Background: Immunotherapies, such as oncolytic viruses, have become powerful cancer treatments, but only some patients with cancer can benefit from them, especially those with advanced-stage cancer, and new therapeutic strategies are needed to facilitate extended survival. The intestinal microbiota may contribute to colorectal cancer (CRC) carcinogenesis and the response to immunotherapy. However, whether and how the intestinal microbiota modulates the effects of oncolytic virus vaccines (OVVs) in CRC remain to be investigated.
Methods: We generated an MC38-gp33 CRC mouse model and treated it with OVV-gp33 in early and advanced stages. Probiotics, fecal microbiota transplantation (FMT), and antibiotics (ABX) were administered to regulate the microbial composition of CRC mice at an advanced stage. The tumor growth rate and survival time of the mice were recorded; 16S rDNA sequencing was used to analyze the microbial composition and flow cytometry was used to detect T-cell subset activity.
Results: OVV-gp33 treatment inhibited tumor growth and prolonged survival in the early stage of CRC but did not have a significant effect on the advanced stage of CRC. Moreover, 16S rDNA sequence analysis and flow cytometry showed significant differences in intestinal microbiota composition, microbial metabolites, and T-cell subsets in early and advanced-stage CRC. Probiotic and FMT treatment significantly enhanced the antitumor effect of OVV in the advanced stage of CRC with an increased abundance of activated CD8 T cells and a decreased ratio of Treg cells, while depletion of the microbiota by ABX eliminated the antitumor activity of OVV with decreased CD8 T-cell activation and upregulated Treg cells.
Conclusions: These results indicate that the intestinal microbiota and microbial metabolites play an important role in the antitumor effect of OVV in CRC. Furthermore, altering the intestinal microbiota composition can modulate the antitumor and immunomodulatory effects of OVV in CRC.
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http://dx.doi.org/10.1007/s10620-024-08346-4 | DOI Listing |
Commun Biol
January 2025
State Key Laboratory of Biocontrol, School of Marine Sciences, Sun Yat-sen University, Guangzhou, China.
Global warming has threatened all-rounded hierarchical biosphere by reconstructing eco-structure and bringing biodiversity variations. Pacific white shrimp, a successful model of worldwide utilizing marine ectothermic resources, is facing huge losses due to multiple diseases relevant to intestinal microbiota (IM) dysbiosis during temperature fluctuation. However, how warming mediates shrimp health remains poorly understood.
View Article and Find Full Text PDFGut Microbes
December 2025
Microbiome-Host Interactions, Institut Pasteur, Université Paris Cité, INSERM U1306, CNRS UMR6047, Paris, France.
Metabolic syndrome is, in humans, associated with alterations in the composition and localization of the intestinal microbiota, including encroachment of bacteria within the colon's inner mucus layer. Possible promoters of these events include dietary emulsifiers, such as carboxymethylcellulose (CMC) and polysorbate-80 (P80), which, in mice, result in altered microbiota composition, encroachment, low-grade inflammation and metabolic syndrome. While assessments of gut microbiota composition have largely focused on fecal/luminal samples, we hypothesize an outsized role for changes in mucus microbiota in driving low-grade inflammation and its consequences.
View Article and Find Full Text PDFBiosci Trends
January 2025
School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China.
Parkinson's disease (PD) is a progressive disease that requires effective staging management. The role of intestinal microbiota in PD has been studied, but its changes at different stages are not clear. In this study, meta- analysis, bioinformatics analysis and in vivo simulation were used to explore the intestinal microbiota distribution of PD patients and models at different stages.
View Article and Find Full Text PDFEur J Pharmacol
January 2025
School of Pharmaceutical Sciences, Universiti Sains Malaysia, Gelugor, 11800, Penang, Malaysia. Electronic address:
Microbiota encompasses a diverse array of microorganisms inhabiting specific ecological niches. Gut microbiota significantly influences physiological processes, including gastrointestinal motor function, neuroendocrine signalling, and immune regulation. They play a crucial role in modulating the central nervous system and bolstering body defence mechanisms by influencing the proliferation and differentiation of innate and adaptive immune cells.
View Article and Find Full Text PDFCrit Rev Oncol Hematol
January 2025
The Cancer Research Institute and the Second Affiliated Hospital, Hengyang Medical School, University of South China (USC), Hunan 421001, China; Hunan Provincial Key Laboratory of Basic and Clinical Pharmacological Research of Gastrointestinal Cancer, USC, Hunan 421001, China; MOE Key Lab of Rare Pediatric Diseases, Hengyang Medical School, USC, Hunan 421001, China; National Health Commission Key Laboratory of Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, USC, Hunan 410008, China. Electronic address:
Colorectal cancer (CRC) is one of the most prevalent and lethal cancers worldwide, ranking third in incidence and second in mortality. While immunotherapy has shown promise in patients with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H), its effectiveness in proficient mismatch repair (pMMR) or microsatellite stable (MSS) CRC remains limited. Recent advances highlight the gut microbiota as a potential modulator of anti-tumor immunity.
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