Nope. Been debunked for both infections and allergens.
https://publichealth.jhu.edu/2022/is-the-hygiene-hypothesis-true
Category: Brownstone Institute
The Koch network, with Charles Koch as the spider in the net, has it hands in many different fake science “institutes” and fund right wing politicians through dark money funds. Some might have heard the Koch name before. They often support right wing politicians through dark funds like Donors Trust etc.