Can fibre reduce your chances of contracting colon cancer?
I have been a fan of Dr Michael Greger for some considerable time. He excels at explaining important and often complex nutrition research in a way that most people can understand. Michael recently wrote about the benefits of fibre to health, its crucial role in feeding the ‘good’ gut bacteria. Put simply out gut bacteria converts fibre into short-chain fatty acids (SCFA). SCFAs deliver a range of benefits and are thought to reduce the chances of contracting colon cancer.
It’s not simply that SCFA promote gut health generally, fibre helps to maintain gut flora. A failure to eat enough fibre can lead to the starvation and decline of healthy bacteria. This typically allows for an imbalance (dysbiosis), where potentially harmful bacteria begin to dominate, perhaps leading to a range of inflammatory diseases and even colon cancer. Further links even suggest a connection to cardiovascular disease, metabolic syndrome and type 2 diabetes.
A relative small amounts of fibre is needed to sustain healthy gut bacteria, in many cases just a handful of chickpeas every day. And yet there is evidence that many people in the USA and UK are failing to include sufficient fibre into their daily diet.
What is fermentation and how is it related to health and well being?
The growing area of study linking human microbiota to health and wellbeing is seeing the development of new learning opportunities. The extent to which microorganisms on our skin and in our bodies meditate our lived experience can be understood through a free Coursera module, Gut check; exploring your microbiome. Maggie and I have completed the first two weeks, I thought potential future students might be interested in hearing more about what this course entails.
This MOOC is produced by the University of Colorado Boulder and the tutors are all linked to the institution; Professor Rob Knight, Dr. Jessica L. Metcalf and Dr. Katherine R. Amato.
As you might expect week one offers an overview of the subject area. Explanations are given for what microbes are in relation to each other (Bacteria, Archaea, Eukaryotes and Viruses) and all living organisms. The role of microbes more generally is explained before looking at how microbes and humans interact. Definitions include the distinction between human microbiota (a community of microbes), and the microbiota (the total genes in the microbiota).
The material highlights a number of interesting microbiome facts including that whilst humans share 99.99% of the same DNA, two humans may only have 10% of their microbiomes in common. This is one of the reasons why gut bacteria is thought to be influential in how we experience life. Although the majority of our microbes live in our gut, there are communities all over us (mouth, skin, vagina). We are born sterile and then communities of microbiota become established at a very early age, changes to these communities happen throughout our lives. The module material clearly illustrates that the microbes we are exposed to have an import role in our lives.
The first week provides a useful introduction to the subject and offers a context for later material. Beyond week 1, the course follows a much stronger academic path. Explaining the science behind the study of microbiota and moving onto subjects such as alpha diversity and ‘fuzzy microbes’. If you’ve tried the MOOC what do you think?
A basic guide to gut health, key terms defined and explained.
Understanding gut health; 1 the basics
The scientific investigation of gut bacteria and its relationship to wellbeing is at a very early stage. There are discoveries every week that support, coexist with or contradict earlier findings. It’s a rapidly developing and dynamic area of human knowledge. The good news is, there are many resources available to anyone who wants to understand and take control of their own health through diet.
As a starting point there are a few concepts that are best understood at the outset. Not everyone uses these terms in the same way but try these definitions as a starting point.
Microorganism is widely used in talking about gut health, it is a general description for any organism that is too small to see with the naked eye. Some scientists prefer not to use the word but you are likely to come across it widely if you start reading about gut bacteria. Bacteria, viruses, archaea and fungi are all typically included in the term.
Microbiota is generally used to denote the population of microbes in any given community or system. Flora appears to have largely the same meaning as microbiota and appears interchangeably. For example gut flora means the same thing as gut microbiota.
The aggregate of all the genes of an entire population of microorganisms in any environment is described as a microbiome.
Typically scientists divide human microbiota into populations linked to their environment, such as skin, mouth, nose, digestive tract, and in females also the vagina. The largest population of microbes occur in the digestive tract, also known as the gut. Bacteria are the largest type of microbe in the human gut and bacteria reflects the dominant interest of scientific research. Gut bacteria are the main recipients of the benefits of prebiotics and probiotics, that is why the term gut bacteria and gut health is so prominent in media accounts of research findings. Technically speaking the plural of bacteria is bacterium but you will rarely see this outside of science journals, bacteria is typically used as the singular and plural form in most everyday situations.
A key point to make is that the gut has an important two way communication system with the human brain. That means to think of fermented food and drinks as only involved in what happens in the intestinal tract is a mistake. What we eat and drink has has the potential to exert a widespread influence across a number of systems.
As science begins to unravel the importance of gut bacteria to health and wellbeing, there’s never been a better time to learn about human microbiota.
