A recent study published in Pediatric Research explores whether probiotics influence the gut microbiome differently in extremely preterm (EP) and extremely low birth weight (ELBW) infants compared to very preterm (VP) and very low birth weight (VLBW) infants. Researchers from the United Kingdom aimed to determine if probiotics might reduce the risk of necrotizing enterocolitis (NEC) in these vulnerable groups.
Probiotics have been extensively studied for preterm infants, with evidence suggesting up to a 50% reduction in NEC risk. However, variability in clinical outcomes due to methodological differences and feeding practices has led to inconsistent guidelines from organizations such as ESPGHAN, WHO, and the American Academy of Pediatrics. Recent concerns, including a case of probiotic-related sepsis, have heightened scrutiny. Meta-analyses indicate that while probiotics can reduce NEC risk in infants under 32 weeks or 1500 grams, their effectiveness for EP/ELBW infants remains uncertain. A Cochrane review noted minimal NEC reduction in this group.
The study included 123 preterm infants, categorized into EP/ELBW (gestational age <28 weeks or birth weight <1000 g) and VP/VLBW (gestational age 29-31 weeks and birth weight ≥1000 g). Samples were collected from the Royal Victoria Infirmary between 2013 and 2016. Probiotics administered contained Bifidobacterium bifidum, Lactobacillus acidophilus, and Bifidobacterium longum subsp. infantis. Researchers analyzed 1431 stool samples from days 0 to 120 using DNA sequencing to assess microbial composition and response to probiotics.
The VP/VLBW group had a median gestational age of 29 weeks and a birth weight of 1315 grams, while the EP/ELBW group had a median gestational age of 26 weeks and a birth weight of 840 grams. Weight z scores slightly differed between the groups. Despite a dramatic reduction in NEC risk, the study found no significant differences in gut microbiome changes between EP/ELBW and VP/VLBW infants. Approximately 86% of EP/ELBW and 87% of VP/VLBW infants were classified as probiotic responders. The impact of probiotics on NEC risk remains unclear, although probiotic administration was the most influential factor on the gut microbiome.
The study indicates that probiotics affect the gut microbiome similarly in EP/ELBW and VP/VLBW infants, but it does not confirm whether these changes directly reduce NEC risk. Further research is needed to determine the clinical implications of probiotic use in EP/ELBW infants, who are at high risk for NEC. These findings could guide clinical decisions on probiotic administration for this vulnerable population.