sense suggests that to counteract existing bacteria that may have deleterious effects, you need large amounts.
And what can go wrong if this balance is distrupted?
In healthy individuals, the immune system recognizes the gut bacteria as normal components in the body. In some people however, the immune system no longer recognizes the bacteria as natural and begins to react against them. The bacteria are recognized as something foreign and the immune system mounts an attack to get rid of it. We suspect that this may be the case in people with Crohn's disease or colitis, which are the two main forms of inflammatory bowel disease.
Are probiotics already being used in people with intestinal diseases?
Yes. Primarily they're used in conditions where we believe there is inflammation and by introducing probiotics the inflammation sometimes improves.
Now we don't know if probiotics in small amounts — like just eating yogurt — have a beneficial effect; it's hard to prove. But we can now give people probiotics in quantifiable amounts, large enough to induce changes in the intestinal flora that we can monitor and demonstrate.
Supplements are primarily used to help people with inflammatory bowel disease — Crohn's disease, ulcerative colitis — or irritable bowel syndrome, "spastic colon." And there are some studies that just came out showing there are some beneficial effects, particularly in something called pouchitis, which is an inflammation in the small bowel that has been reconstructed after a colon has been removed.
It's unlikely that probiotics by themselves will cure severe conditions, but they certainly look like they're going to be very useful as an adjuvant therapy-or something taken in addition to other treatments. And when the disease is brought into remission by more traditional medications, maybe we'll be able to keep them in remission using probiotics.
Do healthy people use probiotics?
Lots of people use them in the name of health and preservation of health. It's hard to prove that it's actually effective, because if you're healthy and you don't get sick, it's hard to prove that what you took is actually preventing you from getting sick.
How are probiotic supplements administered?
You ingest probiotics either in liquid form, or you can sprinkle them on food if you like, but not in something hot, because the high temperature will kill the bacteria.
In what kinds of foods do probiotics naturally exist?
Yogurt is the main one. They are also present in milk, fermented products, and perhaps a little bit in cheeses.
Are probiotics ever harmful?
So far, probiotics appear safe. There is no known case of probiotics causing serious diseases or specific reactions, primarily because probiotics are normal bacteria that we live with all the time but in larger amounts than we usually do. This is a very attractive and beneficial aspect of them, because it is a kind of "natural therapy" and they are not bacteria that cause problems.
Are probiotics regulated by the Food and Drug Administration?
Probiotics are particularly difficult to classify and regulate. The FDA sees probiotic supplements as something that could be classified as a drug, particularly if you make health claims from their use. They could also be classified as a food additive or as a health food.
And there are issues about quality since probiotics are live bacteria. Depending on the product, you can't be sure of the contents in the package. In order to keep them on health food store shelves for months if not years, they must be lyophilized, which means that the water is removed from the bacteria. A dried out bacteria comes back to life when water is added, but lyophilization is not an easy process.
What kind of research is being done using probiotics?
There are studies that have been started in Europe, the U.S. and in Japan looking primarily at the inflammatory conditions of the bowel, and irritable bowel syndrome. There are also some studies looking at some specific type of liver diseases-such as fatty liver-that have been done in a preliminary form. Many of the same studies are being done or have been done in animal models with specific diseases and they look promising.
Probiotics have been re-introduced in a more formal fashion only in the last five years or so. So that's a very short time to do a lot of studies. To have conclusive studies, I think we need at least five more years.