Necrotising enterocolitis, late-onset sepsis and mortality after routine probiotic introduction in the UK

Exploring the dark side of probiotics to pursue light: Intrinsic and extrinsic risks to be opportunistic pathogens

Probiotics, live microorganisms with multiple health benefits, have gained popularity for their roles in maintaining daily health and treating a variety of diseases. However, they have the potential to be opportunistic pathogens in some conditions. This review delves into the intrinsic and extrinsic risks associated with probiotics. Intrinsic risks involve the production of harmful substances, such as toxins and invasive factors, biofilm formation, bacteria emboli, antibiotic resistance with relevant genetic materials, genetic plasticity, and metabolic issues, while extrinsic risks include problems in regulatory oversight and public awareness, host health status and appropriately administration. It emphasizes the need for a balanced view of their therapeutic benefits and potential hazards, advocating for further research to understand the complex interactions between probiotics and the human microbiome, to optimize the safety and efficacy of probiotics.

Impact of probiotics on gut microbiome of extremely preterm or extremely low birthweight infants

IMPACT

Meta-analysis of probiotic administration to very preterm or very low birthweight (VP/VLBW) infants shows reduced risk of necrotising enterocolitis (NEC). Separately reported outcomes for extremely preterm infants (<28 weeks) or extremely low birth weight infants (<1000 g) (EP/ELBW) are lacking meaning some clinicians do not administer probiotics to EP/ELBW infants despite their high risk of NEC. We present data showing the gut microbiome is impacted in EP/ELBW infants in a similar manner to VP/VLBW infants, suggesting that risk reduction for necrotising enterocolitis that is microbiome driven will also be seen in EP/ELBW infants, making probiotic administration beneficial.

Human milk microbiota, oligosaccharide profiles, and infant gut microbiome in preterm infants diagnosed with necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a severe intestinal disease of very preterm infants with mother's own milk (MOM) providing protection, but the contribution of the MOM microbiota to NEC risk has not been explored. Here, we analyze MOM of 110 preterm infants (48 NEC, 62 control) in a cross-sectional study. Breast milk contains viable bacteria, but there is no significant difference in MOM microbiota between NEC and controls. Integrative analysis between MOM microbiota, human milk oligosaccharides (HMOs), and the infant gut microbiota shows positive correlations only between Acinetobacter in the infant gut and Acinetobacter and Staphylococcus in MOM. This study suggests that NEC protection from MOM is not modulated through the MOM microbiota. Thus, "'restoring" the MOM microbiota in donor human milk is unlikely to reduce NEC, and emphasis should instead focus on increasing fresh maternal human milk intake and researching different therapies for NEC prevention.

Neonatal outcomes following introduction of routine probiotic supplementation to very preterm infants

AIM

To evaluate the combined outcome of death and/or severe grade necrotising enterocolitis (NEC) in very preterm infants admitted to Cork University Maternity Hospital, Ireland, before and after introduction of routine supplementation with Bifidobacterium bifidum and Lactobacillus acidophilus probiotics (Infloran®).

METHODS

A retrospective study of infants <32 weeks gestation and < 1500 g surviving beyond 72 h of life was performed. Two 6-year epochs; pre-probiotics (Epoch 1: 2008-2013) and with probiotics (Epoch 2: 2015-2020), were evaluated. The primary outcome was defined as death after 72 h or NEC Bell stage 2a or greater.

RESULTS

Seven-hundred-and-forty-four infants were included (Epoch 1: 391, Epoch 2: 353). The primary outcome occurred in 67 infants (Epoch 1: 37, Epoch 2: 30, p = 0.646). After adjustment, the difference was significant (OR [95% CI]: 0.53 [0.29 to 0.97], p = 0.038). Differences between epochs did not depend on gestational age group (<28 weeks; ≥28 weeks).

CONCLUSION

There was an associated reduction of the composite outcome of severe grade NEC and/or death, after adjustment for confounding variables, with introduction of routine administration of a B. bifidum and L. acidophilus probiotic at our institution.

Impact of Transfer for Surgical Management of Preterm Necrotising Enterocolitis or Focal Intestinal Perforation

OBJECTIVE

To compare outcomes after surgically managed necrotising enterocolitis (NEC) and focal intestinal perforation (FIP) in infants <32 weeks requiring transfer to or presenting in a single surgical centre.

DESIGN

Retrospective review of transferred and inborn NEC or FIP, from January 2013 to December 2020.

PATIENTS

107 transfers with possible NEC or FIP contributed 92 cases (final diagnoses NEC (75) and FIP (17)); 113 inborn cases: NEC (84) and FIP (29).

