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?
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.
Is temperature linked to the quality of your sauerkraut?
In the short time we have been running this blog we have been asked about the optimum temperature for the fermentation process to take place. We have successfully fermented a range of foodstuffs at room temperature, let’s say from 18oC to 22o. There is no method in this, it is simply that Maggie was brought up to leave the fermenting vegetables in the kitchen or a heated utility room. As such we’ve never been tempted to leave them in the garage or garden shed. As different types of cabbage take different amounts of time to ferment into sauerkraut, it always seemed likely that temperature is a variable in the process.
I eventually became impatient not knowing, I was also intrigued by the idea that the quality of our own sauerkraut fermentation could be qualitatively improved by allowing it to take place at a slightly lower or higher temperature. The first two science papers I found dealing with the issue didn’t offer explicit conclusions, however third time lucky! India is one of the world’s big producers of cabbage, the spoiling of the raw cabbage before it gets to the consumer is a significant problem. So Indian interest in fermentation is something that is culturally relevant but also has commercial implications. An article in the Indian Journal of Ecology from 2017, Effect of Temperature on Fermentation and Quality of Sauerkraut provided a lot of useful data.
In an experiment, Pran Krishna Thakur, Payel Panja and Jahangir Kabir tested the quality of sauerkraut produced at a low (15o-20o C), ambient (25o-30o C) and high (35o-40o C) temperatures. The paper is well written if you’d like to know more about yeast and bacterial profiles of sauerkraut fermentation at different temperatures follow the link. However the headline is that the sauerkraut was of a higher quality when fermented at the lower temperature (15o-20o C). This is in line with the general advice, however it’s worth noting that the experiment was undertaken with the shaan variety. I suspect that there may be some variability with different types of cabbage, but that’s a story for another day.
What is gut health? How much does science really know. Where can you get more information from?
The interconnected relationship between microbes and humans is an increasing object of research and general public interest. Microbial communities are all around us, on the equipment you are using now to view this article, in your home, place of study or work. Crucially microbes have a significant presence on our skin and inside our bodies, particularly in the digestive tract, with the highest concentrations found in the colon. It should be pointed out the the consumption of fermented foods is linked to a positive, increased richness in gut flora.
Over the last decade advances in technology have led to improved understanding of the collection of bacteria, fungi and archaea (single cell microorganisms) that make up the human microbiome. More importantly there are ongoing attempts to understand the relationship between an individual’s microbiome and their health and wellbeing. In scientific terms the study of the human microbiome is in its infancy, but there are already a wide range of studies linking microbes living in the human gut to health and wellbeing. Elizabeth Bik has written a journal article outlining this general area of research and its challenges and opportunities. I would recommend The Hoops, Hopes, and Hypes of Human Microbiome Research to anyone wishing to get an overview.
The Bik article was published in 2016, and reflects one perspective (albeit a particularly well informed insight). A search on Google Scholar this morning (13th February 2018) for the term microbiome found over 20,000 entries; each entry likely to correspond to a journal article, book/book chapter, or other document. The point being, that this is a rapidly evolving area of enquiry. The types of human experience which appear to correlate with the microbiome is growing and includes; memory, obesity, depression, cancer, Crone’s disease, the immune system and much, much more. However as Elizabeth Bik points out in her article, the fact the certain microbes are correlated with a particular condition does not necessarily mean they cause it or are caused by it.
If you have a particular interest in gut health my advice is to find some good quality journalism as a starting point. If you need something more then go to the best scientific papers available. In my humble opinion, using one article or piece of research rarely builds a full enough picture. If you find out anything interesting feel free to email us or add it to the comments section below.
How far should we take responsibility for what we eat?
A conversation with a colleague and a question received by email prompts me to remind anyone reading this blog that science is limited in many respects. Scientific claims can be overstated and results can sometimes come about by chance! Our own approach is to consider all evidence on its merits but to apply our own common sense. I would urge everyone else to do the same. Any good scientist is likely to know about the limitations of their findings, and they should be highlighted in their research papers. I would hope for this to be reflected by journalists writing about science.
Part of the motivation for creating this blog is to take a bit more responsibility for my own health, and to encourage others to do the same. We can’t do without reliable high quality science, but that doesn’t mean that research published by scientists or academics is necessarily correct, or should be taken seriously.
In my own field of psychology/contemplative science, research is a starting point and needs to be treated with a healthy scepticism. Once a particular concept has been successfully tested a number of times (replication), only then can it start to be considered as potentially reliable. So if you read something on these pages that interests you, follow the links and check out the source material. And keep the concepts at arms’ length until you feel you can fully engage with the material. All the views expressed on this website are opinions of the contributors and or people writing about gut health. they may not reflect the views of the website owners and must be read in relation to the respective scientific research. Please read our disclaimer.