Leuconostoc, Streptococcus, Abiotrophia, and Prevotella were decreased in the cancer group, while Haemophilus and Neisseria were increased. Total SCFA and FFAR2 expression levels were higher in the control group, while TNFAIP8, IL6, and STAT3 levels were higher in the cancer group. This evidence concerns the gene FFAR2 and cancer.