Early Life Antibiotic Exposure and Weight Development in Children

OBJECTIVE: To examine the timing, frequency, and type of antibiotic exposure during the first 10 years of life in association with (over)weight across this period in a cohort of 979 children. STUDY DESIGN: Within the Child, Parents and Health: Lifestyle and Genetic Constitution Birth Cohort Study, antibiotic exposure record was obtained from general practitioners. Anthropometric outcomes (age- and sex-standardized body mass index, weight and height z-scores, and overweight) were measured repeatedly at 7 time points during the first 10 years of life. Generalized estimating equations method was used for statistical analysis. RESULTS: After adjusting for confounding factors, children exposed to one course of antibiotics compared with none in the first 6 months of life had increased weight- (adjusted generalized estimating equations estimates [adjβ] 0.24; 95% CI 0.03-0.44) and height (adjβ 0.23; 95% CI 0.0002-0.46) z-scores; exposure to ≥2 courses during the second year of life was associated with both increased weight (adjβ 0.34; 95% CI 0.07-0.60), and height z-scores (adjβ 0.29; 95% CI -0.003 to 0.59). Exposure later in life was not associated with anthropometric outcomes. Associations with weight z-scores were mainly driven by exposure to broad- (≥2 courses: adjβ 0.11; 95% CI 0.003-0.22) and narrow-spectrum β-lactams (1 course: adjβ 0.18; 95% CI 0.005-0.35) during the follow-up period. Specific antibiotic used was not associated with body mass index z-scores and overweight. CONCLUSIONS: Repeated exposure to antibiotics early in life, especially β-lactam agents, is associated with increased weight and height. If causality of obesity can be established in future studies, this further highlights the need for restrictive antibiotic use and avoidance of prescriptions when there is minimal clinical benefit

Gut Colonization by Methanogenic Archaea Is Associated with Organic Dairy Consumption in Children

The gut microbiota represents a complex and diverse ecosystem with a profound impact on human health, promoting immune maturation, and host metabolism as well as colonization resistance. Important members that have often been disregarded are the methanogenic archaea. Methanogenic archaea reduce hydrogen levels via the production of methane, thereby stimulating food fermentation by saccharolytic bacteria. On the other hand, colonization by archaea has been suggested to promote a number of gastrointestinal and metabolic diseases such as colorectal cancer, inflammatory bowel disease, and obesity. Archaea have been shown to be absent during infancy while omnipresent in school-aged children, suggesting that colonization may result from environmental exposure during childhood. The factors that determine the acquisition of methanogenic archaea, however, have remained undefined. Therefore, we aimed to explore determinants associated with the acquisition of the two main gastrointestinal archaeal species, Methanobrevibacter smithii and Methanosphaera stadtmanae, in children. Within the context of the KOALA Birth Cohort Study, fecal samples from 472 children aged 6–10 years were analyzed for the abundance of M. smithii and M. stadtmanae using qPCR. Environmental factors such as diet, lifestyle, hygiene, child rearing, and medication were recorded by repeated questionnaires. The relationship between these determinants and the presence and abundance of archaea was analyzed by logistic and linear regression respectively. Three hundred and sixty-nine out of the 472 children (78.2%) were colonized by M. smithii, and 39 out of the 472 children (8.3%) by M. stadtmanae. The consumption of organic yogurt (odds ratio: 4.25, CI95: 1.51; 11.95) and the consumption of organic milk (odds ratio: 5.58, CI95: 1.83; 17.01) were positively associated with the presence of M. smithii. We subsequently screened raw milk, processed milk, and yogurt samples for methanogens. We identified milk products as possible source for M. smithii, but not M. stadtmanae. In conclusion, M. smithii seems present in milk products and their consumption may determine archaeal gut colonization in children. For the first time, a large variety of determinants have been explored in association with gut colonization by methanogenic archaea. Although more information is needed to confirm and unravel the mechanisms in detail, it provides new insights on microbial colonization processes in early life

Gut Microbiota and Body Weight in School-Aged Children : The KOALA Birth Cohort Study

Objective: This study aimed to examine the intestinal microbiota composition of school-aged children in association with (over)weight. Methods: The fecal microbiota composition of 295 children was analyzed using the Human Intestinal Tract Chip. Anthropometric outcomes (overweight [BMI ≥ 85th percentile], age- and sex-standardized BMI and weight z scores) were measured at 6 to 7 years of age, and elastic net was used to select genus-like bacterial groups related to all anthropometric outcomes. Subsequently, multiple linear and logistic regression models were used to model associations between selected bacterial groups and anthropometric measures while controlling for confounders. Results: Prevotella melaninogenica, Prevotella oralis, Dialister, and uncultured Clostridiales II (UCII) accounted for 26.1% of the variation in microbiota composition. Several bacterial groups were inversely associated with the anthropometric outcomes: Sutterella wadsworthensis, Marvinbryantia formatexigens, Prevotella melanogenica, P oralis, Burkholderia, uncultured Clostridiales II, and Akkermansia, while Streptococcus bovis was positively associated with overweight. Microbial diversity and richness, and Bacteroidetes to Firmicutes ratio, were not significantly associated with any of the outcomes. Conclusions: In the largest population-based study on childhood gut microbiota and body weight so far, both new and previously identified bacterial groups were found to be associated with overweight. Further research should elucidate their role in energy metabolism.</p