Gut microbiota and inflammatory factor characteristics in major depressive disorder patients with anorexia.

BACKGROUND: This study aimed to explore the gut microbiota and inflammatory factor characteristics in major depressive disorder (MDD) patients with anorexia and to analyze the correlation between gut microbiota and inflammatory factors, anorexia, and HAMD scores. METHODS: 46 MDD patients and 46 healthy controls (HC) were included in the study. The 46 MDD patients were divided into two groups according to whether they had anorexia:20 MDD without anorexia (MDA0 group) and 26 MDD with anorexia (MDA1 group). We used the Hamilton Depression Scale-24 (HAMD-24) to evaluate the depression status of all participants and 16 S ribosomal RNA (16 S rRNA)sequencing to evaluate the composition of the gut microbiota. Inflammatory factors in peripheral blood such as C-reactive protein (CRP) were detected using enzyme-linked immunosorbent assay (ELISA). Spearman's correlation analysis was used to evaluate the correlation between gut microbiota and inflammatory factors, HAMD scores, and anorexia. RESULTS: 1). CRP was significantly higher in the MDA0, MDA1, than HC. 2). An analysis of α-diversity shows: the Simpson and Pielou indices of the HC group are higher than the MDA1 group (P < 0.05). 3). The ß-diversity analysis shows differences in the composition of microbial communities between the MDA0, MDA1, and HC group. 4). A correlation analysis showed that Blautia positively correlated with anorexia, HAMD scores, and CRP level, whereas Faecalibacterium, Bacteroides, Roseburia, and Parabacteroides negatively correlated with anorexia, HAMD scores, and CRP level. 5). The receiver operating characteristic (ROC) curve was drawn using the differential bacterial genera between MDD patients with or without anorexia as biomarkers to identify whether MDD patients were accompanied with anorexia, and its area under curve (AUC) was 0.85. The ROC curve was drawn using the differential bacterial genera between MDD patients with anorexia and healthy controls as biomarkers to diagnose MDD patients with anorexia, with its AUC was 0.97. CONCLUSION: This study suggested that MDD patients with anorexia had a distinct gut microbiota compared to healthy individuals, with higher level of CRP. Blautia was more abundant in MDD patients with anorexia and positively correlated with CRP, HAMD scores, and anorexia. The gut microbiota might have influenced MDD and anorexia through the inflammatory factor CRP.

Characteristics of gut microbiota and its correlation with hs-CRP and somatic symptoms in first-episode treatment-naive major depressive disorder.

OBJECTIVE: Most patients with major depressive disorder (MDD) have somatic symptoms, but little studies pay attention in the microbial-inflammatory mechanisms of these somatic symptoms. Our study aimed to investigate alterations in gut microbiota and its correlation with inflammatory marker levels and somatic symptoms in first-episode treatment-naive MDD. METHODS: Subjects contained 160 MDD patients and 101 healthy controls (HCs). MDD patients were divided into MDD with somatic symptoms group (MDDS) and MDD without somatic symptoms group (MDDN) based on Somatic Self-rating Scale (SSS). 16S ribosomal RNA sequencing were performed to analyze the composition of the fecal microbiota. The inflammatory factors were measured using enzyme linked immunosorbent assay (ELISA). Correlation among the altered gut microbiota, inflammatory factor and severity of clinical symptoms were analysized. RESULTS: Relative to HCs, MDD patients had higher levels of high-sensitivity C-reactive protein (hs-CRP) as well as disordered α-diversity and ß-diversity of gut microbiota. Linear discriminant effect size (LEfSe) analysis showed that MDD patients had higher proportions of Bifidobacterium, Blautia, Haemophilus and lower proportions of Bacteroides, Faecalibacterium, Roseburia, Dialister, Sutterella, Parabacteroides, Bordetella, and Phascolarctobacterium from the genus aspect. Furthermore, correlation analysis showed Bacteroides and Roseburia had negative correlations with the hs-CRP, HAMD-24, the total and factor scores of SSS in all participants. Further, compared with MDDN, the Pielous evenness was higher in MDDS. Random Forest (RF) analysis showed 20 most important genera discriminating MDD-S and MDDN, HCs. The ROC analysis showed that the AUC was 0.90 and 0.81 combining these genera respectively. CONCLUSION: Our study manifested MDD patients showed disordered gut microbiota and elevated hs-CRP levels, and altered gut microbiota was closely associated with hs-CRP, depressive symptoms, and somatic symptoms.

[Study on toxic effects of toluene on primary cultured hippocampus neurons].

OBJECTIVE: Study the cytotoxicity of toluene and its mechanism, the hippocampus neurons were primarily cultured and were exposed to toluene in vitro. METHODS: The neurons from newborn SD rat's hippocampus were primarily cultured for two weeks, then administered with toluene (3, 6, 9 mmol/L), with blank control group and excipient group being also set up. 24 hours later, Morphology and viability of the cells, the LDH activity, [Ca2+]i, and cell apoptosis were examined. RESULTS: Protuberances of neurons of the toluene-exposed groups were damaged; the bodies of the neurons became round and swollen; the number of the cells decreased; the LDH activity of neurons of high-dose group increased significantly compared with control group (P < 0.05). [Ca2+]i of toluene-exposed groups also increased significantly compared with control group(P < 0.05) in a dose-dependent manner; after diltizem as antagonist of calcium tunnel was added, no increase of [Ca2+]i was found; and evident apoptosis of the exposed cells were also found. CONCLUSION: Toluene was toxic to the neurons after being administered in vitro, which might be ascribed to higher lipid solubility of toluene and it's ability to increase calcium influx, the latter facilitating apoptosis.