Transcript Probiotics for prevention of necrotizing enterocolitis in

Probiotics for preterm neonates –what
lies ahead?
Prof Sanjay Patole, MD, DCH, FRACP, MSc, DrPH
Centre for Neonatal Research and Education
KEM Hospital for Women, University of Western
Australia, Perth
Routine probiotic supplementation (RPS)
 Reduced incidence of NEC associated with introduction of
probiotics in a NICU
Hoyos AH 1999
 Cohort study of probiotics in a North American NICU
Janvier et al. 2014
 Currently 15 tertiary NICUs in Australia provide RPS for
preterm VLBW neonates
Probiotics prevent NEC in preterm neonates
 30 Trials from 17 nations (n=6655), 13 Systematic reviews
 NEC Stage ≥II: RR: 0.39 (95% CI=0.27-0.56), p<0.00001
 All cause mortality: RR: 0.58 (95% CI=0.46-0.75), p<0.0001
 NEC related mortality: RR: 0.38 (95% CI 0.18 -0.82)
 Time to full feeds: WMD: -1.32 (95% CI -1.48 to -1.17)
Probiotics for preterm neonates: Enough is enough!!
Barrington 2012
 Probiotics: fishing in the ocean. Vandenplas 2012
 The politics of probiotics: probiotics, NEC and the ethics of
neonatal research. Janvier 2013
 Probiotics to prevent NEC- Too cheap and easy? Taylor 2014
 Myth: NEC: probiotics will end the disease. Caplan 2011
 Probiotics strain for credibility. Hamilton-Miller 2000
Probiotics for preterms- what lies ahead?
Challenges and opportunities
Extremely preterm neonates
 Extremely preterm neonates are most deserving of probiotic
supplementation.
 Data on ELBW neonates from RCTs (N=1500) and reports on
routine use of probiotics is assuring.
 Probiotic sepsis is easy to treat compared with sepsis due to
other organisms.
Benefits of probiotics in ELBW neonates may be suboptimal
 Frequent exposure to antibiotics
 Frequent stoppage of feeds
 Recurrent episodes of late onset sepsis by CONS
 Dependence on parenteral nutrition
Exposure to antibiotics
 Early postnatal exposure to Ampicillin and gentamicin had
significant adverse effects on evolution of gut flora in infants.
 Antibiotic-treated infants had ↑↑ Proteobacteria (p=0.0049)
and ↓↓ Actinobacteria (p=0.00001), ↓ Bifidobacterium
(p=0.0132) and ↓ Lactobacillus (p=0.0182) compared with
controls 4 weeks after stopping antibiotics.
 Proteobacteria levels significantly higher by week 8 in the
treated infants (p=0.0049).
Fouhy Antimicrob Agents Chemother 2012
Exposure to antibiotics
 Preterm neonates who received 5-7 days of empiric antibiotics
in the 1st week had relative abundance of Enterobacter
(p=0.016) and lower bacterial diversity in week 2 and 3.
 Higher frequency of NEC, LOS, and death in those receiving
early antibiotics vs those not exposed to antibiotics.
Greenwood, J Pediatr 2014 Feb
 Association of prolonged exposure to antibiotics with LOS,
NEC and death in preterm neonates.
Cotten, Kuppala, Alexander, Shah
Intrauterine growth restriction (IUGR)
Dorling et al: Meta analysis of independent case series
 14 studies compared NEC rates in neonates who had fetal
AREDF-UA with controls (forward fetal EDF).
 9 studies showed ↑odds of NEC in those with fetal AREDF.
OR: 2.13 (95% CI: 1.49-3.03)
ADC Fetal Neonatal Ed 2005
 Frequent signs of feed intolerance (e.g. abdominal distension,
visible ropy bowel loops, large/coloured gastric residuals) and
the fear of NEC means it often takes 2-3 weeks to reach 120150ml/kg/day feeds.
 Median (IQR) time to full feeds in IUGR vs AGA extremely
preterm neonates: 20 (15-34) vs. 16 (12-24) days, p=0.008
Shah et al. JMF Neonatal Med 2014 Oct
Kempley et al
 Post-hoc analysis of data on neonates <29 weeks from a RCT
(ADEPT) comparing benefits of starting feeds ‘Early’ (D2) vs
‘Late’ (D6) in preterm neonates (<35 weeks) with IUGR.
 Feed increments as per the protocol should have achieved full
feeds by D16 in the early and D20 in the late group.
ADC Fetal Neonatal Ed 2014
Neonates <29 weeks achieved full feeds significantly later and
had higher incidence of NEC vs those ≥29 weeks.
 Median (IQR) age: 28 (22-40) vs 19 (17-23) days
HR: 0.35 (95% CI: 0.3 to 0.5)
 NEC: 32/83 (39%) vs 32/312 (10%)
RR: 3.7 (95% CI: 2.4-5.7)
NEC and feed intolerance in IUGR
 Fetal hypoxia and redistribution of the GI blood flow to spare
the brain from hypoxic injury
 Hypoxic-ischaemic injury of the gut affects development of its
motor, secretory, and mucosal functions, and increases its
postnatal vulnerability to ileus, altered colonization, and
bacterial invasion.
