Fig. 8.

Gingipain knockout alleviates IR caused by P. gingivalis. Changes in fasting blood glucose (a) and fasting insulin (b) levels in mice orally administered P. gingivalis for 12 weeks (n = 6 in each group). Calculation of the HOMA-IR score (c) and ISI (d) based on fasting blood glucose and insulin measurements (n = 6 in each group). e Insulin tolerance test of mice orally administered P. gingivalis for 12 weeks (n = 6 at each time point). After oral feeding of P. gingivalis for 12 weeks, hyperinsulinaemic–euglycaemic clamping was performed, and the blood glucose levels (upper) and GIR (lower) were measured at different time points in the mice (f, n = 6 at each time point). The differences in blood glucose levels (g) and GIR (h) in the steady state were compared. *P < 0.05; **P < 0.01; ***P < 0.001; ns, no significance