Bifidobacterium animalis Safety in Neonates
Bifidobacterium animalis subspecies lactis is safe and recommended for use in preterm neonates (<37 weeks gestational age) with low birth weight, either as a single-strain probiotic or in combination with Lactobacillus species, based on moderate-to-high quality evidence demonstrating reduced mortality and necrotizing enterocolitis without increased sepsis risk. 1
Evidence-Based Recommendations
For Preterm Infants (<37 weeks gestational age, low birth weight):
B. animalis subsp. lactis is specifically recommended by the American Gastroenterological Association for prevention of necrotizing enterocolitis (NEC) and all-cause mortality 1. The evidence shows:
- Mortality reduction: Combinations including B. animalis subsp. lactis reduced all-cause mortality (OR 0.56,95% CI 0.39-0.80) 1
- NEC reduction: B. animalis subsp. lactis alone reduced severe NEC (OR 0.31,95% CI 0.13-0.74) with moderate-to-high quality evidence 1
- Hospitalization: B. animalis subsp. lactis significantly reduced days of hospitalization (MD -13.00 days, 95% CI -22.71 to -3.29) with high certainty of evidence 1
Specific Strain Recommendations:
The following B. animalis formulations have demonstrated efficacy 1:
- B. animalis subsp. lactis DSM 15954 as a single-strain probiotic
- Combination products containing B. animalis subsp. lactis with Lactobacillus acidophilus, B. bifidum, and B. longum subsp. longum
- Multi-strain formulations with L. rhamnosus GG and B. animalis subsp. lactis BB-12 1
Microbiome Effects Supporting Safety
B. animalis demonstrates favorable colonization patterns in preterm infants 1:
- Persistent colonization: B. animalis shows stronger maintenance of abundance compared to Lactobacillus species, often persisting beyond the supplementation period 1
- Pathogen reduction: Supplementation decreases potentially pathogenic bacteria, particularly Gammaproteobacteria and Klebsiella species 1
- Microbiome maturation: Promotes accelerated transition toward a more mature, stable gut microbial ecosystem resembling term infants 1
Safety Profile
Evidence from >10,000 preterm infants:
Probiotics do not increase sepsis risk in this vulnerable population 1. The data "strongly suggest that probiotics may protect from mortality and do not increase rates of sepsis" 1.
Critical Safety Caveats:
- Product quality is essential: Manufacturing contaminants have caused fatal infections (one case of gastrointestinal mucormycosis from fungal contamination) 1
- Probiotic bacteremia is rare but documented: 14 cases reported in preterm infants, though none resulted in mortality 2
- Quality assurance requirements 3:
- Products must be devoid of transferable antibiotic resistance genes
- Local microbiologists should be able to detect probiotic sepsis
- Pharmaceutical-grade products are preferred over dietary supplements
Contraindications and Cautions:
Exercise caution in 4:
- Immunocompromised patients
- Critically ill patients with indwelling central venous catheters
- Infants with cardiac valvular disease
- Infants with short-gut syndrome
Term Neonates:
For healthy term neonates, there is insufficient evidence to recommend routine B. animalis supplementation. The guideline recommendations specifically target preterm (<37 weeks) and low-birth-weight infants 1. Term infants typically establish healthy Bifidobacterium colonization naturally through breastfeeding 1, 5.
Practical Implementation:
When prescribing B. animalis for preterm neonates 1, 3:
- Verify gestational age <37 weeks and low birth weight as the target population
- Choose pharmaceutical-grade products when available rather than dietary supplements 6
- Consider combination products with Lactobacillus species, which may provide additional benefits 1
- Ensure product quality verification and absence of contaminants 1, 3
- Continue supplementation typically until 34-36 weeks postmenstrual age or discharge 1
The evidence base includes 63 studies in the network meta-analysis supporting these recommendations 1, representing the most comprehensive evaluation of probiotic safety and efficacy in neonates to date.