Or: “What should I eat to make my gut microbiome, and therefore myself, more healthy?”
So obviously, this was Helen’s first question to me. And, like most things in life, the most accurate answer is probably: “It’s complicated.”
For a start, if we’re trying to do this on an evidence-based premise, we’re on shaky ground because:
- there is limited evidence to date on how to alter the human gut microbiome and, as I have alluded to before, we all have different genetics and lifestyles which means there is simply not going to be a “one size fits all” approach (and anything you read or get told that suggests otherwise, any “quick fix” or solution that sounds too easy, almost definitely is); and
- there is limited evidence that changing your gut microbiome makes you more healthy (yet).
Oh, ok. So, why bother at all then?!
Well, this goes back to my point about not always having time to wait for the evidence and having to take a common-sense approach based on the evidence that is available in combination with some “rational scientific theory” from people with some knowledge and experience in the area, i.e. trust your own discerning powers of reason and listen to what the experts have to say.
But this comes with a caveat: remember that experts aren’t always right. Even scientists’ and doctors’ theories can be wrong. They can be swayed by personal prejudices and bias just like anyone else. For my part, I’m always predisposed, to a greater or lesser extent, to more “natural” options, for example. So the “microbiome theory” appeals to the side of me which likes the idea of being “at one with nature” (quite literally!). So can my judgement on this be trusted…?
Well, it is a question I frequently ask myself and I go back to the theory (see What is a microbiome? and What has the gut microbiome got to do with health and disease?); the evidence so far; the arguments for and against; the interpretation of the evidence so far by other scientists like Tim Spector in his book (who is a specialist on reviewing and interpreting health-related evidence); and so far I remain utterly convinced that the gut microbiome does play a critical role in our health.
Apart from a few limited examples, I don’t yet know how to manipulate that to our advantage significantly, but I do believe that we are on the right path and that this will come if we persevere… perhaps in part a leap of faith coming from my own personal values and belief systems, but undoubtedly also also based on my knowledge and experience of advances in medical science and healthcare as a doctor. It is up to you as an individual to come to your own conclusions, but there is part of me that obviously hopes to convince you!
Whilst I am aware that I am biased in that way, doctors and scientists (or anyone) can also fall foul of the effects of personal or anecdotal experience, which can affect even the most rational of thinkers in quite a profound, but potentially misleading, way, both consciously and unconsciously.
For example, just because you, or your neighbour, or your patient, went on a banana diet* and was cured of bone cancer, doesn’t mean that it was the banana diet that cured the cancer, or that the same diet would have the same effect in different people or other cancers. But people have a tendency (understandably) to want to believe in the miracle cure. Particularly when it comes to life-threatening illnesses like cancer.
*no such thing as a banana diet exists as far as I know – this is for illustrative purposes only!
I caution you on this because there are is a lot about the gut microbiome and the magical properties of probiotics out there at the moment and in addition to trying to provide you with the most honest and accurate information I can on these subjects, I also want to help you to effectively assess all of the other information out there so you can better judge for yourself what is helpful and what is applicable to you.
And when making changes to your lifestyle to improve your health, it’s important to remember to do what’s right for you as an individual in your own particular personal circumstances with your own physical, practical, social and financial issues in combination with your own psychological, emotional, spiritual and cultural background. If you are already vegan, for example, because you are ethically opposed to the use of animal products for human benefit, you are probably not going to want to go on a meat-based diet, whatever the evidence or supposed virtues.
Equally, if you have eight children and are struggling to make ends meet, whilst living in a city-centre tower block, you might struggle to convert to purely organic and home-grown food, even if you do think it’s a good idea (which, in an ideal world, I do). It’s common sense! We have to be practical and we have to be true to ourselves. As I am always saying to Helen: “It’s a balancing act.”
And that doesn’t always mean taking the easy option. Putting in some effort, taking on a challenge, making a few sacrifices… these things enrich our lives. But take it easy! Pace yourself. Manage your expectations. You may not feel like you have much time, but I’m a big believer in the principle of slow. Ready for some cliches?
Think of that trusty Tortoise versus his hasty mate, Hare. “Rome wasn’t built in a day.” And, taken from the title of one of my daughter’s favourite stories: “Hurry Up and Slow Down!” At this point I really should refer you to the “Slow Movement”1, a philosophy that I certainly aspire to, if I don’t quite manage to put it into practice on a day-to-day basis…
So, are you ready to take it slow?
Ok, well, the basic principles of optimising your gut microbiome are, as suggested by Tim Spector in “The Diet Myth”2, very much like tending your own garden. And anyone who has ever tried even the most basic of gardening knows that, just like beautiful Rome, gardens don’t just pop up overnight. And just as the modern world is learning of the benefits of an organic approach to gardening, working with nature to create the best conditions for plants to flourish, without the need for potent chemical weedkillers and pesiticides which can have many unfortunate side effects and consequences both in the short and long term, and on both a small and large scale, so we should also perhaps start talking about the same sort of approach to the human body and its “microenvironment”.
