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With potential links to mental, heart, sleep and skin health, it’s no wonder the gut’s often referred to as our ‘second brain’. Read on to learn the effects of an unhealthy gut from an expert
Summary
1What’s the gut?
Your gut tract itself is a nine-metre-long passageway which includes the mouth, oesophagus, stomach, small intestine...
2What’s a healthy gut look like?
A healthy gut is able to digest food properly, absorb nutrients efficiently and eliminate waste regularly...
3What are the signs of an unhealthy gut?
There can be a number of things to look out for including digestive discomfort, lack of energy, disrupted sleep...
Noticed that everyone's suddenly buzzing with tips and tricks on how to look after your gut? You’re not alone. Gut health has quickly become one of the trendiest topics in wellness, with bestselling books, hit podcasts and viral TikToks all shifting the way we think about our digestive system. A healthy gut does more than just break down our breakfast, however. Emerging research1 shows that the trillions of microorganisms living in it could act like a central command centre, possibly influencing everything from our mood and sleep quality to our immune system and energy levels.
So what exactly is ‘good gut health’ and why is it one of our best allies when it comes to feeling well, inside and out? We asked Dr Megan Rossi, leading gut health expert and founder of Smart Strains, to help us digest the facts.
What is the gut?
Your gut is also known as your gastro-intestinal (GI) tract and is part of your digestive system. “Your GI tract itself is a nine-metre-long passageway which includes the mouth, oesophagus, stomach, small intestine, large intestine and the rectum and anus,” explains Dr Rossi.3 “Each part plays a key role in breaking down food, absorbing nutrients and eliminating waste.”
Right now, your digestive system is brimming with a cocktail of bacteria, fungi, viruses and parasites that are all part of what’s known as your gut microbiome – a complex metropolis of microbes (and the chemicals they create) that live in your gastrointestinal tract.2
“Research shows that only around 20% of your gut microbiome is genetically determined, the other 80% is lifestyle.”
Emerging research4 suggests the gut microbiome could be responsible for a list of important bodily functions, which include digesting food and creating short chain fatty acids which help with health. In addition, other research suggests association to brain and immune health but more evidence is needed.
What is a healthy gut?
When health professionals talk about ‘good gut health’, they’re not talking about eliminating ‘harmful’ bacteria through drastic trends – what they really mean is balance. A healthy gut is able to digest food properly, absorb nutrients efficiently and eliminate waste regularly, without causing ongoing issues like bloating or irregular bowel movements.5 But the term also refers to the quality of your gut microbiome too.
“Good gut health means a well-balanced and diverse microbiome that works in harmony with your body,” explains Dr Rossi. “This may be achieved through making lifestyle choices that support the right environment so helpful bacteria can flourish.”
What are the signs of an unhealthy gut?
As your gut is connected to so many other systems in your body, the signs of imbalance can be surprising and wide ranging.6 Here are some of the most common to watch out for that you should speak to your GP about:
- digestive discomfort – ongoing bloating, gas, constipation, diarrhoea or heartburn could all be signs of gut dysbiosis (the technical term for imbalance)
- low energy – poor gut health may leave you feeling constantly drained, even with decent amounts of sleep and good nutrition
- disrupted sleep – trouble falling or staying asleep could be tied to your gut, especially since it helps regulate neurotransmitters like serotonin and melatonin
- skin flare-ups – conditions like acne, rosacea, eczema or just generally inflamed skin may be signs of poor gut health
- mood changes – thanks to the gut-brain connection, emerging evidence suggests there could be a possible link
“Studies have shown that people with certain forms of arthritis often have a slightly different gut microbiome profile compared to those without.”
While occasional gut health symptoms are normal and nothing to fear, persistent or severe digestive issues are worth investigating further and you should always chat to your GP if you’re experiencing:
- blood in your stool
- unexplained weight loss
- ongoing pain or discomfort
- major changes in your bowel habits
How does gut health affect the rest of the body?
While the connection between the gut and skin is still being explored, emerging research suggests that what’s happening in your gut might show up in the bathroom mirror.7
“Just like we’ve got bacteria in our gut, we also have bacteria living on the surface of our skin in what we call the skin microbiome,” says Dr Rossi.8 “These two ecosystems are thought to be in constant communication through the gut-skin axis and there’s a link7 between gut health and inflammatory skin conditions like eczema, psoriasis and even premature ageing.”
Poor gut health, especially when the gut lining is ‘leaky’ (referred to as ‘leaky gut syndrome’ – however not an official medical condition), can allow toxins and harmful bacteria to enter the bloodstream.9 This can trigger systemic inflammation, which may worsen joint pain and conditions like arthritis – a condition which affects 10 million people in the UK.10 “Interestingly, studies11 have shown that people with certain forms of arthritis often have a slightly different gut microbiome profile compared to those without the condition,” adds Dr Rossi.
