This study evaluated the impact of Indian gooseberry powder and Habanero pepper powder on the ceacal microbiota and growth performance of broiler chickens. A total of 48 male Ross 308 broilers were randomly divided into four groups: a basal diet as the control group (CON), a basal diet supplemented with 0.02% chili pepper powder (CPP), a basal diet supplemented with 0.02% Indian gooseberry powder (IGP), and a basal diet supplemented with 0.02% chili pepper powder and 0.02% Indian gooseberry powder (CI200). The chickens’ growth performance was monitored weekly over a period of 42 days. Feed conversion ratio (FCR) differed (P < 0.05) between the CI200 and control groups, with no mortalities observed. Quantitative polymerase chain reaction was used to quantify gut bacterial species, showing that supplementation with IGP increased the abundance of Lactobacillus sp. (P < 0.01) in the ileum and reduced the population of Escherichia coli (P < 0.01) in the caecum of broilers. NextGen sequencing and beta-diversity analysis revealed significant differences between the IGP, CI200 and control groups (P < 0.05). Firmicutes and Bacteroidetes were the dominant phyla across all groups. In the IGP group, the relative abundance of Lactobacillaceae, Bacteroidaceae and Bacillaceae was higher compared to the other groups (P < 0.05), while the counts of Bacillaceae, Corynebacteriaceae and Erysipelatoclostridiaceae were increased compared to the IC200 group in all treatments. No significant difference in bacterial taxa was detected in the CPP group. The increased abundance of bacteria in the IC200 group resulted in significant improvements in chicken weight gain and FCR in this study.