So what’s the big deal about the fermentation of food and drink? Why is there such an interest in it now when it’s been around for thousands of years? The growing ability of science to study microorganisms has opened up research linking the human microbiome to a range of health and wellbeing benefits. Even though this research is at an early stage, there are signs that our understanding of the human condition is entering a new era. Fermentation has a central role in this process, prebiotics and probiotics may be able to make a significant contribution to the quality of our lives and the state of our health.
The awareness that fermented foods may be beneficial is a useful starting point, but there are resources available for anyone wanting to know more. Maggie and I have signed up for the Coursera MOOC, Gut Check; Exploring Your Microbiome. MOOCs are multiple open online courses; essentially short samples of higher and further education. They are typically free and offered by experts in their fields. All materials are available online, and a study commitment of three to five hours for between four to eight weeks are required by students. There is usually an assessment required to complete a MOOC and a verified certificate may be available for a fee.
We will provide a weekly report of the Gut Check MOOC. But for anyone considering signing up for the course, it starts with a basic outline of the microbiome and microbiota (What is the human microbiome? What’s in your gut and how is the human microbiome studied?). It takes a little effort, but it is accessible to most people with a desire to learn and a basic knowledge of biology. This course is offered on the Coursera platform, there are other MOOC providers and free courses available in the same or similar areas of study. We welcome feedback about this or similar resources, feel free to enter your comments in the box below.
The overuse of antibiotics is a major health concern. Probiotics may support the lower consumption of antibiotics by boosting overall health in humans and animals.
I am in the process of writing a basic guide to probiotics, but a general description is,
‘microorganisms contained in some food and supplements that have proven and assumed benefits to human and animal health’.
A key point at the outset is that it is hard to prove causality in such matters. Demonstrating correlation (people that have particular gut bacteria tend to have or not have a particular illness) is much simpler. The evidence linking probiotics and health is both causal and correlational. The point of probiotics is to change (improve) the profile of gut flora so that it has more positive and less negative microorganisms. This is a long road of which we are at the beginning.
Antibiotics are drugs designed to destroy or inhibit the growth of bacteria harmful to humans, animals or other organisms. I acknowledge the potential lifesaving benefits of antibiotics, they are an important part of modern healthcare. But the widespread overuse of antibiotics in industrialized societies is creating superbugs, bacteria that are resistant to all known antibiotics. This problem was the subject of the film Resistance which I recently saw on Netflix. The issue of superbugs is not new and the discoverer of penicillin, Alexander Fleming discussed resistance in the mid 1940s. If you subject bacteria to an effective antibiotics most will die off, but surviving bacteria can develop resistance to that antibiotic. If you repeat the process often enough you risk creating bacteria over time, that become resistant to every antibiotic they have been exposed to.
Sometimes humans are given antibiotics when they are not needed, and so we may carry around bacteria that have a resistance to some antibiotics, this is a problem in itself. A key point that the film Resistance makes is that contemporary farming methods can involve the routine administration of antibiotics to hundreds of millions of animals every year. Antibiotics appear to make some animals grow bigger, thus increasing their cash value. However intensively farmed animals can live in insanitary conditions, exposed to fecal matter for most of their lives. Forcing animals to live in an environment where high levels of dangerous bacteria are present, thus necessitating the use of antibiotics as a routine measure, can be described as a perfect breeding ground for superbugs.
The standards of animal welfare vary from country to country and the use of antibiotics in the EU generally is lower than some other parts of the world. But it’s still a major problem according to a recent report. Conceptually the idea of eating animals is increasingly unacceptable to many people. However the logic of forcing animals to live in terrible conditions their whole lives, only sustained by large amounts of antibiotics is obviously flawed. Not only are people eating animals that have endured life long suffering underpinned by the consumption of drugs. But this process may also be creating bacteria resistant to those drugs. The use of last-resort antibiotics for humans such as colostin, is increasing according to official data. When colostin is used it can indicate other antibiotics were ineffective against the harmful bacteria.
So what has this got to do with fermentation and probiotics? Firstly antibiotics generally kill and inhibited some good bacteria. Where health is at risk this is clearly an appropriate course of action. However as the importance of gut flora to health becomes better understood we should consider the need to maintain gut bacteria at healthy levels. Secondly the better our overall health the lower the risk of illness and presumably the less need there will be to take antibiotics. Just to be clear, probiotics are not a substitute for antibiotics, there are some very dangerous bacteria in our environment for which antibiotics may be the only cure. My position is to abandon the overuse of antibiotics in animals and humans so that when we (and animals) get really sick we will have antibiotic treatments that continue to work. The third point is eating animals that have lived a life in potentially dangerous bacteria, sustained by routine antibiotic consumption seems irrational. Wouldn’t it make more sense to maintain animals in healthy conditions, with feed rich in probiotics, reducing the need for antibiotics in all but essential cases?