Infants and young children logo

Necrotizing enterocolitis in preterm infants 

 - may be helped with a specific probiotic strain combination

Baby foot and probiotic supplement
5 Min read

Preterm infants can be at risk of a condition known as necrotizing enterocolitis (NEC),1 which can be associated with a higher rate of mortality.2 Clinical evidence suggests that a specific combination of three probiotic strains may reduce the risk of NEC.3, 4 


Preterm infants typically have an unbalanced intestinal microbiota making them vulnerable to infections and certain conditions such as necrotizing enterocolitis1

Documented facts

Intestinal health in preterm infants:

Strain: Combination of Bifidobacterium, BB-12® + Streptococcus thermophilus, TH-4® + Bifidobacterium infantis (DSM 33361)3, 4
Level of use: 3.0 - 3.5 x 108 CFU of each strain3, 4
Duration: From birth until hospital discharge3, 4

A significant health issue in preterm infants

Approximately 1-2% of all infants are born very preterm or extremely preterm, i.e. two months or earlier than the estimated due date. This equates to approximately 2.4 million babies globally, each year.6

Preterm babies are at risk of developing necrotizing enterocolitis (NEC), an inflammatory illness. It is the worldwide leading cause of mortality in preterm babies.2
The main cause of NEC is thought to be either an underdeveloped or damaged intestine which has occurred due to lack of blood or oxygen to the intestine, injury to the intestinal lining or bacterial growth on the intestinal wall.7  

NEC affects approximately 5% of infants born very prematurely or extremely prematurely,8 and is associated with a mortality rate of up to 30-50%, depending on birth weight.8, 9

Preterm infant and probiotic supplement

A specific, three-strain probiotic blend may help address NEC issues

A specific, three-strain probiotic blend by Chr. Hansen has been observed to help support the intestinal tract and the development of a healthy immune system and digestive function. The product contains a blend of three different probiotic strains: Bifidobacterium, BB-12®, Streptococcus thermophilus, TH-4® and Bifidobacterium infantis (DSM 33361) (hereafter referred to by use of the trademarks BB-12® and TH-4®). 

BB-12®, TH-4® and B. infantis (DSM 33361) probiotic blend has been clinically studied 

Two clinical studies involving more than 1,200 preterm infants suggest that the BB-12®, TH-4® and B. infantis  (DSM 33361) combination may help reduce the risk of NEC by up to 50%.3, 4

In a randomized, double-blinded, placebo-controlled study of n=145 preterm infants weighing ≤ 1500g, the effect of the BB-12®, TH-4® and B. infantis (DSM 33361) probiotic blend at 1 billion CFU/day (colony forming units) in total was investigated.4 73 infants were allocated to the control group, and 72 were allocated to receive the probiotic blend, diluted in 3ml of breast milk or infant formula, at 1 billion CFU/day.4 Infants were supplemented until they were 36 weeks post-conception.4 Compared to the placebo group, the probiotic group had significantly lower incidence of NEC (16.4% vs. 4.0%; p=0.03, respectively) and significantly less severe NEC (Bell's criteria 2.3 vs. 1.3; p=0.005, respectively).4

A multicenter, double-blinded, placebo-controlled, randomized study of n=1099 very preterm infants weighing ≤ 1500g investigated the effect of the same strain-specific probiotic blend at 1 billion CFU/day in total on the incidence of definite late-onset sepsis and NEC.3 The infants were supplemented until they were discharged from hospital. There was no significant difference in definite late-onset sepsis or all-cause mortality, however, the probiotic group had a 50% lower incidence of NEC at Bell stage 2 or more, compared to the placebo group (2.0% vs. 4.4%; p=0.03, respectively).3


European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) references using the combination of the Bifidobacterium, BB-12® + Streptococcus thermophilus, TH-4® + Bifidobacterium infantis (DSM 33361) probiotic strains for preterm infants for its potential impact on NEC stage 2 or 3.5

Strict, high-quality production processes are imperative, especially for preterm

Since preterm infants are particularly prone to infection, Chr. Hansen has implemented the strictest of production processes. By adding many more requirements on top of what is stipulated, we ensure a safe product that is of the highest quality for this vulnerable group. 

Chr. Hansen’s self-imposed extra requirements include extended contaminant testing and more strict requirements regarding both environmental monitoring and cleaning before and after production, in order to minimize the risk of contamination. 

Further, the product is packed in single-use, sealed packages to help reduce the risk of contamination compared to multi-use containers. To find out more about safety and production process at Chr. Hansen, click here.

Preterm infants are at risk of NEC, however, clinical studies suggest that the specific combination of BB-12®, TH-4® and B. infantis (DSM 33361) may reduce the risk of infants developing NEC. It is particularly important for this at-risk population that the probiotic products are safe and high-quality, aspects that Chr. Hansen take very seriously. 


In partnership with Abbott Nutrition Health Institute, we have developed three podcast episodes in which we discuss probiotics and preterm infants. This podcast series covers topics such as Chr. Hansen-produced probiotics and their demonstrated mode of action. Click here to listen to the podcast series. 

BB-12® and TH-4® are registered trademarks of Chr. Hansen A/S.

The article is provided for informational purposes regarding probiotics and is not meant to suggest that any substance referenced in the article is intended to diagnose, cure, mitigate, treat, or prevent any disease.

Bifidobacterium, BB-12®

The probiotic strain Bifidobacterium, BB-12® is the world’s most documented probiotic bifidobacterium. It has been extensively studied and has been associated with improved outcomes across various health areas.

BB-12® is a trademark of Chr. Hansen A/S

BB-12 consumer logo TM

References Open Close

1. Unger S, et al. Gut microbiota of the very-low-birth-weight infant. Pediatr Res. 2015;77(1-2):205-13. (PubMed)

2. Cotten CM, et al. Prolonged hospital stay for extremely premature infants: risk factors, center differences, and the impact of mortality on selecting a best-performing center. J Perinatol. 2005;25(10):650-5. (PubMed)

3. Jacobs SE, et al. Probiotic effects on late-onset sepsis in very preterm infants: a randomized controlled trial. Pediatrics. 2013;132(6):1055-62. (PubMed)

4. Bin-Nun A, et al. Oral probiotics prevent necrotizing enterocolitis in very low birth weight neonates. J Pediatr. 2005;147(2):192-6. (PubMed)

5. van den Akker CHP, et al. Probiotics and Preterm Infants: A Position Paper by the ESPGHAN Committee on Nutrition and the ESPGHAN Working Group for Probiotics and Prebiotics. J Pediatr Gastroenterol Nutr. 9000;Publish Ahead of Print. (PubMed)

6. Chawanpaiboon S, et al. Global, regional, and national estimates of levels of preterm birth in 2014: a systematic review and modelling analysis. The Lancet Global Health. 2019;7(1):e37-e46. (PubMed)

7. Alganabi M, et al. Recent advances in understanding necrotizing enterocolitis. F1000Res. 2019;8. (PubMed)

8. Neu J, Walker WA. Necrotizing enterocolitis. N Engl J Med. 2011;364(3):255-64. (PubMed)

9. Fitzgibbons SC, et al. Mortality of necrotizing enterocolitis expressed by birth weight categories. J Pediatr Surg. 2009;44(6):1072-5; discussion 5-6. (PubMed)

Left Strain icon

What are

Learn more about what probiotics are and how they can benefit your health

What to 
look for

See key tips on how to choose a high-quality probiotic product


Learn how to review the evidence when considering probiotic strains and effects


Read more about some of the world’s most documented probiotic strains and their diverse, beneficial health effects

Right Strain icon