# Narration and storyboard draft: Hygiene Hypothesis

Authored draft, approximately60–90seconds; no rendered video claimed.

Early microbial exposure can shape immune development, but exposure type, timing and host context matter. Farm observations and controlled mouse experiments support specific protective pathways. Human probiotic trials are mixed: one strain can reduce eczema while another does not, and a favorable secondary result must not replace a null primary endpoint. The large ORBEX bacterial-lysate trial did not significantly prevent its primary wheezing outcome. Daycare biodiversity studies changed immune markers, which is useful but does not yet prove prevention of allergic or autoimmune disease. Our Gamma rating applies to the broad claim that reduced microbial exposure causes both disease classes. Narrower immune mechanisms score higher. The next test needs a predefined microbial intervention, verified engagement, appropriate clinical follow-up and careful tracking of both benefit and harmful exposure-specific effects.

1. Show the exact claim, grade and confidence.
2. Show selected publication milestones; label experimental systems and clinical endpoints.
3. Contrast the strongest result with its source-specific limitation.
4. End with the boundary experiment and primary-source links.

Use authored schematics; do not depict Consensus meters as causal confidence or reproduce publisher graphics without appropriate permission.