Purpose of reviewThere is increased evidence of several impaired gastrointestinal functions with ageing. In the elderly, however, most gastrointestinal functions remain relatively intact because of the large reserve capacity of the intestine and the great secretion capacity of the pancreas. This review will focus on changes in gut microflora observed in the elderly and on the potential benefit of probiotics in this population.Recent findingsRecent studies suggest that age affects the intestinal microflora with a decrease in anaerobes and bifidobacteria population and an increase in enterobacteria. These changes and the reduced intestinal immunity of the aged may favour gastrointestinal infections that are frequent in the elderly.Clostridium difficile-associated diarrhoea, one of the most common nosocomial infections in the elderly, has a profound effect on morbidity, mortality and health costs. Probiotics may have interesting positive effects on intestinal function, and the efficacy of treatment withLactobacilliandSaccharomyces boulardiiinClostridium difficile-associated diarrhoea has been well established in a recent meta-analysis. Studies performed in healthy elderly patients suggest that diet supplementation with probiotics may reduce the impaired immunity associated with ageing.SummaryImportant changes in intestinal microflora of the elderly have recently been demonstrated and may have important clinical consequences. Further studies should be conducted to determine if the consumption of probiotics is associated with a lower infection rate and a higher effectiveness of vaccines.