Researchers at the George Washington University, USA, had just published a comprehensive new paper detailing the link between microbes (viruses, bacteria and fungi) and schizophrenic disorder. This, the authors hope, could lead to more accurate diagnoses and treatment plans down the road.
“The oropharynx of schizophrenics seems to harbour different proportions of oral bacteria than healthy individuals,” said Eduardo Castro-Nallar, a Ph.D. candidate at GW’s Computational Biology Institute (CBI) and lead author of the study. “Specifically, our analyses revealed an association between microbes such as lactic-acid bacteria and schizophrenics.”
Past research has shown that microbial populations have a noticeable effect on the immune system and may be connected to mental health, although studies specifically designed to assess the potential relationship between microbiota and schizophrenia have been few and far between.
In the paper, released in the journal PeerJ, the research team reports on the results of their metagenomic (related to studying genetic material directly from environmental samples) analysis of the oropharyngeal microbiome in 16 individuals with schizophrenia and 16 controls.
The latter group was found to be richer in species but less even in their distributions, i.e., dominated by fewer species, as opposed to schizophrenia patients, who harboured more lactic acid bacteria (such as Lactobacilli and Bifidobacterium) and a lactate-utilizing species Eubacterium halii.
Functionally, the microbiome of schizophrenia patients was characterized by an increased number of metabolic pathways related to metabolite transport systems including siderophores, glutamate, and vitamin B12. In contrast, carbohydrate and lipid pathways and energy metabolism were abundant in controls.
“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.”
While far from conclusive, the study could serve as a spring board for further study into the linkages between shifts in human microbiota and the onset of schizophrenia, as it’s not currently clear which way the causal link goes (if it does at all) – do microbial changes contribute to the disorder or are caused by it?