CCL2 and obesity due to melanocortin 4 receptor deficiency: The use of Clostridium butyricum CGMCC0313.1, Lactobacillus plantarum NCIMB8821 and Clostridium butyricum resulted in a significant decrease in the MCP-1 levels, which led to improved metabolic dysfunction, prevention of obesity and improvement of obesity -related insulin resistance in animals [37, 39, 40].