Pitfalls and novel experimental approaches to optimize microbial interventions for chemotherapy-induced gastrointestinal mucositis

PURPOSE OF REVIEW: There is a growing number of studies implicating gut dysbiosis in mucositis development. However, few studies have shed light on the causal relationship limiting translational potential. Here, we detail the key supportive evidence for microbial involvement, candidate mechanisms by which the microbiome may contribute to mucositis and emerging approaches to model host-microbe interactions with clinical relevance and translational potential.RECENT FINDINGS: Synthesis of existing clinical data demonstrate that modulating the microbiome drastically alters the development and severity of mucositis, providing a strong rationale for its involvement. Review of the literature revealed potential microbiome-dependent mechanisms of mucosal injury including altered drug metabolism, bile acid synthesis and regulation of the intestinal barrier. Current studies are limited in their mechanistic insight due to cross-sectional and would benefit from longitudinal analyses and baseline phenotyping.SUMMARY: The causative role of the microbiome in mucositis development remains unclear. Future studies must adopt comprehensive microbial analyses with functional assessment, and utilize emerging ex-vivo models to interrogate host-microbe interactions in mucositis.