The gut is home to trillions of microbes that influence digestion, immunity, mood and far more. Our probiotics collection brings together targeted, strain-specific formulas alongside the prebiotic fibres that feed them, so you can match a product to a purpose rather than choosing on bacteria count alone.

How probiotics work — and why the strain matters more than the number

A probiotic's effects are specific to its strain, not just its species. Lactobacillus or Bifidobacterium on a label tells you little; the documented benefit belongs to a particular, coded strain (for example Lactobacillus rhamnosus GG, or Lactobacillus plantarum 299v) that has been studied for a specific outcome. This is why a high CFU (colony-forming unit) count is not the whole story — ten billion of a well-matched strain can be more useful than fifty billion of a generic blend. Beneficial bacteria work by competing with less desirable microbes for space and food (colonisation resistance), by helping maintain the gut lining, and by fermenting fibre into short-chain fatty acids such as butyrate, which nourish the gut wall and help regulate immune signalling. Since roughly 70% of immune tissue sits around the gut, this is also why gut and immune health are so closely tied.

What to look for

Choose by purpose and strain: there are strains studied for IBS and bloating, for women's urinary and vaginal health, for children and infants, for mood, and for immune support. Consider whether the product needs refrigeration or is shelf-stable, and whether it is designed to survive stomach acid to reach the colon. Prebiotic fibres — partially hydrolysed guar gum (PHGG), inulin, GOS — feed the bacteria you already have and are a useful companion to, or alternative to, a probiotic.

Who may benefit

People after a course of antibiotics, those with digestive symptoms such as bloating or irregularity, women wanting urogenital support, parents choosing infant or children's strains, and anyone supporting immunity through the gut commonly look to this category.

Frequently asked questions

Does a higher CFU count mean a better probiotic?
Not necessarily. The right strain for your goal matters more than the headline number. A clinically studied strain at a modest dose often outperforms a very high count of generic bacteria.

Should I take a probiotic with antibiotics?
Many people use specific strains during and after antibiotics to support the gut, typically taken a couple of hours apart from the antibiotic dose. Particular strains are studied for this; your healthcare professional can help you choose.

What is the difference between a probiotic and a prebiotic?
A probiotic supplies live beneficial bacteria; a prebiotic supplies the fibre that feeds them. They work well together — and for some people a prebiotic fibre alone is enough to shift the balance of the microbiome they already have.

Explore related ranges in our Digestion & Gut Health, Immunity, Women's Health and Children's Health collections.

Always read the label and follow the directions for use. If you are immunocompromised, pregnant or unwell, talk to your health professional before starting a probiotic. Supplements are not a substitute for a balanced diet.