Mass murder in your gut’s B&B

Why antibiotics should be used wisely…

Most people will use antibiotics at least once in their live, maybe you already have. Since their discovery, antibiotics have been used widely to treat bacterial infections. Antibiotics are very effective in killing or inhibiting the growth of bacteria and have prevented many deaths by treating diseases such as pneumonia and tuberculosis. But, did you know that antibiotics kill more then just these bad bacteria? Our gut is hosting millions of microorganisms, including fungi, yeasts, viruses and most abundantly, bacteria. You could say that our intestinal tract is a well-run Bed & Breakfast. The bacteria stay in our gut and eat our food. In payment they do all sorts of things like supplying energy to our gut and digesting substances our bodies can’t digest. Like most guests at a B&B, these bacteria are harmless and mean well; in fact we need these bacteria. When we take antibiotics, they are not only killing the very small percentage of disease causing bacteria, they are mass murdering our guests in the process! Therefore antibiotics should be used wisely.

All the microorganisms in our gut together are called the microbiome and weigh over 2 kilos! Most prominent among the microorganisms are bacteria. About a 100 trillion bacteria house in our gut, that is many times more than there are stars in the Milky Way. 1 Gram of faeces contains even more bacteria than there are people on earth! However, until recently, not a lot was known about these bacteria.

Just a few years back scientists used to think that everyone had a similar collection of bacteria in their gut and that E. coli was one of the most abundant. When scientists would examine faeces by growing the bacteria in a petri dish, E. coli would always be present in high numbers. However, through new technologies that allow scientists to scan tiny amounts of faeces for bacteria, we now know that E. coli makes up less then 1 per cent of the bacteria in our gut. Apparently many other bacteria were so adapted to the environment of our gut that they just wouldn’t grow on a petri dish. To make things even more complicated it appears as though every individual has a more or less unique population of bacteria in their B&B.

Bacteria are usually associated with disease and you might be grossed out by the fact that all of these tiny little creatures are living inside of you! What most people don’t know is that more than 90% of all bacteria are harmless and are actually very helpful. Although scientists have just begun discovering this whole population of bacteria living in our gut, we already know that these bacteria have multiple ways of paying for their stay in our B&B.

Some substances we eat we can’t digest ourselves. Most bacteria are residing in the lower parts of your gut and the food (or what’s left of it) that comes through there has already been depleted of most nutrients we can use and digest on our own. Your bacterial guests are thus left with your half digested leftovers and finish the job. For example, we do not have the enzymes* to digest the fibres present in some fruits, vegetables and grains, but many bacteria do. By digesting these so called dietary fibres, the bacteria break them down in very small particles that can be absorbed by our gut and used as nutrients.

The good bacteria in your gut also prevent bad bacteria from moving in. When enough good bacteria are staying at your B&B, no vacant rooms will be left when bad bacteria come along. These bad bacteria will therefore be forced to leave your body and look for another place to stay. This principle is referred to as colonization resistance. There are many other functions of the good bacteria in our gut like producing energy and certain vitamins. Without a doubt we are lucky to host bacteria in our gut.

Unfortunately some kinds of bacteria can cause disease and infection. Although antibiotics treat such infections very effectively it also kills a lot of the good bacteria in our gut. This can cause digestive problems and leaves a lot of vacant beds in your B&B for bad bacteria to lie in. Studies have shown that your microbiome takes more than 8 months to recover. Of course it is advisable to use antibiotics in case of bacterial infections that can be dangerous to your health. However, in many countries antibiotics are prescribed to treat a common cold or influenza, which is mainly caused by viruses and not by bacteria. Since antibiotics only treat bacterial infections, this will only kill all those friendly chaps in your gut, leaving you with an empty B&B. Antibiotics should thus be used wisely, because although they’re gross, we need those bacteria in our life.

* Enzymes are tools that are needed for certain processes

- By Tanne van der Wal, 07-10-15