Municipal water
Pipes and treatment prevent fecal-oral death at population scale.
A city that chlorinates water and vaccinates children is not 'too clean' in the sense that kills people with cholera.
The human interface is picking high-risk moments (feces, raw meat, wounds) without trying to bleach an entire childhood.
Body interfaces
Childhood vaccines
They replace some wild lessons with safer ones. The hypothesis does not argue against them.
Farm animals
Early livestock contact is a research clue, not a daycare requirement.
Antibacterial marketing
Residual biocides on every toy add selection without proven allergy benefits.
Green space
Outdoor play in safe parks is a milder reading of diversity than eating soil.
Travel guts
New water can still carry pathogens. Balance is not refusing a safe bottle.
Personal allergy care remains clinical.
Keep exploring
More in Change & defence
Mutation and variants
Populations of genomes, not cartoon villains — RNA viruses copy sloppily, and public-health names track clusters that spread.
Familiarity 92Antibiotic resistance
A shared drug budget under selection in hospitals, farms and wastewater — stewardship, not a lab manual.
Familiarity 85Vaccines and immunity
Antibodies, memory cells and community arithmetic — conceptual, not a prescription and not an anti-vaccine tract.
Familiarity 94Biofilms
Surface cities of microbes — plaque and catheters explain persistence, without a grow-your-own kit.
Familiarity 38Horizontal gene transfer
Sideways DNA traffic — conjugation, transduction, transformation as names and history, not protocols.
Familiarity 45