Integrated Analysis of the Cecal Microbiome and Plasma Metabolomics to Explore NaoMaiTong and Its Potential Role in Changing the Intestinal Flora and Their Metabolites in Ischemic Stroke

Abstract

Ischemic stroke (IS), as a leading cause of disability worldwide, affects intestinal bacterial communities and their metabolites, while recent discoveries have highlighted the importance of the intestinal microflora in the development of IS. Systematic investigations of complex intestinal bacterial communities and their metabolites during ischemic brain injury contribute to elucidate the promising therapeutic targets for IS. However, the associations between intestinal microbiota and related circulating metabolic processes in IS remained unclear. Hence, to identify the changed microflora and their metabolites in IS of NaoMaiTong (NMT), an effective clinical medication, we established the middle cerebral artery occlusion/reperfusion (MCAO/R) model using conventionalized and pseudo-germ-free (PGF) rats. Subsequently, we systematically screen the microflora and related metabolites changing in IS via an integrated approach of cecal 16S rRNA sequencing combined with plasma metabolomics. We found that NMT relied on intestinal flora to improve stroke outcome in conventionalized rats while the protection of NMT was reduced in PGF rats. Total 35 differential bacterial genera and 26 differential microbial metabolites were regulated by NMT. Furthermore, L-asparagine and indoleacetaldehyde were significantly negatively correlated with Lachnospiraceae_UCG.001 and significantly positively correlated with Lachnoclostridium. Indoleacetaldehyde also presented a negative correlation with Lactobacillus and Bifidobacterium. 2-Hydroxybutyric acid was strongly negatively correlated with Ruminococcus, Lachnospiraceae_UCG.001 and Lachnospiraceae_UCG.006. Creatinine was strongly negatively correlated with Akkermansia. In summary, the research provided insights into the intricate interaction between intestinal microbiota and metabolism of NMT in IS. We identified above differential bacteria and differential endogenous metabolites which could be as prebiotic and probiotic substances that can influence prognosis in stroke and have potential to be used as novel therapeutic targets or exogenous drug supplements.

Gut microbes in cerebrovascular diseases: Gut flora imbalance, potential impact mechanisms and promising treatment strategies

“…Regulate intestinal microorganisms and microbial metabolites, inhibiting Enterobacteriaceae to repair the intestinal barrier and promote the prognosis of stroke 1. SD rat (44) Improve the prognosis of IS…”

“…In addition, decoctions, including Pueraria root and rhizome, ameliorated dyslipidemia, elevated blood viscosity, and a high risk of thrombosis after stroke and repaired the ecological imbalance of the gut microbiome and the integrity of the brain-gut barrier (162). NaoMaiTong corrected the dismal prognosis following stroke by restoring gut flora (44). Formulations of Xingu Chengqi stimulate the release of anti-inflammatory factors, such as IL-10, and downregulate proinflammatory factors, Frontiers in Immunology frontiersin.org such as TNF-a, IL-17A, and IL-22 (163).…”

“…Proteobacteria and Firmicutes showed an overall increasing trend, while Bacteroidetes showed a decreasing trend, and there were some contradictions in the changes in Actinobacteria ( 20 , 24 , 25 , 27 , 29 , 38 – 61 ). In addition, there were changes in Verrucomicrobia , Lentisphaerae , Candidatus , Parcubacteria , Deferribacteres , and other species of bacteria ( 20 , 27 , 41 – 44 , 48 , 54 ). However, there were some differences in the changes in different bacteria, different species of bacteria, and different lesion periods within each group.…”

“…Akkermansia colonizes the intestinal mucosa and regulates basal metabolism by generating mucin-degrading enzymes and utilizing mucin as a source of nitrogen and carbon in the epithelial mucous layer ( 42 ). Akkermansia and Lactobacillus growth is frequently observed in intestinal microbiota abnormalities following an IS ( 40 – 44 ). Both are beneficial bacteria that can increase the growth of other beneficial bacteria and create beneficial neuroactive chemicals, which may be related to a compensatory response secondary to the massive reduction of SCFA-producing bacteria, especially butyrate-producing bacteria ( 41 , 77 ).…”

Crosstalk between the Gut and Brain in Ischemic Stroke: Mechanistic Insights and Therapeutic Options

“…Therefore, the development of measures to lower the prevalence of IS and its detrimental consequences is highly warranted. Recent research has demonstrated that the gut microbiota regulates the pathogenesis of IS via the microbiota-gut-brain axis (MGBA) [ 4 , 5 ].…”