Applied Nutrition Probiotic

Live bacterial cultures· evidence: Limited

These products contain live bacteria, usually Lactobacillus, Bifidobacterium and Streptococcus strains, counted in colony-forming units (CFU). Effects in studies depend on the exact strain and dose, so results for one strain cannot be assumed for another, and a higher CFU count is not proof of a better product.

Many trials have been run, but they are mixed and often small, and most look at specific groups of people rather than healthy adults. In healthy people, there is little good evidence that taking live cultures every day makes a noticeable difference. There are no authorised health claims for live cultures in Great Britain, so we make no claims about what they do.

If you want to try them, choose a product that names its strains (with strain codes) and gives the count at the end of shelf life, and give it about four weeks.

Typical dose: Products typically provide 1 to 50 billion CFU a day; check the strain list and whether the count is guaranteed to the end of shelf life.

Safety: Generally well tolerated; some people notice wind or bloating at first. Speak to your doctor before use if you have a weakened immune system (for example during chemotherapy or after a transplant), a central line, are seriously ill, or are buying for a premature baby.

Research we looked at:
NHS. Probiotics. nhs.uk (health A to Z).
NCCIH. Probiotics: what you need to know. National Institutes of Health.
Hill C et al. (2014). The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature Reviews Gastroenterology & Hepatology 11:506-514.

Saccharomyces boulardii· evidence: Limited

Saccharomyces boulardii is a yeast, not a bacterium, so it is not killed by antibiotics in the way bacterial cultures can be. It is one of the more widely studied single cultures.

Most of the research has been in specific groups, such as people taking a course of antibiotics or travelling, and reviews find some positive but inconsistent results. There is little evidence of benefit for healthy people taking it every day. There are no authorised health claims, so we make no claims about what it does.

If you have ongoing gut symptoms, see your GP rather than self-treating.

Typical dose: Studies have commonly used 250 to 500 mg (about 5 to 10 billion CFU) a day.

Safety: Do not use if you have a weakened immune system, a central venous line, are critically ill or have a yeast allergy: rare bloodstream infections with this yeast have been reported in these groups. Speak to your GP or pharmacist first if you take antifungal medicines or are pregnant or breastfeeding.

Research we looked at:
McFarland LV (2010). Systematic review and meta-analysis of Saccharomyces boulardii in adult patients. World Journal of Gastroenterology 16(18):2202-2222.
NCCIH. Probiotics: what you need to know. National Institutes of Health.
NHS. Probiotics. nhs.uk (health A to Z).

Chicory inulin and FOS· evidence: Moderate

Inulin and fructo-oligosaccharides (FOS) are soluble fibres from the fructan family, found naturally in chicory root, onions, garlic, leeks and bananas. Gut bacteria ferment them.

Native chicory inulin has one authorised claim, about bowel function, but only at 12 g a day, far more than the small amounts of FOS added to capsules. Most adults in the UK eat too little fibre (the target is 30 g a day), and food sources are the best place to start.

FOS from other sources, and small amounts in capsules, have no authorised claims.

Typical dose: 12 g a day of native chicory inulin for the authorised claim; start with 2 to 3 g a day and build up slowly. Capsules with added FOS usually give 20 to 300 mg.

Safety: Wind, bloating and loose stools are common, especially if you start with a large amount; build up gradually and drink plenty of fluid. People following a low-FODMAP diet are usually advised to avoid fructans.

Research we looked at:
EFSA NDA Panel (2015). Scientific Opinion on the substantiation of a health claim related to native chicory inulin and maintenance of normal defecation by increasing stool frequency. EFSA Journal 13(1):3951.
SACN (2015). Carbohydrates and Health. Scientific Advisory Committee on Nutrition.
GB Nutrition and Health Claims Register (Department of Health and Social Care).

Cost per daily dose lets you compare packs of different sizes fairly.Worked out from our current prices.