What’s the Best Probiotic?

You’ve probably asked this before: “Which probiotic should I take?” — and as a Registered Nutritionist in London, I know how overwhelming the choices can be. Walk into any health store and you’ll see shelves filled with options: 10 billion CFUs, 50 billion, 100 billion… acidophilus, bifidobacterium, soil-based strains, and more. With so many formulations and claims, it’s no wonder people feel confused about where to start.

But here’s the truth:
There is no one-size-fits-all probiotic.

Why? Because your gut is unique.

Your microbiome—an ecosystem of trillions of bacteria—is as personal as your fingerprint.
And while supplements can play a role, the best probiotic for you depends on three key things:

1. Your Gut Terrain

Even the highest-quality probiotic won’t flourish if your internal environment is imbalanced.
Think of it like planting seeds in dry, depleted soil—without nourishment and balance, they won’t grow.

Your gut lining, digestive function, inflammation levels, and immune health all shape how well probiotics work.
So, before you ask what brand to buy, ask: is my gut ready to receive it?

2. Diversity Over Dosage

Many people believe “more CFUs = better results.” But science tells a different story.

What really matters is strain diversity—different strains do different jobs.
Lactobacillus might support digestion and immunity. Bifidobacterium might calm inflammation. Saccharomyces boulardii might help after antibiotics.
One strain isn’t better than another—they’re just different tools.

3. Support With Pre- and Postbiotics

Probiotics don’t work alone. They need the right fuel (prebiotics) and environment (postbiotics) to thrive.

• Prebiotics are the fibres that feed good bacteria. You’ll find them in leeks, onions, garlic, artichokes, asparagus, oats, flax, and more.

• Postbiotics are the beneficial compounds bacteria produce—like short-chain fatty acids—that help reduce inflammation and support the immune system.

By nourishing your whole ecosystem, you help the good bacteria take root.

So, what’s the real answer?

The best probiotic is:

• The one your unique body needs

• The one that’s supported by your daily habits

• And the one that works in harmony with your lifestyle, stress, sleep, and nutrition