Antibiotic resistance has re-emerged as a critical problem of contemporary medicine. I will discuss the biological processes contributing to the spread of antibiotic resistance. In this talk, I will ask how microbial growth is linked to the spread of antibiotic resistance. Recent work on gut colonization by the enteropathogenic bacterium Salmonella Typhimurium and other Enterobacteriaceae implicates carbohydrates. These nutrients are available at micromolar to low millimolar concentrations in the gut lumen and fuel enterobacteriaceal growth via mixed acid fermentation, anaerobic or microaerophilic respiration. I will discuss how this gut-luminal growth strategy may promote the emergence of new antibiotic-resistant strains.