Objectives:
The authors were inspired by the new phenomenon of socially responsible initiatives, created by pro-socially oriented influencers. Analysis of international reference books has revealed a research gap existing in this field. The area for the conducted studies was a conceptually separate part of the Instagram community, related to pro-social activities. Dichotomous purposes of the paper include: in the epistemological aspect: definition of a new category of social media influencers focusing their interests and activities in social media on social issues, in the empirical aspect: exemplification of the aforementioned phenomenon in pro-social activities of a Polish influencer who represents the international The Body Positive Movement.

Material and methods:
The research was conducted primarily in the qualitative aspect. Individual In-depth Interview, Internet content analysis and research of secondary sources were conducted.

Results:
The studies indicate the existence of niche initiatives among social media influencers who create typical pro-social profiles on Instagram. This category of social media influencers, described and conceptually distinguished, can be called pro-social influencers (pro-social SMI). From the perspective of premises of the Social Influence Theory, analysis of relations between the studied pro-social influencer and her followers showed establishment of particularly durable, emotionally-charged relationships among people with similar views and cherished values.

Conclusions:
The study results and conclusions presented by the authors may offer an incentive for further in-depth studies focused on influencers as the modern initiators of social activities.