INS and type 2 diabetes mellitus: However, Holman et al. (1987) demonstrated that in 29 T2DM non‐insulin‐dependent patients that took 15 g/day guar gum or placebo with main meals for 8 weeks, the supplement did not affect FPG, PPG, and HbA1c levels as well as basal or incremental plasma C‐peptide values (Holman et al., 1987).