Author Interviews, Johns Hopkins, Microbiome, Probiotics, Schizophrenia / 10.04.2017
Probiotics May Influence Schizophrenia Symptoms Through Yeast in Microbiome
MedicalResearch.com Interview with:
Emily G. Severance PhD
Stanley Division of Developmental Neurovirology
Department of Pediatrics
Johns Hopkins University School of Medicine
Baltimore, MD 21287
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Previously, we found that people with schizophrenia and bipolar disorder had an increased susceptibility to Candida albicans yeast infections, which was sex specific and associated with memory deficits. Also in an earlier placebo-controlled probiotic study, we found that although probiotics improved the overall bowel function of people with schizophrenia, there was no effect by this treatment on psychiatric symptoms. Given that C. albicans infections can upset the dynamics of the human microbiome, we decided to re-evaluate the potential benefit of probiotics in the context of a patient’s C. albicans yeast status. Not only was bowel function again enhanced following intake of probiotics, but yeast antibody levels were decreased by this treatment.
Furthermore, psychiatric symptoms were actually improved over time for men receiving probiotics who did not have elevated C. albicans antibodies. Men who were positive for C. albicans exposure, however, consistently presented with worse psychiatric symptoms irrespective of probiotic or placebo treatment.
Emily G. Severance PhD
Stanley Division of Developmental Neurovirology
Department of Pediatrics
Johns Hopkins University School of Medicine
Baltimore, MD 21287
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Previously, we found that people with schizophrenia and bipolar disorder had an increased susceptibility to Candida albicans yeast infections, which was sex specific and associated with memory deficits. Also in an earlier placebo-controlled probiotic study, we found that although probiotics improved the overall bowel function of people with schizophrenia, there was no effect by this treatment on psychiatric symptoms. Given that C. albicans infections can upset the dynamics of the human microbiome, we decided to re-evaluate the potential benefit of probiotics in the context of a patient’s C. albicans yeast status. Not only was bowel function again enhanced following intake of probiotics, but yeast antibody levels were decreased by this treatment.
Furthermore, psychiatric symptoms were actually improved over time for men receiving probiotics who did not have elevated C. albicans antibodies. Men who were positive for C. albicans exposure, however, consistently presented with worse psychiatric symptoms irrespective of probiotic or placebo treatment.










Dr. Kate Merritt[/caption]
Kate Merritt PhD
Post-Doctoral Research Worker
NOC Study (Nitric Oxide in Cognition)
Institute of Psychiatry
De Crespigny Park
London
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Merritt: Research has indicated that levels of one of the main chemicals in the brain, glutamate, may be abnormal in schizophrenia. Almost sixty studies have measured glutamate levels in schizophrenia, however the findings are inconsistent, and it is thought that changes in glutamate levels may vary with the length or the severity of illness. This study therefore analysed all the published reports of glutamate in schizophrenia.
The main findings are that, overall, schizophrenia is associated with elevated glutamate in several brain regions; namely the medial temporal cortex, the basal ganglia and the thalamus. These changes also differed with the stage of illness; in the medial frontal cortex, glutamate was increased in people at risk for developing schizophrenia, but not in people who had been diagnosed with schizophrenia for several years, whereas in the medial temporal lobe the opposite pattern was detected.
Dr. Lena Palaniyappan[/caption]
Lena Palaniyappan
Medical Director
Prevention & Early Intervention Program for Psychoses (PEPP)
London, Ontario
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: It is now well established that patients with schizophrenia show reduced thickness of brain's grey matter in Magnetic Resonance Imaging studies, indicating either a developmental or an acquired deficit in the amount of brain tissue. Such reductions are seen both in treated and untreated patients, suggesting that current treatments do not reverse the process of tissue loss, if at all this is occurring in patients. We wanted to study if subtle increase in brain tissue also accompanied this reduction. We observed that across the group of 98 medicated patients, reduced thickness was consistently accompanied by subtle, but nevertheless noticeable increases in thickness. Such increases were more pronounced in those with a longer duration of illness.
Dr. Alan Brown[/caption]
Alan S. Brown, M.D., M.P.H.
Professor of Psychiatry and Epidemiology
Columbia University Medical Center
Director, Program in Birth Cohort Studies, Division of Epidemiology
New York State Psychiatric Institute
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Brown: Smoking during pregnancy is a risk factor for several pregnancy-related outcomes including low birthweight and preterm birth. Evidence for a link with schizophrenia is scant. We analyzed a maternal biomarker of smoking called cotinine, a nicotine metabolite, in mothers of nearly 1,000 schizophrenia cases and 1,000 controls in a national birth cohort in Finland. We found that heavy smoking in pregnancy was related to a 38% increase in schizophrenia risk in offspring and that as cotinine levels increased even in the more moderate smokers risk of schizophrenia also increased.
Dr. Emily Severance[/caption]
Emily G. Severance, Ph.D
Stanley Division of Developmental Neurovirology
Department of Pediatrics
Johns Hopkins University School of Medicine
Baltimore, MD
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Severance: This research stems in part from anecdotal dialogues that we had with people with psychiatric disorders and their families, and repeatedly the issue of yeast infections came up. We found that Candida overgrowth was more prevalent in people with mental illness compared to those without psychiatric disorders and the patterns that we observed occurred in a surprisingly sex-specific manner. The levels of IgG antibodies directed against the Candida albicans were elevated in males with schizophrenia and bipolar disorder compared to controls. In females, there were no differences in antibody levels between these groups, but in women with mental illness who had high amounts of these antibodies, we found significant memory deficits compared to those without evidence of past infection.








