It’s a privilege to have registered dietitian Laura Clark share her expertise here monthly and this month, she offers insight into the so-called second brain, the gut.
Over to Laura.
Recently it has become all the rage to talk about our insides. In our large bowel we house over a trillion bacterial cells – in fact we have more of these than we have human cells and the power that they have on our health is emerging with fascinating results.
Collectively known as the microbiome and with over 1000 different types, our gut bacteria are as unique to us as our finger print.
The gut is the only organ in the body to have its own nerve supply and messages travel between the gut and the brain through a nerve axis all the time. Whether this be feeling nerves in our stomach before a big exam or registering pain and bloating if we suffer from IBS.
Protecting our future health
There is no doubt that the diversity of our bacteria are part of the puzzle in health protection.
To keep them diverse we need to feed them the right foods. Highly processed diets, containing high levels of fat and sugar and low levels of fibre are associated with poor diversity of bacteria.
Bacteria are capable of producing certain nutrients such as vitamin K, B12 and folate, together with many other compounds with really long names, which help to protect the immune system, fight diseases such as cancer and regulate body functions such as blood pressure. My bacteria clearly have a more productive week than I do!
Evidence is emerging that the compounds our bacteria produce help to modify our hunger hormones and thus help to regulate our appetite. There are also links with mood and anxiety, whereby modifications to the gut bacteria are beginning to show changes to brain chemistry. In the future, we could see bacteria being part of the prescription for treating anxiety and mood-related disorders.
There are also links between exercise and healthy guts with more active women being shown to have more health promoting bacteria (note to self: get off my a*** once I’ve finished writing this blog post). This is also the case for professional athletes whose gut bacteria have been found to be more diverse.
70% of our immune system lies within our gut, making our digestive system our first line of defence. The compounds bacteria produce may help to dampen down inflammation and fight off specific viral and bacterial infections. Stress can influence our microbiome considerably, hence why ongoing stress tends to knock our immune function.
This is just scratching the surface of the potential impact our microbiome has on our health so most importantly how do we look after it and ensure it is as healthy and diverse as possible?
Top tips for a healthy gut
Fibre fibre fibre
Boost the variety of fruit and vegetables in the diet. Don’t just click re-order on the favourites list – challenge yourself and push the boundaries of colour, taste and texture.
Other sources of fibre besides fruit and veg include wholegrains, beans, peas, lentils, nuts and seeds. Aim for at least 20 different types of plant based foods a week.
Fibre is so complex and so overlooked. There’s literally hundreds of different types and how it interacts within the matrix of a food alongside other nutrients is where the magic really happens.
Fibre is broken down by our bacteria – it’s literally their dinner and in breaking it down they produce substances called short chain fatty acids. These fatty acids keep the gut in check, most notably by preventing the growth of harmful bacteria.
This is one of the reasons I’m so keen we focus on fibre in our children and stop sugar taking the limelight so much.
Prebiotics are an example of a particular dietary fibre. These are known to be particular favourites of our good bacteria – they are the equivalent of a Michelin star restaurant. Prebiotics will boost the growth of beneficial bacteria. They may be added into foods, for example inulin or FOS in yoghurt and they also occur naturally in foods including artichokes, onion, garlic, asparagus, leeks, figs and blackberries.
The role of probiotics
Not all probiotics behave the same – they are safe for consumption but whether they truly boost health is yet to be proven. There is good evidence for their use if you are suffering from traveller’s diarrhoea and there is some success in IBS. Until we can specifically work out which bacteria you are lacking in, we are not able to use probiotics to their full potential yet.
You may have heard of fermented foods such as kefir, kimchi and sauerkraut which contain live bacteria. These are thought to support and nourish our good bacteria as well as enriching the quality of our gut microbiome. We need to prove their worth a little more with some solid research but in the meantime if you fancy trying some fermented goodies then go for it – they can be high in salt though so don’t go too crazy!
A note on IBS
All of this microbiome stuff can play quite a part in IBS – studies have shown IBS sufferers may have lower quantities of the good bacteria and dietary interventions which can treat symptoms of diarrhoea and bloating can have a knock on effect on the microbiome (for example the low fodmap diet). It’s worth considering a probiotic in these cases but to manage your symptoms and diet correctly, it is advisable to consult with a Registered Dietitian.
For more guidance on food, symptoms and the gut, take a look at my Good Gut Guide.
Right time for some exercise and a fibre-filled meal I think, anyone care to join me?