43% Human

It used to be said that you are what you eat, but that is old hat. Now it is much more, you are what eats you. I’d better explain. You think you are human. You know you have some dormant genes but still, you are homo-sapiens. That’s what you thought but you are wrong.

The latest science says that only 43% of what you are carrying around are human cells. The balance, the other 57% include bacteria, viruses, fungi, and archaea. Scrub yourself as hard as you dare, shower three times a day and it won’t change. They are in every pore, organ, and corner with most living (if that is a definition of what they do) in the depths of your gut.

Let’s be clear. When you go to your doctor and he asks how much you weigh you are not allowed to divide what was showing on the scales by two. You can’t say I weigh 7 stones and all these microbes weigh another 7. Without them, you wouldn’t function at all well.

Here’s a rather freaky experiment that has been carried out. First, you have to raise some mice in ultra-sterile conditions so that they are almost microbe-free. Then you take some microbes from larger people (political correctness means I can’t say fat) and you put them in the gut of mouse. Then you inject some microbes from thin people. Lo and behold one group of mice get fat and the others thinner!

Reading the BBC website, if we add all the genes of the microbiome (that is what the collection of everything we have), then to the 20,000 human genes you can add somewhere between another 2 and 20 million.

Prof Sarkis Mazmanian, a microbiologist from Caltech, argues: ‘We don’t have just one genome, the genes of our microbiome present essentially a second genome which augments the activity of our own. What makes us human is, in my opinion, the combination of our own DNA, plus the DNA of our gut microbes.’

Science is rapidly uncovering the role the microbiome plays in digestion, regulating the immune system, protecting against disease, and manufacturing vital vitamins. We are symbiotic with these little creatures.

However, with antibiotics and vaccines, we have spent much of the last 100 years trying to kill the worst of the microbiome such as smallpox, and tuberculosis. There is a real concern among scientists that we have also killed off some of the good guys. The changes in our microbiome are being linked to diseases such as inflammatory bowel disease, Parkinson’s, and even depression and autism. It is also being considered as a treatment for obesity.

Prof Knight who performed those experiments on mice said, ‘This is pretty amazing right, but the question now is will this be translatable to humans.’

Well, the answer is probably, yes. I know that similar fat reducing experiments have been carried out on humans with the same results.

Faecal microbiota transplant (FMT), also known as a stool transplant is the process of transplanting faecal bacteria from a healthy individual into a recipient. In the United States, the Food and Drug Administration has regulated human faeces as an experimental drug since 2013.

Back to the BBC and Dr Trevor Lawley at the Wellcome Trust Sanger Institute. He is trying to grow the whole microbiome from healthy patients and those who are ill. ‘In a diseased state there could be bugs missing, for example, the concept is to reintroduce those.’

Some researchers think that monitoring our microbiome will soon become a daily event that provides a goldmine of information about our health. Prof Knight said: ‘It’s incredible to think each teaspoon of your stool contains more data in the DNA of those microbes than it would take literally a tonne of DVDs to store. At the moment every time you’re taking one of those data dumps as it were, you’re just flushing that information away. Part of our vision is, in the not too distant future, where as soon as you flush it’ll do some kind of instant read-out and tells you are you going in a good direction or a bad direction. That I think is going to be really transformative.

That will make going to the toilet a more interesting experience and all those men that like to read on the loo will be able to put the newspaper aside for their health check print out.

Last week, after a series of CT scans I was signed off by my Gastroenterologist, Dr Youd. We took the opportunity to talk generally about gastro problems and the range of solutions. Dr Youd was very clear. Many problems are often reflected in stomach and gut problems and more interestingly the cures and solutions are varied.

After many prodding and probing examinations, my solution was radical but simple. Now I eat a highly restricted, gluten and many other things free, diet. Basically, my microbiome has become messed up, and now just can’t cope and is intolerant to a varied diet. Do I miss some foods? Of course, I do but I miss the food variety far less than the continual stomach ache.

We read about personalised cures with medicine tailored for our specific gene set. That will have tremendous benefits. However, as someone always willing to match my money with my mouth if I was to take a £5 bet I think that understanding the microbiome and being able to manipulate it, will give up many more significant benefits than tailored gene therapy.

And, as I want to win my bet, if there any researchers reading this then know that I am up for a new and different influx of microbes. My good ones have gone walkabout and I want some new ones.

If that means that end up being only 42% human, then so be it.