BACKGROUNDBacteroides spp. are frequently detected in anaerobic infections, with a mortality rate of 50 % attributed to inadequate antimicrobial therapy. Recently, Bacteroides spp. have shown increased resistance to metronidazole (MNZ) and carbapenems. Therefore, identifying appropriate drugs for treating infections caused by Bacteroides spp. is necessary. Hence, this meta-analysis aimed to compare the clinical efficacy of combination therapy with MNZ versus carbapenems for the treatment of infections due to Bacteroides spp.METHODSScopus, EMBASE, PubMed, CINAHL, and Ichushi databases were searched for relevant articles that met the inclusion criteria through October 2024. Clinical efficacy was defined as the percentage of patients who achieved complete resolution or remarkable improvement in all signs and symptoms of the infection; therefore, no additional antibiotics or procedures were necessary, and the percentage of eradication of Bacteroides spp.RESULTSOf the 482 citations identified for screening, five studies with a total of 306 patients were enrolled. All included studies were randomized clinical trials, two were open-label studies, and three were double-blind studies. All the included patients had intra-abdominal infections (IAIs). The combined therapy with MNZ was comparable with the carbapenem group in clinical efficacy in the treatment of infections due to Bacteroides spp. (risk rate 1.03, 95 % confidence interval 0.93-1.14).CONCLUSIONSCombined therapy with MNZ could be an effective treatment option for infections caused by Bacteroides spp., similar to carbapenems.