You always get some good with the bad. No, this is not an airy philosophical debate on good and evil, but statement based on hard, scientific data. Groundbreaking research in Switzerland shows that infection from the stomach bug Helicobacter pylori (H. pylori) — which causes painful gastritis and stomach and intestinal ulcers — protects against asthma. The findings, published in the Journal of Clinical Investigation on Saturday, confirm the hygiene hypothesis that blames increasing asthma cases around the world on lowered exposure to bacteria in early childhood, which prevents the body from developing a healthy immunity.
In simple words, the bug that gives your stomach grief — H. pylori infects half the world’s population — also makes you breathe easy. It is resistant to stomach acids , which helps it survive in the stomach without symptoms for a long time. Under some conditions, however, it causes gastritis, gastric and duodenal ulcers, and stomach cancer, which is why antibiotics are prescribed to wipe it out even if you do not have symptoms.
The double whammy, of course, is the overuse and misuse of antibiotics, which is now an established trigger of asthma. Other airway irritants are air pollution and pollen, food colour and additives, obesity, smoking, poorly ventilated homes and workplaces (10% of adult asthma is work-related), cold weather, exercise and stressors such as domestic violence and even relationships breaking down.
The triggers, of course, work only on people with sensitive (hyperallergic) airways. What makes airways sensitive is your immune system’s threat perception. An asthma attack occurs when an allergen or another stress factor causes an immune reaction that leads to inflammation (swelling) in the airways, which narrows air passage and reduces air flow in the lungs. This causes wheezing, shortness of breath, chest tightness, and coughing, which can last for a few minutes to days, depending on the severity and length of exposure. If not treated, asthma attacks can kill.
Apart from exposure to organisms that cause disease, harmless — bacteria and fungi found in vegetation and dust also offer protection by preventing the immune system from overacting to allergens. Two large studies support this. One, from the University of Columbia in the US, reported that asthma cases went down by 25% among children who lived in neighbourhoods with lots of trees. Another, from the Institute of Epidemiology in Munich, Germany, used blood test reports to confirm that having a pet dog boosts children’s immune system and lowers their risk of asthma as compared with children occasionally exposed to inhaled allergens such as house mites, animal fur and pollen.
Previous studies have shown that living in farms among animals, having many older siblings and attending day care at an early age offer protection against asthma, most likely because all these situations translate into more exposure to germs — both good and bad — in early childhood.
This celebration of germs and dirt is likely to make you wonder, how dirty is dirty enough? It is premature to advocate giving children dirt or germ pills for breakfast, but don’t worry about the occasional slush football or romp in the park with the family pet as long as they wash up — the children not the dogs — before meals. And if you find yourself feeling squeamish about the dirt, remind yourself that it’s good for health. Given the consistency at which new superbugs are popping up around the world, they need a super-charged immunity to survive without popping antibiotics three times a day.