BackgroundIndividuals with type 2diabetes mellitus (T2DM) commonly present with gastro intestinal symptoms. Exact pathophysiology behind these symptoms is not elucidated. Previous studies reported the role of adrenoceptors on gut motility. However, no study has been conducted to observe whether adrenergic beta receptor (ADRB) 2 and 3 gene polymorphism could influence the gut motility in T2DM. Materials and Methods:Three hundred T2DM patients and 200 age and sex matched healthy controls were enrolled for this study. Participants were subjected to lactulose hydrogen breath test for estimation of orocecal transit time (OCTT). To carry out polymorphism study, buffy coat of EDTA blood was used for DNA isolation followed by polymerase chain reaction and restriction fragment length polymorphism. Results:In this study, the frequency of C allele as well as CC genotype of ADRB3 gene polymorphism and A allele as well as AA genotype of ADRB2 gene polymorphism were significantly higher in patients than controls and was associated with increased risk for T2DM. On comparison of gut motility, OCTT was found to be significantly prolonged (p<0.01) in individuals with CC genotype compared to TT or CT genotype in ADRB3 polymorphism and AA genotype, compared to AG and GG genotype in case of ADRB2 polymorphism. Combined effect of both adrenoceptors on gut motility revealed that individuals having AG or AA genotype in combination with other genotypes had significantly prolonged OCTT. Conclusion:It could be concluded that beta adrenoceptor gene polymorphism has significant role on regulation of gut motility in T2DM.