Influence of Adiposity on the Gut Microbiota Composition of Arab Women: A Case-Control Study

SIMPLE SUMMARY: Obesity is a global health problem associated with increased mortality and morbidity rates. Concurrently, with important advances in therapeutic options for obesity, the global prevalence of obesity has not decreased, and the burden of obesity has become a concerning issue of our times. In addition, the mechanisms underlying this pathology and the etiological factors are incompletely understood. Thus, understanding and clarifying the possible etiological factors for obesity is essential. Over the last decade, researchers have been focusing on the gut microbiota as an element that is implicated in the aetiology of obesity. However, there is limited available epidemiologic evidence in the Middle East, especially in Saudi Arabia. In addition, very little evidence exists elsewhere on the association between the gut microbiota composition and obesity markers in young women of childbearing age. In light of this, we designed a case-control study that explored the gut microbiota composition of Saudi Arabian women with obesity compared with healthy controls using whole-genome shotgun sequencing. Our findings highlight the role of the gut microbiota in obesity and provide significant insight into creating modulation strategies for obesity management through fecal microbiota transfer, antibiotics, probiotics, and prebiotics, offering potential targets for guiding the choice of strain probiotics for gut microbiota modulation in the treatment of obesity. ABSTRACT: Recent evidence has suggested that the gut microbiota is a possible risk factor for obesity. However, limited evidence is available on the association between the gut microbiota composition and obesity markers in the Middle-Eastern region. We aimed to investigate the association between gut microbiota and obesity markers in a case-control study including 92 Saudi women aged 18–25 years, including participants with obesity (case, n = 44) and with normal weight (control, n = 48). Anthropometric, body composition, and biochemical data were collected. The whole-genome shotgun technique was used to analyze the gut microbiota. The Shannon alpha and Bray–Curtis beta diversity were determined. The microbial alpha diversity was significantly associated with only the waist-to-hip ratio (WHR) (p-value = 0.04), while the microbial beta diversity was significantly associated with body mass index (p-value = 0.048), %body fat (p-value = 0.018), and WHR (p-value = 0.050). Specific bacteria at different taxonomic levels, such as Bacteroidetes and Synergistetes, were positively associated with different obesity markers. Alistipes was higher in the control group compared with the case group. The results highlight the association of the gut microbiota with obesity and suggest that the gut microbiota of Saudi women is associated with specific obesity markers. Future studies are needed to determine the role of the identified strains in the metabolism of individuals with obesity.