A study published in Cell Host & Microbe suggests that the imbalances caused by antibiotic use in infancy could potentially lead to diseases later in life. The researchers have established a three-way link: 

• Unnecessary antibiotic use in infants.
• Use of antibiotics leading to the imbalance in the gut microbial population (dysbiosis).
• Dysbiosis leading to diseases later in life.

The microbial population in the gut, collectively called the gut microbiome, plays a crucial role in the general wellbeing of an individual. DoveMed has previously reported on the importance of the microbiome not only in aiding digestion, but also in regulating memory, mood, learning, etc. (Gut Feeling: A Scientific Basis?). The human gut is often referred to as the “second brain” and possesses its own nervous system. 

The microbes in the gut are intricately balanced and live in harmony. A single bacterial species could potentially upset or restore balance. In mice, disturbing the microbiome harmony has been shown to impact aggressive behavior. An imbalance in the gut microbiome could be caused by a variety of reasons such as aging, diet, environmental factors, and antibiotic use.

Antibiotics are the most prescribed medication for children and account for one-fourth of all their medications. There is a general belief that antibiotics are over-prescribed and that a third of the prescriptions are unnecessary. 

In the study being reported here, Dan Knights, the senior author of the research article and a computational biologist and assistant professor in the University of Minnesota’s Department of Computer Science and Engineering and Biotechnology Institute, and colleagues developed a framework to understand the effect of antibiotic use in infancy on the development of diseases and conditions like allergies, asthma, autoimmune disorders, infectious diseases, diabetes, and even obesity, later in life.

“Diseases related to metabolism and the immune system are increasing dramatically, and in many cases we don’t know why,” said Dan Knights (according to the University of Minnesota’s website). He continues, “Previous studies showed links between antibiotic use and unbalanced gut bacteria and others showed links between unbalanced gut bacteria and adult disease. Over the past year, we synthesized hundreds of studies and found evidence of strong correlations between antibiotic use, changes in gut bacteria, and disease in adulthood.”

Studies have shown that the gut microbiome begins to get established “in-utero” and continues after birth. Dynamic changes take place in the microbial population as the system matures in a baby. The research group in the current study has further established that the age of an infant could be predicted within 1.3 months based on the maturity of the gut bacterial population. This finding could lead to tests designed to correlate an infant’s age with his/her gut microbiome maturity, which may be out-of-balance owing to the use of antibiotics and, therefore, medical interventions to restore balance.

“We think these findings help develop a roadmap for future research to determine the health consequences of antibiotic use and for recommendations for prescribing them,” Knights said. “The clinical test we demonstrated would also allow us to think about interventions at an early age.”

Written by Mangala Sarkar Ph.D.