The sulfur microbial diet and increased risk of obesity: Findings from a population-based prospective cohort study

Abstract

Background & aims: Gut-produced hydrogen sulfide (H₂S) has been associated with increased gut permeability and inflammation, which may be related to higher obesity risk. We investigated the association of sulfur microbial diet, a dietary index associated with 43 sulfur-metabolizing bacteria, with the incident obesity and whether the relationship was modified by the genetic predisposition to obesity.

Methods: We included 27,429 participants with available body mass index (BMI) data from the UK Biobank. The sulfur microbial diet score was assessed using the 24-h dietary assessment method. Obesity and abdominal obesity were defined according to the World Health Organization criteria. Body fat percentage was assessed using a body composition analyzer. The genetic risk score (GRS) was calculated by 940 BMI-related variants.

Results: We documented 1472 and 2893 cases of obesity and abdominal obesity during a mean follow-up of 8.1 years. After multivariable adjustment, the sulfur microbial diet score was positively associated with obesity (HR_Q4vsQ1 = 1.63; 95% CI = 1.40-1.89, P-trend = 0.001) and abdominal obesity risk (HR_Q4vsQ1 = 1.17; 95% CI = 1.05-1.30, P-trend = 0.002). We also observed that increased sulfur microbial diet score was positively related to several adiposity indicators, including a 5% increase in BMI, WC, and body fat percentage. Moreover, the sulfur microbial diet had no significant interactions with genetic risk on obesity incidence.

Conclusions: Our results emphasized the significance of avoiding the sulfur microbial diet for obesity prevention across all levels of genetic risk.

Keywords: Gene–diet interaction; Obesity; Sulfur microbial diet; UK Biobank cohort study.