| Studies have shown that gut microbiota is of vital importance to human health and that its effect on cancers has attracted extensive attention in recent years,ranging from boosting cancer immunity to promoting cancer progression and influencing therapeutic effects.The interaction between gut microbiota and cancer is well established for gastrointestinal cancers,but it is less clear for cancers in the lung or other distal intestinal cancers.Non-small cell lung cancer(NSCLC)accounts for a large proportion of cancers and is one of the major causes of cancer deaths in the world.Therefore,the study of the relationship between gut microbiota and NSCLC is helpful to better understand the interaction mechanism,improve the effect of prevention,treatment,and patient survival.In this paper,clinical specimens such as feces and urine of NSCLC patients and their first-degree family members meeting the inclusion criteria were collected in the Radiotherapy Department of Cancer Prevention and Treatment Center,Sun Yat-sen University from 2018 to2021.Multi-omics techniques including 16 S r RNA gene sequencing,metagenomic sequencing and untargeted metabolomics,bioinformatics analysis,machine learning models combined with clinical information and indicators were used to study the effect of intestinal microecology on the diagnosis,prognosis and adjuvant therapy of NSCLC patients.To characterize the multi-omics composition of intestinal microecology in NSCLC patients,investigate the effect of dynamic changes and stability of gut microbiota on prognosis during Concurrent chemoradiotherapy(CCRT)and evaluate the efficacy of adjuvant therapy during CCRT treatment and the relationship with gut microbiota.The main research contents and results of this paper are as follows:1.A total of 145 stool and 118 urine samples were systematically collected from patients with NSCLC and their first-degree family members.Multiomic techniques were used to characterize the gut microbial composition,microbial function and urine metabolism of NSCLC patients.The results showed that the gut microbial composition of patients with NSCLC patients were significantly different from the healthy individuals.A total of 11 microorganisms were significantly different at the genus level.Including significantly increased abundances of Streptococcus,Veillollena and Flavonifractor,while significantly decreased abundances of Prevotella,Butyricicoccus,unclassified＿f＿Lachnospiraceae,Terrisporobacter,CHKCI002,Family＿XIII＿UCG-001,Eubacterium nodatum and Pyramidobacter spp.The microbial function distribution and urinary metabolism were significant differences,which were found to be related to Prevotella and Tryptophan(TRP)metabolism.2.Stool samples from 18 patients with locally advanced non-small cell lung cancer(LA-NSCLC)and 13 first-degree family members were examined using metagenome sequencing to correlate the baseline gut microbial with progression-free survival(PFS)outcomes(6 cases in the Long-PFS group with PFS ≥ 11 months and 12 cases in the Short-PFS group with PFS < 11 months).The results showed that the baseline gut microbial composition of patients with LA-NSCLC correlated with PFS,The Firmicutes/Bacteriotides(F/B)value and alpha diversity in Long-PFS group were higher than in the Short-PFS group.4 genera and 16 species were significantly enriched in the Long-PFS group,while 14 species were significantly enriched in the Short-PFS group.Additionally,the characteristic of fungi,archaea and viruses were more abundant in the Long-PFS group.Furthermore,It was found that there were significant differences between the Long-PFS group and the Short-PFS group in various antibiotic-related pathways,antibiotic resistance genes were enriched in the Short-PFS group,and showed a correlation in genes related to vancomycin antibiotic resistance.3.A total of 102 stool samples were collected from patients with NSCLC during concurrent chemoradiotherapy(CCRT)treatment(T0: before CCRT;T1: 2 weeks after the start of CCRT;T2: after CCRT).The 16 S r RNA gene and metagenome sequencing techniques were used to investigate the relationship between dynamic changes of gut microbiota during CCRT treatment.The results showed that the dynamic changes of gut microbiota in NSCLC patients were significantly associated with PFS,the α diversity of the Long-PFS group was significantly higher at T1,and the patients with higher α-diversity at T1 had significantly longer PFS.A total of 8 biomarkers were predictive of PFS at T1,and the AUC of 0.87(95%CI,0.71-0.94).Univariate Cox proportional risk analysis confirmed that Shannon index(HR=2.978,P=0.037)and PD index(HR=3.741,P=0.015)at T1 were significantly associated with PFS,and the multifactorial Cox analysis showed that PD index(HR=8.036,P=0.016)and the abundance of Dorea sp(HR=4.186,P=0.043)at T1.Notably,pathways involving fatty acid and carbohydrate metabolism differed significantly in the functional analysis.4.Stool samples of 19 patients with NSCLC(7 in the Long-PFS group with PFS ≥11months and 12 in the Short-PFS group with PFS<11 months)during CCRT treatment(T0:before CCRT;T1: 2 weeks after the start of CCRT;T2: before the second CCRT;T3: after CCRT)and 14 healthy first-degree relatives were analyzed by metagenome sequencing to study the relationship between intestinal microbial stability and prognostic outcome during CCRT treatment.The results showed that patients with high microbial stability(lower PC1 and PC standard deviation)were associated with longer PFS.The m S score-Core Microbiota was significantly associated with PFS(P=0.002)in T2-T3.The α diversity of probiotics(genus level,P=0.033;Species level,P=0.038)and Faecalibacterium Prausnitzii(P=0.030)were significantly higher in the Long-PFS group.Multivariate Cox analysis showed that the change in Streptococcus thermophilus during treatment was an independent predictor of PFS.5.A total of 69 patients with NSCLC were included in this study,and another 69 patients were selected as controls to determine the effect of thymidine α1 application on radiation pneumonitis(RP)during CCRT treatment and to assess the effects and changes in the gut microbiome.The results showed that thymidine α1 application during and after CCRT significantly reduced the incidence of grade ≥2 RP and the incidence of G3-G4 lymphopenia.There were no significant differences in terms of baseline intestinal microbial diversity and composition or dynamic changes.6.A total of 71 patients were included in this study,and another 71 patients were selected as the control group,to study the effect of Oral nutrition supplement(ONS)in CCRT treatment and its relationship with intestinal microbes.The results showed that the PG-SGA score was significantly lower in the oral nutritional supplement group during CCRT treatment(P=0.002).There was no significant difference in the composition and changes of gut microbiota between the ONS group and the non-ONS group,but the response to ONS intervention was significantly related to the composition of gut microbiota(P=0.048),and the F/B value of the response to ONS group was significantly higher(P=0.036).In summary,this thesis systematically characterized the intestinal microecology multi-omics structure of NSCLC patients;The dynamic changes and stability of gut microbiota in NSCLC patients during CCRT treatment were related to the prognosis.And evaluate the effects of thymosin α1 and oral nutritional supplements in NSCLC patients during CCRT treatment,and explore its relationship with intestinal microbes. |
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