Intersection between microbial-derived metabolites and modulation of the tumor microenvironment

Seminal work by others has demonstrated that alterations in microbial metabolism directly influence tumor behavior and response to therapy, and it is now acknowledged that the symbiotic relationship between mammalian organisms and ‘microbiomes’ is a new hallmark of cancer (Ferrari and Rescigno, 2023). Bachem et al. showed that microbiota-derived butyrate enhances anti-melanoma immunity by preserving tumor-specific CD8+ T cell stemness in tumor-draining lymph nodes. Mechanistically, butyrate acts directly on CD8+ T cells and promotes a FOXO1-dependent transcriptional program, thereby increasing CD127+ stem-like CD8+ T cells while limiting terminal exhaustion. These findings suggest that microbial metabolites can enhance anti-tumor T cell immunity and improve immune checkpoint blockade efficacy (Bachem et al., 2025). Jia et al. demonstrated that Lactobacillus johnsonii enhances immune checkpoint blockade efficacy across cancer types by promoting stem-like CD8+ T cell immunity. At the molecular level, L. johnsonii cooperates with Clostridium sporogenes to generate indole-3-propionic acid, which increases H3K27 acetylation at the Tcf7 super-enhancer and activates progenitor exhausted CD8+ T cells. These findings identify a microbiota-derived epigenetic metabolite axis that preserves T cell stemness (Jia et al., 2024).

This Research Topic highlights metabolic reprogramming as a key driver of tumor microenvironment remodeling and cancer progression. Metabolites derived from tumor, stromal, immune, and microbial cells reshape nutrient availability and immune function while creating exploitable metabolic vulnerabilities. Targeting these metabolic dependencies may therefore provide new therapeutic opportunities, especially when integrated with immune checkpoint inhibitors or other existing anticancer therapies to enhance treatment efficacy.