New Insights into Synergistic Boosts in SCFA Production Across Health Conditions Induced by a Fiber Mixture.

Background/Objectives: Short-chain fatty acids (SCFAs) produced by gut microbiota from dietary fiber fermentation play crucial roles in health and disease. While most research focuses on individual fibers, this study investigated whether a fiber mixture could synergistically increase SCFAs, exceeding the expected average production of individual contributions and microbial signatures associated with this phenomenon. Methods: We quantified synergistic SCFA production using secondary analysis of in vitro fecal fermentation data from 33 participants across four health conditions (healthy controls, Crohn's disease, ulcerative colitis, and Parkinson's disease), by comparing observed fiber mixture output to expected additive contributions from individual components and identified microbial signatures associated with synergistic SCFA production through differential abundance and network analyses. Results: The fiber mixture consistently outperformed most individual fibers and demonstrated synergistic SCFA production, yielding 32.8 ± 20.1% more total SCFAs than expected. This synergistic effect was observed across all four health conditions studied, with many individuals showing >50% synergy and some exceeding 80%. Differential abundance analysis revealed that individuals exhibiting synergistic responses were enriched in taxa from Lachnospiraceae and Ruminococcaceae families, key butyrate-producing groups that likely facilitate cooperative interactions. Network analysis confirmed these families as central hubs in synergy-associated microbial interactions. Conclusions: These findings suggest that fiber mixtures can harness cooperative microbial interactions to synergistically enhance SCFA production regardless of health status, offering potential for developing more effective prebiotics for superior therapeutic outcomes.