Should I not wash my hands sometimes?

We have been taught from childhood that cleanliness and hygiene is very important to ward off diseases and maintain good health. Washing hands after travelling in public transport, using public toilets or using elevators is highly recommended. Eating food or preparation of dishes should always be preceded by washing hands thoroughly. Hand hygiene is given so much importance; but then is too much cleanliness actually bad for you?

Well at least this article from the Daily Mail says so. Excerpts from the article:

Don't wash your hands! A bit of dirt is good for you: Experts say cleaning less often would protect against allergies by allowing helpful bacteria into the body

• Dr Justin Sonnenburg said modern diets lacking in fibre may cause irreversible damage to vital gut bacteria
• He suggested not washing your hands after gardening or petting a dog
• Low-fibre diets that we now eat might not be enough for future generations
• He also suggests reducing our reliance on antibiotics.
  

Sure enough, there is conflicting information on health and hygiene these days. But then it's a universal truth that too much of a good thing is also bad and the key is moderation in all our activities. Perhaps this holds true for cleanliness and hygiene also.

But then I would think twice about not washing my hands after petting a cat or dog. And would I be brave enough to not wash hands after gardening --  more so, after reading this article or this contradictory article from The Daily Mail? I bet not!