New LGG probiotic strain thrives in milk, potentially “more effective” at protecting infants

03 May 2021 --- Researchers have created a new strain of Lacticaseibacillus rhamnosus GG (LGG), which can thrive and grow in milk, opening new opportunities for infant nutrition.

LGG is the most studied probiotic bacterium in the world, note the researchers, but its use has been limited as it is unable to utilize the lactose or casein found in milk. It currently has to be separately added to probiotic dairy products.

“The new LGG strain is not genetically modified, which makes it possible to consume it and any products containing it without any permit procedures,” says Per Saris, professor of microbiology from the faculty of agriculture and forestry at the University of Helsinki, Finland, who led the project. 

The recent breakthrough was made in collaboration with the National Institute for Biotechnology and Genetic Engineering in Pakistan. 

A powerful probiotic
Saris explains that the strain has many documented benefits: “LGG has previously been shown to alleviate infantile atopic dermatitis and boost the recovery of the gut microbiota after antibiotic therapies.” 

LGG has previously been shown to boost the recovery of the gut microbiota after antibiotic therapies, notes Saris.“Lactic acid lowers the pH of the surface of the intestine, reducing the viability of many gram-negative pathogenic bacteria, such as E. coli, Salmonella and Shigella, which threaten the health of infants.”

Previous attempts have been made to make LGG adjust to milk through genetic engineering. However, stringent restrictions have prevented the use of such modified bacteria in human food.

Plasmid exchange
The method used to achieve the new strain of LGG is known as conjugation. It is a technique utilized by certain bacterial groups to transfer their traits to other bacteria. 

In the process, a bacterium produces a copy of its plasmid, a ring-shaped piece of DNA in the bacterium. 

Next, the bacterium transfers the plasmid to an adjacent bacterium. The spread of plasmids, which carry traits useful for bacteria, can be rapid among bacterial communities.

In the case of LGG, the plasmid that provided the ability to make use of lactose and casein originated in a specific Lactococcus lactis bacterial strain grown in the same place.

A new era of LGG
The new strain can be used as a starting point in the development of new dairy products where the probiotic concentration increases during the production stage. In other words, the probiotic need not be separately added to the final product.

Furthermore, the new LGG strain can potentially be better equipped to grow, for example, in the infant gut where it would be able to utilize the lactose and casein found in breastmilk, producing more lactic acid than the original strain.

“In larger numbers, the new LGG strain can potentially be more effective at protecting infants than the old strain,” adds Saris. 

Good bacteria reigns 
Probiotics are emerging as important ingredients to support health in both children and infants. A study by BioGaia recently found a combination of strains could reduce fever and sore throat pain in children with pharyngitis and tonsillitis.

Moreover, dairy suppliers have recently spotlighted probiotics as an important trend in the space. 

Edited by Missy Green