And so, the concept of the microbiome was born.
Follow Your Gut not only give us a true perspective on where scientific knowledge actually is, but it also teaches us about how scientists work to keep us safe.
Now, we probably all know that we have “good” bacteria residing in our guts. In fact, our whole body exists not just as an assortment of organs and blood and skin, but we also host trillions of microbes.
Once again however, we are being foiled and confused by the plethora of books and articles about healthy guts and what foods to eat. And no doubt many of these books do convey some element of the truth. However, many appear to have taken hold of what are simply theories and areas of investigation at this stage and written about the topic without solid evidence.
The fact is that there is more we don’t know about the microbiome than we presently know. In striving for the truth, I came across a little book called Follow Your Gut by Rob Knight and Brendan Buhler. It’s a fabulous lighthearted wee book that concisely and clearly explains what the microbiome is and isn’t and precisely what we know and don’t yet know.
I hope you find this synopsis useful in itself and I am sure that you’ll enjoy the book too.
Synopsis by chapter.
Introduction
Our bodies co-exist with trillions of microscopic microbes that are essential for our wellbeing. There are in fact, 10 times more microbial cells in us than human cells. Different microbial communities reside in our mouths, skin and gut. Whilst each person’s DNA is very similar, their microbiomes can differ by 90%.
We know that these differences help to explain allergies, why one person gets sick, or another doesn’t cope as well with stress, or why mosquitos bite some and not others.
It’s a hugely exciting time (really – astounding doesn’t even go half way to conveying the level of excitement!). This has occurred due to advancement of computing power and improvements in DNA reading programs. Up until recently, our body bacteria identification process was slow and costly. It is only with this DNA reading advancement that we now know that there are trillions of different bacteria happily residing within us. Whilst there is a long way to go, microbiome research is uncovering potential treatments for many illnesses including obesity, arthritis, autism and depression.
Chapter 1: The Body Microbial
The book builds in a logical fashion, starting off explain about the types, volumes and locations of our microbes.
Interesting facts include that our microbes weigh about the same as our brains, that there are 10 times more microbial cells than human cells in our bodies and even our microbial genes out number ours by nearly 100 to 1. We are in fact 99% microbe and 1% human.
Not only does each individual host different collections of microbe, but our mouth, noses, skin, gut and genital areas have completely different populations. Even our right and left hands harbor different microbial communities. What’s perhaps even more astounding is that each of our microbiomes are sufficiently different that each individual could potentially be forensically identified.
Further, we all hear about all the harmful bacteria when food poisoning outbreaks etc. occur. But, it transpires that most of us actually carry E.Coli, Helicobacter Pylori and Streptococcus microbes.
Most of the microbes are in the intestine. Up until recently we only knew of those that proved easy to grow in a laboratory. Now, we know that E.Coli forms only a tiny percentage of the bacteria in our guts. These other microbes are important in food digestion and drug metabolism and have been linked to many issues from obesity to colon cancer and heart disease. We’re only beginning to be able to ask and answer these questions now.
Chapter 2: How We Get Our Microbiome
It is thought that before birth we may not have any microbes and that when we are born we are coated with vaginal microbes, thus providing us with our very first microbial protection. Babies born by C-section do not benefit from this and do tend to be more likely to suffer from issues such as asthma and possibly food allergies and obesity.
Food and the environment then gradually changes our microbiome into adulthood. Children who’ve been exposed to a more varied microbial community (such as when living on farm) tend to have fewer immune problems such as hay fever.
Different cultures around the world have different gut microbiomes and there is significant difference in those who eat high meat versus high fibre diet.
However, we don’t yet know specifically how diet affects the gut microbial population.
Chapter 3: In Sickness and In Health
The possibilities for cures raised by the discovery of the microbiome are nothing less than awesome. And whilst we don’t yet know how to apply microbial treatments for problems like IBD, autism, MS, Ulcerative colitis, Crohn's disease and depression, the ongoing studies are uncovering huge potential for new types of cures.
But whilst we may all like to dive in and follow, as yet unproven, newest fad diet that proclaims to cure all ills, the scientific community continues to work on proving why and how the concepts work or don’t work. It’s complex!
