Table 1.
Preclinical and clinical studies on the microbiota and therapeutic efficacy against solid tumors in the past decade.
| Studies | Therapeutic drugs or targets | Microbiota or microbial intervention | Efficacy | Mechanisms |
|---|---|---|---|---|
| Chemotherapy | ||||
| Zhang et al. 26 | 5-Fluorouracil | Fusobacterium nucleatum | Nonbeneficial | Induce BIRC3 expression via theTLR4/NF-κB pathway |
| Yuan et al. 27 | 5-Fluorouracil | Antibiotics increase Proteobacteria | Nonbeneficial | - |
| Deng et al. 28 | Tegafur plus oxaliplatin | Fusobacterium nucleatum | Nonbeneficial | - |
| Geller et al. 29 | Gemcitabine | Gammaproteobacteria | Nonbeneficial | Bacterial CDD inactivates gemcitabine |
| Yu et al. 30 | 5-Fluorouracil/oxaliplatin | Fusobacterium nucleatum | Nonbeneficial | Activate TLR4/MyD88 signaling and autophagy |
| Daillère et al. 31 | Cyclophosphamide | Enterococcus hirae | Beneficial | Translocation increases CD8/Treg ratio within tumor |
| Barnesiella intestinihominis | Beneficial | Increase IFN-γ+ γδ+ T cells within tumor | ||
| An and Ha 32 | 5-Fluorouracil | Lactobacillus plantarum | Beneficial | Decrease cancer stem-like cells |
| Lehouritis et al. 33 | Fludarabine phosphate/CB1954 | E. coli Nissle 1917, Listeria welshimeri Serovar 6B SLCC5334 | Beneficial | Drug modification |
| Gemcitabine/cladribine | Nonbeneficial | - | ||
| Vande et al. 34 | Gemcitabine | Mycoplasma hyorhinis | Nonbeneficial | Bacterial CDD and nucleoside phosphorylase decrease cytostatic activity |
| Iida et al. 35 | Oxaliplatin/cisplatin | Antibiotic treatment | Nonbeneficial | Reduce myeloid-cell ROS |
| Viaud et al. 36 | Cyclophosphamide | Lactobacillus johnsonii, Lactobacillus murinus, Enterococcus hirae | Beneficial | Induce bacterial translocation, which stimulates pathogenic Th17 and memory Th1 immune responses |
| Immunotherapy (Underlined microbiota were involved in the mechanisms) | ||||
| Zheng et al. 37 | PD-1 | Akkermansia muciniphila, Ruminococcaceae spp. | Beneficial | - |
| Proteobacteria | Nonbeneficial | - | ||
| Peters et al. 38 | PD-1/CTLA-4 | Faecalibacterium prausnitzii, Coprococcus eutactus, Prevotella stercorea, Streptococcus sanguinis, Streptococcus anginosus, Lachnospiraceae bacterium 3 1 46FAA | Beneficial | - |
| Bacteroides ovatus, Bacteroides dorei, Bacteroides massiliensis, Ruminococcus gnavus, Blautia producta | Nonbeneficial | - | ||
| Zhao et al. 39 | PD-1 | Antibiotic treatment | Nonbeneficial | - |
| Matson et al. 40 | PD-1 | Enterococcus faecium, Collinsella aerofaciens, Bifidobacterium adolescentis, Klebsiella pneumoniae, Veillonella parvula, Parabacteroides merdae, Lactobacillus sp., Bifidobacterium longum | Beneficial | Decrease Tregs |
| Ruminococcus obeum, Roseburia intestinalis | Nonbeneficial | - | ||
| Gopalakrishnan et al. 41 | PD-1 | Ruminococcaceae/Faecalibacterium | Beneficial | Increase peripheral and infiltrating effector T cells |
| Bacteroidales | Nonbeneficial | - | ||
| Pushalkar et al. 42 | PD-1 | Intratumoral microbiota | Nonbeneficial | Induce immunosuppressive tumor microenvironment |
| Routy et al. 43 | PD-1 | Akkermansiacea muciniphila, Enterococcus hirae, Alistipes indistinctus | Beneficial | Increase CD4+ central memory T cells, IL-12 secretion of DC, and intratumor CD4/Foxp3 ratios and elicit Th1 immune responses |
| Derosa et al. 44 | PD-1/CTLA-4 | Antibiotic treatment | Nonbeneficial | - |
| Chaput et al. 45 | CTLA-4 | Faecalibacterium prausnitzii, butyrate-producing bacterium, Gemmiger formicilis | Beneficial | Induce Tregs in the gut |
| Bacteroidetes/Bacteroides | Nonbeneficial | - | ||
| Frankel et al. 46 | PD-1/CTLA-4 | Bacteroides caccae, Streptococcus parasanguinis, aecalibacterium prausnitzii, Bacteroides thetaiotamicron, Holdemania filiformis, Dorea formicogenerans | Beneficial | - |
| Kaderbhai et al. 47 | PD-1 | Antibiotic treatment | Nonbeneficial | - |
| Sivan et al. 48 | PD-1 | Bifidobacterium | Beneficial | Induce DC maturation and intratumor CD8+ T cell accumulation |
| Vetizou et al. 49 | CTLA-4 | Bacteroides thetaiotaomicron, Bacteroides fragilis | Beneficial | Elicit Th1 immune response and DC maturation |
| Burkholderia cepacia | Beneficial | Synergize with TLR2/TLR4 | ||
| Iida et al. 35 | IL-10R plus CpG oligonucleotide | Alistipes, Ruminococcus | Beneficial | Activate tumor-infiltrating myeloid cells via TLR4 and increase TNF response |
| Lactobacillus fermentum | Nonbeneficial | Decrease TNF response | ||
The mechanisms refer to the underlined components when only a portion of the microbiota have been clarified. TLR, Toll-like receptor; CDD, cytidine deaminase; Tregs, regulatory T cells; Th, T helper; DC, dendritic cells; TNF, tumor necrosis factor.