Table 1.

Animal studies linking early-life antibiotic exposure to obesity risk.

Study	Model	Antibiotic Use and Age of Administration	Outcome
Cho et al. [81]	C57BL/6J mice	Subtherapeutic antibiotic therapy (STAT) (penicillin, vancomycin, a combination of the two, or chlortetracycline); weaning	Greater fat mass; increased Lachnospiraceae; increased fecal short-chain fatty acid (SCFA) concentrations
Cox et al. [113]	C57BL/6J mice	Low-dose penicillin; maternal during last week of gestation and during lactation	Male offspring accelerated early growth; greater fat mass as adults; reduced satiety hormone peptide tyrosine tyrosine (PYY); lower Lactobacillus; acceleration of normal age-related microbiota development
Klancic et al. [114]	Sprague–Dawley rats	Low-dose penicillin; maternal during last week of gestation and during lactation	Impaired post-partum weight loss in dams; lower Lactobacillus and higher Enterobacteriaceae in dams; higher body fat and liver triglycerides in offspring; lower Lactobacillus in offspring at weaning; impairments reversible with prebiotic oligofructose co-administration
Klancic et al. [115]	Sprague–Dawley rats	Pulsed therapeutic doses of azithromycin; postnatal days 19–21, 28–30, 37–39	Higher body weight in male and female offspring at 10 weeks of age; higher fat mass and insulin resistance in males; reduced Lactobacillaceae in males and females; prebiotic oligofructose co-administration corrected insulin resistance
Che et al. [116]	Piglets	Low-dose chlortetracycline and virginiamycin; post-weaning	Increased growth rate and food intake; enriched Methanosphaera species; enrichment in carbohydrate metabolism pathway
Schulfer et al. [117]	C57BL/6J mice	STAT penicillin G; maternal during pregnancy through to 4 weeks of age of pups	Co-housing unified microbiota within cages lowering weight of STAT mice relative to non-cohoused mice; co-housing could not attenuate impact of STAT once mice switched to a high fat diet
Nobel et al. [118]	C57BL/6J mice	Pulsed therapeutic doses of amoxicillin or tylosin; post-weaning	Early growth acceleration; tylosin increased hepatic steatosis; enrichment of genes for lipopolysaccharide synthesis
Morel et al. [119]	Sprague–Dawley rats	High dose amoxicillin; suckling period postnatal day 5 to 15	Transient increase in food intake, but no effect on body weight or fat mass
Mozes et al. [120]	Sprague–Dawley rats	Amoxicillinum trihydricum; maternal up to 15 days lactation and post-weaning from day 21 to day 40 in small and normal litter sizes	Small litters had increased weight gain, which was not influenced by antibiotic treatment; Lactobacillus decreased with antibiotic