I’m Katie, a women’s functional health coach sharing what I've learned about gut health, hormones, nutrition and the nervous system - without making wellness more complicated than it needs to be.

For more, come say hi at @harayahealth on Instagram & TikTok.

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I make my own kombucha now. I'm as surprised as you are.

There is a jar on my bathroom counter with a beige, rubbery disc floating in it. It looks like something preserved in an old medical museum. Yet...it is technically, alive.

This is my SCOBY (see portrait below). He is my child born off Amazon.com but raised with me here in London. Living with him has given me a very specific identity crisis. Half of me is a mad scientist, holding a jar of what looks like a liver up to the light and muttering fascinating. The other half is his mother. I check he's been fed. I worry when he looks a bit thin. And I've accepted that he'll ferment at his own speed, and no amount of hovering will hurry him along. For a recovering over-planner, that last one is genuine personal growth.

Fully unhinged. Fully committed. Fully aware that "I make my own kombucha now" is the most wellness-influencer sentence I've ever typed.

Hear me out. There are two reasons.

The first is my gut. For years my approach to it was subtraction. Cut this, cut that, feel more tired, cut something else. These days I'm much more interested in what I can add. Fermented foods are one of the easiest additions I know, and kombucha is the one I actually enjoy.

The second is knowing what's in it. I've been making more of my food from scratch to avoid unnecessary additives or bad shit that a lot of food producers sneak in. Re kombucha, some shops make theirs pasteurised (heated, so the live microbes don't survive). Some are topped up with juice or sweeteners. When I make mine, the ingredient list is tea, sugar, water, my SCOBY, and whatever I flavour it with.

Very simple.

That sent me down a rabbit hole about probiotics. And honestly? It's a mess out there.

Let's make that make sense

Probiotics and prebiotics are not the same thing

Your gut is home to trillions of microbes, known together as your microbiome. The two words one letter apart do completely different jobs.

• Probiotics are live microbes that, in the right amount, have been shown to do something useful. In my kitchen, that's the SCOBY himself.
• Prebiotics are food for microbes. In my kitchen, that's the sugar I dutifully feed him.

In your gut, prebiotics are not sugar, so please don't take that away from this. They're mostly certain types of fibre, plus plant compounds called polyphenols. You can't digest them; the bacteria already living in you can. When they feed, they make short-chain fatty acids, which help look after your gut barrier (the lining that decides what gets through).

Probiotics bring microbes to visit. Prebiotics feed the ones who already live there.

Both are in ordinary food

For prebiotics: oats, beans and lentils, onions, garlic and leeks, slightly green bananas, and tea, berries and hibiscus for the polyphenols. If your gut is sensitive, onions, garlic and beans can make you more bloated at first, so add them slowly.

For live microbes: natural yoghurt labelled "live cultures", kefir, chilled-aisle sauerkraut and kimchi (jars on the ordinary shelf are usually pasteurised, meaning heated, so nothing survives), miso stirred in at the end rather than boiled, some aged cheeses, and kombucha.

Fermented foods aren't technically probiotics, because nobody has identified or counted what's in them. But in a small Stanford study, healthy adults who ate more of them for 10 weeks ended up with a more varied microbiome and lower markers of inflammation. Small study, promising rather than settled.

And since I've spent three paragraphs making you look at mine: there's very little human research on kombucha specifically, and every batch varies. I drink it because I like it, not because it's a miracle in a bottle.

Why the supplement aisle is a mess

If you've stood in Boots comparing "50 billion" with "100 billion" like they're mortgage rates, this is for you.

The effects of probiotics are strain-specific. The name has three parts: genus is the surname, species is the first name, strain is the ID number. Two women called Sarah Smith are not the same person, and two Lactobacillus rhamnosus are not the same probiotic. Research on one tells you nothing certain about another.

