‘Gut Ecology’ is the name of a book brought out by the St. Marks Academic Institute which is dedicated to ‘advancing scientific knowledge of colorectal disorders’. I think the book, which features topics like ‘The gut microflora: traditional and molecular identification techniques’, and ‘The ‘unculturables’’ deserves to be a bestseller. Not that I would understand the contents, but I have to admire the dedication and scientific spirit it takes to spend a lifetime researching and writing on such topics! Guts indeed!
But what exactly would the book be about? Let’s break it down. Ecology is the study of organisms and how they interact with the environment around them. An ecologist studies the relationship between living things and their habitats. ‘Gut’ is commonly used to refer to the stomach, entrails, parts or the whole of the digestive tract. So a ‘gut ecologist’ would study the insides of our digestive tract to understand the micro-organisms (collectively referred to as gut microbiota) that live there, and how they interact in our digestive system.
For very long, the presence and role of micro-organisms in our body was not known. It was in the 1670s and ‘80s when Antoine van Leeuwenhoek started using his newly developed handcrafted microscopes that scientists started studying them. Leeuwenhoek described and illustrated five different kinds of bacteria present in his own mouth and that of others, in a letter he wrote to the Royal Society of London in 1683. He later also compared his own oral and faecal microbiota, and proved that there are differences in micro-organisms in body sites. (See why I say it takes guts to be in this field!)
Now we know that the human gastrointestinal tract—from mouth to anus– is divided into sections, and each provides a different environment and different kinds of micro-organisms thrive in each section. In all, about 100 trillion micro-organisms (most of them bacteria, but also viruses, fungi, and protozoa) exist in the human gastrointestinal tract. In fact, the colon contains the highest microbial density recorded in any habitat on Earth, representing between 300 and 1000 different species. There are actually about as many bacterial cells in our bodies as there are human cells, and they contribute over a kilogram to our weight! So Stewart Brand, the American writer, environmentalist and editor of the highly influential Whole Earth Catalogue was right when he said, ‘If you don’t like bacteria, you’re on the wrong planet.’
These organisms are such an integral part of the functioning of the human body that they are sometimes called ‘the forgotten organ’.
A foetus has no bacteria at all in the system. Through the process of birth, it picks up a good number, and then in the first few years of its life, the child picks up a huge number of different bacteria from its environment. Fascinatingly, like fingerprints, a person’s gut microbiota composition is unique to each individual.
These micro-organisms influence our energy metabolism and many other areas of human health, from immunity and the progress of diseases, to appetite, to nutrition uptake, and even personality! They therefore greatly influence our health, well-being, weight etc.
External factors influence the composition of these micro-biota but by changing our diet or fasting can change the composition of these life-forms in our systems, in a matter of days or weeks, and this is why it is important to pay attention to what we eat. This is also the reason why medical science is increasing focus on prebiotics and probiotics. If like me, you are confused about the two terms, here are simple definitions:
* Probiotics are foods or supplements that contain live microorganisms intended to maintain or improve the “good” bacteria (normal microflora) in the body.
* Prebiotics are foods (typically high-fiber foods) that act as food for human microflora. Prebiotics are used with the intention of improving the balance of these microorganisms.
Kudos to the scientists who work so hard to help us understand our bodies and their functioning, ready to spend their lives poring over microscopes to figure out how we can live healthier and better!