A rising corpus of research is demonstrating how the healthy gut microbiome, a group of microorganisms that coexist in the gut, affects various aspects of adolescent development. While there are several physiologic changes occurring at this time, the most obvious and occasionally upsetting one is the appearance of acne.
The majority of people treat their acne with topical medications, however about 25% of teenagers need systemic antibiotics like minocycline to help with symptom relief and skin clearing. These systemic antibiotic therapies frequently need for prolonged usage, perhaps for as long as two years. It’s significant because the implications of such prolonged antibiotic treatment during adolescence are unknown.
In a study that was published online on March 9 in The American Journal of Pathology, scientists from the Medical University of South Carolina (MUSC) demonstrate how the gut microbiome’s composition affects the development of adiposity, or the deposition of central (abdominal) fat. Long-term antibiotic therapy during adolescence disrupted the microbiome, which then dysregulated the expression of genes involved in lipid metabolism in the liver, leading to an increase in the deposition of fat. It’s interesting to note that the fat accumulated after the antibiotic treatment was terminated.
The first author of this study and a graduate student in the Novince lab studying the effects of disruption of the gut microbiome on host physiology, Matthew Carson, summarized that prolonged antibiotic exposure during adolescence can have long-lasting negative effects on liver metabolism and encourage adiposity.Early research examining the effects of antibiotics during infancy, such as those administered to children with recurrent ear infections, discovered that these treatments raised the likelihood of higher fat accumulation and obesity later in life. Researchers at the time believed that the gut microbiota reached maturity in the first few years of life, but more recent studies have shown that this process continues throughout adolescence and results in a stable gut microbiome.
What effect does antibiotic use have on adolescent fat storage then?
In order to find out, Carson and Novince gave mice throughout pubertal/postpubertal growth—the age that corresponds to adolescence in humans—a clinically appropriate dose of the antibiotic minocycline. They discovered that the therapy with minocycline significantly altered the gut microbiome. Moreover, treatment with minocycline changed the liver’s metabolism,showing a particular dysregulation in the expression of genes involved in fatty acid and cholesterol metabolism. These changes resulted in a four-times greater increase in fatty tissue.