New pathogenic and protective microbes associated with diarrhoea identified

Researchers have identified microorganisms that may trigger diarrheal disease and others that may protect against it.

O. Colin Stine, a professor of epidemiology and public health at the University of Maryland School of Medicine, said they were able to identify interactions between microbiota that were not previously observed, and we think that some of those interactions may actually help prevent the onset of severe diarrhea.

A much better understanding of these interactions is important, Stine adds, as they could lead to possible dietary interventions. Moderate to severe diarrhea (MSD) is a major cause of childhood mortality in developing countries and ranks as one of the top four causes of death among young children in sub-Saharan Africa and South Asia.

Stine and Mihai Pop, an associate professor of computer science at the University of Maryland, College Park led the six-year project funded by 10.1 million dollars from the Bill and Melinda Gates Foundation.

The researchers used a technique called high-throughput 16S rRNA genomic sequencing to examine both "good" and "bad" microbiota-the tens of trillions of microbes that inhabit the human intestinal system-in samples taken from 992 children in Bangladesh, The Gambia, Kenya and Mali under the age of 5 who were suffering from MSD.

The researchers identified statistically significant disease associations with several organisms already implicated in diarrheal disease, such as members of the Escherichia/Shigella genus and Campylobacter jejuni. They also found that organisms not widely believed to cause the disease, including Streptococcus and Granulicatella, correlated with the condition in their study. In addition, the study revealed that the Prevotella genus and Lactobacillus ruminis may play a protective role against diarrhoea.

The research has been published in the journal Genome Biology.