We all know about probiotics – usually they contain strains of Lactobacillus or bifidobacteria. Lactobacillus (typically acidophilus) is a Lactic Acid producing strain, and the acidity keeps certain pathogens in check. Bifidobacteria was the first bacterium strain you can across as a baby passing through the birth canal, and it is very effective at protecting you from pathogens.
Now research from the University of Meryland has shown that one strain of Lactobacillus seems capable of orchestrating many of the players.
A number of senior adults were given a yogurt-type drink containing Lactobacillus rhamnosus (LGG). After a month, the profiles of other bacteria in the volunteers’ guts changed markedly for the better.
“We found that LGG transiently enriches for functions to potentially promote anti-inflammatory pathways in the resident microbes."
LGG seems to help increase the numbers and orchestrate the balance of a number of key friendly gut bacteria known like Bacteroides, Eubacterium, Faecalibacterium, Bifidobacterium and Streptococcus, which produce short-chain esters that are highly anti-inflammatory; one (sodium butyrate) can even kill cancer cells, especially in colon cancer. (It may even have its own benefits but these were not studied in the research).
Ref: mBio, April 2015; "Functional Dynamics of the Gut Microbiome in Elderly People during Probiotic Consumption."