One clarification before I bombard you again about microbes. One of my mentors has suggested that I should make it clear that I am not saying that living in filthy conditions such as those which caused the major epidemics in history is a good thing. I'm happy to do that, what I am about is trying to make the connection between conditions seventy years ago and the present day to see if there are any lessons to be learned.
Many researchers, looking at the increased incidence of conditions like asthma, allergies and food poisoning have made a connection between these and antibiotics. Remember that when I was a lad antibiotics were not available. If you got a microbial infection, tough, you went to bed, kept warm and waited for your immune system to kick in and deal with it. In some cases this didn't happen and you either became chronically ill for a long period or even died. A simple case of food or blood poisoning could be fatal. Antibiotics changed all this, the medical profession had a magic bullet, a course of Penicillin cured almost anything. This was particularly useful in the first year of life, historically the most dangerous time for death from infection. Antibiotics changed all this and was even used as a precaution to guard against the infection occurring in the first place. Modern, large scale studies have shown that babies who were given repeated courses of antibiotics in their first year, sometimes for very serious ailments, are more likely to suffer from allergies, asthma and dermatitis in later years. What was a life-saver can become a curse.
Another culprit is the advertising industry who use fear as a marketing tool. Think of the number of advertisements you see daily claiming that 'Product X' kills 99.9% of known germs. We are exhorted to use sprays and other products to make sure our surfaces are 'clean' enough to eat off. This is fine, there is a place in my life for bleach but consider this, the lower the microbiological component of your world, the less the exposure to the beneficial effects of testing and educating your immune system. It may be that we had it about right when I was a lad, we tried to keep clean but didn't attempt to sterilise everything. This is good in an operating theatre but a bit over the top in daily life.
In other studies the amount of time we spend indoors has an effect as well. Think of the number of children who are on their computers and phones when all those years ago they would have been roaming the fields, building dams in streams and getting gloriously dirty. With hindsight we were doing what was best for us even though we didn't know it at the time. So my message is, keep clean by all means but don't be frightened of what we used to call 'Clean Dirt'. Eating garden soil or rolling in a bit of sheep muck isn't necessarily the end of the world!
Children playing in the beck on School Lane in Earby a century ago.