Emerging evidence suggests gut microbiome alterations significantly influence irritable bowel syndrome (IBS) symptoms with fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) implicated in triggering symptoms.This study investigated the impact of low and high FODMAP biscuit models on gut microbiota including: Biscuit Flour Control (BiFC), Low-FODMAP Control (LFC), Low-FODMAP High-Fibre Prototype (LFP), and Wholemeal Flour Control (WMC). Biscuits were subjected to in vitro digestion which was followed by in vitro colonic fermentation. 16S rRNA gene sequencing and fatty acid analyses were performed at the end of fermentation.Alpha diversity analysis revealed samples fermented with LFP induced higher diversity compared to samples fermented with BiFC and LFC. The relative abundance of Escherichia-Shigella was significantly lower in LFP fermentates than BiFC fermentates. LEfSe analysis showed LFC fermentates were characterized by higher levels of Citrobacter and Ligilactobacillus. Significantly reduced acetate and butyrate levels were found in LFP fermentates compared to LFC fermentates. WMC fermentates had higher acetate and propionate levels compared to other biscuit fermentates.In conclusion, incorporating low-FODMAP, high-fibre food prototypes may enhance gut microbial diversity and reduce potentially pathogenic bacteria such as Escherichia-Shigella. These findings highlight the potential of personalized dietary interventions, such as the manipulation of biscuit formulations, in modulating gut microbiota and managing IBS symptoms. Industrial relevanceThe low FODMAP diet has been developed as an effective method to moderate the symptoms of IBS patients by reducing bloating and gas in the colon. Our results revealed that the low-FODMAP, high-fibre biscuit model proved more effective than the low-FODMAP biscuit for generating a gut microbiota that could contribute to easing IBS symptoms. Future research should focus on improving this formulation and adapting it to treat the different forms of IBS. This study also demonstrates the efficacy of using colon fermentation models to devise food formulations for gut microbiome-associated diseases.