Why does good gut health matter so much for your overall health?

Your gut is about so much more than digestion. If you have IBS, you may think of your gut as the place where the bloating, constipation, diarrhoea, cramping and gas happen but your gastrointestinal system is doing an enormous amount of work every day — and its influence extends far beyond your digestive symptoms.

Your gut is involved in digestion, nutrient absorption, immune function, metabolism, communication with the brain and your relationship with trillions of microorganisms and as we're increasingly recognising, looking after these systems is an important part of healthy ageing.

Your gut is your interface with the outside world. Everything you eat enters your gastrointestinal tract before nutrients are absorbed into your body. The lining of your digestive system therefore has an important job. It needs to allow nutrients, water and other useful compounds to pass through while helping to protect the body from potentially harmful substances. This barrier is supported by several layers of defence, including the intestinal lining, mucus, immune cells and your gut microbiome.

When this system is functioning well, there is a carefully controlled relationship between what's inside your gut and what's allowed to interact with the rest of your body. When things become disrupted, digestive symptoms can be one of the signs that something isn't quite right.

In addition, a large proportion of the body's immune tissue is located in and around the gastrointestinal tract and that makes sense when you consider what passes through it every day. Your gut is constantly interacting with food, microorganisms and substances from the outside environment. The immune system within the gut has to distinguish between what is harmless, what is beneficial and what needs to be dealt with. Your gut microbiome also plays an important role in this relationship, communicating with immune cells and producing compounds that can influence the wider body.

This is one reason why gut health is increasingly being considered as part of the bigger picture of overall health, rather than simply a digestive issue.

Your gut and your brain are constantly communicating - you may have experienced this yourself:

You're nervous before an important meeting and suddenly need the loo. You're stressed and your digestion goes haywire. Or you finally relax on holiday and your gut seems to settle down. This isn't your imagination, Yyour gut and brain are in constant two-way communication through what is known as the gut-brain axis. The nervous system, immune system, hormones and gut microbiome are all involved in this complex communication network. This helps explain why stress and emotional wellbeing can influence digestive symptoms, and why looking after your gut sometimes means looking beyond food.

And then there's your gut microbiome...your digestive tract is home to trillions of microorganisms, including bacteria, fungi and other microbes. Collectively, these make up your gut microbiome and many of these microorganisms are an essential part of a healthy digestive ecosystem.

They interact with the foods we eat and produce a range of compounds that can influence digestion, metabolism, immune function and communication between the gut and the rest of the body.

This is one of the reasons dietary diversity matters. Different plant foods provide different types of fibre and other compounds for our gut microbes to use. So when we talk about eating a varied diet, we're not just talking about getting a good range of vitamins and minerals. We're feeding an ecosystem.

Why does all of this matter for healthy ageing? This is where gut health becomes particularly interesting. As we get older, maintaining muscle mass, bone health, metabolic health, brain health, immune function and energy becomes increasingly important. And all of these depend, to some degree, on having access to the nutrients and building blocks your body needs. Your gut is responsible for digesting food and absorbing those nutrients. So if your digestive system isn't functioning well, or if your symptoms mean you're eating a very restricted diet — it can become harder to get the variety and quantity of nutrients your body needs. This is why I don't see gut health as simply being about getting rid of bloating. It's about creating a digestive system that supports your wider health and helps you build resilience for the years ahead.

So what does a “healthy” gut actually look like?

There isn't one perfect gut and there certainly isn't one perfect microbiome, but there are some important foundations:

A varied, nutrient-dense diet, particularly plenty of different plant foods and sources of fibre, alongside adequate protein and healthy fats. A diverse and resilient microbial community supported by the food we eat and the lifestyle we lead. Effective digestion and nutrient absorption - so that we're able to make use of the nutrients in our food. A well-functioning gut barrier and immune system which maintains the important boundary between the contents of the gut and the rest of the body. Good communication between the gut and brain supported by managing stress, getting enough sleep and staying physically active. And, importantly, a gut that allows you to eat a broad and enjoyable diet without unnecessary restriction.

So why does the gut become dysfunctional?

That's the interesting bit.

Your gut is incredibly adaptable, but it can also be influenced by many things including diet, antibiotics and other medications, infections, stress, sleep, hormones, alcohol, physical activity and changes in the microbiome.

Often, it's not one thing.

It's a combination of factors that gradually shifts the balance and sometimes, as I mentioned in my previous blog, one particular event can simply be the straw that breaks the camel's back. So if you're experiencing ongoing digestive symptoms, rather than asking only: “what food is causing this?” it can be much more useful to ask “what has happened to my gut and what does it need now?”

That's where my four-step approach comes in: CONSIDER → ADD IN → REPLENISH & NOURISH → BALANCE

Because the goal isn't simply to have fewer digestive symptoms, it's to build a healthier, more resilient gut that supports you for the long term.

And that, ultimately, is part of healthy ageing.