You are here

Ask Dr. Sears: Probiotics

Q. What are your thoughts on probiotics, where live cultures of bacteria are used to replenish the good bacteria that might have been wiped out after taking too many antibiotics? How does this work? Does it help?

A. Probiotics are medically defined as organisms in fermented foods that promote good health and establish the right balance of intestinal bacteria. Billions of bacteria reside in healthy intestines where they contribute to the health of the colon. Probiotic supplements are just these same bacteria packaged as supplements in powder or in capsule form.

Do probiotics help? Well, when I teach parents and older children about intestinal health, one of my lessons is "Put the right bugs in your bowels." It's a symbiotic relationship—these bugs reside in the warm environment of the colon and in return they do the following good things for the body:

Keep harmful bacteria in check

The resident probiotic bacteria fight any harmful germs that may enter the intestines. Probiotics are now being used in nearly all intestinal inflammatory illnesses.

Help antibiotic-induced diarrhea

I always prescribe probiotics to be used during, and for at least two weeks after, antibiotic treatment. Antibiotics kill the bad germs that can cause infections throughout the body, but they also can kill the beneficial bacteria in the bowels. Probiotics replenish the healthful bacteria that may have been killed by the antibiotics and restore the balance between healthful and harmful bacteria in the bowels.

Work as preventive medicine

Studies have shown that probiotics can lessen the spread of diarrhea outbreaks in daycare settings. Probiotics seem to significantly decrease the shedding of viruses in the stools of affected children.

Produce good fats

These healthful bacteria ferment the soluble fiber in food, producing healthful short-chain fatty acids that nourish the cells of the large intestine, thereby promoting healing of infected intestinal lining. These protective fatty acids are also thought to reduce the development of intestinal cancer and inhibit the growth of harmful bacteria and they travel to the liver where they can decrease the liver's production of excess cholesterol.


The health benefits of probiotics have been known for over a hundred years. In fact, in the early 1900s Professor Metchnikoff at the Pasteur Institute in France won the Nobel Prize for his studies relating to probiotics after he noticed the prolonged lifespan of Bulgarian peasants who consumed a lot of yogurt.

Probiotics have been used in preventive medicine throughout Europe for many years. They are just now gaining more scientific credibility and popularity in the United States. For example, a study done in 2001 showed that giving probiotics to pregnant mothers with high risk for allergies was associated with significantly decreased incidence of eczema in their babies. This is thought to be because probiotics promote the overall health of the immune system.

You may already have probiotics in your diet if you eat yogurt. Many yogurts contain the probiotics acidophilus, bifidus, and bulgaricus. When buying yogurt, be sure the label says "live and active cultures." This is the official statement of the National Yogurt Association signifying that healthful probiotic bacteria have been added after pasteurization. Avoid yogurts that do not carry this label. If you are looking for a supplement, the probiotic that I personally prescribe in my pediatric practice is Culturelle, which is lactobacillus GG, the probiotic that has been used in many scientific studies.

comments