Probiotics are live bacteria that are associated with specific health benefits when consumed in the right amounts. To be classified as a probiotic, products must contain live bacteria, they must have health benefits that are supported in human studies, and at a certain amount (CFU) of live bacteria.¹ Specific probiotic strains have demonstrated benefits in many areas of health including immune health, digestive health, women’s health and oral health.

What is the definition of a probiotic?

The World Health Organization has defined probiotics as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.¹ That’s us, we are the host. Many foods and supplements contain live bacteria, but only bacterial strains with a scientifically supported health effect may correctly be termed probiotics. 

Fermented foods such as kimchi and sauerkraut contain live bacteria and have been associated with health benefits, but they are not considered probiotics as they have not been the subjects of human clinical studies, and the ‘adequate amount’ that must be consumed to gain the health benefit has not been determined.

Probiotic bacteria must be alive …

Probiotic products contain millions to billions of live bacteria. However, like any living organism, bacteria naturally die. Therefore, the number of live bacteria in a probiotic product will reduce between the date it was manufactured and the date it is purchased. The number of live bacteria is known as Colony Forming Unit (CFU).

… and the right amount must be consumed

As discussed, to be classified as a probiotic, the health benefits must be supported in human studies. The specific health benefit of each probiotic is then related to the amount (CFU) of live bacteria that was used to show its benefit. As the health effect is only supported at that amount (CFU) of live bacteria, we should consume it at that level to achieve the desired effect.^{2, 3}

So now we know that: 

Genus, species, strain – does it matter? 

Probiotics are identified through their genus, species, and strain. The strain is important as it is at this level that the probiotics have been studied, not at the more general species level.⁴

For example, the clinical results associated with the Chr. Hansen probiotic strain Lactobacillus rhamnosus, LGG^® (hereafter referred to by use of the trademark LGG^®) are primarily connected to digestive and immune health,^{5, 6, 7, 8} whilst the clinical results of Lactobacillus rhamnosus, GR-1^® (hereafter referred to by use of the trademark GR-1^®) are primarily linked to women’s vaginal and urinary health.^{9, 10} Both of these strains are part of the Lactobacillus rhamnosus species, but it is by the specific strain (i.e. the LGG^® or GR-1^® strain) that has been associated with study results.

Probiotics beneficially affect our health

Probiotics have been extensively studied for decades and have demonstrated benefits across different health areas in human clinical trials. Examples of health areas where certain probiotic strains have been associated with positive health effects are listed below.

Digestive system health 

The digestive system is a health area in which probiotic products have demonstrated a beneficial effect. In several clinical studies, supplementation with probiotic products containing the Chr. Hansen Bifidobacterium, BB-12^® (hereafter referred to by use of the trademark BB-12^®) strain has been associated with improved regularity of bowel movements in adults with infrequent bowel movements,^{11, 12, 13} and with reduced incidence of crying and fussing in babies.¹⁴ Click to read more about probiotics and excessive crying and fussing in babies.

Immune health

Studies suggest that immune health in babies and children may be impacted following probiotic supplementation with the Chr. Hansen BB-12^® and LGG^® strains. Some studies have associated these specific probiotic strains with fewer respiratory infections,^{15, 16} a reduction in the incidence of respiratory infections lasting more than 3 days,⁷ significantly fewer days with respiratory symptoms,⁷ and a reduction in the incidence of ear infections.¹⁶

Click to read more about probiotics and respiratory health.

Women’s health

Urogenital health has also been studied following the use of probiotic products. For instance, studies have associated improvements in urinary tract health⁹ and vaginal health with the Chr. Hansen probiotic blend, UREX^™ (containing Lactobacillus rhamnosus, GR-1^® and Lactobacillus reuteri, RC-14^®).^{10, 17, 18, 19} 

Oral health 

Probiotic supplementation has also demonstrated positive results relating to oral health. In some studies, the consumption of products containing the Chr. Hansen LGG^® probiotic strain by children, has been associated with a reduction in the risk of tooth decay based on clinical and microbiological evaluation, and with a reduction on saliva and dental plaque levels of a specific bacteria that contribute to tooth decay.^{20, 21}

Key take-aways

When choosing a probiotic product, it must be remembered that: 

• The documented health benefits of probiotic strains are specific to the probiotic strain and to the amount (CFU) of the probiotic strain that was investigated in the associated human clinical trials.
• The benefits observed are not generalizable to other health areas or strains.

For more information on our Chr. Hansen strains, click here.

BB-12^®, GR-1^®, LGG^® and UREX^™ are registered trademarks of Chr. Hansen A/S.

The article is provided for informational purposes regarding probiotics and is not meant to suggest that any substance referenced in the article is intended to diagnose, cure, mitigate, treat, or prevent any disease.