During the coronavirus pandemic we are constantly being reminded to practise good hygiene by frequently washing our hands and regularly cleaning the spaces where we live and work.
But there have been some suggestions using hand sanitiser and practising other hygiene measures too often could weaken our immune system, by reducing our body’s exposure to germs and with it the chance to “train” our immune defences.
For healthy immune function, it is important that we are exposed to a diverse range of bugs in the environment, known as microbes. Most of these do not make us sick.
The belief that a high level of cleaning and personal hygiene weakens our immune system is a common interpretation of what is called the “hygiene hypothesis”.
The hygiene hypothesis is a theory that suggests a young child’s environment can be “too clean”, and they will not be exposed to enough of these microbes to effectively stimulate their immune system as it develops.