Full Circle Digital Magazine August 2013 | Page 34

H E A L T H

• B A C T E R I A – F R I E N D O R F O E ? • PA U L K E N N E D Y

by Paul Kennedy

“For decades, adverts for detergent have led us to believe that bacteria are bad.”
500 and 1000 species of bacteria. The exact number varies from person to person, and the overall composition is unique to you. This unique ‘microbiome fingerprint’ is influenced by diet, genetics, and the environment we live in - this is particularly important at a young age, while the microbiome is still maturing. In our intestine, common bacteria help us digest certain foods which we normally couldn’t digest; they assist in the digestion of certain complex carbohydrates into useful end products. They have been shown to produce vitamins such as vitamin K and biotin, as well as a nutrient called butyrate, which is a molecule that provides energy to the cells of the intestinal wall and aids in digestion. Gut bacteria also instruct our gut walls to make more blood vessels, to aid in nutrient uptake by the body. The microbiome has also been recently implicated in metabolic diseases, including a link between obesity, diabetes, and gut microflora. Diabetic and obese people have been shown to have lower levels of butyrate-producing bacteria than their healthy counterparts, as well as a marked change in overall gut microbiome composition. It isn’t clear yet whether these changes are a cause or effect of the disease, but it is clear that we have underestimated the role of the microbiome in these so-called lifestyle diseases. Bacteria have an even more direct role to play in protecting their hosts from disease. This happens in two further ways first, bacteria on the skin and any other surface (including the digestive system) provide what is referred to as the ‘barrier effect’. This means that the presence of these microorganisms physically prevents pathogens from affecting the body, by controlling environmental conditions to make it difficult for pathogens to grow there. Secondly, recent research shows that bacteria in the gut and the skin can actually change how our immune system responds to pathogens. Development of a strong immune system during childhood relies on the presence of a healthy microbiome, both on the skin and in the gut. Studies show that many early life factors, such as exposure to antibiotics, type of milk fed, and degree of hygiene, can all affect the composition of the microbiome. Exposure to the right bacteria at a young age is essential for a strong immune system; the microbiome also actively regulates our immune system using signalling molecules to help protect against specific pathogens, when they attack through the gut, or the mucus membranes in the nose and throat. Clearly, our ‘good bacteria’ are playing an active role in keeping us healthy and disease-free. Does this mean we should stop taking antibiotics, and throw out the hand sanitiser? Probably not - antibiotics are responsible for saving millions, if not billions, of lives and are a key weapon against serious bacterial pathogens. But it is likely that the over-eager prescription of antibiotics in western medicine is fundamentally changing the composition and function of our microbiome, especially in young children whose immune systems are still in development. And we clearly do not fully understand the importance of these bacteria to our health. As for the obsessive crusade to rid our skin and our homes of every last ‘germ’, that is surely u ???????????????????????????????????????????!???????????????????????????????????????????????????%???????????????????????????????????????????????????????????????????????????????????????????????????()???????????????????????????????????????????????????????????????5???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ???A?????????????@???????????????????????????????????????????????????????????????????]????????????????????????????????????????q????t???????????????????????????????????????????????????q?????t????????????????????????????????????????????????????M?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????I?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????]???????????e???????????????????????????????????????????????????????????????????????????????????????????????????????????????Q????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????M????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????e???????????????????Q???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????%?????????????????????????????()U10?
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