The significance of less abundant genera within the gut microbiota, such as Parabacteroides, remains largely unexplored. Despite its low levels, Parabacteroides is highly conserved and potentially beneficial across populations. This trial aimed to evaluate whether a four-week intake of glucolacto-oligosaccharides (GLO), previously reported as an enhancer of Parabacteroides, improves defecation frequency as the primary outcome. It also assessed holistic gut health and underlying microbiota-based