Background　Postoperative　nausea　and　vomiting　(PONV)　is　a　common　complication　following　surgery.　Despite　various　preventive　measures,　satisfactory　outcomes　have　not　been　achieved.　This　study　explores　the　potential　of　gut　microbiota　interactions　with　the　host　in　understanding　and　preventing　PONV,　using　16S　absolute　quantitative　sequencing　technology　to　uncover　new　insights.Methods　Patients　who　experienced　nausea　and　vomiting　within　24　h　after　surgery　were　divided　into　a　PONV　group　(n　=　22)　and　a　non-PONV　group　(n　=　22).　Microbial　communities　linked　to　PONV　were　assessed　through　bioinformatics　analysis.　Fecal　samples　from　both　groups　were　transplanted　into　rats,　which　were　then　anesthetized　with　isoflurane　for　100　min.　Pica　behavior　was　monitored　over　the　next　24　h　to　assess　nausea　and　vomiting　in　the　rats.Results　Significant　differences　in　alpha-　and　beta-diversity　were　observed　between　the　PONV　and　non-PONV　groups.　Six　key　microorganisms　were　identified,　with　Bifidobacterium,　Bilophila,　and　Oscillibacter　showing　a　negative　correlation　with　PONV　severity.　Receiver　operating　characteristic　(ROC)　analysis　demonstrated　that　Bifidobacterium　could　reliably　predict　PONV.　Rats　receiving　feces　from　the　PONV　group　exhibited　significantly　higher　kaolin　consumption　within　24　h　post-anesthesia　compared　to　those　receiving　feces　from　the　non-PONV　group.Conclusion　These　results　suggest　a　potential　new　mechanism　for　PONV　involving　gut　microbiota,　offering　a　theoretical　basis　for　preoperative　prediction　of　PONV　based　on　gut　microbial　composition.