Ingestion of antibiotic-resistant (AR) bacteria may lead to transmission of AR genes in the gut microbiota and cause AR bacterial infection, a significant public health concern. However, it is not clear if and how microbes from the food matrix (food microbes) may influence resistance transmission. Thus, we assessed the colonization of a β-lactam resistant Salmonella Heidelberg strain (donor) and a β-lactam susceptible S. Typhimurium strain (recipient) and the transfer of the resistance genes in the mouse gut in the presence or absence of food microbes that were derived from washing freshly-harvested carrots. Mice were pre-treated with streptomycin and then inoculated with both donor and recipient bacteria in the presence or absence of food microbes. Donor, recipient and potential transconjugant bacteria were enumerated in fecal samples using selective culture techniques. Transfer of AR genes was confirmed by whole genome sequencing. Gut microbial composition was determined by 16s rRNA amplicon sequencing. Significantly lower numbers of donor and recipient were shed from mice that were inoculated with food microbes compared to those without food microbe inoculation. S. Typhimurium transconjugants were only recovered from mice without inoculation of food microbes. However, non-Salmonella transconjugatns, including Escherichia coli, Enterobacter, Citrobacter and Proteus were detected from mice with inoculation of food microbes. The results suggest that the food microbes may modulate AR gene transfer through changing the gut microbiome compositions.