The future of medicine is inside your body

You are not the lone resident of your body. You are more like the captain of a team of millions of individuals, each self-interested but wearing your jersey. Recent studies suggest that people with more diverse populations of bacteria living in their guts are less prone to obesity, cardiovascular disease and diabetes. In fact, the one out of four individuals with low microbial diversity appear more likely to gain weight and gain it more quickly than their high-diversity friends.

More than being indicators of our tendencies, microbes may be directly engineering our metabolism or modifying the way our bodies encounter nutrients. For example, in mouse studies, exchanging the microbes of a thin mouse for those from an obese mouse increased the mouse's weight without dramatically changing the diet.

We are still learning about these complex interactions and which specific organisms might be responsible but it's an important area for the medical and agricultural sectors. If a doctor or veterinarian is considering only the health of the team captain and ignoring the rest of the team, it will not be a great season.

In the future, we may be able to treat conditions such as obesity and diabetes simply by adjusting the levels and diversity of microbes in our systems, rather than taking drugs. And our metabolism is just the beginning. There are hints that our microbes are sending chemical signals that affect our psychological and emotional function as well.

Scientists recently discovered that some soil microbes increase our levels of serotonin, a neuro-transmitter found to have a calming effect on temper and to increase intelligence.It has been suggested that this alteration in our mood may make us more social, allowing the bacteria to be transmitted between hosts and therefore to multiply.

In the future it may be possible to take an asthma-style inhaler full of friendly, uplifting microbes when you are having a bad day - instant warm fuzzies. Imagine stopping off at a food outlet for a delicious fruit shake with a microbial additive that will help you focus in class or get over that disastrous crush on your neighbour.

A new review suggests that by 2050 the number of individuals who will die of antibiotic resistant superbugs is expected to outpace even cancer at an estimated 10 million people per year. Much like the "peak oil" crisis, the "peak antibiotic" point has likely transpired. The hunt is on for the next set of solutions to this worldwide health crisis.

Another promising area of microbial research is the acceptance of a form of medicine that saved lives during the first half of the 20th century. Bacteriophages (phages for short) are viruses that seek out and destroy specific bacterial targets in order to replicate themselves. These entities have been the natural parasites of bacteria for billions of years and they are very good at it.

Phage therapy is the application of a cocktail of appropriate phages to combat specific bacteria. The beauty of phages as medicine is three-fold. They are extremely specific to particular pathogens and can be tailored to suit. They replicate themselves when they destroy their targets, enhancing effectiveness at the infection site. And when the infection is gone, they simply leave the system to be recycled naturally.

Cold war era politics kept the lessons of appropriate phage use outside of the mainstream but it looks increasingly likely that phage therapy will be approved for use in humans once again.

Gone will be the days of taking an antibiotic with broad-spectrum killing of the important and beneficial microorganisms in our bodies.