Probiotics as potentiators of cancer immunotherapy

The composition of the microbiome undeniably plays a role in the host-immune response to carcinogenesis. Over-the-counter probiotic dietary supplements can alter low-level taxonomic species microbiota composition to generally mimic the most-investigated and beneficial immune-sensitizing bacteria in animal studies. Probiotics manufactured for FDA certification can alter high-level or low-level taxonomic gut microbiota composition to mimic that found in responders to immune checkpoint blockade (ICB) therapy, or to reproducibly alter the immune phenotype in predetermined ways respectively. It remains to be seen, whether changes at either, or both, level of taxa, in and of themselves, are sufficient to reproducibly demonstrate additive or synergistic effects with ICB therapy. Probiotics, considered as innocuous and pharmacologically inactive substances are poised to come into their own as potentiators of anti-cancer immunotherapy