On the other hand, the predominance of gram-negative bacteria as a result of dysbiosis in obesity could alter the protein structure of the intestinal cell junctions, increasing the permeability of the intestinal surface as well as bacterial lipopolysaccharides (LPS) absorption leading to pro-inflammatory cytokines such as IL-6, tumour necrosis factor-alpha and C-reactive protein release, increasing the inflammatory process during obesity development [75]. This evidence concerns the gene CRP and obesity due to melanocortin 4 receptor deficiency.