Reduced Sulfur Diet Reshapes the Microbiome and Metabolome in Mild-Moderate Ulcerative Colitis.

This pilot study investigated the effects of a reduced sulfur (RS) diet on the gut microbiome composition and fecal metabolome in individuals with remitted or active ulcerative colitis (UC). Thirteen participants maintained their habitual diet (control), while nine followed an RS diet for eight weeks (Wk8). Stool and plasma samples were collected at the baseline and Wk8. The sulfur intake decreased in the RS group (-28 g/1000 kcal) versus the control group (-1.7 g/1000 kcal; < 0.001). The RS group exhibited a significant decrease in lipopolysaccharide-binding protein (-5280 ng/mL), while these levels increased in the control group (620 ng/mL; < 0.05). The microbiome analysis showed an increased alpha diversity at Wk8 ( < 0.01), suggesting a microbial shift with a RS intake. The metabolic alterations indicated enhanced nitrogen disposal (increased uric acid, methyluric acid, N-acetyl-L-glutamate) and a higher energy demand (elevated ubiquinol and glucose-pyruvate). The RS diet increased beneficial microbes , , and , while decreasing pathobionts and . Methyluric acid correlated positively with (β = 0.70) and negatively with (β = -0.77) suggesting these microbes utilized this metabolite and influenced the microbiome composition. In conclusion, a RS diet promoted microbial diversity, metabolic adaptations, and reduced inflammation, highlighting its potential as a novel strategy for UC management.