The telltale sign your skin problems are actually coming from your gut, according to an expert.

You've tried it all. 

The fancy cleanser. The fragrance-free moisturiser. That $120 serum your best friend swears by. 

You've experimented with slugging, barrier creams and even tried a deeply questionable herbal tea. And still, your skin is doing the absolute most — in the worst possible way. 

But what if the root cause of your breakouts, dryness, redness and even eczema isn't actually what's going on your skin… but what's happening inside your body?

Enter: Carla Oates, aka The Beauty Chef. You've probably seen her bestselling glow powders on beauty shelves or heard someone in Pilates mention "gut health" and "microbiome" in the same sentence. 

Watch: Carla Oates and Kelly McCarren talk skin and gut health on You Beauty.

But what you might not know is that Carla has been talking about the gut-health connection for decades — long before it was trendy.

A former beauty writer, Carla started her journey into gut wellness the old-fashioned way: out of desperation. After suffering from eczema, allergies and acne as a teen — and then watching her daughter develop similar skin issues — she turned to food as medicine. 

On a recent episode of You Beauty, Carla joined host Kelly McCarren to explain what's really going on when your skin flares up — and why your skin woes might have a lot more to do with last night's dinner than you think.

"I think some of the signs that your gut health might be affecting your skin health [are] if you get skin and gut flare-ups simultaneously. That can be a dead giveaway," she told You Beauty. 

Translation? If your skin starts breaking out, flaring up, or getting itchy, red or blotchy soon after you've eaten something questionable — and your stomach joins in with a bloating, gassy, 'please help me' performance — it could be your body raising a gut-shaped red flag.

Some reactions — like eczema — can show up days or even weeks after the trigger, making it feel like an impossible game of 'what did I eat and why is my elbow itching?'.

LISTEN: Carla Oates shares her secrets to glowing skin with Kelly McCarren on the You Beauty podcast. Post continues below.

If that sounds painfully familiar, there's a simple way to test the theory that your skin issues are rooted in your gut: start supporting it, and watch what happens.

"If you do start to put in some practices that look after your gut, like you start to take probiotics, for example, and you notice a difference in your skin, that's a really good sign… gut health is probably at play," she said. 

That's because your gut is not just a digestion machine, but is also a key player in your immune system, your hormone regulation, your brain health and yes, your skin. Meaning gut inflammation doesn't just affect your internal systems, but shows up right on your face.

In other words, your moisturiser might be fighting a battle it was never equipped to win.

Instead, focusing on gut-loving foods, supplements like probiotics, and reducing stress (yes, we know that's easier said than done) could be the real game-changer for your skin. 

As for how long it takes to notice a difference? Your body might feel better within days. But you should allow a full skin cycle — around four weeks — before expecting big shifts when it comes to your face. 

"It takes your skin… 28 days to renew," said Carla. 

"I mean, I have had people say they see a difference almost straight away, but I think that's also because you feel better. You glow a little bit because you're happier."

Of course, if your skin issues are chronic or severe, it's important to chat to your GP, dermatologist or naturopath to get some expert medical advice. But for those of us stuck in the skincare spiral — spending hundreds on creams while ignoring the deeper signs our bodies are sending — this might be the wake-up call we needed. 

Because sometimes, the answer isn't another serum; sometimes it's sauerkraut. 

Feature image: Instagram/@carlaoatesthebeautychef.