One of the greatest philosophical questions asked was and is :’ What makes us human?’; and like all famous philosophical enquiries, this question as well has no definite answer. To give this metaphysical question a spin of biology, let us consider the biological aspect of being Human. There are about 30 trillion human cells which make up our being, but along with these 30 trillion human cells, there resides a distributed community consisting of about 39 trillion bacteria living in our own human body (Estimated figures derived from a research study conducted in Weizmann Institute of Science, Israel; research paper published in August ,2016).

So, if a major part of the trillions of cells that resides in our human body aren’t even of human origin, what does it really mean to be human ? This question has no ready answer and that is a good thing. One cannot be too sure of anything. So, with that prelude to this particular discussion, let us take an informative and hopefully engaging journey through the various nuances of the microbial guests we host in our body and how these guests influence the business of living on a daily basis inside of us and how we can broker the best deal with them so as to run a successful campaign of healthy living.

 Given the bad reputation bacteria has earned for themselves, thanks to the many bad publicity campaigns by consumer product companies reiterating the dangers of bacteria and how we need to sterilize ourselves from time to time using the products that they sell, we can understand the main challenge that exists in raising awareness about the good ones out there(or inside us). They are our guests but not freeloaders, they are essential to human health and development and research has shown that they aid in digestion, produce anti-inflammatory chemicals and compounds and help in training our immune cells to distinguish between their friends from their foes to say the least. Because, ultimately our relationship with them can be summed up with a quote from one of the famous movies which I have edited in a small way to bring out the essence. ” ‘Bacteria’ are still good, they fight, they kill, they betray one another. But they can rebuild. They can do better. They will. They have to.”

Alright then, let us start at a place where it all begins; life. As we freely float in our mother’s hospitable womb while developing into a fully formed fetus, we are yet to be fully acquainted with our soon to be guests for life, bacteria. For the most of us , who go through the normal mode of delivery, we are first inoculated with our dose of the bacterial soup while we make our way through the birth canal to say hello to the world. And, for some of us who are delivered through C-section, we miss out on this bacterial priming from the mother. Well, we do not receive all our guests at one point, it couldn’t be that simple. So, we pick some of them up from our mother’s skin during breastfeeding, not only that, along with the mother’s milk, we receive its other constituents which help in nourishing the strains of bacteria that have already inhabited inside of us and preventing the growth of pathogenic bacteria.  So, an infant fed on baby formula instead of the mother’s milk would be disadvantaged in this way. So, we can relate to the transfer of this microbial inoculum from the mother to her child as another form of inheritance and hence must be preserved like heritage itself.

For the establishment of a well defined human Microbiota ( All the microbes which dwell in and on us), three stages are considered important: before pregnancy, during pregnancy and the first three years of the child’s development. This is because, the diversity of the microbes inhabiting the baby’s body are continually evolving and attains an adultlike pattern in about three years. These three years are also the time period in which the baby’s physical development (metabolism, immunity) and mental development (cognition) takes place. So, you can imagine how this dynamic nature of development can be altered through the use of antibiotics at these crucial stages where the microbes are still adjusting in its new home for life and hence must be taken into factor. There are studies which portray a clear relationship between C-sections and exposure to prenatal(Before and during pregnancy) and postnatal(After pregnancy) antibiotics to increased risk of obesity, diabetes and allergic diseases and people who suffer from such conditions show a different microbial pattern in their guts from their healthy counterparts. Matter of fact, researchers are finding a way to correlate the microbial landscape in our gut for prognosis (forecasting) and diagnosis of diseases.

The famous adage ‘you are what you eat’ takes an extensive form if you look at it through the interactions your diet can have with the microbiota present inside of you. Ultimately, our microbial guests are only fair in expecting a return from their hosts for their contribution in the processes of life of the host.  Because there is a ready interaction of our diet with the microbiota in our gut, the food we consume has extreme relevance in directing our state of health. And because microbiota are also the major stakeholders of the food we consume, it is not surprising that studies conducted have revealed a mechanism by which our microbiota can influence our behavior as well as our dietary pattern to a certain extent. This is derived from the fact that vagus nerve which connects the brain and the digestive system and microbes in our gut can produce neuroactive compounds which can act on the brain and also the fact that these microbes interact with the immune cells which have their own relationship with the brain and this represents a bi-directional relationship between the brain and the gut microbiota. So, the next time you have a fight with your partner, present them with some delectable food and hope that it would calm them down because, science? All jokes aside, this declares a unique relationship with the food you consume and your state of mind.

Well no wonder probiotics market stands around 30 billion dollars as of now. Of course I cannot cover the entirety of the scope of human microbiota in this article and I will not try to as well.  But the next time you are about to consume something, wrap your head around this: We are not a self sufficient organism, we are a dynamic ecosystem consisting of various populations of microbes interacting with one another and with our cells to shape this magnificent forest that is the human being. This clearly depicts the importance of looking at food and health in an entirely different perspective. After all, you are not eating for just one but many.

“One cannot think well, love well, sleep well, if one has not dined well.” 
― Virginia Woolf, A Room of One’s Own.

For sources for this article, do contact me. I would be more than willing to share them with with  you.

-Shashank.S