It’s not uncommon to get a prescription for antibiotics when you’re dealing with an infection. But could the pills you’re taking make you gain weight? In a recent study at Emory University in Atlanta, researchers observed a link between intestinal bacteria and weight gain in lab mice. Researchers found that mice that were bred without a certain protein that regulates intestinal bacteria were heavier than the mice that did have the protein. The study's researchers point to antibiotics as one of the factors that could cause such changes in intestinal bacteria in humans, according to reports.