Subsequently, qRT-PCR results showed that H. pylori Cag A + infection combined with HFD significantly increased the expression levels of sterol regulatory element binding transcription factor 1 (Srebf1), fibroblast growth factor 21(Fgf21), the critical factors of lipid metabolism, Il-1β, and Tnf-α in the liver (Fig. 7A-D). Here, TNF is linked to infection.