(P39-01-26) Fiber and Anthocyanin Mixtures in Ameliorating Ulcerative Colitis-Associated Microbial Dysbiosis

Objectives: Patients with ulcerative colitis (UC) often restrict fiber intake due to poor tolerance. Designed prebiotic fiber mixtures have been shown to improve tolerance and enhance short-chain fatty acid (SCFA) production. Complexation of fiber with anthocyanins increases polyphenol stability and colonic delivery. This study aims to evaluate prebiotic fiber mixtures alone and in combination with anthocyanins to enhance butyrate production in UC-associated bacterial dysbiosis.

Methods: Two fiber mixtures (FMA and FMB) were tested alone and in combination with anthocyanin powder (AP), for a total of 5 treatments (FMA, FMA+AP, FMB, FMB+AP, AP). After simulated upper gastrointestinal digestion (INFOGEST), digested fibers were fermented using a pooled fecal sample from pediatric donors with colitis. Samples were incubated for 0, 12, 24, and 48 hours. At each timepoint, pH, gas production (syringe displacement), and SCFA (GC-MS) were measured. DNA was isolated at 0, 24, and 48 h using the DNeasy PowerSoil Pro Kit (Qiagen). The V3-V4 region of the 16S rRNA gene was amplified and sequenced on a MiSeq platform.

Results: Anthocyanin addition to FMA did not show synergistic effects, as butyrate levels decreased. However, combining anthocyanins with FMB led to higher SCFA levels, particularly butyrate. Although FMB alone increased SCFA production, the addition of anthocyanins reduced gas output. FMB+AP also exhibited the highest fermentation efficiency (more butyrate per gas unit), suggesting improved tolerability. Additionally, FMB+AP increased Shannon diversity and butyrate-associated genera (Lachnospira, Fusicatenibacter, Roseburia, and Butyribacter), while reducing opportunistic taxa (Intestinibacter and Sellimonas). Both FMA and FMA+AP reduced a few UC-associated taxa (e.g., Sarcina, Haemophilus), but increased several facultative anaerobes often elevated in UC (Klebsiella, Citrobacter, Enterococcus, and Enterobacteriaceae).

Conclusions: Specific dietary fiber mixtures can synergize with anthocyanins to enhance butyrate production and increase beneficial bacteria. Notably, FMB+AP increased SCFA levels, promoted butyrate-producing taxa, and reduced gas formation under colitis-associated dysbiosis.

Funding Sources: Heartland Children’s Nutrition Collaborative Award and USDA-NIFA Foundation Awards