RESULTS

In infants with a final diagnosis of NEC, medical management after transfer was as common as when inborn (41% TC vs 54% p = 0.12). Unadjusted all-cause mortality was lower in inborn NEC (19% vs 27%) and FIP (10% vs 29%). In infants undergoing surgery unadjusted mortality attributable to NEC or FIP was lower if inborn (21% vs 41% NEC, 7% vs 24% FIP). In regression analysis of surgically treated infants, being transferred was associated with increased all-cause mortality (OR 2.55 (1.03-6.79)) and mortality attributable to NEC or FIP (OR 4.89 (1.80-14.97)).

CONCLUSIONS

These data require replication, but if confirmed, suggest that focusing care for infants at highest risk of developing NEC or FIP in a NICU with on-site surgical expertise may improve outcomes.

Age of onset of necrotising enterocolitis (NEC) and focal intestinal perforation (FIP) in very preterm and low birthweight infants: a systematic review

OBJECTIVE

Review of age of onset of necrotising enterocolitis (NEC) and focal intestinal perforation (FIP) in very preterm (≤32 weeks) and/or very low birthweight (VLBW, ≤1500 g) infants.

DESIGN

Preregistered review undertaken according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses in July 2021 and updated October 2021.

DATA SOURCES

MEDLINE/ PubMed, Embase, CINAHL and Cochrane Central Register of Controlled Trials.

ELIGIBILITY

Eligible studies reported age of onset of NEC and/or FIP in randomised controlled trials of >200 or observational studies of >500 infants.

DATA EXTRACTION AND SYNTHESIS

Titles/abstracts were screened; eligible articles underwent data extraction. Age of onset as day of life (DOL) and/or corrected gestational age (CGA) were extracted alongside study information, such as NEC definition, included population, intervention, location and dates studied. Weighted means were used to compare onset by birth gestation, study type, NEC definition, trial intervention, location and dates studied. Comparison was done by Mann-Whitney U test or one-way analysis of variance.

RESULTS

Of the 747 screened studies 188 were eligible. Removal of duplicates, studies without onset data and ineligible populations left 10 RCTs and 14 observational studies contributing 51 NEC cohorts; 49 reported onset DOL and 14 CGA. 2984 cases of NEC had average DOL onset of 16.7 (15.5 in RCTs, 16.9 in observational studies), and CGA onset of 30.1 weeks. Gestation did not impact DOL onset. No other demographic feature impacted NEC onset. Few studies included data on FIP.

CONCLUSIONS

Average onset of NEC in exclusively very preterm/very low birthweight infants is in the third week of life and unlike in cohorts including more mature or heavier infants is not impacted by birth gestation.

How frequent is routine use of probiotics in UK neonatal units?

OBJECTIVE

There is a lack of UK guidance regarding routine use of probiotics in preterm infants to prevent necrotising enterocolitis, late-onset sepsis and death. As practices can vary, we aimed to determine the current usage of probiotics within neonatal units in the UK.

DESIGN AND SETTING

Using NeoTRIPS, a trainee-led neonatal research network, an online survey was disseminated to neonatal units of all service levels within England, Scotland, Northern Ireland and Wales in 2022. Trainees were requested to complete one survey per unit regarding routine probiotic administration.

RESULTS

161 of 188 (86%) neonatal units responded to the survey. 70 of 161 (44%) respondents routinely give probiotics to preterm infants. 45 of 70 (64%) use the probiotic product Lactobacillus acidophilus NCFM/Bifidobacterium bifidum Bb-06/B. infantis Bi-26 (Labinic™). 57 of 70 (81%) start probiotics in infants ≤32 weeks' gestation. 33 of 70 (47%) had microbiology departments that were aware of the use of probiotics and 64 of 70 (91%) had a guideline available. Commencing enteral feeds was a prerequisite to starting probiotics in 62 of 70 (89%) units. The majority would stop probiotics if enteral feeds were withheld (59 of 70; 84%) or if the infant was being treated for necrotising enterocolitis (69 of 70; 99%). 24 of 91 (26%) units that did not use probiotics at the time of the survey were planning to introduce them within the next 12 months.

CONCLUSIONS

More than 40% of all UK neonatal units that responded are now routinely administering probiotics, with variability in the product used. With increased probiotic usage in recent years, there is a need to establish whether this translates to improved clinical outcomes.

Effects of Sepsis on Immune Response, Microbiome and Oxidative Metabolism in Preterm Infants

This is a narrative review about the mechanisms involved in bacterial sepsis in preterm infants, which is an illness with a high incidence, morbidity, and mortality. The role of the innate immune response and its relationship with oxidative stress in the pathogenesis are described as well as their potential implementation as early biomarkers. Moreover, we address the impact that all the mechanisms triggered by sepsis have on the dysbiosis and the changes on neonatal microbiota.