The gut-brain axis is a hot topic in wellness right now, and for good reason. “Your gut and brain communicate constantly through a two-way axis,” explains Dr Rossi, “with signals travelling back and forth between your digestive system and your central nervous system, potentially influencing everything from mood and memory to stress levels.”12
A healthy gut microbiome also produces neurotransmitters like serotonin (about 90% of which comes from your gut)13 which regulate mood, anxiety and stress. In fact, Dr Rossi points to clinical trials14 which showed that a gut-supporting diet may have a significant improvement on people’s depression scores.
Did you know that most of your immune system is housed in your gut? As Dr Rossi explains: “As much as 70% lives along your nine meter digestive tract15 and if the bacteria there aren’t well fed, they can activate the immune system which can create low grade inflammation that makes us more vulnerable to invaders.”
As well as your immunity, your gut microbes may also be quietly supporting, or sabotaging, your heart health efforts. “Our microbes are thought to play a role in metabolising things like cholesterol,” explains Dr Rossi.16 “But we also know that if we overfeed them with ultra-processed foods or lots of protein without enough fibre, they could start producing certain toxic compounds that have been linked to heart disease.”17
If you’re struggling with unexplained sleepless nights or constant fatigue right now, before doing anything you should speak to your GP. After that it might be worth looking into your diet. “We know that lack of sleep18 can negatively impact your gut health,” says Dr Rossi, “but newer research19 shows this relationship is bi-directional, and that nourishing the gut may actually improve sleep quality, too.”
Animal studies20 have even suggested that the gut microbiome may influence brain fog and mental clarity too, hinting at a close connection between your microbes and how rested and alert you feel day-to-day.
What factors affect gut health?
“It’s easy to assume gut health is mostly down to genetics, but research21 shows that only around 20% of your gut microbiome is genetically determined,” Dr Rossi stresses. The other 80% is shaped by lifestyle habits,22 which include:
- diet – eating enough fibre, with plant diversity and minimal ultra-processed foods may help your gut microbes to thrive
- sleep – poor sleep could disrupt gut balance, with research23 showing that partial sleep deprivation can alter the gut microbiome composition in as little as 48 hours
- stress – chronic stress could suppress the parasympathetic ‘rest-and-digest’ system, slowing your digestion and leading to issues like constipation
- lifestyle – just like your biceps or glutes, your digestive tract is a muscle and regular exercise may stimulate it to contract more efficiently
Four ways to support your gut health
Although you can’t change some risk factors – like the medication you’re taking or your genetics – making some simple lifestyle changes may support gut health. We asked Dr Rossi to share some golden rules for gut wellness…
1. Aim for 30 plants per week
You’ve heard of the five-a-day rule but what about 30 plant points a week? “Try and eat as many different varieties of plants as you can, as your gut thrives on diversity from roughage,” says Dr Rossi. “Rather than just shopping the veg aisle, try to also get 30 different types from across the entire ‘Super Six’ spectrum, which includes whole grains, nuts and seeds, legumes, fruit, vegetables and herbs or spices.”
2. Garnish your plate with fermented foods
If you’re yet to add fermented foods like live yoghurt, kefir, kimchi or sauerkraut into your diet, here’s a compelling reason to dip your toe into the food trend. “Studies have found that a high fermented food diet may increase your bacterial diversity,” Dr Rossi notes.
3. Prioritise regular, quality kip
Emerging research19 shows the relationship between sleep and your microbiome is a two-way street: poor sleep can disrupt your gut and an unhappy gut can make it harder to rest.
Dr Rossi notes, “When you prioritise a consistent bedtime routine and aim for seven to nine hours of quality sleep, you’re not only recharging your brain but might be supporting your whole digestive system at the same time.” Win-win.
4. Stay hydrated, especially when increasing fibre
Increasing fibre intake is great for your gut but it’s only half the story. Without enough fluids, increasing your intake may lead to discomfort or sluggish digestion, so you really need to be supporting your H20 levels at the same time.
“Water helps fibre do its thing, especially when it comes to its natural laxating effect,” says Dr Rossi. So as you add more whole grains, fruits and veggies to your diet, don’t forget to drink plenty of water throughout the day.
The final say
When it comes to your overall wellbeing, it’s clear your gut plays a starring role – it may be influencing everything from your mood to your skin and even how soundly you sleep. The good news? Supporting it doesn’t require a total lifestyle overhaul. Small, consistent changes like adding more plants to your plate, sleeping well, managing stress and staying hydrated could have a big impact over time.
So, what about the gut and brain connection? We asked an expert so you don’t have to.
Disclaimer – This article provides informational advice and is not a substitute for medical care. Curated by experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.
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