Disclosed is the use of a composition comprising shortened fibres of poly-&bgr；-1&rarr；4-Nacetylglucosamine (&ldquo；sNAG nanofibres&rdquo；) in the manufacture of a medicament for treating an intestinal disease or a condition associated with a bacterial imbalance in a subject in need thereof, wherein the medicament is manufactured to be topically administered, wherein the sNAG nanofibres are less than 10 &mu；m in average length, wherein the sNAG nanofibres comprise 70% or more than 70% of the N-acetylglucosamine monosaccharides, and wherein the sNAG nanofibres do not have an effect, or substantially have no effect, on bacterial growth or survival of Staphylococcus aureus bacterial cultures in vitro.
