Researchers Link Bacteria in the Throat to Schizophrenia

A study from GW researchers shows that certain microbes (pictured here) in the throat may be related to schizophrenia. (
August 25, 2015

Researchers at George Washington University’s Computational Biology Institute (CBI) have identified a potential link between microbes (viruses, bacteria and fungi) in the throat and schizophrenia. The discovery may offer a way to identify causes of the disorder and could lead to new treatments as well as diagnostic tests.

“The oropharynx [back of the throat] of schizophrenics seems to harbor different proportions of oral bacteria than healthy individuals,” said Eduardo Castro-Nallar, a Ph.D. candidate in GW’s CBI and the study’s lead author. “Specifically, our analyses revealed an association between microbes such as lactic-acid bacteria and schizophrenics.”

Recent studies have shown that microbiomes—the communities of microbes living within our bodies—can affect the immune system and may be connected to mental health. This study, published in the journal PeerJ, furthers the possibility that shifts in oral communities are associated with schizophrenia.

Mr. Castro-Nallar and his research team used DNA sequencing to compare 16 individuals with schizophrenia with 16 controls. The research sought to identify microbes associated with schizophrenia, as well as components that may contribute to changes in the immune state of the person. In this study, the group found a significant difference in the microbiomes of healthy and schizophrenic patients.

“Our results suggesting a link between microbiome diversity and schizophrenia require replication and expansion to a broader number of individuals for further validation,” said Keith Crandall, director of the CBI and contributing author of the study. “But the results are quite intriguing and suggest potential applications of biomarkers for diagnosis of schizophrenia and important metabolic pathways associated with the disease."