Microbiomes’ Role in Systemic Inflammation and Cancer: Unveiling Hidden Connections

Recent studies have revealed intricate links between host-associated microbiomes and systemic health. While the gut microbiome has received major attention, the contribution of extra-intestinal microbiomes (including the oral, respiratory, skin, and urogenital microbiomes, as well as other tissue-associated microbial communities) to systemic inflammation and cancer risk remains comparatively underexplored. This Research Topic aims to clarify how diverse microbial communities interact with host systemic pathways, with a particular focus on inflammatory signaling and carcinogenesis.By leveraging advanced metagenomic, metatranscriptomic, metabolomic, and immune-profiling approaches, contributors can investigate how microbiome composition and function influence distant body sites and biological systems. Evidence from gut microbiome research suggests that microbial metabolites, immune modulation, and chronic inflammatory signaling may act as shared mechanistic bridges connecting local microbial ecosystems to systemic disease outcomes. Extending these concepts beyond the gut, this Topic will explore how microbes and microbial products may translocate, disseminate, or signal systemically—via circulation, mucosal barriers, and immune networks—to shape remote tissue environments and potentially promote tumor initiation, progression, or therapy response.This Research Topic also welcomes work examining the molecular mechanisms by which opportunistic pathogens and dysbiotic communities contribute to persistent inflammation, immune evasion, DNA damage, and microenvironment remodeling across organ systems. A clearer understanding of these pathways could support new preventive, diagnostic, and therapeutic strategies that target extra-intestinal microbiomes to reduce systemic inflammatory burden and cancer risk.This Topic aligns with the mission of Frontiers in Cellular and Infection Microbiology by advancing mechanistic understanding of host–microbe interactions across the body and expanding microbiome research beyond a gut-centric view.We welcome articles addressing, but not limited to, the following themes:-Extra-intestinal microbiome ecology across body sites: community structure and function in oral, respiratory, skin, urogenital, and other tissue-associated microbiomes; dysbiosis signatures linked to systemic inflammation and cancer risk.-Microbiome functions driving chronic inflammation: microbial pathways (e.g., biofilm formation, proteolysis, oxidative stress) associated with persistent immune activation and low-grade systemic inflammatory states.-Microbial metabolites and small-molecule signaling in carcinogenesis: metabolite networks (e.g., SCFAs, bile acid derivatives, polyamines, indoles) shaping DNA damage, epigenetic regulation, and proliferative or apoptotic signaling.-Microbial toxins, virulence factors, and genotoxic mechanisms: toxins/enzymes/surface structures that promote mutagenesis, tissue remodeling, immune evasion, or oncogenic signaling.-Barrier disruption and permeability changes: mechanisms altering epithelial integrity, mucus, tight junctions, and local immunity that increase systemic exposure to microbes or microbial products.-Microbial translocation and systemic dissemination pathways: movement of microbes or microbial components beyond their niche (e.g., bloodstream/lymph, aspiration, device-associated routes) and links to inflammation and tumorigenesis.-Immune programming and trained immunity: effects of extra-intestinal microbiomes on innate/adaptive immune setpoints, tolerance breakdown, immune exhaustion, and inflammatory signaling relevant to cancer development.-Microbiome–tumor microenvironment crosstalk: microbial influences on angiogenesis, stromal remodeling, hypoxia responses, metastasis, and tumor heterogeneity.-Microbiomes and cancer therapy response/toxicity: modulation of efficacy and adverse events during immunotherapy, chemotherapy, radiotherapy, and antibiotic exposure, including infection risk and mucosal/skin toxicities.-Rigorous multi-omics, spatial, and longitudinal designs with translational endpoints: integrated metagenomics/metatranscriptomics/metabolomics/immune profiling, causal inference and mechanistic models, and evaluation of microbiome-targeted interventions (pre/pro/postbiotics, phages, narrow-spectrum antimicrobials, clinical care strategies). Topic editors: Tao Lin, Pushpa Pandiyan Source: https://www.frontiersin.org/research-topics/80421/microbiomes-role-in-systemic-inflammation-and-cancer-unveiling-hidden-connections