Is it necessary to live in too clean environment ? using of various types of sensitizer, cleaning soaps? or just like that live naturally without any fear of that expectant opportunistic creatures that may invade our bodies with all their deleterious weapons! Over use of such means may be simply two edges sword. This is the premise of the puzzle (hygiene hypothesis),our environment is too clean and our immune systems are no longer as heavily taxed with fighting off germs and bacteria. Increased rates of allergies and other conditions like asthma partly attributed to deviation in immune response because of poor immune response towards the infectious agents might be caught by normal contact with them