Sex- and Age-Dependent Associations between Parabacteroides and Obesity: Evidence from Two Population Cohort

Parabacteroides levels are reported to be low in obese individuals, and this genus has shown an anti-obesity capacity in animal studies. Nevertheless, the relationship between Parabacteroides and obesity in different subpopulations, e.g., with respect to age and sex, and its association with subsequent weight change have rarely been explored. The cross-sectional associations of Parabacteroides genus- and species-level OTU abundance with obesity were explored in the Guangdong Gut Microbiome Project (GGMP), which included 5843 adults, and replicated in the Guangzhou Nutrition and Health Study (GNSH), which included 1637 individuals. Furthermore, we assessed the prospective associations of Parabacteroides and its main OTUs’ abundance with the subsequent changes in body mass index (BMI) in the GNSH. We found that Parabacteroides was inversely associated with obesity among females and participants aged 40–69 years in the GGMP and the replicated cohort in the GNSH. After a 3-year follow-up, there was no significant correlation between Parabacteroides and the subsequent changes in BMI. However, Seq4172 (P. johnsonii) showed a negative correlation with subsequent BMI changes in the female and middle-aged (40–69 years) subpopulations. Overall, our results indicate that Parabacteroides have an inverse relationship with obesity and that Seq4172 (P. johnsonii) have a negative association with subsequent changes in BMI among females and middle-aged populations in perspective analyses.