The field of gut microbiota is of growing interest, especially in the recent discoveries of its interaction with host immune responses, which when disrupted, can further alter immunity. It also plays a role in cancer development, its microenvironment and response to anticancer therapeutics. Several recently published experimental studies had explored the efficacy of modifying microbiota to enhance the response of checkpoint inhibitors, suggesting its beneficial function in cancer management and potential to be targeted as a therapeutic agent to enhance efficacy of checkpoint inhibitors. Here we review available evidence, mechanisms and hypotheses of its use to enhance cancer response.