Friendly Gut Germs Cut Allergies in Kids

Immune system needs trigger to work properly

By Edward Edelson
HealthScout Reporter

FRIDAY, April 6 (HealthScout) -- A healthy dose of friendly bacteria very early in life appears to increase children's resistance to allergic conditions such as eczema, a Finnish study finds.

The study supports the so-called "hygiene hypothesis," which holds that modern sanitation makes children more vulnerable to asthma, allergies and other conditions because they're not exposed to enough germs to trigger healthy immune responses early in life, says Dr. Dean Metcalfe, chief of the laboratory of allergic diseases at the National Institute of Allergy and Infectious Diseases.

"It is an intriguing study that needs to be repeated. At least this study shows strong evidence that administration of capsules of good bacteria decrease the number of children getting eczema. That was the only disease they studied, and by inference we should see similar studies focusing on asthma," Metcalfe says.

The hygiene hypothesis says that "there is something beneficial about the relationship you have with these bacteria. They help your body learn how to deal with infections. This study goes further and says that, if you look at gut flora, here are certain bacteria that are better than others," Metcalfe says.

The April 7 issue of The Lancet describes how researchers at the Turku University in Finland studied 159 mothers-to-be with family histories of asthma, eczema or allergic rhinitis. Starting six months before their due dates and continuing for six months after birth, the women were given either capsules of lactobacillus, harmless bacteria that normally live in the intestinal tract, or an inactive substance.

The rate of eczema in children of mothers given the bacteria was half that of the placebo group, the researchers say. The children were tracked up to age 2.

The kind of bacteria found in the human gut in industrialized countries has changed markedly over the last century, and that change does seem to affect the immune system, says Dr. Simon Murch, a senior lecturer and consultant at the Royal Free and University School of Medicine in London and author of an accompanying editorial.

"It is increasingly recognized that the interaction with bugs in our gut is not an inert one. Bacteria within the gut play a role in educating the immune system," Murch says.

He cites a Swedish study which found "good links between bacteria in the gut and allergies. The gut does seem to be the critical organ in asthma."

While the Finnish study has "only preliminary data and a small number, it is certainly an exciting finding. If this can be confirmed, it may well lead to changes in the way newborns are handled," Murch says.

Metcalfe says the incidence of asthma and other allergies has notably increased in recent decades, with several possible causes. One is an increase in industrial pollution. Another is that more people are living in homes with carpeting in which allergy-provoking dusts and insects gather and thrive.

But Metcalfe says childhood exposure to bacteria, or the lack of it, appears to play a role. Allergies are less common in children from large families and in children in day care, both of which expose them to bacteria from other children.

What To Do

Keeping children away from infection is still the wise strategy, Metcalfe says. "Until I understand this better, I would not be brash enough to tell the patients I care for to encourage minor infections. If this study is repeated and found to be correct, we could see a time when doctors might be able to recommend that women take these capsules, but the data are not there yet."

The National Institute of Arthritis and Musculoskeletal and Skin Diseases has information on eczema. For more about asthma, allergy and other conditions, visit the National Institute of Allergy and Infectious Diseases.

Read other HealthScout articles about allergies and children.

SOURCES: Interviews with Simon Murch, M.D., senior lecturer and consultant, Royal Free and University School of Medicine, London; Dean Metcalfe, M.D., chief, laboratory of allergic diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Md.; April 7, 2001 The Lancet

Copyright © 2001 Rx Remedy, Inc.

Last updated 4/6/2001 11:00:00 AM.

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