老年甲型流感重症肺炎患者肠道菌群失调与肺炎链球菌感染的关系

Relationship between intestinal flora imbalance and Pneumococcus infection in elderly patients with severe pneumonia caused by influenza A virus Arzugul

目的探讨老年甲型流感重症肺炎患者肠道菌群失调与肺炎链球菌感染的关系,为临床完善治疗方案提供依据。方法选取2021年1月至2023年6月我院老年甲型流感重症肺炎患者166例作为观察组,其中合并肺炎链球菌感染的51例患者纳入双重感染组,其余115例纳入单一感染组。根据患者年龄、性别匹配同期健康体检者83例作为对照组。比较观察组、对照组及2个亚组间肠道双歧杆菌、乳杆菌、拟杆菌、肠球菌的数量,双歧杆菌属与肠杆菌属数量比值(B/E值)。采用Logistic回归模型分析双重感染的影响因素。绘制限制性立方样条图分析B/E值与双重感染的剂量-效应关系。结果观察组患者肠道双歧杆菌[(4.68±0.59vs9.33±0.65)lgCFU/g]、乳杆菌[(5.14±0.64vs9.05±0.76)lgCFU/g]、拟杆菌[(4.12±0.62vs7.45±0.73)lg CFU/g]数量及B/E值(0.94±0.20 vs 1.18±0.22)均低于对照组,肠球菌[(8.59±0.84 vs 6.22±0.71)lg CFU/g]数量高于对照组(均P<0.05)。双重感染亚组患者肠道双歧杆菌[(4.33±0.58 vs 4.84±0.60)lg CFU/g]、乳杆菌[(4.78±0.62 vs 5.30±0.65)lg CFU/g]、拟杆菌[(3.71±0.59 vs 4.30±0.63)lg CFU/g]数量及B/E值(0.79±0.20vs 1.01±0.21)均低于单一感染亚组,肠球菌[(9.16±0.86 vs 8.34±0.83)lg CFU/g]数量高于单一感染亚组(均P<0.05)。留置胃管(OR=1.396,95%CI:1.096~1.778)、留置深静脉管(OR=1.493,95%CI:1.120~1.989)是老年甲型流感重症肺炎患者合并肺炎链球菌感染的独立危险因素,而B/E值(OR=0.355,95%CI:0.200~0.628)是其独立保护因素。B/E值(χ^(2)=13.356,P<0.001)与老年甲型流感重症肺炎患者合并肺炎链球菌感染存在非线性剂量-效应关系,当B/E值≤0.93时,B/E值(β=-0.916,95%CI:0.236~0.679,P=0.008)是合并肺炎链球菌感染的独立保护因素。结论老年甲型流感重症肺炎患者存在肠道菌群失调的现象,且与合并肺炎链球菌感染存在“L型”非线性剂量-效应关系。

Objective To explore the relationship between intestinal flora imbalance and Pneumococcus infection in elderly patients with severe pneumonia caused by influenza A virus,so as to provide evidence for clinical treatment.Methods A total of 166 elderly patients with severe influenza A virus pneumonia in our hospital from January 2021 to June 2023 were selected as the observation group,of which 51 cases with Pneumococcus infection were included in the dual-infection subgroup,and the other 115 cases were included in the single-infection subgroup.According to age and sex,83 healthy subjects in the same period were matched as the control group.The counts of intestinal Bifidobacterium,Lactobacillus,Bacteroides and Enterococcus in observation group,control group and two subgroups were compared,and the ratio of Bifidobacterium to Enterobacterium counts(B/E value)was compared.Logistic regression model was used to analyze the influencing factors of combined infection.The dose-effect relationship between B/E values and combined infection was analyzed using restricted cubic spline plots.Results In the observation group,the counts of Bifidobacterium[(4.68±0.59 vs 9.33±0.65)lg CFU/g],Lactobacillus[(5.14±0.64 vs 9.05±0.76)lg CFU/g],and Bacteroides[(4.12±0.62 vs 7.45±0.73)lg CFU/g],as well as the B/E ratio(0.94±0.20 vs 1.18±0.22)were lower,while the count of Enterococcus[(9.16±0.86 vs 8.34±0.83)lg CFU/g]was higher than those in the control group respectively(all P<0.05).In the dual-infection subgroup,the counts of Bifidobacterium[(4.33±0.58 vs 4.84±0.60)lg CFU/g],Lactobacillus[(4.78±0.62 vs 5.30±0.65)lg CFU/g],Bacteroides[(3.71±0.59 vs 4.30±0.63)lg CFU/g]and the B/E ratio(0.79±0.20 vs 1.01±0.21)were lower,while the count of Enterococcus[(9.16±0.86 vs 8.34±0.83)lg CFU/g]was higher than those in the single-infection subgroup respectively(all P<0.05).The retention of gastric tube(OR=1.396,95%CI:1.096-1.778)and deep venous tube(OR=1.493,95%CI:1.120-1.989)were independent risk factors for Pneumococcus combined infection in elderly patients with severe pneumonia,and B/E value(OR=0.355,95%CI:0.200-0.628)was independent protective factor.There was a nonlinear dose-effect relationship between B/E value(χ^(2)=13.356,P<0.001)and Pneumococcus combined infection in elderly patients with severe pneumonia.When less than 0.93,B/E value(β=−0.916,95%CI:0.236-0.679,P=0.008)was an independent protective factor for the combined infection.Conclusion The intestinal flora of elderly patients with severe pneumonia caused by influenza A virus was disordered,and there was an L-shaped nonlinear dose-effect relationship with Pneumococcus combined infection.