This systematic review and meta-analysis examine the effects of exercise on the gut microbiota (GM) of adults. The study included 25 studies with a total of 1044 participants, focusing on the impact of exercise on GM diversity, particularly using the Shannon index, Simpson index, Chao1 index, and observed OTUs. The results showed that exercise significantly increased the alpha diversity of adult GM, as measured by the Shannon index, compared to control groups. Exercise was also found to alter the composition of GM, notably decreasing Bacteroidetes and increasing Firmicutes, indicating a shift in the Firmicutes/Bacteroidetes ratio. Subgroup analyses revealed that females and older adults exhibited more significant changes in the Shannon Index and observed OTUs. The study highlights that exercise may be a promising way to improve GM in adults, with the Shannon index showing a significant increase after exercise. However, the effects of exercise on GM diversity vary by gender and age, suggesting the need for further research. The findings indicate that exercise can influence specific bacterial phyla, such as Firmicutes and Bacteroidetes, and may enhance the abundance of beneficial bacteria like Bifidobacterium, Akkermansia, and Lactobacillus, which are associated with improved gut health and metabolic functions. Additionally, exercise was linked to increased production of short-chain fatty acids (SCFAs), which are important for gut barrier function and metabolic health. Despite these findings, the study acknowledges limitations, including the potential influence of diet on GM composition and variations in sequencing regions used across studies. Future research should explore the physiological interactions between the gut and muscles, as well as the effects of various environmental factors on GM composition. The study emphasizes the importance of considering demographic factors and exercise intensity when assessing the impact of exercise on GM diversity. Overall, the results suggest that exercise can positively influence GM diversity and composition, contributing to improved gut health and metabolic outcomes in adults.This systematic review and meta-analysis examine the effects of exercise on the gut microbiota (GM) of adults. The study included 25 studies with a total of 1044 participants, focusing on the impact of exercise on GM diversity, particularly using the Shannon index, Simpson index, Chao1 index, and observed OTUs. The results showed that exercise significantly increased the alpha diversity of adult GM, as measured by the Shannon index, compared to control groups. Exercise was also found to alter the composition of GM, notably decreasing Bacteroidetes and increasing Firmicutes, indicating a shift in the Firmicutes/Bacteroidetes ratio. Subgroup analyses revealed that females and older adults exhibited more significant changes in the Shannon Index and observed OTUs. The study highlights that exercise may be a promising way to improve GM in adults, with the Shannon index showing a significant increase after exercise. However, the effects of exercise on GM diversity vary by gender and age, suggesting the need for further research. The findings indicate that exercise can influence specific bacterial phyla, such as Firmicutes and Bacteroidetes, and may enhance the abundance of beneficial bacteria like Bifidobacterium, Akkermansia, and Lactobacillus, which are associated with improved gut health and metabolic functions. Additionally, exercise was linked to increased production of short-chain fatty acids (SCFAs), which are important for gut barrier function and metabolic health. Despite these findings, the study acknowledges limitations, including the potential influence of diet on GM composition and variations in sequencing regions used across studies. Future research should explore the physiological interactions between the gut and muscles, as well as the effects of various environmental factors on GM composition. The study emphasizes the importance of considering demographic factors and exercise intensity when assessing the impact of exercise on GM diversity. Overall, the results suggest that exercise can positively influence GM diversity and composition, contributing to improved gut health and metabolic outcomes in adults.