Your Immune System Starts in Your Gut — Here’s What That Actually Means

When most of us think about immune support, we think of vitamin C, zinc, echinacea and maybe an orange juice when we feel something coming on.

But immune health is much bigger than what we take when we’re already run down.

As a naturopath, one of the first areas I think about when supporting immune health is the gut, because your digestive system and immune system are incredibly closely connected.

Your gut isn’t just responsible for breaking down food. It’s constantly interacting with the outside world, helping decide what should be absorbed, what should be tolerated and what requires an immune response.

And that’s exactly why supporting your gut can be such an important part of supporting your immune system.

Your gut and immune system are constantly talking

Your digestive tract is home to trillions of microorganisms, collectively known as the gut microbiome.

These bacteria and other microbes interact with the cells lining your gut and with the immune tissue surrounding it.

In fact, a large proportion of the body’s immune activity is associated with the gastrointestinal tract.

A healthy gut environment helps support normal immune signalling, maintain the integrity of the intestinal barrier and support the way your immune system responds to what it encounters every day.

In other words, your gut and immune system aren’t working independently of one another.

They’re constantly communicating.

Your gut barrier matters too

I often describe the intestinal lining as one of the body’s most important gatekeepers.

It creates a physical barrier between the contents of your digestive tract and the rest of your body, while still allowing nutrients to be absorbed.

When we talk about gut health, we’re not only talking about bloating, bowel movements or digestion.

We’re also thinking about the health of the gut lining, the microbiome living there and the way that entire environment interacts with the immune system.

Things like stress, illness, travel, changes in diet, lack of sleep and certain medications can all influence the gut microbiome.

Which is why I much prefer to think about immune health as something we support every day, rather than something we suddenly focus on when we’re already sick.

So, what actually supports immune health?

There’s rarely one magic ingredient.

The foundations matter much more than people realise.

Eat enough fibre

Your gut microbes use different types of dietary fibre as fuel.

A varied intake of vegetables, fruit, legumes, nuts, seeds and whole grains, where tolerated, helps support microbial diversity and overall gut health.

Rather than obsessing over one “superfood”, I’m much more interested in what you’re doing consistently.

Different plants feed different microbes, so variety really does matter. Aim for 30+ different plant foods a week.

Eat enough protein

Protein is another basic that often gets overlooked.

The amino acids found in protein are needed for countless processes throughout the body, including the production of immune cells and antibodies.

If your diet is chronically under-fuelled, no supplement can completely make up for that.

Aim for 1.5-2grams of protein per kilo of body weight.

Prioritise sleep

Sleep and immune function are closely connected.

One bad night isn’t going to destroy your immune system, but chronically poor sleep can make it much harder for the body to function at its best.

If you’re constantly getting run down, sleep is absolutely something worth looking at.

Manage stress where you can

I don’t love telling people to “just stress less”, because for most of us that isn’t particularly helpful.

But the gut, nervous system and immune system are interconnected, and prolonged stress can influence digestive function and the microbiome.

Think instead about the small things you can actually repeat.

Walking. Getting outside. Eating regularly. Exercising. Switching off earlier. Taking a few minutes to slow down. Building recovery into your week.

It doesn’t need to be perfect.

It just needs to be consistent.

Where probiotics fit in

Probiotics can form part of a broader immune and gut health routine, but not all probiotics are the same.

Different probiotic strains have been studied for different purposes, which is why I care much more about strain selection than simply putting the highest possible CFU number on a label.

When I formulated SolBiome Multi+ Probiotic, I wanted to create something that supported more than digestion alone.

Multi+ contains four specifically selected probiotic strains:

• Lactobacillus plantarum 299V

• Lactobacillus rhamnosus SP1

• Lactobacillus rhamnosus GG

• Lactobacillus paracasei LPC-37

Together, they deliver 32.5 billion CFU per capsule.

Alongside its broader gut, stress and skin indications, Multi+ is formulated to support immune system health.

But I don’t look at probiotics as a replacement for fibre, sleep, food, movement or stress management.

I look at them as one part of the bigger picture.

One small daily habit that supports the gut environment consistently.

What about antibiotics?

This is one of the questions I get asked most often.

Antibiotics can be incredibly important when they’re medically necessary, but they don’t only affect the bacteria causing an infection.

They can also disrupt some of the beneficial bacteria living in the gut.

That doesn’t mean antibiotics are “bad” or something we should avoid when we genuinely need them. It simply means the gut may need some extra support during and after a course.

I generally recommend taking a probiotic alongside antibiotics, rather than waiting until the course has finished.

Then continue your probiotic for at least one month after finishing your antibiotics.

This gives your gut microbiome ongoing support during the period after treatment, rather than stopping as soon as the medication ends.

During this time, I’d also focus on the basics:

• eat a varied, fibre-rich diet where tolerated

• stay well hydrated

• prioritise sleep

• include plenty of plant foods

• avoid unnecessarily restrictive diets unless medically indicated

The goal isn’t to “undo” the antibiotics.

Sometimes antibiotics are absolutely necessary.

It’s simply about supporting the gut environment before, during and after treatment.

If you’re taking Multi+, that means one capsule daily, and continuing for at least four weeks after your course is complete.

Always follow the instructions provided with your medication, and if your doctor or pharmacist gives you different advice, follow their recommendations.

Consistency matters more than panic-buying supplements

One of the biggest things I try to remind people is that immune health isn’t created by what you do for three days when you feel a cold coming on.

It’s much more influenced by what you repeatedly do when you’re feeling well.

Eating enough fibre.

Getting enough protein.

Sleeping properly.

Moving your body.

Managing stress.

Supporting your gut.

Taking your probiotic.

None of these things are particularly glamorous, but together they create the foundations that allow your body to do what it’s designed to do.

And when it comes to gut and immune health, I’d choose consistent daily support over panic-buying supplements at the first sign of a sniffle every single time.

Always read the label and follow the directions for use. Supplements should complement, not replace, a balanced diet. If you have an existing health condition, are pregnant or breastfeeding, or take medications, speak with your healthcare practitioner about what is appropriate for you.