The influence of fibre inclusion and transit time regulation on the performance, health status, microbial activity and population, physico-chemical characteristics of the hindgut digesta and intestinal morphology in early weaned pigs were examined. For these experiments, wheat bran (WB) was used as fibre source and loperamide as a drug (LOP) to increase the digesta transit time. In Expt 1, a total of 128 early weaned pigs were randomly distributed in a 2 × 2 factorial combination of WB inclusion (0 v. 40 g/kg) and LOP administration (0 v. 0·07 mg/kg body weight) during 13 d. For Expt 2, a total of twenty-four piglets were allotted to three dietary treatments for 15 d with the same basal diet (control diet) as Expt 1; a diet with 80 g/kg of WB and the combination of WB and LOP. In Expt 1, LOP improved the average daily feed intake and average daily gain of the animals (P = 0·001 and 0·007, respectively). The same result was obtained when WB was combined with LOP. The WB–LOP group also showed a higher concentration of SCFA (P = 0·013), acetic acid (P = 0·004) and propionic acid (P = 0·093). On the other hand, WB inclusion reduced the organic matter and crude protein digestibility (P = 0·001) and tended to decrease the enterobacteria population (P = 0·089). In Expt 2, WB increased the butyric acid concentration (P = 0·086). We concluded that the inclusion of WB to modify the intestinal microbiota activity combined with LOP may be beneficial to animal health and performance.