Impaired bowel function is frequent in tube-fed patients, and diarrhoea is associated with decreased faecal short-chain fatty acids (SCFAs) concentrations. The aim of this study was to compare the effects of a multi-fibre-enriched formula (15 g/l) and a fibre-free isoenergetic and isonitrogenous formula on faecal SCFAs and microbiota in long-term enteral nutrition (EN) patients.