 Postprandial rise in SMA flow is compromised
 Pseudo-obstruction due to meconium plug, ↑ LOS
IUGR
 Significantly decreased intestinal weight and length, ileal
and colonic weight/cm, and villous sizes at birth in piglets
with IUGR vs same-age controls.
 ↑ Markers of apoptosis and ↓ markers of proliferation
D’Inca J Nutr 2010
 ↓Bioavailability of butyrate in IUGR could adversely affect
colonocyte proliferation, colonic homeostasis, and reduce
mucin secretion.
Gaudier 2004, Barcelo 2000
IUGR
 IUGR impairs mucus barrier development and is associated
with long-term alterations of mucin expression.
 Lack of an efficient colonic barrier induced by IUGR may
predispose to colonic injury in neonatal as well as later life.
 Continuously impaired intestinal development in neonatal
piglets with IUGR.
Fanca-Berthon 2009, Wang 2010
IUGR
Effect of IUGR on cecocolonic microbiota from birth to
adulthood in rats with vs without IUGR
 Bacterial density ↑ at D5 and ↓ at D12 in IUGR
 Adult rats with IUGR had fewer Bifidobacteria at D40 and
more bacteria related to Roseburia intestinalis at D100
Fanca-Berthon JPGN 2010
Baseline fecal Bifidobacteria in IUGR
 No baseline differences in the proportion of detectable B.
counts between extremely preterm IUGR and AGA neonates.
 Probiotic: IUGR vs AGA: 7(33%) vs 22 (42%), p=0.603
 Control: IUGR vs AGA: 1(6%) vs 1 (2%), p=0.429
Patole et al. PLOS ONE 2014 March
(Post-hoc analysis of data on <28 week IUGR vs AGA)
Response to probiotic suppl. in IUGR
 Response to probiotic did not differ between IUGR and non-
IUGR neonates (p=0.589), after adjusting for baseline counts
and treatment allocation.
 IUGR neonates on probiotic (vs placebo) showed a non-
significant trend towards a younger postnatal age at FEF
(adjusted for age at start of MEF):
 Median (IQR) age: 16 (12-26) vs 19 (11-25) days
Probiotics can facilitate enteral nutrition
 Secreted products
 Products of fermentation (SCFA)
 Influence on intestinal neuroendocrine factors
 Gut mediators secreted as an immune reaction to probiotics
Soret 2010, Barbara 2005, Cherbut 2003
Opportunities for advancing knowledge
 Assessing nutritional benefits of probiotics is important.
Jape-Athalye et al AJCN 2014 Nov.
 Colonisation depends on strain properties, and host related
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factors such as gestational and postnatal age
Animal models: Strain selection for clinical use (Wu 2013)
Early vs Late: Highest colonization rate when the suppl. was
started between 24 and 48 hours after birth. (Yamasaki 2012)
Single ve Multi-strain probiotic (Ishizeki 2013)
Live vs Inactivated/killed probiotic (Awad 2010)
Opportunities
 Real life benefits of probiotics may not be as dramatic as
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reported in RCTs.
Reporting outcomes and safety data on RPS is important to
know real life benefits and uncommon/rare adverse effects.
Strain specific population data for guiding clinical practice.
Assessing the economic benefits of probiotics is important.
Advances in technology: Improve tolerance of probiotic
strains to bile, acid, and oxygen for enhanced benefits.
Challenges
 Cooperation between various stakeholders is urgently
required for quality control and classification of probiotics.
 Field difficulties and priorities in resource limited set ups
 Politics of probiotics
 Probiotics will not be a panacea for NEC, an illness that is
known to present at different postnatal ages with different
triggers and different presentations.
Challenges: Probiotic bacteremia/sepsis
 Case series of Bifidobacterium longum bacteremia in three
preterm infants on probiotic therapy. Zbinden et al. Neonatology. 2015
 Bifidobacterium longum bacteremia in preterm infants
receiving probiotics. Bertelli et al. Clin Infect Dis. 2014
 Fatal gastrointestinal Mucormycosis in an infant following
use of contaminated ABC Dophilus powder from Solgar Inc.
http://www.cdc.gov/fungal/rhizopus-investigation.html
Resource limited set ups
Probiotic issues
 Product/Strain selection, Cost, Cold storage?
 Import or locally available? Quality assurance and check?
 Microbiology back up on site? Baseline data?
 Priorities: VLBW, ELBW, IUGR? Hospital vs Community?
Strategies for prevention of NEC
 Antenatal glucocorticoids, Maternal/Donor breast milk
 Avoid formula, Standardised feeding protocol
 Avoid undue prolonged exposure to antibiotics
Probiotics for preterm neonates
All good?
PIPs trial
 Multi-centre double blind randomised placebo controlled trial
 B. breve BBG-001 ( 2.1 to 5.3 × 108 cfu daily) in infants
<31weeks
 Randomised before 48 hrs.
