This study has investigated the relationship between the gut microbiota compotision and the growth performance in pigs from birth to the finishing stage, focusing on nutrient metabolism. Of 59 crossbred pigs [(Landrace × Large Yorkshire) × Duroc] from seven sows, individuals with high and low daily gain (DG) were assigned to high DG (HDG, n = 11) and low DG (LDG, n = 8) groups. Fecal samples collected at weaning (21 days), growing (95–106 days) and finishing (136–152 days) stages were analyzed for amino acids, short-chain fatty acids, and microbial composition using 16S rRNA sequencing. Although birth and weaning weights were similar in both groups, the HDG group had significantly higher weights in the growing and finishing stages (P < 0.01). The microbial composition of the LDG group revealed a higher abundance of f_Lachnospiraceae;__ at weaning (P < 0.05), whereas the HDG group contained higher abundance of g_Streptococcus and g_Prevotella 7 at the finishing stage (P < 0.05). Functional analysis revealed increased amino acid metabolism in the HDG group at the finishing stage (P < 0.05). During the growing stage, total free fecal amino acid content was low in the HDG group (P < 0.05); at weaning, levels of isobutyric and isovaleric acids, key amino acid fermentation products (P < 0.05, P < 0.01), were higher. These findings indicate growth stage-specific differences in the gut microbiota and metabolic profiles between groups with different growth performance, suggesting microbial and metabolic characteristics may influence growth performance.