Necrotizing enterocolitis (NEC) is a life-threatening infection that causes the tissues of the intestine to die. First described in the medical literature back in 1965[1], this illness can require surgical intervention, extensive hospital stays often ranging from 90 days to more than 6 months[2], and has been a significant cause of disease and death in premature infants[3]. The vast majority of those[4] who contract NEC are born premature and the annual medical costs for treating NEC has been estimated to be around $5 billion[5] in the U.S.
While the root causes of NEC are not entirely understood[2], it has been theorized that the infection could be due, in part, to the invasion of the gut by harmful bacteria[6]. Other factors that may play a part in infant NEC are shown in Figure 1. The use of probiotic therapy may be able to reduce the overgrowth of these invasive species[7] and decrease the risk of contracting NEC. Probiotic bacteria, such as Bifidobacterium, produce acidic end products[7] that can lower the pH of the intestine, creating unfavorable breeding grounds for pathogens. A recent meta-analysis of 24 trials[8] found that probiotic use for the prevention of NEC in preterm infants was able to decrease the mortality rates and severity of NEC. However, there still remain questions about the best strain of bacteria, dosage to be used, and appropriate duration of therapy.

Bifidobacteria are of particular interest as a possible treatment to combat NEC. Research has shown this bacterial species to be ubiquitous in the gut of healthy infants[9], demonstrated an inclination for it to resist the colonization of certain pathogens[10], and has associated the bacteria with the development of the immune system[11]. Bifidobacterium contains many different subspecies, some of which may be more protective against NEC than others. Probiotics containing higher amounts of these subspecies would likely be sought out in the treatment of NEC. Commercially available Bifidobacterium-containing probiotics usually have an array of these subspecies.
For medical practitioners to be able to effectively utilize these products, they must be tested to verify bacterial classification, viability, and purity[12]. Researchers in the present study evaluated 17 probiotic products to determine if the detectable species of Bifidobacterium match the listing on the product label.
Necrotizing enterocolitis (NEC) is a life-threatening condition that disproportionately affects infants born prematurely. The use of probiotics containing Bifidobacterium may be useful in the treatment of NEC. However, these probiotics must be tested to ensure the contents claimed on the label match the product. This study tested 17 commercially available probiotic products.