Blueberries appear to offer a wide range of benefits including supporting guthealth.
Being a meditation scientist I often write about lifestyle choices that support augmented brain function and structure. As a general rule food that is associated with a healthy brain also positively correlates with improved general health and well-being. So having just blogged an article explaining how blueberry consumption can reduce effective brain age by up to 2.5 years I looked up potential relationships between blueberries and the gut microbiome.
Berries in general and blueberries, in particular, are good natural sources of polyphenols and therefore limit the effect of oxidisation, a cause of cell damage. But we also know that polyphenols lead to a healthier gut through the creation of metabolites which in turn support communities of beneficial bacteria.
As we age, chronic diseases become more likely1, when low-grade inflammation is an underlying factor, scientists refer to this as the “inflammaging” syndrome. In the gut, health inflammaging is linked to a weakening of a number of internal systems (homeostasis) including a reduction in the efficiency of the immune barrier. In experiments with mice, it was suggested that polyphenols reduced intestinal inflammation and led to the modulation of the gut microbiota. The evidence is that berries are rich sources of polyphenols and so are likely to have a positive impact on chronic diseases linked to gut health, particularly in older populations.
According to the Blueberry Council, the benefits of blueberries extend beyond inflammaging.
Experiments have demonstrated an improved insulin response in blueberry-fed mice when compared to controls.
Further evidence for augmented cognitive function in animals and humans has been found.
There are also preliminary studies supporting a relationship between blueberry consumption and reduced growth in cancerous cells.
Polyphenol is found in a wide range of fruit and vegetables as well as nuts and pulses. Here are some of the top 100 food sources of polyphenol according to a study published in 20102.
Your diet can play a significant role in your chances of becoming obese, suffering from asthma or a range of other illnesses.
Discovery, a general science programme from the BBC World Service, has put together a helpful three part guide to the human microbiome. It is made for the wider World Service audience so it presents the issues in an interesting but accessible way. The discussion of the subject matter is engaging, and important contributions are made by leading scientists in the field such as Prof Rob Knight, from the University of California and Prof Tim Spector from Kings.
The show provides a general outline broken down into three parts; Manipulating Our Hidden Half, Dirt and Development and Gateway to the Mind. The idea that humans (in common with other animals) have not one but two genomes is central to this mini series. Our human genome is the one handed down to us through our parents, set in stone at conception. The so called second genome is made up of a vast pool of genetic diversity present in the microbes found throughout and within our bodies. The Human Microbiome Project has begun the process of analyzing the large number of microbes present in us. Two key issues that have started to excite scientists in recent years are,
the extent to which microbes can influence human health and experience.
the ability of individuals to alter their own microbial profile.
For example, it is generally observed that increased diversity of different kinds of helpful bacteria in the gut, is correlated with improved wellness. Studies in obesity, allergies, asthma and auto immunity suggest that gut bacteria may have a crucial role in meditating our health. This opens up the prospect that lifestyles remedies such as changes to diet may offer us significant potential benefits. It also raises the question about the long term benefits of medication known to have a detrimental affect on gut bacteria such as antibiotics.
This then takes us back to the discussion of probiotic and prebiotic food and drinks. When you consume products rich in helpful bacteria (probiotics) or the soluble fibre known to support microbial diversity in the large intestine (prebiotics), you are likely to be improving your health in a number of ways. It cannot yet be said that there is a direct causal relationship between your diet and certain illnesses. However the scientists are starting to think of gut bacteria as increasing or decreasing the chances of suffering from particular health problems.
At the time of writing all three programmes were freely available online or to download here.
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.
If wine is good for your health, its relationship with gut bacteria may be part of the answer.
One of the rapidly emerging truths about the relationship between our health and gut flora is that it’s not simple to demonstrate causality. Specific food and drinks can be both positive and negative in different ways at the same time Each person may react to substances in different ways dependent on a number of individual factors.
However science can offer general indications (sometimes something more specific) about what might be beneficial. A 2016 study from the University of Groningen, indicated that wine, coffee and tea all appear to have a probiotic effect, increasing the diversity of the bacteria inside our digestive system (microbiome). The quality and quantity of bacteria in the gut microbiome is apparently increased by the consumption of certain drinks. Health studies have for years suggested that wine, drunk in moderation, may be beneficial for your health. It is possible its role in maintaining and increasing helpful gut bacteria might be part of the explanation.