The research objective was to assess the influence of a dietary inulin supplement (the way of obtaining it and its level) on chosen lipid parameters in fattener blood plasma as well as on volatile fatty acid content in the cecum and colon. The experimental trial involved 140 growers, (PL × PLW) × Duroc crossbred pigs, with an initial body weight of 29.0 ± 0.5 kg, and assigning them into 7 diet groups. Group I was the control group; the others had diets supplemented with 1%, 2% and 3% inulin (water extract in group II-IV and water-alcohol extract in V-VII groups). Blood samples for examination were collected three times during the fattening period (at 40, 70 and 100 kg BW). Large bowel contents obtained at animal slaughter made it possible to determine the volatile fatty acid level and pH. The blood plasma was examined to establish the content of triacylglycerols, total cholesterol and high density lipoprotein fraction (HDL). Inclusion of the investigated prebiotic has affected the level of some volatile fatty acids in the bowel contents. The group with 3% water-alcohol inulin extract supplementation showed increased concentration of acetic, isobutyric and butyric acid (cecum) as well as acetic and butyric acid (colon). Throughout the whole fattening period, an increase was observed in (p ≤ 0.01) HDL cholesterol fraction in each diet group with inulin additive (II-VII), i.e. by 48, 49, 44, 47, 41 and 40%, respectively, as compared to the control (I). On the other hand a decrease (p ≤ 0.01) of triacylglycerols content was noted in group II and VII in comparison to the control group. All the fatteners fed mixtures containing inulin had a lower total cholesterol/HDL cholesterol ratio in comparison to the control group (p ≤ 0.01). The key findings of the study have shown that an increased inulin level positively affected the chosen lipid parameters in fattener blood plasma as well as the production of short-chain fatty acids in the large intestine. However, no substantial influence of an inulin extraction method on the studied parameters was noted.