The connection between your gut microbiota and your central nervous system is becoming more of a focus in recent years as we are now realising that having poor gut health could also be linked to having mental health disorders such as anxiety and depression. If we restore the balance of our gut-brain axis, could we also improve certain mental health disorders? Or could improving gut function help to support those who already have a clinical diagnosis of a medical condition?
The term ‘gut-brain axis’ refers to the constant communication between the brain and the gut, and how closely they work together.
We do know that in general, the best way to improve your gut health is to:
- Eat a balanced, healthy diet high in fibre to promote gut transit
- Drink around 2 litres of fluids
- Get enough sleep to help our body repair and recover
Many of you will have also heard that probiotics can also play a role in aiding our gut health by replacing the ‘good bacteria’ that is needed in our gut. Therefore, could probiotics play a role in supporting anxiety or depression?
We spoke to leading dietician Sammie Gill from Symprove to find out a bit more about probiotics and the role they could play. Symprove is the UK’s fastest growing probiotic supplement that is backed by scientists and health experts.
Could you explain how probiotics help to heal the gut?
“Probiotics are classed as live beneficial microbes that when consumed modulate the gut microbiome. Probiotics may work in several ways when they reach the gut – for example, some probiotics can release beneficial molecules such as short chain fatty acids (SCFAs), or prompt release from other microbes. Probiotics can also help weed out potentially harmful microbes, improve gut barrier function and support the immune system (of which 70% resides along the gut).”
Do you think that probiotics could be used to improve mental health conditions such as depression and anxiety?
“For a long time, the gut and the brain were thought of as separate entities – the gut was responsible for digestion and the brain was responsible for emotions.
Fast forward to the present day, we know this isn’t the case at all.
The gut and the brain have a very intimate relationship and are in constant communication with one another – called the ‘gut-brain axis’.
An unhappy gut will send signals to the brain letting it know, and an unhappy brain will send signals to the gut letting it know. It’s a two-way street. For example, gut symptoms can be the result of our emotions (low mood, anxiety, stress) or the cause of our emotions (low mood, anxiety, stress).
But how exactly do they communicate? It’s complex, but they talk using four key channels, including the gut microbiome, the nervous system, the hormonal system, and the immune system.”
How do you choose the right probiotic?
“There is good evidence for taking probiotics in certain scenarios. For example, gut disorders (such as IBS) and antibiotic associated diarrhoea.
Not all probiotics are equal and different strains do different things, so it’s important to take a prescriptive approach.
Choose a probiotic that has the health benefits you’re seeking or that has been shown to manage the symptoms you are hoping to target. If you’re considering taking a probiotic, do your homework and choose one that is science-backed – contact the probiotic manufacturer and ask for links to their published research.
ISAPP have a handy probiotic checklist that provides guidance on how to choose a probiotic Probiotic Checklist: | ISAPP”
Are there any side effects associated with taking probiotics?
“Generally, no. Some people may experience transient side effects as the gut adjusts – for example, mild bloating or change in poop habits.”
Are probiotics suitable for people with chronic bowel conditions e.g. IBD, diverticulitis, bowel cancer. IBS, incontinence, Coeliac, constipation, those with a stoma?
“The evidence level varies depending on the gut condition. For example, there is evidence for trialling a probiotic if you have been diagnosed with IBS – this forms part of NICE guidelines. There is also some evidence to suggest it may be worth trialling a probiotic for constipation. On the other hand, there is less evidence in IBD, though Ulcerative Colitis appears more amenable to probiotics than Crohn’s disease.”
There are clinical studies into the efficacy of probiotics, whilst these suggest that there is indeed a strong link between the gut and the brain and will be a valuable area of study in the future, the use of probiotics to improve gut health and by proxy, mental health is still on the fence.
