Antibiotics for Children and Adults May Lead to Lifelong Obesity

Antibiotics have been associated with weight gain before, but new research indicates it may have the same effect on infants, too. Given that childhood obesity is linked to obesity later in life, prescribing antibiotics for children presents more problems for a nation already in the throes of an epidemic.

“We typically consider obesity an epidemic grounded in unhealthy diet and [lack of] exercise, yet increasingly studies suggest it’s more complicated,” says Dr. Leonardo Trasande from the New York School of Medicine.

Antibiotics for Children and Adults Kill All Bacteria, Good and Bad

Traditional physicians typically prescribe antibiotics to kill harmful bacteria. But one side effect is the annihilation of beneficial bacteria in the gut. In addition to regulating gut health, these “good” bacteria affect the entire body, as evidenced in researcher Stephen Collins’ findings. The attack on this beneficial bacteria has even been shown to lead to mental illness, as beneficial bacteria are key in maintaining a healthy mental state.

“It may be that those changes in gut bacteria not only contribute to the generation of gut symptoms, like diarrhea or pain, but may also contribute to this altered behavior that we see in those patients,” including depression and anxiety.

“Microbes in our intestines may play critical roles in how we absorb calories,” says Dr. Trasande. “Exposure to antibiotics, especially early in life, may kill off healthy bacteria that influence how we absorb nutrients into our bodies, and would otherwise keep us lean.”

Microbiologist Cormac Gahan from University College Cork says gut bacteria could affect weight by affecting “energy extraction” and hormones.

Antibiotics for Children: Infant Obesity may Lead to Adult Obesity

In Dr. Trasande’s study, the killing off of good bacteria was likely the cause of the weight gain in studied infants. Among 11,532 children born at 2500 g in the Avon Longitudinal Study of Parents and Children (ALSPAC), administered antibiotics for children between birth and 5 months of age resulted in weight gain between the age of 10 and 20 months. They were 22 percent more likely to be overweight at age 38 months.

Antibiotics don’t just affect a baby’s weight, however. According to research involving over 44,000 infants, Dr. Taveras (co-director of the One Step Ahead clinic) determined that babies overweight by the age of 2 were more likely to be obese by age 5 or 10. Another study published in Preventative Medicine reviewed epidemiologic literature published between 190 and 1992 and determined that:

• About a third (26 to 41 percent) of obese preschoolers were obese as adults.
• About half (42 to 63 percent) of obese school-aged children were obese as adults.

Gahan says the research is in its early stages and will continue.