Abstract Salecan, a linear extracellular polysaccharide consisting of β-(1,3)-d-glucan, has potential applications in the food industry due to its excellent toxicological profile and rheological properties. The aim of the present study was to evaluate the effects of dietary supplementation with 8% Salecan on the gastrointestinal microbiota in mice. In the Salecan group, the following significant differences (p<0.05) from the cellulose group were found: increased body weight gain, greater mass of cecum and cecal contents, and higher butyrate concentrations in the cecal and colonic contents at wk 4. Moreover, populations of Lactobacillus and Bifidobacterium increased 3- and 6-fold, respectively, in the cecal contents of mice consuming Salecan. These results suggest that the dietary incorporation of Salecan, by providing SCFAs and increasing beneficial microbiota, may be beneficial in improving gastrointestinal health, and have relevance to the use of Salecan as a dietary supplement for human consumption.