Microbiome
Gut Bacteria and Schizophrenia — A surprising link
Schizophrenia is a complex psychiatric condition characterized by hallucinations, delusions, disorganized speech, and behavior. Many factors have been implicated in its genesis, ranging from specific gene mutations to childhood trauma.
The role of gut bacteria (microbiome) in schizophrenia development is a relatively new hypothesis — but it is being studied rigorously. In the past, we have perceived bacteria as passive residents of the body. But, recent research is shedding light on their role in various diseases — from cancers to metabolic disorders.
What have bacteria got to do with schizophrenia —which is characterized by structural, biochemical and functional neurological changes?
To decipher bacteria's role in schizophrenia, researchers have studied the microbial composition between fecal samples from schizophrenia patients and those from healthy controls (ordinary people). Interestingly, researchers have found higher counts of specific organisms and lower counts of others in schizophrenia. This means dysbiosis (or altered microbiome) is a possible factor.
Here is the conclusion from one study:
“Ruminococcus and Roseburia was significantly lower, whereas the abundance of Veillonella was significantly higher in Schizophrenia patients ”
— Shijia Li et al. Sci Rep. 2021.
But, the mere presence of certain bacteria in schizophrenia patients is not enough to demonstrate their causal role. We need to learn more about how these organisms trigger the pathological process.
This is what a high-quality research paper published in Science Advances validates. Researchers have taken schizophrenia microbiome fecal samples and transplanted them into germ-free mice. These mice — demonstrated "lower glutamate and higher glutamine and GABA in the hippocampus and showed schizophrenia-like behaviors." Such findings strongly suggest that the SCZ microbiome can trigger the hallmark neurochemistry.
Besides this, few authors have even correlated certain bacteria species with the severity of schizophrenia.
“Succinvibrio and Corynebacterium were associated with the severity of symptoms for the first time”
— Shijia et al.PeerJ. 2020
Based on such pieces of evidence, we came to know that bacteria have links with schizophrenia. Scientists are now speculating if restoring gut bacteria (probiotics) could serve as a measure to manage this condition. Surprisingly, few studies (like those below) have shown clinical improvement in schizophrenia following probiotic use.
“Probiotic and vitamin D for 12 weeks to chronic schizophrenia had beneficial effects”
— BMC Psychiatry. 2019
The links between gut bacteria and schizophrenia indicate the diverse impact of the microbiome on health and disease.
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