Bifidobacterium lactis Probio-M8 treated and prevented acute RTI via regulating gut microbiota and metabolites.

The results showed that Probio-M8 treatment although slightly changed the gut microbial structure of the patients, it significantly changed the composition, In-depth metagenomic analysis showed that, at 4-week post-discharge, significantly more species-level genome bins (SGBs) of Bifidobacterium animalis, Corynebacterium pyruviciproducens, Clostridium sp. CAG:58 were increased significantly, while the abundant of Escherichia coli, Streptococcus parasanguinis, Schaalia odontolytica decreased significantly in probiotic group (P<0.05). Furthermore, significantly more microbial bioactive metabolites (e.g., glutamate, N.acetylspermidine, pyridoxamine and alpha-muricholate) but less stearoylethanolamide was detected in the probiotic group than placebo group during/after intervention (P<0.05). Interestingly, we found the relative abundance of Escherichia coli was negatively with IL-10 (r=-0.22, P=0.0022), whereas positively with influenza score (r=0.26, P=0.00024). In addition, alpha-muricholate was negatively with fu-like symptoms and pharyngeal and nasal symptoms score (r=-0.2, P=0.0051; r=-0.2, P=0.0056, respectively). Collectively, our results suggested that administering Probio-M8 may regulate the host inflammatory response by regulating the balance of intestinal microorganisms, bioactive metabolites, and related pathways and bring health-promoting effects to patients with RTIs.

研究结果显示，尽管Probio-M8干预仅轻微改变了患者的肠道微生物结构，却显著调控了其肠道菌群组成。深入的宏基因组分析表明，在出院后4周时，益生菌组中显著富集的物种级基因组bins（species-level genome bins, SGBs）包括动物双歧杆菌（Bifidobacterium animalis）、产丙酮酸棒杆菌（Corynebacterium pyruviciproducens）以及梭菌属CAG:58（Clostridium sp. CAG:58）；而大肠埃希菌（Escherichia coli）、副血链球菌（Streptococcus parasanguinis）与解齿斯卡尔维亚菌（Schaalia odontolytica）的丰度则显著降低（P<0.05）。此外，干预期间及干预后，益生菌组检测到的微生物生物活性代谢物水平显著高于安慰剂组，包括谷氨酸（glutamate）、N-乙酰亚精胺（N.acetylspermidine）、吡哆胺（pyridoxamine）与α-鼠胆酸（alpha-muricholate），而硬脂酰乙醇酰胺（stearoylethanolamide）的水平则显著更低（P<0.05）。值得注意的是，我们发现大肠埃希菌的相对丰度与白细胞介素10（IL-10）呈负相关（r=-0.22, P=0.0022），而与流感评分呈正相关（r=0.26, P=0.00024）。另外，α-鼠胆酸的相对丰度与流感样症状及咽鼻症状评分均呈负相关（分别为r=-0.2, P=0.0051；r=-0.2, P=0.0056）。综上，本研究结果表明，给予Probio-M8干预可通过调控肠道菌群平衡、微生物生物活性代谢物及相关通路，调节宿主炎症反应，进而为呼吸道感染（Respiratory Tract Infections, RTIs）患者带来健康获益。