Association between small intestinal bacterial overgrowth and beta-cell function of type 2 diabetes

J Int Med Res. 2020 Jul;48(7):300060520937866. doi: 10.1177/0300060520937866.


Aims: Previous studies suggest that small intestinal bacterial overgrowth (SIBO) is associated with type 2 diabetes. However, few studies have evaluated the association between SIBO and beta-cell function in type 2 diabetes. The aim of this study was to evaluate whether beta-cell function was associated with SIBO.

Materials and methods: One hundred four patients with type 2 diabetes were included in this study. Based on the presence of SIBO, the patients were divided into SIBO-positive and SIBO-negative groups. Oral glucose tolerance tests were performed. Insulin sensitivity was measured using 1/homeostasis model assessment of insulin resistance (1/HOMA-IR) and the insulin sensitivity index (ISIM). Insulin release was calculated by HOMA-β, early-phase insulin secretion index InsAUC30/GluAUC30, and total-phase insulin secretion index InsAUC120/GluAUC120.

Results: Compared with the SIBO-negative group, patients in the SIBO-positive group showed a higher glucose level at 120 minutes, HbA1c, 1/HOMA-IR, and ISIM and a lower HOMA-β level, early-phase InsAUC30/GluAUC30, and total-phase InsAUC120/GluAUC120. Multiple linear regression analysis showed that body mass index, glucose at 0 minutes, and SIBO were independently associated with the early-phase and total-phase insulin secretion.

Conclusion: SIBO may be involved in lower levels of insulin release and worse glycemic control.

Keywords: Type 2 diabetes; beta-cell function; glucose; glycemic control; insulin release; small intestinal bacterial overgrowth.

MeSH terms

  • Diabetes Mellitus, Type 2*
  • Glucose Tolerance Test
  • Humans
  • Insulin / metabolism
  • Insulin Resistance*
  • Insulin Secretion


  • Insulin