• Gut Microbiota and Immune Response to Vaccines
  • Shaghayegh Sharifi,1,* Fateme Jafari,2
    1. Department of Basic Science, Rasht Branch, Islamic Azad University
    2. Department of Medical Sciences, Gorgan Branch, Islamic Azad University, Iran


  • Introduction: Several animal and human studies have highlighted the crucial role of the gut microbiome in vaccine immunogenicity. Age has also been identified as an important factor influencing this process. The microbiome contributes to the education, maturation, and modulation of the adaptive immune system. Some studies have demonstrated its role in maintaining lung immune homeostasis during respiratory viral infections. It also strengthens host defense mechanisms. In addition, human cohort studies have shown an association between the gut microbiome composition and the immunogenicity of COVID-19 vaccines. Notably, the presence of specific taxa such as Faecalibacterium prausnitzii has been linked to prolonged antibody persistence. These findings emphasize the potential of the gut microbiome to shape vaccine responses and to support the body in combating viral infections.
  • Methods: In this study, we searched online databases including PubMed, ScienceDirect, Scopus, Google Scholar, MDPI, and PLOS ONE. A total of 20 articles were collected, and after screening, 10 recent studies published between 2019 and 2025 that were most relevant to the subject were selected. The main keywords used were: gut microbiome, vaccine efficacy, probiotics, and immunogenicity.
  • Results: Multiple studies have examined the relationship between the gut microbiome and vaccine efficacy, showing that the microbiome can activate specific immune pathways and influence both innate and adaptive immunity. Research also highlights the complex gut-lung interaction and the key role of the microbiome in regulating immune responses to vaccines against respiratory pathogens. Additionally, the gut microbiome contributes to the migration of gut-derived innate lymphoid cells to the lungs, which helps activate innate immunity and modulate disease progression and host immune responses. Scientists have also introduced modifications in the design of respiratory vaccines based on the importance of gut microbiome. Other studies have linked the infant gut microbiome to immune responses to the rotavirus vaccine. Systematic reviews provide strong evidence for the role of probiotics as therapeutic interventions in COVID-19, demonstrating their potential to reduce disease severity. Furthermore, specific bacteria, such as *Faecalibacterium prausnitzii*, have been shown to affect immune responses to SARS-CoV-2 vaccines and enhance the persistence of anti-S antibodies.
  • Conclusion: The findings highlight the importance of maintaining a healthy and balanced gut microbiome in enhancing vaccine effectiveness and immune responses. Moreover, the recommendations of scientific organizations, including the European Academy of Pediatrics, to use probiotics for the prevention of upper respiratory infections emphasize the potential role of these interventions. Therefore, strengthening the gut microbiome and incorporating probiotics can be considered a promising approach in the design and improvement of future vaccines.
  • Keywords: gut microbiome, vaccine efficacy, probiotics, immunogenicity