Zwittink RD, et al. - This study was designed to ascertain the effect of short and long intravenous antibiotic administration on intestinal microbiota development in preterm infants. Observations revealed a great impact of intravenous antibiotic administration during the first postnatal week on the infant’s gastrointestinal microbiota. However, quick cessation of antibiotic treatment allowed for its recovery. Short and, more extensively, long antibiotic treatment caused disturbances in microbiota development that could affect healthy development of the infant via interference with maturation of the immune system and gastrointestinal tract.

Methods

• Researchers collected faecal samples from 15 preterm infants (35 ± 1 weeks gestation and 2871 ± 260 g birth weight) exposed to no, short (≤ 3 days) or long (≥ 5 days) treatment with amoxicillin/ceftazidime during the first six postnatal weeks.
• Determination of microbiota composition was performed via 16S rRNA gene sequencing and by quantitative polymerase chain reaction (qPCR).

Results

• Short and long antibiotic treatment resulted in significant reduction in the abundance of Bifidobacterium right after treatment (p=0.027) till postnatal week three (p=0.028).
• Bifidobacterium abundance continued to be reduced till postnatal week six with long treatment (p=0.009).
• Researchers noticed that antibiotic treatment was effective against members of the Enterobacteriaceae family, but allowed Enterococcus to thrive and remain dominant for up to two weeks after antibiotic treatment discontinuation.
• No influence on community richness and diversity was evident in relation to antibiotic treatment.
• Community richness and diversity showed a positive association with postnatal age (p < 0.023) and with abundance of Bifidobacterium (p=0.003).