Sequencing technology has created an avenue to characterise schizophrenia through underlying probing of the gut microbiome, which could in turn provide clues to aid in the diagnosis and prognosis of schizophrenia.
Researchers at Peking University and the Chinese Academy of Sciences and compared the differences in gut microbiota between healthy controls and those who had been diagnosed with schizophrenia, using 16S rRNA sequencing.
They then investigated whether gut microbiota could serve as a biomarker to help in the diagnosis of schizophrenia, making sure to restrict "inclusion criteria strictly to control confounding bias".
As a last step, they looked into differences in faecal microbiota between 64 schizophrenia patients and 53 healthy controls.
Microbiota biomarkers
The researchers noted that at the phylum level, the abundance of Proteobacteria in the schizophrenia patents was "significantly increased".
At the genus level, Succinivibrio, Megasphaera, Collinsella, Clostridium, Klebsiella and Methanobrevibacter were higher in relative abundance, while Blautia, Coprococcus and Roseburia were more prominent in the healthy controls.
They observed that 12 significant microbiota biomarkers could be used as diagnostic factors for determining if someone was schizophrenic or not.
They added that "several metabolic pathways differed significantly between healthy controls and schizophrenia patients, including vitamin B6 and fatty acids".
Factors to consider
However, the researchers also acknowledged the limitations of the study, one of which was its cross-sectional design that included only schizophrenic individuals of Chinese Han nationality. As such, they deemed the sample size too small.
At the same time, they did not manage to full eliminate the impact anti-psychotic drugs had on the gut microbiota.
As such, they wrote that the sample size should be bigger and that they should select "multi-ethnic patients" whose first episode of schizophrenia had not been treated, and involve them in "longitudinal follow-up studies to observe the dynamic changes of gut microbiota".
Despite this, they added that comparing the differences in gut microbiota between healthy individuals and those with schizophrena presented a new aspect of gut microbiota’s health potential.
They concluded: "There are some differences of gut microbiota between schizophrenia patients and healthy controls, and the insights from this study could be used to develop microbiota-based diagnosis for schizophrenia."
Source: Schizophrenia Research
https://doi.org/10.1016/j.schres.2018.01.002
"Analysis of gut microbiota diversity and auxiliary diagnosis as a biomarker in patients with schizophrenia: A cross-sectional study"
Authors: Yang Shen, et al.