According to a new study by experts at UCL and the London School of Hygiene & Tropical Medicine, the assumption that modern civilization is excessively clean, leading to faulty immune systems in infants, should be swept under the rug.
The ‘hygiene theory’ in medicine claims that early childhood exposure to specific microbes protects against allergy disorders by aiding immune system development.
Nonetheless, there is a widespread belief (public narrative) that Western 21st-century civilization is overly clean, which implies toddlers and children are less likely to be exposed to germs early in life and hence grow allergic to them.
Researchers argue that humans are not “too clean for our own good” in this report, which was published in the Journal of Allergy and Clinical Immunology. The lead author, Emeritus Professor of Medical Microbiology Graham Rook (UCL Infection & Immunity), said: “Exposure to microbes in early life is crucial for the ‘education of the imm.”
“Organisms that fill our stomachs, skin, and lungs also play an vital part in preserving our health far into old age: therefore we require exposure to these beneficial microbes throughout our lives, mostly from our moms and other family members, as well as the natural environment.”
“Yet, for more than 20 years, there has been a public narrative that hand and home cleanliness measures, which are critical for preventing disease-causing bacteria, are also preventing beneficial organisms from being exposed.”
“We set out to reconcile the seeming tension between the requirement for cleaning and hygiene to keep us free of pathogens, and the need for microbial inputs to populate our intestines and set up our immune and metabolic systems,” the researchers write in a review of evidence.
To begin with, the microorganisms prevalent in modern homes are, to a large extent, not the ones we require for immunity.
Second, vaccines not only protect us against the infection they are designed to prevent, but they also enhance our immune systems*, so we no longer need to risk mortality by being exposed to viruses.
Finally, we now have actual evidence that the microorganisms found in the natural green environment are particularly beneficial to our health; household cleaning and cleanliness have no influence on our exposure to the natural environment.
Finally, new research** shows that when epidemiologists discover a link between cleaning the house and health problems like allergies, it’s usually not because of the removal of organisms, but rather because of lungs exposure to cleaning agents that cause damage that fosters the development of allergic responses.
“So cleaning the house is excellent, and personal cleanliness is good,” Professor Rook continued, “but to prevent virus spread, it needs to be targeted to the hands and surfaces most typically engaged in infection transmission, as detailed in some detail in the paper.”
We can reduce direct exposure of youngsters to cleaning chemicals by targeting our cleaning procedures. “Exposure to our moms, family members, the natural environment, and immunizations can give all the microbiological inputs that we need.”
These exposures are not incompatible with intelligently targeted hygiene or cleaning.”
Sally F. Rook, BA, MB, BChir, MD, and Rook, BA, MB, BChir, MD
Bloomfield, PhD, Journal of Allergy and Clinical Immunology, 5 July 2021
* Vaccinology: Is it Time to Change the Paradigm? DOI: 10.1016/j.jaci.2021.05.008
** Food allergy as a biological food quality control system, according to The Lancet Infectious Diseases 2020
** Does the epithelial barrier hypothesis account for the rise in allergies, autoimmune, and other chronic illnesses?
2021, Nature Reviews Immunology