Table 2.
Human studies linking early-life antibiotic exposure to obesity risk.
| Study | Participants/Subjects | Antibiotic Use and Age of Administration | Outcome |
|---|---|---|---|
| Zhang et al. [121] | 454 mother-offspring dyads from Southeastern USA; singleton infants born ≥28 weeks gestation with no congenital abnormalities | Beta-lactam antibacterials, penicillins; other beta-lactam antibacterials; sulfonamides and trimethoprim; macrolides, lincosamides, streptogramins; aminoglycoside antibacterials; and other antibacterials; maternal antibiotic use in 1st, 2nd, 3rd trimester and 1st year after delivery; and infant antibiotic use in first year of life | Second trimester antibiotic exposure associated with higher weight-for-length score at 12 months; 13 bacterial amplicon sequence variants (ASVs) at 3 months, and 17 ASVs at 12 months varied between control and antibiotic exposed |
| Chen et al. [122] | 1172 Mother-offspring dyads from Singapore cohort of Chinese, Malay or Indian ethnicity; singleton infants | Antibiotic type not investigated; infant antibiotic exposure in the first year of life | Elevated risk of childhood obesity for any antibiotic exposure; higher body mass index (BMI) z-score in boys but not girls; reduced Eubacterium hallii; higher Tyzzerella 4 was positively correlated with childhood adiposity and repeated antibiotic use |
| Korpela et al. [123] | 162 vaginally born Dutch and Finnish children | Antibiotic type not investigated; lifetime antibiotic use to 5–6 years of age | After several courses of antibiotics low relative abundance of Actinobacteria and high relative abundance of Firmicutes at 3 months of age associated with high BMI at 5–6 years |
| Korpela et al. [124] | 236 Finnish children aged 2–7 years | Penicillin; macrolides; lifetime antibiotic use | Macrolides use decreased Actinobacteria and increased Bacteroidetes and Proteobacteria; long-term reduction in microbial richness with macrolide use; >2 courses of macrolides in first 2 years of life strongly correlated with childhood BMI |
| Korpela et al. [125] | 226 Finnish children aged 2–6 years | Penicillin-type antibiotics; lifetime antibiotic use | Breastfeeding duration negatively associated with BMI z-score in children with no early-life antibiotic use; with early-life antibiotics the duration of breastfeeding was no longer associated with BMI z-score; early-life antibiotic use associated with reduced Bifidobacterium abundance |
| Tun et al. [126] | 757 infants from Canadian cohort; singleton birth at ≥35 weeks of gestation with a birth weight of ≥2500 g | Cleaning product use but also maternal intrapartum antibiotic prophylaxis; infant antibiotic treatment by 3 months | Prevalence of overweight at 3 years higher after intrapartum antibiotic prophylaxis and infant antibiotic treatment; higher Lachnospiraceae abundance in infancy increased odds of overweight at 3 years of age |