16S rRNA gene sequencing reveals altered gut microbiota in young adults with schizophrenia and prominent negative symptomsOriginal 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 study examined gut microbiota in young adults with schizophrenia showing prominent negative symptoms, a group that is poorly characterized. Stool samples underwent 16S rRNA gene sequencing, with sequences clustered into operational taxonomic units. Symptoms were rated with the positive and negative syndrome scale (PANSS). Analyses included diversity metrics, LEfSe, Spearman correlation, and random forest classification.
Who was studied?
Participants were young adults aged 18 to 30 years in China, recruited at Xijing Hospital. After exclusions, the study analyzed 30 patients with prominent negative symptoms, 32 with prominent positive symptoms, and 36 healthy controls. Groups matched the negative-symptom patients on sex, age, smoking, alcohol, and BMI. People with obesity, metabolic disease, or recent antibiotic or probiotic use were excluded.
What were the most important findings?
Beta-diversity separated the groups (Bray-Curtis P 0.001), but alpha-diversity did not differ significantly. Negative-symptom patients had higher Fusobacteria and Proteobacteria and lower Firmicutes at the phylum level, plus 27 genera differing from controls. A six-genus panel (Coprococcus, Monoglobus, Prevotellaceae NK3B31 group, Escherichia-Shigella, Dorea, and Butyricicoccus) distinguished patients from controls with an AUC of 0.939. Several short-chain-fatty-acid-producing genera were depleted in patients. The microbiota could not reliably separate negative-symptom from positive-symptom schizophrenia (minimum error rate 0.544).
What are the greatest implications of this study?
The findings suggest gut dysbiosis may participate in schizophrenia with negative symptoms and could offer peripheral diagnostic markers. Enriched inflammation-linked phyla and depleted short-chain-fatty-acid producers hint at roles for inflammation and metabolism in negative symptoms. The authors propose probiotics or short-chain fatty acids as possible adjunct strategies. Limits include a small cross-sectional sample, past antipsychotic use, single stool sampling, and 16S sequencing that cannot resolve function.