Gut microbial biomarkers for the treatment response in first-episode, drug-naïve schizophrenia: a 24-week follow-up studyOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This 24-week follow-up study looked for gut microbial biomarkers that diagnose schizophrenia and predict antipsychotic treatment response. Stool samples underwent 16S rRNA gene sequencing of the V3-V4 regions. Treatment response was measured by change in the Positive and Negative Symptoms Scale total score after risperidone. A random forest model was built to distinguish patients from controls. Inflammatory markers, hypersensitive C-reactive protein and homocysteine, were also measured.
Who was studied?
The sample was 107 first-episode, drug-naive schizophrenia patients and 107 healthy controls from China. Controls were matched by age, gender, education, smoking, and body mass index. Patients were treated with risperidone monotherapy titrated to 4 to 6 mg per day. Samples were collected at baseline and after treatment, with 60 patients completing the full 24 weeks.
What were the most important findings?
Patients showed lower alpha-diversity than controls at baseline, on both the Shannon and Simpson indices, and a significant beta-diversity difference. A 10-microbe model separated patients from controls with an area under the curve of 0.867 in the verification set. Nineteen genera differed at baseline, and 14 of them belonged to the Firmicutes phylum. After 24 weeks, Lachnoclostridium decreased and Romboutsia increased. Baseline Lachnoclostridium and Romboutsia levels were significantly associated with treatment response.
What are the greatest implications of this study?
The results suggest schizophrenia patients carry a characteristic gut microbiota, and that certain microbes may predict how well risperidone works. Baseline levels of specific genera were tied to symptom improvement. Because the design was observational, it cannot prove the microbiota causes schizophrenia or drives the drug response. Findings apply to risperidone and may not generalise to other antipsychotics. Microbiota-targeted strategies were proposed as a future direction.