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Antibiotic Prophylaxis and Weight Gain in Infants

JAMA Pediatr; ePub 2016 Dec 27; Edmonson, et al

Publish date:

Prolonged antibiotic prophylaxis with trimethoprim-sulfamethoxazole does not have a concurrent effect on weight gain or the prevalence of overweight or obesity in healthy infants and young children, a recent study found. This secondary analysis of data from the Randomized Intervention for Children with Vesicoureteral Reflux Study from 2007 to 2011 included 607 children (median age 12 months; 92% female) randomized to receive trimethoprim-sulfamethoxazole (n=302) or placebo (n=305), once daily, for 2 years. Researchers found:

  • Weight gain in the trimethoprim-sulfamethoxazole group and the placebo group was similar.
  • There was no significant difference in weight gain at 6, 12, or 18 months or in the prevalence of overweight or obesity at 24 months (24.8% vs 25.7%).
  • In subgroup analysis, there was no significant interaction between weight gain effect and age, sex, history of breastfeeding, prior antibiotic use, adherence to study medication, or development of urinary tract infection.

Citation:

Edmonson MB, Eickhoff JC. Weight gain and obesity in infants and young children exposed to prolonged antibiotic prophylaxis. [Published online ahead of print December 27, 2016]. JAMA Pediatr. doi:10.1001/jamapediatrics.2016.3349.

Commentary:

The relationship between antibiotic use and obesity is currently an area of intense scrutiny. It is well described that antibiotic administration can promote weight gain in young animals, and so antibiotics are often given to livestock.1 In humans, antibiotic use has been associated with weight gain in children with cystic fibrosis, HIV, and underweight children in developing countries.2 Studies in healthy children have not been consistent, though some suggest that early exposure to antibiotics leads to increased weight gain over both short and longer periods of time. In fact, one study showed that exposure to antibiotics in the first year of life was associated with an increased risk of overweight and central adiposity in preadolescence.3 These effects may be mediated through changes in the microbiome in the gut, promoting less efficient use of calories ingested. The current study does not support the hypothesis that antibiotics promote obesity in humans. It should be noted that the study has important limitations, including the examination of the effect of only 1 antibiotic and follow-up for a relatively short period of time, so one can’t draw too firm or broad of a conclusion from this study. That said, the potential for increasing obesity is another reason, along with antibiotic resistance, to be thoughtful in our decisions about when to use antibiotics. —Neil Skolnik, MD

  1. Gaskins HR, Collier CT, Anderson DB. Antibiotics as growth promotants: mode of action. Anim Biotechnol. 2002;13(1):29-42.

  2. Prendergast A, Walker AS, Mulenga V, Chintu C, Gibb DM. Improved growth and anemia in HIV-infected African children taking cotrimoxazole prophylaxis. Clin Infect Dis. 2011;52(7):953-956.

  3. Azad MB, Bridgman SL, Becker AB, Kozyrskyj AL. Infant antibiotic exposure and the development of childhood overweight and central adiposity. Int J Obes (Lond). 2014;38(10):1290-1298.

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