{Reference Type}: Journal Article {Title}: A New Alternative Nutritional Source Hawthorn Vinegar: How It Interacts with Protein, Glucose and GLP-1. {Author}: Seyidoglu N;Karakçı D;Ergin Eğritağ H;Yıkmış S; {Journal}: Nutrients {Volume}: 16 {Issue}: 13 {Year}: 2024 Jul 8 {Factor}: 6.706 {DOI}: 10.3390/nu16132163 {Abstract}: (1) Background: There is a balance between nutrition, glycemic control, and immune response. Their roles in physiological mechanisms are essential for maintaining life quality. This study aimed to evaluate hawthorn vinegar's metabolic effects, and describe its possible mechanism. We also pointed out several vinegar production methods to clarify the antioxidant features. (2) Methods: In the study, three vinegar techniques were applied to vinegar: traditional production of hawthorn vinegar (N), thermal pasteurization (P), and ultrasound method (U). Thirty-two female adult Wistar albino rats were randomly separated into four groups: Control, N1 (regular vinegar; 1 mL/kg bw), P1 (pasteurized vinegar; 1 mL/kg bw), and U1(ultrasound treated vinegar; 1 mL/kg bw). Vinegar was administered by oral gavage daily for 45 days. Initial and final weights, the percentage changes of body weight gains, and Gamma-Glutamyl Transferase (GGT) values of plasma and liver were measured. The total protein, globulin, and albumin values of plasma, liver, and intestinal tissue were determined. In addition, plasma glucagon-like peptide-1 (GLP-1) and glucose concentrations were evaluated. (3) Results: There was a statistical increase in total intestinal protein value and an increasing tendency in total protein in plasma and liver in group U1 compared to group Control. However, the GGT concentrations in plasma and liver were slightly lower in group U1 than in group Control. In addition, there were significant increases in plasma GLP-1 values in all experimental groups compared to the Control group (p: 0.015; 576.80 ± 56.06, 773.10 ± 28.92, 700.70 ± 17.05 and 735.00 ± 40.70; respectively groups control, N1, P1, and U1). Also, liver GLP-1 concentrations in groups P1 and U1 were higher than in group Control (p: 0.005; 968.00 ± 25.54, 1176 ± 17.54 and 1174.00 ± 44.06, respectively groups control, P1 and U1). On the other hand, significant decreases were found in plasma glucose concentrations in groups N1 and U1 as to the Control group (p: 0.02; Control: 189.90 ± 15.22, N1: 133.10 ± 7.32 and U1: 142.30 ± 4.14). Besides, liver glucose levels were lower in all experimental groups than in group Control statistically (p: 0.010; 53.47 ± 0.97, 37.99 ± 1.46, 44.52 ± 4.05 and 44.57 ± 2.39, respectively groups control, N1, P1, and U1). (4) Conclusions: The findings suggest that hawthorn vinegar can balance normal physiological conditions via intestinal health, protein profiles, and glycemic control. Additionally, ultrasound application of vinegar may improve the ability of hawthorn vinegar, and have positive effects on general health.