Probiotics and prebiotics: Do they work?
Thursday, June 14, 2012
Most parents have heard of probiotics and prebiotics and may wonder whether these supplements hold the key to optimum health for their children. The answer: Much of the information so far is promising, but a lot more needs to be gathered before doctors can agree with the popular media about the amazing claims made about these substances.
To understand all the fuss, we need to take a short tour through the body. Bacteria live with us from the moment we enter the world until the day we die, and even after that. The richest population of bacteria is inside our intestines, with up to 500 different species and trillions (I am not exaggerating) of individual bacteria living in the large intestine of an average adult. At birth the intestines are sterile, but by 48 hours old, babies have a substantial amount of bacteria in their intestines. These bacteria, intestinal "flora," are critical to digestion, aid in the development of parts of the immune system, and contribute to good health.
Probiotics are supplements that contain specific kinds of bacteria intended to change the flora in the intestines and improve health. Prebiotics are food for probiotics. Growing evidence suggests taking probiotics as a supplement or within food may prevent certain illnesses.
Human milk, which is a natural prebiotic and may also contain naturally occurring probiotics, is considered the healthiest diet for babies under 6 months old. Studies evaluating supplemental probiotics in infants have shown a decrease in the duration of diarrhea by one day when given early in the course of a viral gastroenteritis ("stomach flu") and they may help prevent antibiotic-associated diarrhea, reduce the incidence of colic and prevent cold symptoms. More evidence is needed, but probiotics may help decrease allergic diseases in childhood when given to pregnant moms and continued in the baby for six months after birth.
Some infant formulas are now supplemented with probiotics. These formulas are not harmful, but they have not been proven to be any healthier than formulas without probiotics. So far, there is not good evidence for the long-term use of probiotics in treating disorders such as Crohn's disease, irritable bowel syndrome and constipation.
Knowing some of these benefits may make it tempting to assume every child should take probiotics/prebiotics, but it's too soon to make that recommendation. More evidence needs to be gathered about the long-term impact and questions remain about the proper amount, species and duration of use.
It's important to note that probiotics can be dangerous in those with disorders of the immune system and ill preterm babies. Parents who want to add probiotics/prebiotics to their child's diet should discuss their child's specific needs with their pediatrician.
Editor's note: This column is intended as information only. It is not medical advice.
Dr. Lisa Thornton, a mother of three, is director of pediatric rehabilitation at Schwab Rehabilitation Hospital and LaRabida Children's Hospital. She also is assistant professor of pediatrics at the University of Chicago. E-mail her at email@example.com.