Which form of probiotic should I choose?

Choose the form that fits your day, then check the strains. All four are common in our range. Form How it works Suits Capsule Fixed dose, often acid-resistant coating Daily routine, travel Powder sachet Mix into water or food Higher doses, no swallowing Drops Dosed by the drop Babies and young children Liquid Water-based, taken as a drink People who prefer no pills Capsules are the practical default for most adults.

Probiotic Supplements: Strains, CFU and Forms

Probiotics are live bacteria and yeasts that you take as a food supplement. In the UK and the EU, the word probiotic itself counts as a health claim, and no probiotic health claim has been approved. The only authorised claim for live cultures concerns yoghurt cultures and the digestion of lactose in yoghurt. That shapes how we write about this category. We describe what is in the product: the strains, the number of live cultures and the form. Anything more would be a promise we cannot stand behind.

Strain names tell you more than a big CFU number

Most labels list a genus and a species, such as Lactobacillus acidophilus. Stronger labels add the strain code, for example Lacticaseibacillus rhamnosus GG. That matters, because research on live cultures is strain-specific. What one strain did in a study says little about the next one. CFU stands for colony forming units: the number of live cultures in one dose. It is useful information, not a ranking. Check whether that count is guaranteed until the end of shelf life or only at the time of manufacture. Many formulas also add fibre such as inulin, which you will find on its own in our prebiotic fibres collection.

Capsules, powders, drops and liquids suit different routines

Capsules: fixed dose, easy to travel with, often with a coating that protects the cultures from stomach acid.
Powder sachets: higher doses and flexible amounts, handy if you dislike swallowing capsules.
Drops: mostly used for babies and young children, dosed by the drop.
Liquids and chewables: a simple option for people who take supplements with breakfast.

One form is not automatically better. What counts is that the cultures reach your gut alive and that you actually keep taking them.

How we choose the probiotics we stock

We look at three things: the strain, the dose and the combination. We prefer products that name the full strain, state the live count at the end of shelf life, and give clear storage instructions. We stock both refrigerated and shelf-stable products, because a fridge-only powder is no help to someone who travels every week. We buy directly from the brands, so what is on the label is what you get, and our compliance team checks every product before it goes live. You can read how we select brands and products.

Who these supplements suit, and what to expect

People most often start a probiotic during or after a course of antibiotics, while travelling, or simply to keep a daily routine going. The cultures you swallow do not settle permanently, so consistency matters more than dose size. Give it two to four weeks of daily use before you judge whether a product suits you. Mild wind or a change in bowel habit in the first days is common. If you have a weakened immune system or an existing health condition, speak to your doctor before you start.

Diet still does most of the work here. Fermented foods and a varied, fibre-rich diet feed the bacteria already living in your gut, and a supplement is a top-up, not a replacement. Probiotics sit next to fibres, enzymes and everyday basics in our wider supplement range, so you can build a routine that you can keep up.

Probiotics are live bacteria and yeasts, taken as a food supplement or eaten in foods such as yoghurt and kefir. They are often called live, good or friendly bacteria. The idea is to top up the bacteria already present in your digestive system. Note that UK and EU rules treat the word probiotic as a health claim, and no probiotic health claim has been approved so far. That is why labels describe strains and live counts instead of promising specific effects.

CFU stands for colony forming units: the number of live cultures in one dose. Products range from around one billion to over fifty billion CFU. A higher number is not automatically better, because the effect studied in research is tied to a specific strain and a specific dose. Two details matter more than the headline figure. First, whether the strain is named in full. Second, whether the CFU count is guaranteed until the end of shelf life rather than only at the time of manufacture.

Choose the form that fits your day, then check the strains. All four are common in our range.

Form	How it works	Suits
Capsule	Fixed dose, often acid-resistant coating	Daily routine, travel
Powder sachet	Mix into water or food	Higher doses, no swallowing
Drops	Dosed by the drop	Babies and young children
Liquid	Water-based, taken as a drink	People who prefer no pills

Capsules are the practical default for most adults.

Follow the label, because it depends on the product. Some formulas are designed for an empty stomach in the morning, others to be taken with a meal, since a little food and fat can buffer stomach acid. What matters most in practice is picking a moment you will not forget. Many people take theirs with breakfast for that reason. If a product asks for a full glass of water or a specific timing, that instruction is part of how it was tested.

Give it two to four weeks of daily use before deciding. The cultures do not colonise your gut permanently, so effects depend on a steady daily supply rather than a loading dose. Some people notice a change in digestion within days, others notice little at all, and that is a genuine outcome too. If nothing has changed after a month, it is usually more useful to try a different strain than to raise the dose of the same one. Fibre-rich food supports everyday digestion alongside it.

Only if the label says so. Older and some higher-dose or liquid formulas are cold-chain products and lose live cultures at room temperature. Most modern capsules are freeze-dried and stabilised, so a cool, dry cupboard is fine. Refrigerated does not mean stronger, and shelf-stable does not mean weaker. Heat, moisture and direct sunlight are the real enemies, so keep the bottle closed, avoid the bathroom shelf and do not decant capsules into a pill box for weeks on end.

Many people do, and it is one of the most common reasons for starting. The usual practical approach is to leave a gap of about two hours between the antibiotic and the probiotic, so the medicine is not acting on the live cultures at the same moment. Plenty of people continue for one to two weeks after finishing the course. Antibiotics are prescription medicines, so check timing with your pharmacist or GP, especially if you take other medication.

Saccharomyces boulardii is a yeast, not a bacterium. It is classed as a variety of Saccharomyces cerevisiae, and because it is a yeast it is not affected by antibiotics in the way bacterial cultures are, which is why it is often chosen for that period. Lactobacillus and Bifidobacterium strains are bacteria and make up most multi-strain formulas. Some products combine both. If you are severely immunocompromised or have a central line, do not start yeast or bacterial cultures without medical advice.