Lab4 Probiotics - a group of four human strains of friendly bacteria

The Lab4, Lab4B and Lab4P consortia of bacteria, which the ProVen Probiotics products contain, were developed based upon a 30-year history of research and development in the probiotic industry – first with animals and subsequently with humans.

What are Lab4, Lab4B and Lab4P?

Lab4 and Lab4B are lactic acid bacteria (LAB) that have been isolated from the gut flora of healthy humans and then screened for appropriate probiotic characteristics, ranging from resistance to stomach and bile acids, to robust capability for large-scale in-vitro cultivation and commercialisation.

The Lab4 consortium combines four strains of lactic acid bacteria isolated from human gut flora – two strains of Lactobacillus acidophilus, one Bifidobacterium animalis subsp. lactis and a Bifidobacterium bifidum.

The Lab4B consortium also combines four strains of lactic acid bacteria that have been specifically designated to reflect the gut of newborn babies and infants. This combination contains the same Bifidobacterium animalis subsp. lactis and Bifidobacterium bifidum as the Lab4 consortium, but contains Lactobacillus salivarius and Lactobacillus paracasei instead of the two Lactobacillus acidophilus strains.

Since their inception, the Lab4 and Lab4B consortia have been the subject of more than 10 major human clinical trials as well as over 100 basic and mechanistic scientific investigations. Most of this work has been published in peer-reviewed journals.

Lab4P comprises the four core Lab4 strains with Lactobacillus plantarum, an additional strain of live bacteria native to the human digestive tract that has been shown to help support weight loss. 

Background to Lab4, Lab4B and Lab4P

The isolation and selection of bacterial strains suitable for inclusion in human probiotic products involved a two-stage screening program of organisms based on a range of characteristics. The program of testing was based on microbiological principles coupled with in vitro screening techniques and first-hand knowledge of the efficacy of probiotics within the animal husbandry sector.

Selection was based on a two-phase system to ‘weed out’ strains at various stages through the selection process to enable the most appropriate strains to be selected. Two of the key requirements for the strains were durability and ‘competitivity’ – to ensure good growth and the ability to survive when faced with opportunistic pathogens.

Probiotic Selection

The selected probiotic organisms were screened and selected using the following criteria:

Things you should know about Lab4 probiotics


Human strains

Lab4 and Lab4B strains are benign microorganisms cultured from humans.


Colonise digestive tract

Resistant to stomach acid and bile salts and capable of attachment to epithelial cells.​


No Gas

Acidophilus and Bifidus are non-gas-forming strains of bacteria.


Beneficial effects

Lactic acid bacteria have frequently been shown to generate beneficial effects.​

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