Preventive and Ameliorative Effects of Alanine Supplementation on High-Fat Diet–Induced Obesity and Metabolic Dysfunction via the Gut–Liver–Adipose Axis in C57BL/6J Mice

TL;DR

Alanine helps prevent and reduce obesity and related metabolic issues in mice by affecting the gut, liver, and fat tissues.

Contribution

Alanine's preventive and therapeutic effects on obesity are demonstrated through the gut–liver–adipose axis in mice.

Findings

Alanine reduced weight gain and improved blood markers in mice on a high-fat diet.

Alanine lowered fat tissue mass and improved glucose tolerance in obese mice.

Changes in specific gut bacteria may indicate Alanine's role in preventing obesity.

Abstract

The present study aimed to investigate the role of alanine (Ala) in regulating obesity and glucose homeostasis in C57BL/6J mice. Two independent experiments were conducted: a preventive model (Experiment 1: 10 weeks of concurrent high-fat diet (HFD) and Ala administration) and a therapeutic model (Experiment 2: 10 weeks of Ala treatment following a 10-week HFD-induced obesity period). In Experiment 1, Ala significantly attenuated HFD-induced weight gain (35.16 g vs. 30.82 g, p < 0.001), improved serum biochemistry profiles, and downregulated the expression of inflammatory proteins (p < 0.05). In Experiment 2, Ala administration reduced white adipose tissue (WAT) mass (1.82 g vs. 1.15 g, p < 0.001) and improved glucose tolerance (p < 0.05). The above benefits were validated by experimental analysis. Microbiota analysis from Experiment 1 suggested that changes in the relative abundance of Acinetobacter, Lachnospiraceae_NK4A136_group, and Haemophilus could serve as a potential indicator of species associated with obesity prevention. Taken together, the above findings suggest that Ala has the potential to prevent and treat obesity through the gut–liver–adipose axis.

Figures