Fibres found in food are mainly carbohydrates that are not broken down or absorbed during human digestion but instead pass to the colon to be fermented by microbes. Gases produced during bacterial fermentation (hydrogen, methane, and carbon dioxide), can cause unpleasant gastrointestinal symptoms in some individuals, such as bloating, flatulence, and stomach pain. Gas production varies between individuals and is influenced by the chemical structure of dietary fibres, the gut microbes' ability to ferment fibre, intestinal pH, and the transit time of intestinal contents. This randomized clinical trial in healthy adults will investigate how individual variations in the microbiome influence the level of gastrointestinal (GI) symptoms induced by different fibre types during short-term exposure.