Ruminations

Eureka! Bacterial Exposure Useful to Children's Immune Systems

"We found [in laboratory mice] exactly what we found in the children [exposed to bacteria-laden dust]."
"If we gave the Amish dust, we protect the mice [research experiment]. If we give the Hutterite dust, we do not protect them."
Dr. Donata Vercelli, associate director, asthma and airway research center, University of Arizona

Image credit: Ad Meskens via Wikimedia Commons

The conclusion that new research reached, and the study published recently in The New England Journal of Medicine, is not exactly new, but it is additional validation of previous studies that hypothesized that allergies are more common in today's generation of children than they have been historically because of the simple fact that modern hygiene is that more effective in ensuring that young children in their infancy don't too often come in direct contact with germs.

We protect our very young children from exposure to dirt and grime and all the germs and pathogens that may be in them so religiously that our children's immune systems don't have the opportunity to build natural immunity as they would if exposure did occur and parents were less rigorous in protecting children from dirt and from natural surroundings. It has been known for years that children develop asthma as a result of too-clean environments.

This time around, investigating scientists feel they have discovered what it is that prevents asthma in children and that something can be microbes from farm animals which in farming communities are invariably carried into the home through dust particles hosting those microbes. If and when children become exposed to microbes whose presence stimulates the immune system in their earliest years of development, protection against asthma can fairly well be assumed.

Children from two very disparate but similar groups, the Amish of Indiana and the Hutterites of North Dakota, became part of an experiment. Rare among the Amish, affecting no more that two to four percent of their population, asthma is common among Hutterite communities, with fifteen to twenty percent affected, in comparison.

Amish communities originated in Switzerland, while Hutterites developed as a culture in Austria. What they have in common is that both groups have large families and see value in practising
a simple lifestyle, with similar diets, and children from both groups experiencing little exposure to tobacco or polluted air. Both of these groups look askance on indoor pets, and both maintain meticulously clean and tidy home interiors.

One significant difference is present in their farming methods, with the Amish living on single-family dairy farms and the Hutterites on large, industrialized communal farms. The Amish eschew the use of electricity, using horses to haul their plows, and for transportation purposes, with barns close to their homes, where the children are permitted to play. The Hutterites, on the other hand, house their cows in huge barns, distanced from their homes and children do not tend to play in those barns.

Thirty Amish children comprised part of the study, none of whom had asthma, but they all did have a lot of neutrophils -- white blood cells, acting as 'paramedics' for the immune system. The neutrophils emerge from bone-marrow, as evidence of a continual low-grade reaction to microbial presence in their system. Of the 30 Hutterite children in the study, six had asthma, and all of the Hutterite children had much ewer neutrophils in their bloodstream.

Their blood, by contrast, swarmed with another type of immune cell, eosinophils, which have a tendency to provoke allergic reactions. The researchers' study led to analyzing dust from the Amish and the Hutterite homes, to discover that the Amish dust was full of debris from bacteria, while the Hutterite dust was free of such debris.

When the researchers tested the dust on laboratory mice, the little creatures furnished evidence of the hypothesis that exposure to microbial bacteria resulted in few incidents of asthma because of an energized immune system, prepared to react at any given time to protect the body's integrity, while the reverse was true of the bacteria-free dust; it led to a potential for the onset of asthma as a result of a non-exposed immune system that had no reason to send out its 'paramedics' which had become lazy through disuse.