Major gut microbial taxa and their predominant influence on systemic immunity and response to immunotherapy

Gut TaxaImmune effect/Treatment responseStudy typeCancer typeReference
Predominately positive influence
 Faecalibacterium prauznitziiBoosts effector T-cells and dampens T-regs [38].HumansMelanomaGopalakrishnan et al. (2018)
 Faecalibacterium spp.Increases efficacy of anti-CTLA-4 immunotherapy [44].HumansMultiple myelomaChaput et al. (2017)
 Eubacterium limosum Clostridiales spp. Ruminococcaceae spp. Phasolarctobacterium spp.Boost CD8+ T-cells and enhance anti-PD-1 responses [33].Cell lineColorectal AdenocarcinomaCell line (MC38)Tanoue et al. (2019)
 Fusobacterium ulcerans Fusobacterium variumBoost CD8+ T-cells and enhance anti-PD-1 responses [33].Cell lineMC38Tanoue et al. (2019)
 Akkermansia muciniphiliaIncrease in memory T-cells and decrease in T-regs in the TME [39].HumansEpithelial tumorsRouty et al. (2018)
Increases mucus layer of the gut to prevent lipopolysaccharides absorption [39, 41].Humans; reviewEpithelial tumorsRouty et al. (2018); Routy et al. (2018)
Mixed influence
 Bacteroides fragilisIncreases efficacy of anti-CTLA-4 immunotherapy [42].Human/Animal/Cell lineEpithelial tumorsVetizou et al. (2015)
Promotion of T-regs through polysaccharide-A [40].HumansN/ATelesford et al. (2015)
Higher IL-12 levels in transplant recipients [47].Animal/Cell lineCervical cancerUribe-Herranz et al. (2018)
 Bacteroides thetaiotaomicronIncreases efficacy of anti-CTLA-4 and anti-PD-1 immunotherapy [Vetizou et al. showed in anti-CTLA–4 alone; Frankel et al. showed in dual setting] [42, 45].HumansMelanomaFrankel et al. (2017)
 Bacteroides spp.Inferior response of anti-CTLA-4 immunotherapy [44].HumansMultiple myelomaChaput et al. (2017)
 Bifidobacterium longumIncreases CD8+ T-cells [43, 46].Animal/Cell lineMelanomaSivan et al. (2015)
 HumansMelanomaMatson et al. (2018)
 Bifidobacterium bifidumInduces naïve T-cell differentiation into T-regs and increases IL-10.Increases the integrity of epithelial barrier [41].ReviewN/ARouty et al. (2018)
Predominately negative influence
 EnterobacteriaceaeInferior response and survival [41].ReviewN/ARouty et al. (2018)