The effect of oral l-arginine alone or in combination with sodium butyrate on glucagon-like peptide-1 secretion in non-diabetic adults with obesity

Background: L-arginine and sodium butyrate may improve glycemic control and reduce appetite by increasing glucagon-like peptide-1 (GLP-1) secretion. This warrants further investigation in individuals with obesity. Aims: This study aimed to examine the effects of oral L-arginine, alone and with sodium butyrate, on circulating levels of GLP-1 and glucose, and subsequent appetite, in adults with obesity. Methods: Seven adults (5 females and 2 males) with obesity participated in the study. Each participant underwent three different interventions at 2-week intervals following consumption of a standard meal (Ensure^® 250 mL): 1) no intervention, 2) oral L-arginine administered 60 min before the meal, and 3) a combination of oral L-arginine and sodium butyrate administered 60 min before the meal. Blood samples for GLP-1 and glucose were collected, and hunger and fullness were assessed using visual analog scales over a 165-min period. Statistical analysis was performed using Friedman test for repeated measures. Wilcoxon signed-rank tests with Bonferroni correction were used for pairwise comparisons. Results: Oral L-arginine combined with sodium butyrate significantly increased the area under the curve of plasma GLP-1 (AUC_GLP−1) compared to no intervention (p = 0.0156). L-arginine alone showed a trend towards increased AUC_GLP−1 compared to no intervention (p = 0.031). No significant differences in glucose levels were observed between interventions. Neither intervention affected subjective satiety measures. Conclusion: Oral L-arginine and sodium butyrate increased circulating GLP-1 levels in adults with obesity. L-arginine alone showed a similar trend.