Factors affecting the gut microbiota of rural residents under different physical activity levels: a cross-sectional study

Background Physical activity levels modulate the gut microbiota and thereby influence health status. However, few studies have focused on rural populations. This study aimed to identify the factors influencing the gut microbiota of rural residents under different physical activity levels. Methods A total of 311 rural residents (range: 18–90 years) were included in this cross-sectional study. Physical activity levels were assessed using the International Physical Activity Questionnaire (IPAQ). Gut microbial composition was evaluated via 16S rRNA gene sequencing. Spearman’s rank correlation coefficient was used to examine the associations between gut microbiota and physical activity level, age, Body mass index (BMI), and sex. Multiple regression analyses were also performed to further explore these associations. Results Among the surveyed rural residents, 9.97% engaged in low-intensity physical activity, 23% in moderate-intensity physical activity, and 67% in high-intensity physical activity. Across different levels of physical activity, age was the most broadly influential variable affecting the microbiota. Sex and smoking/alcohol habits had significant effects on specific genera. BMI was positively correlated with Escherichia_Shigella ( r = 0.192, p < 0.001) and negatively correlated with Bacteroides ( r = −0.121, p = 0.033). After adjusting for covariates in multiple regression analysis, Blautia [B (95% CI): −0.002 (−0.003, −0.001)] was negatively associated with age, Collinsella [B (95% CI): −0.015 (−0.027, −0.004)] was negatively associated with sex, and Segatella [B (95% CI): 0.000005 (0.0000006, 0.0000009)] was positively associated with physical activity level. Although Spearman correlation and multiple linear regression analyses revealed that the relative abundances of a few bacterial genera were positively or negatively correlated with physical activity level, all effect sizes were very small. Conclusion Our study indicated that there were no differences in gut microbiota diversity across different physical activity levels, and only specific genera were associated with physical activity level. Age was the most important factor influencing the gut microbiota. In addition, sex, BMI, smoking, alcohol consumption, and pesticide exposure were also significantly associated with gut microbiota composition. However, the LPA group was composed predominantly of males (93.5%), and the effects observed in the LPA group were essentially limited to males.