#1 Gut Microbiome

Let’s start with the word microbiome.  It literally means, micro = something that you can’t see with the naked eye and biome = an ecosystem of flora and fauna.  As clear as mud?  Try this instead.   It’s a collection of trillions of microorganisms, (mostly bacteria but also archaea, fungi, and viruses) their DNA and the environment they live in, which inhabit your (mostly large) intestine.  Until recently, scientists didn’t really know much about it, but with breakthroughs in DNA technology, new capabilities in managing big data and a growing number of trials and studies, we are learning a great deal more about this fascinating “organ” (yes, it’s so important its now referred to it as an organ).

So, if that’s what it is, why is it important?  Well… because it influences your wellbeing, and not just your gut health; it affects your digestion, metabolism, your immune system, and hormone regulation.  It can even influence your susceptibility to obesity and inflammatory conditions such as IBS, your response to chemotherapy, how your body responds to glucose and your brain health.  And, while your gut microbiome is something that you’re born with, it is constantly influenced by the food you eat, the drugs you take and the environment you live in.  So, unlike your ‘fixed’ genetics, your gut microbiome can be changed – for better or for worse – pretty quickly.  In fact, research suggests that changes in dietary intake can affect your gut microbiome in as little as 2 or 3 days.

Hopefully, if you’ve made it to this point, I’ve piqued your interest and you’re happy to read on.  But, if you’re pressed for time and looking for a quick takeaway, skip to the end and have a look at ‘3 THINGS’.

For those continuing …. let me attempt to articulate what the trillions of microbes in your gut actually do….

The large intestine leverages these trillions of microbial inhabitants to ferment the non-digestible components (aka fibre) in your diet.  In so doing, it produces short chain fatty acids (SCFAs) and gases, mostly propionate, butyrate and acetate, which carry out a number of important functions in your body.  These range from providing energy to colon cells, preventing gut dysbiosis and satiety signalling through to reducing inflammation, improving blood sugar management, and aiding metabolism.  This ‘24/7’ chemical factory operating in your colon, needs diversity and balance to work optimally.  Put another way, it needs the right mix of so-called “good” and “bad” microbes to function well.  This balance is influenced by a myriad of factors including diet, exercise, alcohol, sleep, the seasons, intermittent fasting and medication.  Since the influencing factors are so wide ranging, everybody’s gut microbiota is distinct to them (you might say we each have our own unique ‘gut-print’) as well as being constantly in flux.

So, if having the right balance and diversity is key, how do you achieve this?  Here we can think of it in terms of ‘gut-nurturers’ and ‘gut-hinderers’.  Let’s examine the hinderers first, starting with antibiotics.  Antibiotics do a great job attacking harmful, infection causing bacteria, but they also damage the population of good bacteria in your body.  The effects of antibiotics on your gut microbiome may last many weeks, and in some instances can do permanent damage.   Now, let’s look at sleep.  Studies have shown that insufficient sleep alters the gut balance in favour of ‘bad bugs,’ the kind that are associated with disease like obesity and type 2 diabetes.   Exercise too has also been linked to poorer gut health and studies have shown that people who don’t exercise, have less microbial diversity and greater numbers of ‘bad bacteria’.  Alcohol has a similar effect, reducing the population of good bacteria thus enabling the bad guys to take-over, potentially creating dysbiosis if consumption is excessive.  However, it’s worth mentioning one particular silver lining!  Moderate red wine consumption has been shown to increase the population of good bugs, most likely because it contains polyphenols (more on those later).  Diet, as you can imagine, is the most significant modifier of the gut microflora and hindering factors relating to food include a limited diet, diets low in fibre or high in ultra-processed foods.  Drilling down deeper into dietary hinderers, poor variety is problematic since a diverse microbial population requires a diverse intake of nutrients to thrive.  Low fibre diets in contrast cause issues, since fibre and prebiotics nourish the good bacteria in your gut.  Fewer prebiotics mean fewer ‘good bugs’, and fewer ‘good bugs’ mean the ‘bad bugs’ are more likely to outcompete the ‘good bugs’ creating imbalance.  Talking of ‘bad bugs’, ultra-processed foods like soda, sweetened breakfast cereals and flavoured crisps, contribute to gut dysbiosis because the nature of their processing eliminates their fibre while often adding fat, salt, sugar, artificial sweeteners, preservatives, and emulsifiers, all of which are associated with increases in bad microbes.

On the flip side, we can highlight the absence of antibiotics, sufficient sleep, limited alcohol consumption, and a diverse diet rich in fibre and prebiotic foods (like pulses, berries and oats) as ‘gut-nurturers’.  Furthermore, polyphenols need a mention as ‘gut-nurturers’ as they act in a similar way to prebiotics, encouraging the growth of beneficial gut bacteria.  Polyphenols are found in all plants, but those particularly high in these powerful antioxidants include cocoa powder, chocolate, berries, some spices like cloves and star anise and dried herbs like peppermint, sage and rosemary.  Last, but by no means least, under the heading of ‘gut-nurturers’ are probiotics.  Probiotics contain a variety of micro-organisms which can “top up” the good bugs in your gut. You can find them in products like live yogurt, kefir, sauerkraut, and kimchi.

So, there we are, a whistle-stop tour of the gut microbiome.  What it is, what it does, and some things that influence it.  I hope you’ve enjoyed it.  Next time, I’ll be sharing some thoughts on carbohydrates, their importance to health and whether they deserve their reputation as ‘villains of the macronutrient world!’  Until then, enjoy the sun, stay hydrated, and be kind to your microbiome (e.g., feed it lots of plants).

Wishing you good health,

Jools