Effects of Gut Bacteria on Infants By Adrienne Bacon

Statement of Problem 1 in every 8 infants born in the US is preterm, < 37 weeks Preterm infants have high incidences of necrotizing enterocolitis (NEC), nosocomial infections, sepsis and death. NEC typically occurs in the 2 nd -3 rd week of life in preterm, formula-fed infants. NEC affects close to 10% of infants who weigh <1,500g with mortality rates of 50% or more depending on severity. NEC is the second most common cause of morbidity in preterm infants. Causing 472 deaths in 2010 and 386 deaths in The number one cause is respiratory distress syndrome (RDS), causing 825 deaths/year.

Gut bacteria Since 80% of the immune system is in the gut it is important to look at what can be done to decrease these occurrences. The gastrointestinal tract (GIT) of a fetus in the womb is considered to be sterile, and the first exposure to bacteria is from the mother during vaginal birth. Those delivered by C-section are not exposed to the same bacteria as vaginally birthed babies. Since the majority of preterm infants are delivered via C-section, they may be missing out on valuable bacteria. Basically a baby needs to develop its own microbiome. The microbiome is all of the benign and beneficial microbes that live in the body, and they help digest food and keep pathogen loads in check.

Can probiotics and prebiotics help or prevent these conditions? Necrotizing enterocolitis Death and nosocomial infections Sepsis in very pre-term infants

1 st Study A double-blinded, placebo-controlled trial in 2012 of 750 randomly selected infants, <= 2000g, were randomly assigned during the first 48 hrs of life to either daily probiotic or placebo group. The purpose was to find out if probiotics could prevent death and/or nosocomial infections in preterm infants. The bacterium used was Lactobacillus reuteri. Resulted in a trend toward a lower rate of nosocomial pneumonia (2.4% vs. 5%), 40% decrease in NEC, and feeding intolerances and duration of hospitalization of infants <= 1500g (32.5 vs. 37 days) were lower in the probiotic group 1.

2 nd Study A double-blinded, placebo-controlled, randomized trial of 1,099 very preterm infants, <1500g at birth, were either given a probiotic combination of Bifidobacterium infantis, Streptococcus thermophiles, and Bifidobacterium lactis or a placebo. 96.9% were being breast-fed. They found that this combination of bacteria significantly reduced NEC in very preterm infants (2% vs. 4.4%), but not definite late-onset sepsis or mortality 2.

3 rd Study A cohort that started in July 2011 in Canada. A probiotic mixture of 4 bifidobacteria were given to all admitted infants of <32 weeks gestation every day starting with the first feed for 2 weeks. They compared the outcomes of the infants who received probiotics (294) with those from the previous infants who did not receive probiotics (317). The infants who received probiotics had a reduction in NEC (9.4% to 5.4%), decrease in death (9.8% to 6.8%), and a significant reduction in the combined outcome of death or NEC (17% to 10.5%). There was no effect of probiotics on health care-associated infections 3.

Conclusion This is a very new area of research and hundreds of bacterial strains are yet to be discovered, and still not known what ones provide the best outcomes for infants. In my opinion, anything that can reduce the chance of a preterm infant developing necrotizing enterocolitis is worth trying. Helping infants develop a strong microbiome can decrease their chances of a large range of diseases that may happen later in life. Researching the microbiome is new and DNA testing is helping us to understand what exactly is the best bacteria to help us develop a healthy immune system.

References 1.Rojas MA, Lozano JM, Rojas MX, et al. Prophylactic probiotics to prevent death and nosocomial infection in preterm infants. Pediatrics Nov;130(5):e Accessed May 4, Jacobs SE, Tobin JM, Opie GF, et al. Probiotic effects on late- onset sepsis in very preterm infants: a randomized controlled trial. Pediatrics Dec;132(6): Accessed May 4, Janvier A, Malo J, Barrington KL. Cohort study of probiotics in a north american neonatal intensive care unit. J Pediatr May;164(5): Accessed May 4, 2014.