Prevotella and Klebsiella proportions in fecal microbial communities are potential characteristic parameters for patients with major depressive disorder.

BACKGROUND: The diagnosis of major depression disorder (MDD) and other mental disorders were depended on some subjective survey scales. There are confirmed relationship between the gut flora and the mental states of MDD patients.

METHODS: The V3-V4 region of the 16S rRNA gene was extracted from the fecal microbial communities in MDD patients, PCR amplified and sequenced on the Illumina Miseq platform.

RESULTS: More phylum Firmicutes, less Bacteroidetes, and more genus Prevotella, Klebsiella, Streptococcus and Clostridium XI were found in MDD patients. The changes of the proportion of Prevotella and Klebsiella were consistent with Hamilton depression rating scale.

LIMITATIONS: The conclusion was limited by small sample sizes and potential uncontrollable influence factors on fecal microbiota.

DISCUSSION: Prevotella and Klebsiella proportion in fecal microbial communities should be concerned in the diagnosis and therapeutic monitoring of MDD in future.