In my previous post “What has the gut microbiome got to do with health and disease?” I introduced you to the idea of microbial dysbiosis. Surely, we have a lot to learn from the humble gardener, on a microscopic scale, or from the marine biologists, botanists, zoologists, environmental consultants and ecologists out there, who have to deal with large-scale biological imbalances or “dysbiotica” every day. They will tell you that eco-systems are so complex that altering one small detail may have widespread, even catastrophic, but unforeseen, consequences. And it is likely that a similar situation lies within us (an example of some “rational scientific theory“ extrapolated from what experts do know, by the way, rather than “set in stone” evidence). But if we accept all that (which I do), the big question is, how do we restore the balance?
The main message from Tim Spector’s book2 is that diversity is key. This is both in terms of the foods you eat and in terms of the microbes you want living in your gut. One of his closing statements is: “you won’t go wrong if you just treat your own microbes like you would your own garden” (which I mentioned before, but of course the metaphor doesn’t really work if you go for the “total neglect” or “concrete it over” approach to your garden, but I hope you can see what he’s getting at!). He then goes on to summarise what this means, as detailed earlier in his book:
Give them plenty of fertiliser – prebiotics, fibre and nutrients.
Plant new seeds regularly in the shape of probiotics and new foods.
Give the soil a rest by fasting.
Experiment, but avoid poisoning your microbiotic garden with preservatives, antiseptic mouthwashes, antibiotics, junk food and sugar.
Now there are many things other than diet which probably impact your gut microbiome, some of which I have mentioned before (e.g. your genes, the way you are delivered as a baby, whether and how long you are breastfed for, and how clean an environment you grow up in); some of which are referred to here (e.g. mouthwashes and antibiotics); and others which I have not really touched upon but may well also be just as important (e.g. exercise, sleep/shift patterns, environmental pollution, stress/trauma, and many more).
However, Tim Spector2 explains his own theories about how and why many of these factors are important, with some evidence to back it up, so I would suggest you read his book if you want more information about these things. I find them all fascinating, and hope to find more time to explore them later, but for now I am going to pace myself, manage my own expectations, and take one step at a time… and that is by currently focusing on one thing (mostly): diet.
So, the terms prebiotics and probiotics have finally been mentioned. Hopefully the context will help you to understand them a little better. In simple terms:
Probiotics are the microorganisms or “bugs” that we want to help colonise our guts – the “seeds” we want to plant in our “microbiotic gardens”.
Prebiotics are substances which essentially feed these microorganisms or “bugs”; the “fertiliser” to help the “seeds” grow (if we don’t create the right environment, the plants won’t grow and thrive).
However, what Helen and I wanted to know, and what I assume many of you will too, is how these terms actually relate to the food we eat, and how they can help us to improve our own diets in an individually-appropriate and sustainable way.
Well, if you are still keen to come with us on our path towards achieving a healthier gut microbiome, here are my responses and suggestions based on what I have read and have been able to work out so far:
The Gut Microbiome, Probiotics and Prebiotics: Probiotics [need LINK] [coming soon]
The Gut Microbiome, Probiotics and Prebiotics: Probiotics and Chemotherapy [need LINK][coming soon]
The Gut Microbiome, Probiotics and Prebiotics: Prebiotics [need LINK][coming soon]
The Gut Microbiome, Probiotics and Prebiotics: Summary and Key Points [need LINK][coming soon]
Glossary and Useful links (also see Useful Resources page)
Gut Microbiome: a microbiome is a collection of micro-organisms living together in one place (see What is a microbiome? page and microbes below); also known as microbiota (see What is a microbiome? ); your gut is another word for your digestive system or, more commonly, your small and large bowels (see What is your gut?)
Microbial Dysbiosis: the microbiome (see above) in disarray (an “unhealthy imbalance”) unable to adequately fulfil its role of promoting good health for its human host and probably promoting disease (see What is a microbiome? and What has the gut microbiome got to do with health and disease?)
Dysbiotica: see microbial dysbiosis above – an “unhealthy imbalance” in an ecosystem (see What has the gut microbiome got to do with health and disease?)
Microbes: micro-organisms, “germs”, living things which are too small to see with the naked eye (see What is a microbiome? page) including bacteria, yeasts and viruses
Probiotics: according to Wikipedia, The World Health Organization‘s (WHO) 2001 definition of probiotics is “live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host”. However, this is apparently controversial in that it is not acceptable to the European Food Safety Authority because it embeds a health claim which is not measurable. See: https://en.wikipedia.org/wiki/Probiotic .
Prebiotics: these are food ingredients that induce the growth or activity of beneficial microorganisms, again according to Wikipedia, taken from the following article: Hutkins RW; Krumbeck JA; Bindels LB; Cani PD; Fahey G Jr.; Goh YJ; Hamaker B; Martens EC; Mills DA; Rastal RA; Vaughan E; Sanders ME (2016). “Prebiotics: why definitions matter”. Current Opinions in Biotechnology. 37: 1-7. PMC 4744122 PMID 26431716. doi:10.1016/j.copbio.2015.09.001.
Microorganisms: living things which are too small to see with the naked eye (see What is a microbiome? page) including bacteria, yeasts and viruses
References
- The Slow Movement: https://en.wikipedia.org/wiki/Slow_movement_(culture)
- The Diet Myth – The Real Science Behind What We Eat: book by Tim Spector, Professor of Genetic Epidemiology at King’s College London and author; see http://www.tim-spector.co.uk/