A new animal research study recently published ahead of print in Environmental Pollution tested the effect of erythromycin on fat accumulation in the nematode, C. elegans. The study found that exposure to erythromycin increased the percentage of fat content and over-eating in C. elegans.

In human epidemiological research, multiple studies have demonstrated an association between early exposure to antibiotics and childhood obesity. However, a study published in 2020 in JAMA Network Open that restricted its participants to siblings and twins failed to show an association between early antibiotic exposure and childhood obesity. The association seen in other studies may be due to unmeasured factors such as a family tendency for obesity and not due to antibiotics.

Luo Z, Yu Z, Yin D. Obesogenic effect of erythromycin on Caenorhabditis elegans through over-eating and lipid metabolism disturbances. Environmental Pollution. Volume 294, 2022, 118615, ISSN 0269-7491.

Azad MB, Owora A. Is Early-Life Antibiotic Exposure Associated With Obesity in Children? JAMA Netw Open. 2020;3(1):e1919694. doi:10.1001/jamanetworkopen.2019.19694

Leong  KSW, McLay  J, Derraik  JGB,  et al. Associations of prenatal and childhood antibiotic exposure with obesity at age 4 years.  JAMA Netw Open. 2020;3(1):e1919681. doi:10.1001/jamanetworkopen.2019.19681