Objective To analyze the differences in oral hygiene and oral microbiota between the patients with schizophrenia and healthy individuals in Baoshan City.Methods 26 patients with schizophrenia from Baoshan Third People's Hospital were selected as the SCZ group and 26 healthy individuals matched by age and BMI as the HC(Healthy control)group.Demographic data,physical indicators,and oral conditions were collected.Saliva samples from 52 subjects were collected and 16S rDNA gene sequencing was used to compare the differences in oral hygiene and oral microbiota between the patients with schizophrenia and the healthy individuals.Results The difference in oral microbial community richness between the SCZ group and the HC group was statistically significant(P<0.05),with the SCZ group containing higher species than the HC group;at the genus level,except for Fusobacterium in the SCZ group and Actinomyces in the HC group,the top 5 dominant bacterial species in both groups were consistent;the results of species difference analysis showed that Fusobacterium and Campylobacter in the SCZ group were higher than those in the HC group(P<0.05).Conclusion The partial dominant bacterial species in the oral cavity of the patients with schizophrenia have changed to sulfate-reducing bacteria that produce hydrogen sulfide.Excessive production of hydrogen sulfide or polysulfide may damage the energy metabolism of mitochondria.