Purpose The purpose of this study is to evaluate the effects of prebiotic, probiotic and synbiotic supplementation on liver histopathology and TLR-4, NFκB and TNF-α gene expression involved in the inflammatory cascade and pathogenesis of experimental nonalcoholic fatty liver disease (NAFLD). Design/methodology/approach Wistar male adult rats (n = 40) were submitted to hypercholesterolemic conditions (60 days). On Day 30 of hypercholesterolemic conditions, rats were subdivided in five groups: negative control (NC), positive control (PC), prebiotic (PRE), probiotic (PRO) and synbiotic (SYN). All rats were sacrificed on Day 60. Liver tissue was used to verify histopathological changes and gene expression. Gene expression of TLR-4, TNF-α and NFκB was evaluated in liver tissue using RT-qPCR. Findings Histopathological analysis: PC showed more changes than NC, and PRE and SYN showed fewer alterations than PC. Gene expression analysis: PRE showed higher TLR-4, and NFκB and TNF-α compared to PC. Also, PRE showed higher TLR-4 when compared to PRO and SYN. SYN group revealed higher TLR-4 and NFκB expressions compared to PC. PRO group also showed higher NFκB expression compared to PC. Originality/value NAFLD is a significant health concern, and it found that prebiotic, probiotic and synbiotic supplementation could have positive effects as a nonpharmacological approach to control this disease.