Babies in their mother’s womb are free of bacteria but as they emerge through the birth canal they immediately pick up an starter colony of bacteria from their mother. Over the first two to three years of life this colony becomes more diverse – initially through breast feeding and then through all of the bacteria the child encounters through exploration and interactions with other people and pets. A child’s natural tendency to put everything in its mouth may be nature’s way of populating its microbiome!
Children born through caesarean section face a special challenge because they do not get that initial starter colony from their mothers and their microbiomes are more characteristic of their initial hospital environment. Research indicates that the composition and development of our infant microbiome during the first 2 ½ years of life shapes many aspects of immune system function for the rest of our lives so it is important that special care be given to the cultivation of a healthy and balanced Microbiome in babies born through caesarean section.
As we go through life we are exposed to millions of bacteria every day and any of those that find their way into our mouths eventually make their way through our digestive system and into our gut. The acid bath in our stomach and the chemicals in our primary digestive system kill some of these bacteria but most make their way into our large intestine where they encounter a diverse but very selective bacterial community living in an oxygen free (anerobic) environment.
When it is working properly our microbiome acts like an immigration check point. Bacteria that are judged to be compatible and constructive are allowed to move in and make their place in the community. Those that are harmful or dangerous are attacked and either suppressed or killed. It is important to understand that almost everyone’s contain small quantities of potentially harmful bacteria including e-coli and clostridium difficile. However, a healthy microbiome manages keeps these harmful bacteria from over propagating and gaining the upper hand.
Ideally, our Micro Biome is the product of a lifetime of activities and interactions. However, two factors can adversely affect both the health and diversity of our Micro Biome. The first is our evolution away from the rich bacterial environment that our hunter/gatherer/farmer ancestors once knew and into a world where killing or avoiding all bacteria is considered part of a “healthy” lifestyle. The second adverse factor is broad spectrum antibiotics that indiscriminately kill both good and bad bacteria. These antibiotics clearly don’t wipe out all bacteria because there are both good and bad bacteria that have adapted enough to become antibiotic resistant. However, a single five day course of antibiotics can reduce the diversity and size of our microbiome by ⅓ and the casual use of antibiotics has a cumulative long term adverse effect on our microbiomes.
The evolution of Western diets towards processed foods that are high in carbohydrates and sugar and low in dietary fiber has intensified our attack on our gut bacteria by depriving them of the nutrition that they need to stay healthy. Our gut bacteria evolved to subsist on dietary fiber and as we eat less fiber we starve our microbiome and encourage those bacteria that feed on the mucous lining of our gut instead of on the dietary fiber we provide.