The gut microbiome refers to the vast ecosystem of microorganisms that live in our very own digestive tracts. Though the number of genes in all the microbes in our bodies is 200 times greater than the number of genes in the human genome, only recently has its importance truly been explored – could it be the key to the prevention of obesity, diabetes and more?

Despite their connotations, microorganisms can play a vital role in a variety of different bodily processes. One of many include their ability to utilise certain foods that the stomach and small intestine are unable to – the microbiome provides vital pathways for the metabolism of non-digestible carbohydrates, such as resistant starches and unabsorbed sugars, resulting in the recovery of energy for the host.

Moreover, these ‘good’ microorganisms are pivotal in combatting aggressions from bad ones, for the intestinal epithelium is the main barrier between our immune systems, and the external environment. The cells that line the epithelium avert threats from pathogens through receptors that bind to specific molecules associated with bacteria, culminating in the release of white blood cells.

However, the long-term impact of these microbes have the potential to be far more wide-reaching, with regards to obesity, for example. Their roles in digestion and metabolism, as well as through increasing energy production from the diet and the regulation of fatty acid tissue composition, are all involved in obesity. This raises the question – can we manipulate our gut microbiota to facilitate weight loss, and prevent obesity? Put simply, the answer is yes. The bottom line is eating a diverse diet rich in whole foods can lead to the development of a diverse microbiota – this includes fruit, vegetables, fermented foods and whole grains. The Western diet, unfortunately, doesn’t fulfil this level of variety – it is estimated that 75% of the world’s food is produced from only 12 plants and 5 animal species. Improving upon this can not only lead to a fall in liver issues, but also facilitate the tackling of another key issue today – allergies.

A growing sector of research has recently linked rises in allergy rates and asthma to what is now known as ‘the hygiene hypothesis’. Also known as the ‘microbiome depletion theory’, its medicinal definition is that a lack of early childhood exposure to infectious agents, symbiotic microorganisms (such as gut flora) and parasites increases susceptibility to allergic diseases by suppressing the natural development of the immune system, and our immune tolerance. In modern society, parents often try to create an environment as clean as possible for their children to live in, but this theory would suggest this pristine upbringing can cause a host of problems – in this case, minimal exposure to microbes around us essentially means the diversity of microbes inside of us are low, reducing our immune tolerance, and hence leading to more allergies.

Moving further up our bodies, very recent research has linked the importance of the gut flora to the brain. Data now indicates that gut flora communicates with the CNS – potentially through endocrine pathways, therefore influencing brain function and behaviour. Studies show that roles of gut flora include the regulation of anxiety, mood, cognition and pain, and the concept of the connection between both the microbiome and the brain could lead to a strategy being developed for using the flora to treat complex CNS disorders.

On balance, the emerging biology of the microbiome has the potential to save lives and cure diseases all over the body. As the struggle of creating new and innovative drugs and medicines continues, the microbiome provides another pathway for exploration, and one which will continue to be looked into by researchers and fellow academics within the field.

Saeyon Nanthakumar

Photo Credits due to: Saeyon Nanthakumar