Which is why most of the shelf falls apart on inspection:

1. No strain on the label. If the name stops after two words, you can't link it to any research.
2. The number is from the factory. Microbes die on the shelf. "At time of manufacture" tells you what went in, not what's left when you swallow it. One recent lab analysis found nearly half the products tested had fewer live microbes than their label claimed.
3. Bigger isn't better. Trials test a specific dose of a specific strain. A vast number of something untested isn't an upgrade, it's a bigger number.

If you're buying one anyway

The evidence that healthy people benefit from a daily just-in-case capsule is thin. The clearest case is around a course of antibiotics, where some probiotics may lower the chance of antibiotic-related diarrhoea. There's also research on specific strains for IBS symptoms like bloating and pain, with mixed results. Because it's strain-specific, that's a question for your pharmacist or GP, not a guess in the aisle.

What a decent label shows you:

• the full name including the strain code (the letters or numbers after the species)
• the amount guaranteed until the use-by date, not at manufacture
• a dose matching the research on that strain, for your reason
• storage instructions you'll actually follow (fridge ones live in the fridge)
• a brand that can point you to the study

If it can't tell you which strain it is and why...don't buy it.

Try This

Add one fermented food to something you already eat this week. A spoonful of sauerkraut on your desk lunch, or some kefir with breakfast.

Start with a spoonful, not the whole jar. Going from nothing to lots can make you gassier for a few days, which is not what you want before a 10am client meeting.

FOR REGULAR GIRLS 💩

Because good digestion deserves good food.

Hibiscus Ginger Kombucha

Pink, fizzy, tangy, and it looks very fancy. It takes about 20 minutes of actual effort and a week or two of waiting while he does his thing.

The unusual ingredient is a SCOBY (a symbiotic culture of bacteria and yeast, aka your new child) plus some starter liquid.

First ferment (makes about 1.5 litres)

• 1.5 litres water
• 3 black or green tea bags
• 100g white sugar
• 1 SCOBY
• 200ml starter liquid (plain kombucha from your last batch, or from your SCOBY's bag)

Instructions:

1. Boil 500ml of the water, steep the tea for 5 minutes, remove the bags and stir in the sugar until it dissolves.
2. Add the remaining litre of cold water. Let it cool completely, because heat will kill the SCOBY.
3. Pour it into a clean glass jar, then add the SCOBY and starter liquid.
4. Cover with a cloth held on with an elastic band. Leave it somewhere warm and out of direct sunlight.
5. Taste it with a straw from day 7. It's done when it's tangy with a little sweetness left, usually 7–12 days.
6. Keep the SCOBY and 200ml of the liquid for your next batch.

The sugar is food for the SCOBY, and much of it gets used up during the ferment.

Second ferment (the hibiscus and ginger bit), per 500ml flip-top bottle

• 1 tbsp dried hibiscus flowers
• 3–4 thin slices of fresh ginger
• 1 tsp sugar or honey (optional, for extra fizz)

Instructions:

1. Put the flavourings in the bottle, then fill it with kombucha, leaving 2–3cm at the top.
2. Seal it and leave at room temperature for 2–4 days.
3. Open it once a day to release the pressure. This is not optional unless you'd like to redecorate your kitchen.
4. Strain it into a clean bottle and put it in the fridge.

Brewing safely

• Use glass, not metal or glazed ceramic. Kombucha is acidic enough to pull things out of the container.
• Always use starter liquid. Its acidity is what keeps unwanted microbes out.
• Brown stringy bits are yeast and completely normal. Fuzzy, dry spots of blue, green or black on top are mould. If you see those, bin the whole batch, SCOBY included.
• Skip homemade kombucha if you're pregnant or your immune system is compromised.

Why your gut will thank you

The fermentation brings live microbes. The tea and hibiscus bring polyphenols, the plant compounds your gut bacteria feed on, and hibiscus and ginger are two more plants in your week. Ginger has been studied for nausea and may help food move through the stomach. Is it a replacement for your Friday glass of wine? No, because we're allowed wine.

Until next time,

Katie x

Big thank you from me for joining my little corner of the internet for women who want to understand their bodies better - from gut health and hormones to nutrition, stress and everything in between.