**4. Conclusions**

In conclusion, the used dietary fibers modulate the fermentation patterns of cyanidin-3- *O*-glucoside in a fiber-type-dependent manner. Depending on its structure, each compound provided a specific carbon source for the fermentation of different bacterial populations, thereby influencing the beneficial taxa and producing different amounts of SCFAs and gases in vitro. The present work illustrated the interaction among anthocyanins, polysaccharides, and gut microbiota, which could provide a reference for elucidating the health effects of the supplementation of C3G-polysaccharide diets. For future research, the individual dietary fiber groups will be included to study the potential synergistic effects of C3G and dietary fiber on fermentation patterns.

**Author Contributions:** All authors participated in the design of the study. Conceptualization, W.B. and L.T.; data curation, Z.Y. and P.L.; formal analysis, Z.Y. and T.H.; funding acquisition, W.B. and L.T.; investigation, Z.Y. and P.L.; methodology, Z.Y., P.L., J.L., and L.T.; supervision, L.T.; visualization, J.A.; writing—original draft, Z.Y. and T.H. The authors thank Vicki Moore for correcting the English and Oebiotech (Shanghai, China) for performing 16S rRNA sequencing. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by the Natural Science Foundation of China (NSFC, Nos. 31901706 and No.31911530698), the Natural Science Foundation of Guangdong (2019A1515012237), the Science and Technology Program of Guangzhou (201903010081), the Pearl River Talent Plan (2017GC010387), the Youth Science and Technology Innovation Talent of Guangdong TeZhi Plan (2019TQ05N770), and the International Science and Technology Cooperation Project of Guangdong (2021A0505030043).

**Institutional Review Board Statement:** This study did not require ethical approval.

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** Data available in a publicly accessible repository.

**Conflicts of Interest:** The authors declare no conflict of interest.
