Probiotics 🧠 are they worth it?
Week 4 of '8 Weeks to a Thriving Gut' series
Welcome back to Week 4 of 8 Weeks to a Thriving Gut.
So far, we've covered:
The basics of the gut microbiome (Week 1).
The superstar nutrient fibre (Week 2).
Prebiotics, the ultimate fuel for your microbes (Week 3).
Today, we’re tackling one of the most common questions I get asked:
“Should I take a probiotic supplement?”
👉 Bonus PDF Probiotic Checklist download for paid subscribers (scroll to end).
The global probiotic market is booming - worth billions - with companies keen to sell you pills, powders, and potions as the ultimate solution to gut health.
But in reality, you don’t need a general probiotic supplement.
Instead, you’ll get far more benefits by focusing on supporting your existing gut microbes with fibre-rich, prebiotic-packed foods (and try these surprising free microbe-rich alternatives).
That said, there’s early evidence that specific probiotic strains can play a targeted role for certain health concerns - when chosen carefully, like for:
Just be warned, the probiotic industry is a bit like the Wild West - it’s not well-regulated, and full of products making bold claims but often lacking solid evidence.
A study looked at 93 probiotic products sold by major retailers in the US and found that only 35% had clear scientific proof to back them up. The other 65% might work, but their labels didn’t provide enough information to check.
Here’s what we’ll cover today:
What are probiotics? A beginner’s guide to understanding probiotics, and what to consider when taking them.
How to find the right probiotic. Tips for identifying strains, understanding doses, and checking the science.
Bonus for paid subscribers: A downloadable Probiotic Checklist containing an extra deep dive on what to look for.
What is a probiotic?
‘Live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.’
In simpler terms, a probiotic has three key features:
It’s a live microbe (like a certain bacteria or yeast).
It survives your digestive system and reaches your gut alive.
It provides a proven health benefit when taken in the right amounts.
Not all probiotics are the same, and not all microbes in food or supplements qualify as probiotics.
Many yoghurts and fermented products contain live microbes, but unless the strain and dose are clinically tested, they might not meet the strict definition of a probiotic.
Probiotics are visitors, not residents
Probiotics are like nicely behaved visitors to your gut.
They take up camp for a few days, contribute while they’re there - interacting with your resident microbes, producing helpful compounds, and supporting your gut environment - and then move on.
They don’t stay permanently because your gut is already occupied by trillions of microbes that are highly adapted to you and have secured their spots.
Probiotics can’t compete for space long-term, but they still play a useful role while they pass through.
To keep getting their benefits, you need to take them regularly - once you stop, they’re usually gone within about three days.
If you’re curious about trying a probiotic, here’s what to do:
Give it 8–10 weeks and pay attention to any changes. If you don’t notice a difference, it’s okay to stop.
If you’re on medication, pregnant, a child, immuno-compromised, have a health condition, or are unsure, check with your doctor first.
How to choose a probiotic - pinpoint the right microbe
Every microbe has a unique name, usually described at three levels:
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