Mapping the Themes and Intellectual Structure of Micro-Influencers: A Systematic Review and a Bibliometric-Analysis [version 2; Peer Review: 2 Approved, 1 Approved with Reservations]

Abstract* Background Social media marketing dynamics have been reshaped with the rise of micro-influencers, with the offering of community-driven and authentic brand engagement that goes beyond traditional celebrity endorsements and advertising. This study aims to systematically examine the micro-influencer research published between 2020 and 2025, focusing on identifying themes, research gaps, methodological characteristics, and providing future directions. Methods This paper focuses on providing a thorough systematic literature review (SLR) incorporating the PRISMA protocol on micro-influencers, while identifying interdependencies and relationships. 68 research papers were derived from the Scopus database, analysed through bibliometric and content analysis. Bibliometric analysis was conducted using a combination of VOSviewer and Biblioshiny packages. Results were analysed through thematic clusters, co-occurrence, and bibliographic coupling analysis. Results The analysis depicts a steady growth in publications accelerated with digitalisation and post-COVID consumer shift that placed a commercial value on small-scale influencers. Research is fragmented across authenticity, trust, engagement, sponsorship disclosure, and niche-domains for micro-influencers. The literature is geographically skewed towards the West and high-income Asian countries. Less longitudinal, mixed-method, andneuroscientific evidence with strong methodological concentration across quantitative survey, and computational methods was present. Algorithmic visibility, emerging platform comparisons, influencer labour, and non-commercial uses of micro-influencers were underexplored themes. Five research areas were identified from clustering. Conclusion Despite the rapid expansions, micro-influencer literature remains theoretically fragmented and unevenly distributed. This review provides a comprehensive analysis of the literature on micro-influencers, synthesises these fragmented findings into an integrated cocneptual framework and provides implications and future research directions. Most studies focused on analysing a single platform with cross-sectional designs. This study highlights the need for thorough theoretical integration with methodological diversification, considering emerging platforms to better understand how micro influencers shape digital communication.