Different dietary patterns affect the gut microbial compositions and diversity. Consistently, microbiome alterations are linked to digestion, immunity, and productivity. Nakai (SQ) is a perennial bamboo species rich in proteins and fiber. Previous studies have confirmed the health benefits of SQ; however, the effects of SQ supplementation on gut microbiome and production performance are unclear. Herein, Landrace pigs were supplemented with SQ extract (SQE) and gut microbial compositions as opposed to the control group were assessed using 16S rRNA sequencing. Additionally, the influences of SQE supplementation on average daily gain (ADG) and backfat thickness (BF) were assessed after slaughter. In the SQE group, Firmicutes and Actinobacteria phyla increased significantly, whereas Bacteroidetes and Spirochaetes phyla markedly decreased ( < 0.05). The expression level of and genera increased, whereas that of , , and decreased ( < 0.05). The microbial richness was similar between groups; however, microbial diversity decreased in the SQE supplementation group. Additionally, the SQE supplementation in pigs resulted in a slight increase in ADG. In contrast, BF in the SQE group decreased notably ( < 0.05). These results underscore the significant influence of SQE supplementation on the gut microbiota and demonstrate the potential of SQ as a valuable feed resource for enhancing animal productivity.