Table 2: Linear regression analyses with the SCFA one at a time as the dependent variable and starch, nonnutritive sweeteners, metformin, gender (not shown), and age (not shown) as simultaneous independent variables.

Dependent variableStarch#Nonnutritive sweetenersMetformin
B (95% CI) valuePartial corr.B (95% CI) valuePartial corr.B (95% CI) valuePartial corr.

Total SCFA0.108 (0.009, 0.206)0.0320.232−0.488 (−0.986, 0.009)0.054−0.21011.1 (1.9, 24.0)0.090.184
Acetic acid0.057 (0.008, 0.106)0.0240.244−0.207 (−0.455, 0.042)0.102−0.1795.3 (−1.1, 11.8)0.1060.177
Propionic acid0.017 (−0.002, 0.036)0.0840.189−0.066 (−0.164, 0.032)0.183−0.1462.1 (−0.4, 4.7)0.1040.178
Isobutyric acid0.001 (−0.002, 0.004)0.5030.074−0.011 (−0.026, 0.004)0.139−0.1620.4 (0.0, 0.8)0.0450.218
Butyric acid0.030 (0.006, 0.054)0.0150.264−0.159 (−0.280, −0.037)0.011−0.2742.1 (−1.1, 5.2)0.2000.140
Isovaleric acid0.001 (−0.003, 0.006)0.5290.069−0.016 (−0.038, 0.007)0.170−0.1500.6 (0.0, 1.2)0.0460.217
Valeric acid0.001 (−0.003, 0.005)0.6030.057−0.022 (−0.043, −0.002)0.029−0.2370.5 (−0.02, 1.0)0.0610.204
Isocapronic acid0.000 (0.000, 0.000)0.7460.0360.000 (0.000, 0.000)0.4380.0850.01 (0.00, 0.02)0.0020.327
Capronic acid0.000 (−0.002, 0.003)0.8190.025−0.008 (−0.020, 0.004)0.205−0.1390.11 (−0.22, 0.43)0.5130.072
Index A0.000 (−0.001, 0.000)0.705−0.0420.001 (−0.001, 0.004)0.2510.1260.005 (−0.06, 0.07)0.8730.018
Index B0.002 (−0.005, 0.010)0.5170.071−0.027 (−0.063, 0.010)0.156−0.1550.98 (0.02, 1.95)0.0450.218

False discovery rate-adjusted q values for butyric and valeric acids were 0.088 and 0.116, respectively. #Fibre and starch were significantly correlated (Pearson’s r = 0.60, ). Since fibre was not significantly associated with either butyric acid or valeric acid, starch was used in the analyses.