Probiotics 101
Probiotics are live microorganisms that, when taken in adequate amounts, can support normal body functions as part of a balanced diet and lifestyle. This page explains the basics in plain English.
This content is for general information only and does not replace medical advice.
Last updated: 02/01/2026
What are probiotics
Probiotics are beneficial microbes, commonly bacteria, that are studied for their role in supporting normal gut function and the body’s natural microbial balance.
Not all probiotics are the same. Different strains can behave differently.
What does CFU mean
CFU stands for colony forming units. It is a measure used to describe the amount of live microbes in a serving. More CFU is not automatically better. The right amount depends on the strains used and the context.
Why strains matter
You will often see names like Lactobacillus and Bifidobacterium. These are genera. Within them are species and strains. Research is often strain specific, so it is normal to see different outcomes across different probiotic products.
Probiotics vs prebiotics
- Probiotics: the live microbes
- Prebiotics: fibres that feed beneficial microbes already present in the gut
Some supplements combine both. That is sometimes called a synbiotic.
How long do probiotics take
Probiotics are not instant. Many people track consistency over weeks rather than days. Individual experiences vary based on diet, lifestyle, and starting microbiome differences.
Storage and stability
Always follow the label. In general:
- Store in a cool, dry place away from direct sunlight
- Keep the lid closed between uses
- Do not exceed the best before date
- If a product requires refrigeration, the label will state it
How to choose a probiotic responsibly
Use this simple checklist:
- Clear labelling with serving size and product format
- Quality standards and documented manufacturing
- Strain transparency where applicable
- Sensible claims focused on general wellness support, not medical promises
- A format you will take consistently (capsules, gummies, etc.)
Who should speak to a healthcare professional first
If you are pregnant, breastfeeding, taking medication, have a medical condition, or are under medical supervision, speak to a healthcare professional before using supplements.