“The utility of probiotics is questionable as no form is currently regulated by the FDA, including natural sources such as yogurt, kefir, or sauerkraut. Patients may be more likely to use these natural sources of probiotics both due to increased accessibility as well as the resurgence in food trends of a return to more ancient food preparation techniques. Recent research has shown that the use of fermented foods in diets did confer gastrointestinal and cognitive benefits. However, until more evidence behind the use of probiotics as therapy for anxiety and depressive disorders is available, probiotics in any form cannot be considered a reliable therapy to anxiety and depressive disorders as compared to psychiatric medications. Furthermore, gender differences as well as comorbidities (other health issues alongside the main health condition) such as obesity, lifestyle, and tobacco and alcohol use may impact the overall benefit of probiotics.”
If you want to start looking into probiotic health but in a more natural way, there are many foods that have higher amounts of the ‘good bacteria’ that we require for gut health. Generally, foods that are fermented produce the right enzymes that are needed for a happy gut.
A study led by Professor Christopher Gardner found that 6 servings of fermented foods a day helped to increase the diversity of our gut microbiome and reduce inflammation in our body. A serving was defined as 175ml of kombucha, yoghurt or kefir, 85g of sauerkraut, kimchi or other fermented vegetables and 60ml of a vegetable brine drink
Here are a few examples of foods that are natural probiotics that you may want to add to your diet.
Here are a few examples of foods that are natural probiotics that you may want to add to your diet.
- Natural Yoghurt – yoghurt is probably the most recognised food when it comes to probiotics. A natural, no added sugar yoghurt is best and look for labels that contain live active cultures
- Kefir – is an Icelandic yoghurt drink that is a little more sour than normal yoghurt. It’s great used in breakfast bowls or in a smoothie for extra probiotic goodness
- Kimchi – this is a traditional Korean dish that is made with fermented cabbage but with a spicy kick. This is great used in rice dishes or to give your lunchtime salad an edge!
- Sauerkraut – is again, made from fermented cabbage and could be used as a good alternative to fried onions such as on your hotdogs/ burgers and served as an accompaniment alongside meat
- Pickled cucumber (gherkins) – pickles are a great source of good bacteria and could be an easier transition if you find Sauerkraut difficult to eat
- Miso – miso is made from fermented soybeans and is most commonly used in japanese cuisine in soups and as a glaze or sauce on meat, fish or tofu
- Kombucha – is a type of fermented tea, which is not only a probiotic but is also rich in B vitamins that boost energy and aids digestion and bloating
- Some cheeses – hard cheeses such as Cheddar or Gouda are made using lactic acid, which produces the gut friendly bacteria. You could start by adding some grated Cheddar into your soup
- Olives – Olives are a good probiotic source and even some types of olive such as Sicilian olives have antioxidant properties and can help to reduce inflammation
- Sourdough bread – the starter in a sourdough produces lactic acid to give this bread its probiotic characteristics. Incidentally, this is also the reason why some people also find sourdough bread easier to digest than other bread
As well as working at increasing our intake of fermented food, Professor Tim Spector at Zoe https://zoe.com/post/tim-spector-gut-tips listed other ways in which we can help to improve the health of our gut microbiome.
The following 4 habits may help boost your gut health:
- Improving our fibre intake by aiming to eat 30 different plants each week – by doing this, our gut microbiome will be more diverse and a high fibre diet* will help keep your bowel moving. Plant foods don’t just mean vegetables but also nuts, seeds, legumes, herbs and spices
- Eating colourful plants in particular is beneficial as these contain polyphenols which ‘good’ bacteria thrive on. Foods such as nuts, berries, brightly coloured fruits and veg and even dark chocolate!
- Give your gut time to repair overnight by avoiding snacking late into the evening. At night there is a team of gut microbes that help to clean your gut and keep it healthy
- Limit processed and in particular, ultra processed foods – not only are these generally high in sugar and fat leading to conditions such as diabetes and heart disease but they are also don’t help to support our gut microbiome leading to an unhealthy gut and potentially an unhealthy mind
You can find information about bowel conditions here including the symptoms and treatment of irritable bowel syndrome, for which probiotics could be beneficial. Symprove also has some great information on probiotics and where they could be useful.
It is important that you consult your GP or healthcare provider before making any dietary changes.
*Some bowel conditions don’t tolerate a high fibre diet so please check with your doctor first