Sunday, 28 June 2015
Book Review - Missing microbes ...How Killing Bacteria Creates Modern Plagues by Martin Blaser
This was one of the books I took to Malta with me as holiday reading. Some people may think it's a bit of a weird book to read instead of the latest novel... however I find books like this fascinating and have loved learning about health and what happens in the body since as long as I can remember. I started reading it on the plane and managed to get some time (between all of our sight seeing jaunts) to sit around the pool and read some more...finishing it the day I came home. And now it's time to tell you a bit about its contents....
Dr Martin Blazer is the director of the Human Microbiome program at NY University and has a long list of accreditation's to his name. He has studied the role of bacteria for over thirty years and so has a wealth of knowledge on the subject, having been involved in a series of research projects (which he cites, together with numerous others to illustrate his points).
He explains that each of us consists of an estimated 30 trillion cells, but are host to more than 100 trillion bacteria and fungal cells, housed on and in our bodies... these have co-evolved with us through generations of time. This means that 70-90% of all cells in/on us are actually non human! Some microbes have specialized properties and live and thrive in various areas of our bodies such as our skin, mouth, nose, gut, nasal passages, ears and in women, the vagina. Collectively these organisms are termed as our "Microbiome".
We acquire these microbes early in life from our mothers during the birth process and they play a critical role in keeping us healthy. They are not merely passengers on and in us but are metabolically active providing us with various functions such as clotting our blood. We "out source" key metabolic function to these microbes and they help carry out enzymatic processes on our behalf in exchange for us feeding them. This relationship not only ensure their survival but ours too. One of the major functions that our microbes provide us with is immunity.
A NIH study that Martin cites showed that our microbes have millions of unique genes (about 2 million each compared to our human genome which only has 23,000! 99% of our unique genes in our bodies are therefore microbial.... meaning we are at most 1% human!
However parts of our microbiome are starting to disappear... the number of our microbes is reducing and the variety of species we carry is getting smaller and less diverse. This he explains is partly due to the overuse of antibiotics in humans and animals (in the food we consume), the high incidence of Cesarian sections being carried our (so the microbes are not passed from mother to child as effectively) and the grand scale use of sanitizers. This loss of diversity is having a big affect in multiple ways.
Although child deaths has decreased from 4/10 children to 5/1000 since 1850 it appears that we are now getting sicker. In just 20 years obesity, type1 diabetes, asthma, food allergies and eczema...have all increased and the missing microbes are looking like the culprits.
Lack of microbes is effecting development in children, effecting metabolism, immunity and even cognition and (he says) we are now seeing widespread immune disorder not seen on such a scale before.
Another study he cites showed that our unique bacterial genes varied dramatically between 2 groups of people. 77% of people have approx 800,000 genes and 23% of people had 400,000. The low gene count being more likely to be obese..... linking missing microbes to obesity.
Most microbes that we carry are harmless but we can also carry many pathogens (disease causing bugs). However some of them can live peacefully with us. At least a 1/3 of us are carrying some particular pathogens (staph aureus, strep etc) in our nasal passages and are .....healthy, having no adverse effect. Some can colonize the nose for life and we would never know it. He explains that for most people, they are a part of their unique microbiome.
The problem comes when a carrier get ill.... for example with a normal cold virus...the doctor does a throat culture and strep could show up... the doctor then prescribes antibiotics to prevent rheumatic fever but all the time the symptoms are being caused by a virus... a classic case of mistaken identity and overuse of antibiotics. Some Statistics he gives are, that in general, our children get about 17 courses of antibiotics before they are 20 years old! (Centre for disease control). This not only has a knock on effect for the microbiome passed on to the next generation at birth but implications of increased populations of drug resistant bacteria that are not so friendly or easy to treat. But what If you think you haven't had an antibiotic in years?..... then you may be very mistaken.
Martin takes you through a fascinating journey of the links between farming practices and antibiotic usage to increase weight gain in cattle and links it to what may be happening to our overweight children today. He also take you through the research on H pylori... the fiend of stomach ulcers and stomach cancer.... but adds new light and perspective with a number of research projects that perhaps changes the common belief that " the only good Helicobacter pylori is a dead one" and gives reasoning and citations to demonstrate that under some circumstances H. pylori could be good for us. (for example individuals without H pylori were twice as likely to have Gastro-oesophageal reflux disease (GORD)). He suggests that perhaps some individuals should keep h. pylori or even have it restored.
His research over the years has highlighted a concern about the disappearance of many microbes from our "ancestral bacterial heritage" that may have positive unique functions. Normal individuals have lost between 15-40% of their microbial diversity and the genes that they posses and therefore also the functions that they carry out on our behalf ... this makes us more susceptible and less able to resist disease.
I like the fact that he holds a very balanced view with antibiotic usage and explains that serious bacterial infections will always be with us and that antibiotic usage will always be needed to fight these, however health practitioner need to... "avoid the reflexive urge to pull out the prescription pad" for more minor ailments to stop further adverse effects.
Martin explains things in an easy to understand way and also gives the necessary research that has been carried out to support his views and prove his points. The evidence he cites is very compelling and people everywhere need to take note and reevaluate: individual health seeker and medical professional alike.... the latter needing to have an open mind of it's potential challenges to existing practices within medicine. The book is highly informative and a great read and I would highly recommend it to everyone.