A biological study was undertaken to analyse the metabolic effect of feeding rats with an experimental diet in which cellulose was substituted with 20% contribution of chemically-modified potato starches (subjected to oxidation, esterification, cross-linking and dual modification). Caecum digesta mass was significantly higher in rats fed the experimental potato starch preparations compared to control group. Luminal ammonia concentration and pH of caecal or colonic content were lower as an effect of diets with all the investigated preparations. Compared to the cellulose-containing diet (control), all modified potato starch preparations raised the content of SCFA in caecum digesta when fed to rats. Significant lowering of the levels of triacylglycerols and total cholesterol was noticed for all chemically-modified starch preparations. The activity of β-glucuronidase determined upon the administration of potato starch preparations into rat diets was significantly lower as compared to the control diet. The results indicate that the chemically-modified potato starch preparations are a good substrate for the intestinal microecosystem and may promote the beneficial status of the gastrointestinal tract of rats.