The gut microbiota has emerged as a central factor affecting human health and disease, and inflammatory diseases are no exception. The potential role of the gut in the pathophysiology of inflammatory diseases has recently begun to attract increased attention. The inventors show in the murine model of DSS-induced colitis that the prebiotic, polydextrose (PDX), ameliorate survival, increases colon-length and weight gain after settlement of colitis and thus demonstrate that the fibre provides anti-inflammatory properties. Thus PDX would be suitable for the treatment of inflammatory diseases.