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 studies looking into the effects of antibiotics during infancy, such as those given to patients with recurring ear infections, found that these therapies increased the risk of higher fat accumulation and obesity later in life. At that time, researchers thought the microbiome matured in the first few years of life; however, recent investigations have determined that the gut microbiome continues to develop into a stable state throughout adolescence.
So how does antibiotic use influence fat accumulation during adolescence?
To answer that question, Carson and Novince administered a clinically relevant dose of minocycline to mice during pubertal/postpubertal growth – the equivalent age of adolescence in humans. They found that the minocycline treatment caused a significant change in the gut microbiome. Furthermore, minocycline treatment altered liver 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.
