Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:This dysbiosis may impact the presence of interleukin-17 (IL17)-producing T-helper cells (Th17) and regulatory T cells (Tregs), as the development of these cells is heavily reliant on the microbial composition (Atarashi et al. 2011; Ivanov et al. 2009; Kriegel et al. 2011).
Category: