Antibiotics are commonly prescribed to children to treat various infections. Recent epidemiological studies revealed a strong link between early use of antibiotics and diseases in adulthood.
Antibiotic use during infancy induces imbalances in gut microbiota, called ‘dysbiosis’. This dysbiosis has been associated to infectious diseases, allergies and other autoimmune disorders, and even obesity, later in life.
In earlier studies, researchers also reported on how gut microbes are important for the production of serotonin (a brain chemical traditionally associated with regulation of emotions and behavior), and their imbalances in production outside the brain, that are also linked to diseases ranging from irritable bowel syndrome and cardiovascular disease, to osteoporosis. Thus, one could imagine how important these gut microbes are. In fact, the gut microbiome’s respond to antibiotics and their potential link to disease development are especially complex to study in the changing infant gut.
Other studies have shown profound short- and long-term effects of antibiotics on the diversity and composition of the bacteria in our bodies, called our microbiome.
In a recent study, led by Biomedical Informatics and Computational Biology program graduate student fellow Pajau Vangay, a predictive model with potential clinical importance for measuring healthy development of bacteria in the gut of young children has been developed. Their findings were published in the scientific journal Cell Host & Microbe titled ‘Antibiotics, Pediatric Dysbiosis, and Disease’.
“Diseases related to metabolism and the immune system are increasing dramatically, and in many cases we don’t know why,” said the study’s senior author Dan Knights, a computational biologist and assistant professor in the University of Minnesota’s Department of Computer Science and Engineering and Biotechnology Institute. “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.”
Prof. Knights and his colleagues developed a framework to map how antibiotics may be acting in the gut to cause disease later in life.
In the case of allergies, for example, the use of antibiotics may eradicate key gut bacteria that help immune cells mature. These cells would have been essential for keeping the immune system at bay when confronted with allergens. Even if these bacteria return, the immune system remains impaired. In the context of obesity, antibiotic-induced changes in the gut microbiota resulted in increased levels of short-chain fatty acids that affect metabolism.
Their study also examined the development of bacteria in the gut. Researchers demonstrated that an infant’s age could be predicted within 1.3 months based on the maturity of their gut bacteria. This finding could lead to a clinical test and interventions for children whose microbiome is developmentally delayed due to antibiotics or other factors.
Prof. Knights concludes: “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”. “The clinical test we demonstrated would also allow us to think about interventions at an early age.”
However, scientists recommend future studies into the microbiome-mediated effects of antibiotics focused on four types of dysbiosis: loss of keystone taxa, loss of diversity, shifts in metabolic capacity, and blooms of pathogens.