Changes in Weight Status and the Intestinal Microbiota Among College Freshman, Aged 18 Years

Purpose: The transition to college is a vulnerable period for weight gain and the onset of obesity. Gut microbes differ in obese compared with lean individuals, but gut microbiota in adolescent-aged college freshmen during a known period of weight gain have never been studied. This pre–post observational pilot study assessed associations between intestinal microbiota changes and weight-related outcomes in healthy adolescent college freshmen living in on-campus dormitories at Arizona State University (n = 39). Methods: We measured anthropometrics (waist circumference [WC], height, weight, and body mass index [BMI]) and collected fecal samples at the beginning and end of the 2015–2016 academic year. Fold changes in species-level microbes across time were measured by quantitative real-time polymerase chain reaction and used in correlation and multivariate regression analyses. Results: A total of 24 female and 15 male adolescents (aged 18.54 ± .67 years) participated in this study. Over the academic year, BMI and WC increased by .97±1.28 kg/m² and 2.64±4.90 cm, respectively. Correlation analyses indicated a significant negative association between Akkermansia muciniphila and both percentage WC change and percentage BMI change (r = −.66, p < .01; and r = −.33, p = .04, respectively). Multivariate regression analysis controlling for sociodemographics showed a significant association between A. muciniphila and percentage WC change, but not percentage BMI change (R² = .53, p < .01; and R² = .24, p = .15, respectively). Conclusions: As this was the first study in a university-based adolescent population to show a relationship between A. muciniphila and weight-related outcomes, further research is needed to explore these findings.