Microbiome and One Health in GCC countries: current status, research gaps, and future directions.

Background: Microbiome science has emerged as a central component of the One Health framework, linking human, animal, and environmental health. Although global microbiome research has expanded rapidly, a comprehensive evaluation of microbiome research development and integration across the Gulf Cooperation Council (GCC) countries remains lacking. This systematic review aimed to characterize microbiome research in the GCC countries, identify major research gaps, and evaluate alignment with One Health principles while proposing a strategic framework to support coordinated regional development. Methods: This systematic review followed PRISMA 2020 guidelines. A structured search of PubMed, ScienceDirect, Google Scholar, and EBSCO databases identified microbiome-related studies published up to January 31, 2025. Eligible studies included original research conducted in the GCC countries (Saudi Arabia, Qatar, Kuwait, United Arab Emirates, Oman, and Bahrain) investigating human, animal, or environmental microbiomes. Findings were synthesized descriptively to assess study distribution, research design, analytical methodologies, and thematic focus. Results: A total of 110 studies met the inclusion criteria. Human microbiome studies accounted for 49% of publications, followed by environmental microbiome studies (40%) and animal microbiome studies (11%). Research output increased substantially after 2020 but remained uneven among the GCC countries, with Saudi Arabia contributing 44% of publications, whereas Bahrain and Oman together accounted for fewer than 7%. Most studies were observational and primarily used 16S rRNA gene sequencing on Illumina platforms. Human studies focused mainly on gut and oral microbiomes and frequently investigated metabolic disorders such as obesity and diabetes. Animal microbiome research was limited and largely centered on camels, with minimal investigation of livestock relevant to food security. Environmental studies predominantly examined soil and desert environments. No included study simultaneously investigated human, animal, and environmental microbiomes within an integrated One Health study design. Conclusion: Microbiome research in the GCC countries is growing but remains uneven and largely disconnected across human, animal, and environmental studies, with limited adoption of One Health approaches. A coordinated regional strategy integrating governance, infrastructure, funding, and workforce development is needed to advance translational microbiome research and strengthen the GCC's contribution to global health, food security, and environmental sustainability.