Antibiotic whether or not antibiotics cause obesity in humans. Studies have found a correlation between early exposure of antibiotics (<6 months) and increased body mass (at 10 and 20 months). Another study found that the type of antibiotic exposure was also significant with the highest risk of being overweight in those given macrolides compared to penicillin and cephalosporin. Therefore, there is correlation between antibiotic exposure in early life and obesity in humans, but whether or not there is a causal relationship remains unclear. Although there is a correlation between antibiotic use in early life and obesity, the effect of antibiotics on
Antibiotic use in livestock antibiotic given to the livestock. Since the primary study, there have been many well-documented events showing that antibiotic usage in livestock results in direct influence of antibiotic resistance in humans. Major bacterial infections in humans can be traced back to livestock. The family Enterobacteriaceae includes many opportunistic bacteria, including "E. coli", which are commonly found in livestock. Other bacteria include "Klebsiella" and "Staphylococcus aureus". They cause infections in the urinary tract, digestive system, skin, and bloodstream, and account for a significant portion of antibiotic-resistant bacterial infections. The practice of using antibiotics for growth stimulation is problematic for these reasons: Donald