Probiotics Help Treat Pneumonia

Probiotics could serve as an alternative to antibiotics for treating pneumonia and other respiratory diseases, suggested a new study published today in the open-access eLife journal. In mice previously infected with influenza A virus, Lactobacillus (lung bacteria strain) provided a barrier against Streptococcus pneumoniae (S. pneumoniae) colonization when applied therapeutically following infection. Streptococcus pneumoniae bacterium causes severe pneumonia in the elderly population.

'Commensal' bacteria that live inside the healthy organisms' host provide a competitive barrier against invading bacterial pathogens.

"It is already well known how commensal bacteria in the gut fight off pathogens," explains co-first author Soner Yildiz, Postdoctoral Research Fellow at the University of Geneva, Switzerland. "But how lung bacteria such as Lactobacillus carry out this role is less clear."

To address this gap, researchers studied the role of lung microbiota against Pneumococcus colonization in mice. The team identified commensal bacteria as Lactobacillus murinus (L. murinus), with further gene sequencing and microscopy showing that the bacteria are tightly linked to mouse lung tissue.

The researchers next exposed cultures of L. murinus to S. pneumoniae. They identified that L. murinus inhibited pathogen growth through the release of lactic acid.

"This antibacterial activity was not limited to S. pneumoniae," says co-first author João Pereira Bonifacio Lopes, PhD student at the University of Geneva. "It also affected S. aureaus, the pathogen that can cause bloodstream, bone and joint infections, as well as pneumonia."

They also treated mice with L. murinus following influenza A infection and found that the bacteria provided a barrier against pneumococcal colonization in the animals.

"This suggests that resident commensals in the lung could be applied as probiotics to counteract lung colonisation by pathogenic bacteria," concludes senior author Mirco Schmolke, Group Leader at the University of Geneva.

Source-Medindia