THE HUMAN-GERM CONNECTION

Dr Douglas Street

When ONE thinks of germs, generally negative images come to mind. We now know that most germs are harmless and many are actually helpful. As a matter of fact, germs are actually part of us, a reality some may find unappealing.

Bacteria occupy all the surfaces of our bodies, both internally and externally. They occupy our skin, our gastro-intestinal tract (from mouth to anus), genital tract, eyes, and nose.

Bacterial cells are much smaller than ours and it has been estimated that they outnumber human cells in our bodies by a factor of 10:1. So in terms of numbers, we are actually made up of more bacterial cells than human cells! They used to be referred to as our normal flora, but the term microbiome is in current use as the term 'flora' is more appropriate for plants.

The mixture of bacteria varies according to the part of the body and from person to person, and also from one time to the next. They seem to influence or are influenced by certain disease states. They are also affected by our diet and use of antibiotics.

These bacteria are not just lying there. They are interacting quite intimately with our bodies, especially our immune system. As a matter of fact, 70 per cent of our immune system is in our gut, interacting with these bacteria!

Diet can affect the microbiome. Having a diet high in fructose can change the microbiome to one that causes greater absorption of sugars and fats, greater inflammation, and liver injury. This may lead to increased production of body fat (especially around the intestines) and reduced sensitivity to insulin (which predisposes to diabetes). Also a high-fat diet can bring about changes that lead to increased inflammation, increased absorption of energy and potentially harmful substances. A diet high in red meats can increase the risk of heart disease due to the production of TMAO, which reduces the amount of cholesterol removed from the body via the intestines. A high-protein diet increases the production of by-products, which promote the growth of cancer cells.

The skin also shows certain changes in the microbial composition in certain disease states. For example, there is normally a larger proportion of staph aureus in atopic eczema.

As with many situations, genes do play a role in these interactions.

Ensure that you take care of your microbiome as they help take care of you.

Dr Douglas Street is a general practitioner and has private practices at Trinity Medical Centre, Trinity Mall at 3 Barnett Street in Montego Bay, and Omega Medical Centre at Plaza de Negril, Negril. Send feedback to drdougstreet@yahoo.com.