Antibiotics could contribute to weight gain according to researchers and two specifically targeted studies conducted using rodents and livestock for comparison purposes to study the body’s response to antibiotic exposure. Reports claim that changes in the bacteria within the gut could provide a precursor to fat build-up (adipose tissue), and these altered bacteria might explain how antibiotics fatten livestock, as well as people, if exposed early and often in life. Moreover, the mutated bacteria could help explain how certain genes predispose organisms to obesity.
The first study, which was published in the International Journal of Obesity on August 21, 2012, found that infants treated with antibiotics before 6 months of age were 22 percent more likely to be overweight by age 3. The study yielded evidence that an alarming number of 11,000 kids in the United Kingdom, who were overweight by the time they were 3 years old, had taken antibiotics within their first six months of life.
Another study that addresses the contention that antibiotics could contribute to weight gain was published in Nature magazine on August 22, 2012. During the study, researchers replicated the process used by farmers for decades to fatten up their livestock–they exposed young mice to a steady low dose of antibiotics. The results of the study suggest that antibiotics altered the composition of bacteria in the guts of the mice and also changed how the bacteria broke down nutrients. Moreover, these changes in the gut composition and processing of nutrients resulted in increased body mass index (BMI) of the subjects. Meaning these mutations lead to a higher fat mass among the antibiotic-treated mice by activated genes that convert carbohydrates into fatty acids. As a result, the genes related to lipid conversion in the liver are triggered. Ultimately, these mutations in the molecular pathway trigger fat build-up. The end result being just as livestock is fatten, the antibiotic-fed mice put on weight, and theoretically so would humans.
Both of these studies that suggest a link between antibiotic use and weight gain were authored by the same researcher, Dr. Martin Blaser, who is a microbiologist at New York University in New York. He claims parents could be unintentionally setting the wheels in motion to alter their children’s gut microbiome (gut bacteria composition) by treating common ailments and ear infections with antibiotics early in life and potentially making them susceptible to obesity in the future. These reports also indicate the overall importance of the gut’s microbiome role in an organism’s health and development of disease. Additionally, the findings suggest the potential consequences to the health of an organism when its gut composition is altered. Moreover, the findings re-emphasize the importance of avoiding the abuse of antibiotics, which has also been linked to antibiotic-resistance and the development of superbugs (drug-resistant bacteria). An example of a well-known superbug would include the virulent methicillin-resistant Staphylococcus aureus, which is more commonly known as MRSA.
Furthermore, antibiotic overuse could not only contribute to weight gain, but has also yielded possible links to other body system disturbances, such as allergies, acid reflux, irritable bowel syndrome (IBS), and asthma. However, the researchers are quick to clarify that while early antibiotic use might present as a much larger factor than anticipated into the incidences of obesity, it is far from the only contributor. Obesity is caused by a combination of factors including poor diet, lack of exercise, genetics, and other health conditions that can restrict mobility and compromise proper bodily functions. Many experts hope the findings of these studies can be replicated on a larger scale and feel the study is a massive step forward in understanding the relationship between antibiotics and obesity. Moreover, they feel the study should encourage people to re-evaluate some of their preconceived notions about obesity.
By Leigh Haugh