Thursday, July 3, 2014

MIssing Microbes: A book review

I recently purchased the book Missing Microbes: How the Overuse of Antibiotics is Fueling our Modern Plagues and finally got the time to read it. This book hits me on so many levels.  First, it's on a topic I find very interesting, the bacteria in our guts and the functions they perform for us that we're unable to perform on our own.  Second, the author takes a very balanced approach in looking at how antibiotics, as well as C-sections, have contributed to significant changes in our microbiome that may be a causative factor in many of the diseases we see today.  Finally, it provides insight in to how and why we may want to change the way we look at things when it comes to our healthcare system.

The book begins by taking a look at the rise of "Modern Plagues" that have only recently become prevalent in Western society but have yet to become epidemic in more traditional ones.  Obesity, Type 2 diabetes, allergies, and asthma are just a few things he tackles in this section.  Next he moves on to the microbes that were once our chief enemy and how they have always, and will continue to well past our extinction, rule the planet.  He then moves on to the microbes that have become our friends, our microbiome.  Our microbiome is the collection of bacterial cells that live within our body and outnumber our own.  In fact, he states that without us our microbes would do just fine; but without all of the microbes that cover our skin, colon and every crevice of our body, we would essentially be losing an organ critical to our survival.  In other words, we would likely be dead.

Probably one of the more telling things he mentions early in the book is how microbial diversity keeps our inner ecosystem in balance.  Just like a forest teeming with life, diversity promotes inner balance.  However, when a keystone species within that ecosystem is lost, the ecosystem, or a large part of it, collapses as other species that were dependent on that one also thin out or disappear. Furthermore, while we focus on microbial species that are abundant in humans, these may not necessarily be the lynchpins that hold everything in place.  A great example of this is how people assume calcium is the most important mineral for maintaining bone density because it is the most abundant while current research seems to point to magnesium as being more important.  Most abundant doesn't necessarily mean most important, it only means most plentiful  This is important because the differences between our microbial genes are far more important than our human genes.  Wiping out an entire species can have huge implications on our health.

He discusses the usual dance of functions associated with the microbes in your colon, immunity as well as nutrient generation and absorption, but adds a few functions that I was unaware of.  These include blood pressure regulation, estrogen regulation, and generation of chemicals required for optimal brain development.  This could perhaps be the link between gut bacteria and autism.  The scary part is that you don't need to wipe these microbes out forever to have bad consequences, removing them during a critical time in development can have pretty serious effects.

For most of the book Dr. Blaser focuses on the stomach microbe H. Pylori and how antibiotics wipe it out.  He states on many occasions throughout the book that we don't know that losing H. Pylori is the cause of the problem, but we do know that losing H. Pylori or another microbe associated with it is not good.  This is a refreshing take because most authors try to push their agenda as being the primary reason we are seeing XYZ, but Dr. Blaser doesn't take that approach, he is much more scientific and points to changes throughout the microbiome as being important, not just the loss of a single species.

Another balanced approach he takes is towards antibiotics.  Many times throughout the book he praises antibiotics and the many problematic pathogens they have eradicated.  What he sees as the two most problematic issues with antibiotics is over-prescription and the profit system around the pharmaceutical industry.  A decade ago antibiotics were prescribed for basically everything as there was no observable downside to using them, an attitude that has been overturned by current research in to the microbiome.  Antibiotics have their use and should be taken when appropriate, but only when appropriate.  The days of haphazardly taking an antibiotic for a virus, something they don't work against, need to be over.

The biggest hurdle Dr. Blaser sees going forward is the way the pharmaceutical industry is set up.  It makes no sense for a profit driven company to develop a targeted antibiotic because that limits the number of people they can sell it to.  Broad spectrum antibiotics are where the research goes because they have a wider application and, thus, a wider customer base.  The problem here is that in addition to wiping out the bad bugs, they wipe out the good bugs and could potentially wipe out a keystone species if it is sufficiently small in numbers or multiple rounds of broad spectrum antibiotics slowly decimate the population.

Finally, another problem that is taking center stage these days is the use of antibiotics in livestock.  While most people look at the use of antibiotics in these animals as a preventative measure due to the poor conditions they are kept in, they are actually given antibiotics because it makes them grow larger.  In fact, 70-80% of the antibiotics sold today are used specifically for this purpose.  There are multiple problems with doing this including promoting antibiotic resistant microbes, antibiotic residues creeping in to our food, and runoff from farms contaminating the water supply with antibiotics.  He goes over the many repercussions of antibiotic exposure, not just from taking them in therapeutic doses, but from constant low dose exposure that we likely get from these avenues every day.

Throughout the book Dr. Blaser sheds a lot of light on how our microbiome helps us, how it has been changed, and the consequences of these changes.  While there is a focus on H. Pylori as this is the microbe he has spent most of his life studying, he is extremely thorough in covering everything.  I highly recommend this book to anyone who is concerned for their health or their child's.  A relationship between IBD, GERD, heartburn, and several other non-lethal but potentially annoying health issues can be traced to changes in our microbes.  Dr. Blaser does a great job of describing how and why these things happen and provides a prudent approach for preventing them through changes in healthcare policy and our attitude towards the necessity for drugs and procedures that may not be necessary.

Missing Microbes by Martin Blaser, MD