We know for instance that the microbial populations are different in obese and slim people; in people that eat high meat / fat diets (the increase in the microbes associated with heart disease is dramatic); and within people with the above mentioned diseases. We also know that even Kwashiorkor, thought to be caused by protein deficiency is actually related also to microbiome imbalance. However, individual genetics and other factors are also involved.
Chapter 4: The Gut-Brain Axis: How Microbes Affect Your Mood, Your Mind, and More
The microbiome-gut-brain axis is the term used to describe the interaction between our microbiome and its involvement in the digestion of food, hormone production, drug metabolism and our immune system and how that all affects our brain. Again, the possibilities for new cures for issues such as depression and anxiety are immense.
However, whilst we do all love to latch on to new, seemingly harmless, cures and new “fads” we just don’t yet know the full story. Unfortunately, the answers and even the questions are truly complex. And whilst some potential microbial cures for anxiety and depression and symptoms associated with autism have been proven in mice, there are a significant number and variety of mechanisms that remain to be studied and understood.
A further interesting contemplation is whether the rise in inflammatory issues such as arthritis, diabetes and depression may relate to our increasing distance from the soil and clean living. (Soil microbes are considered as helpful modulators of the immune system – but don’t all dash out and eat soil!).
Chapter 5: Hacking Your Microbiome
Given that eating a high meat or high fibre diet or drinking alcohol or taking antibiotics change our microbiome, surely we can eat our microbiome back to health? Unfortunately it’s not that easy.
Prebiotics are, most often, soluble fibres such as galacto-oligosaccharides that are fermented by bacteria in the colon and provide energy to maintain gut health. They aim to mimic the effect of high fibre diets.
Probiotics may be provided by fermented foods such as yoghurt or as suppositories. Unfortunately, the health claims of pre and probiotics has not yet been proven. Further, there are a plethora of products available to buy that may not actually survive life on the supermarket shelves. Should we wish to treat a condition such as IBD, choosing a rigorously scientifically tested product would be more likely to help.
Faecal transplantation may also be a beneficial treatment. This involves transplanting microbes from a healthy person into the ill person. Again, the medical potential here is very exciting, but there are a number of very complex aspects to figure out.
There may also be new possibilities to vaccinate people against the bacteria that we now know are implicated in some heart issues, colon cancers or even depression.
The potential for new remedies, as you can see are hugely exciting, but we shall have to remain patient because, as yet, we do not know which and how many interacting microbes relate to specific areas of disease and health.
Chapter 6:Antiobiotics
Everyone knows of antibiotic resistance, but we do still complain when our doctor won’t give us antibiotics when we think we need them. We should be happy for this control. It’s a fact that 70% of bacteria that cause infections in US hospitals are now resistance to antibiotics. There are two problems for our microbiome. First, the antibiotics target both good and bad bacteria. And second, the more our microbes are exposed to antibiotics, the greater opportunity they have to adapt and survive; further reducing the effect of antibiotics.
Studies have also shown that antibiotics may in fact cause obesity, especially for those who receive them early in life. Children treated with antibiotics may also be more likely to develop asthma and allergies as a result of the early disruption of their microbiome.
The issues with antibiotics are further compounded in situations where broad spectrum pills are used or when we don’t complete the full course. Of course, antibiotics are essential in many situations and there are few other options right now. Fortunately however, technology is advancing our ability to specifically identify microbes by their DNA and thus we have hope that newer, more effective and less damaging cures will be developed.
Chapter 7: The Future
And finally, the little book summarises all of the potential benefits that the understanding of microbes in our environment and bodies will bring. Technology will allow us to know which pain killers will work best, to enable improved ways to treat illnesses related to microbiome imbalance; to potentially vaccinate against obesity and depression and repel mosquitos.
However, we don’t yet comprehend about unintended consequences of messing with our microbiome through these potential treatments.
If you do want to know more about your own microbiome, contact the Human Microbiome Project.
Thank you Rob Knight and Brendan Buhler and TED for providing this brilliant wee book that clarifies all about what we know and don’t know on the Gut-Brain axis and other aspects of our microbiome.
Read more of this astounding, groundbreaking science here.
.
If you would like to hear of further book summaries, and news on dogs, behaviour and nutrition, please do sign up for the RSS feed or follow the blog. Thanks.