 Primary outcomes: NEC ≥ Bell Stage II, LOS, Death.
 ITT analysis adjusted for sex, gestation and randomisation
within 24 hours and allowing for clustering of multiples.
Costeloe et al. Arch Dis Child 2014;99: A23-A24
PIPs results
 1310 infants randomised
 Median gestation 28.0 weeks, Birth weight1010g
 Age starting intervention 44 hours
 No adverse events related to the intervention
 No benefits in ANY of the outcomes of interest
Conclusions:
 B. breve BBG-001 did not have any advantage
 Highlight need to assess the efficacy of different strains
 Challenges the validity of combining trials using different
probiotic interventions in meta-analyses
Thank you!!
Prebiotics in preterm neonates
7 RCTs (n=417), NEC: 5 trials (n=345), LOS: 3 trials (n=295)
 NEC: RR: 1.24 (96% CI: 0.56-2.72)
 LOS: RR:0.81 (95% CI: 0.57-1.15)
 TFF: 3 RCTs (n=295); no improvement
 Bifidobacteria growth ↑↑ in prebiotic group
WMD: 0.53 (95% CI: 0.33, 0.73) *106 colonies/g, p <0.00001)
 Reduced stool viscosity and pH
 No significant adverse effects
Srinivasjois Clin Nutr 2013 Dec
Opportunities in the field of prebiotics
 Large RCTs of Prebiotics vs placebo, Pro vs Synbiotic
 Assess consumption of specific HMOs by different
probiotic strains for developing optimal pre and probiotic
combinations (Synbiotic)
Garrido et al. Microbiology 2013
 Maternal vs donor breast milk HMO and secretor status
*Before vs After RPS: <33 weeks (n=834 vs 990)
NEC/All cause mortality: 73 (9%) vs 52 (5%)
 OR: 0.57 (0.38-0.85), p=0.005
NEC (≥ Stage II): 25 (3.0%) vs 15 (1.5%)
 OR: 0.53 (0.27-1.01), p=0.054
All cause mortality: 56 (7%) vs 39 (4.0%)
 OR: 0.58 (0.37-0.91), p=0.019
Any gut perforation: 31 (3.7%) vs 15 (1.6%)
*(Dec 2008-Nov 2010) vs (June 2012-May 2014) @ KEM Perth
Before vs After RPS: <28 weeks (n=250 vs 250)
(1) NEC/All cause mortality: 52 (21%) vs 34 (14%)
 OR: 0.62 (0.37-1.02), p=0.05
(2) NEC (≥ Stage II): 16 (6%) vs 10 (4%),
 OR: 0.66 (0.29, 1.49), p=0.31
(3) All cause mortality: 42 (17%) vs 26 (10%)
 OR: 0.59 (0.33-1.03), p=0.06
(4) Any gut perforation: 22 (8.8%) vs 9 (4.1%)
12%
KEMH <28 Wks
10%
ANZNN<28 wks
KEMH>= 28 wks
ANZNN >= 28 wks
Incidence
8%
6%
4%
2%
0%
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Year
 “It can be argued that infection with lactobacilli is preferable
over potential pathogens like Klebsiella, Enterobacter, or
yeast.”
Kliegman and Willoughby. Pediatrics 2005
 “The debate may be shifted from whether it is safe to give
probiotics to whether it is safe not to give probiotics to
premature neonates.”
Sanders et al, Gut Microbes 2010
Single vs multistrain probiotics
 Colonisation of an ecosystem providing a niche for > 400
species is anticipated to be more successful with multistrain
rather than monostrain probiotics.
 “Given the association of development of monoflora with
impending NEC, probiotics may protect VLBW neonates by
enforcing diversity of flora or by preventing colonization with
pathogens”.
Kleigman et al. Pediatrics 2005
 Based on the complexity of gut flora and the pathogenesis of
NEC, and the multiple mechanisms of benefit of probiotic
strains, multistrain probiotics may be more effective than
single-strain probiotics.
 Combination of probiotic strains in a product does not
necessarily add to the benefits of each strain.
Consensus meeting report: London, Nov 2009
 Strain combinations can be antagonistic, compatible or
synergistic.
Salminen et al. 2009
Dose
 There will be an optimal dose below which benefits may not
occur, as survival and proliferation to adequate numbers after
overcoming the barriers (e.g. gastric acid, bile, competing
pathogens), is not ensured.
Lewis et al. 1998, Martin et al. 2008
 To be functional, probiotics have to be viable and in sufficient
dosage levels, typically 106 to 107 cfu/g of the product.
Galdeano et al. 2004, Shah et al. 2000
 No standardised number of probiotic bacteria that would ensure
an effect.
 The effective quantity, for a given effect and a given strain, is
the quantity which has demonstrated an effect in a clinical trial.
Consensus meeting report- London, November 2009.
Scientific advances
 Microencapsulation, improving thermal tolerance of strains
 ↑ Gastric transit, GI persistence, and efficacy by cloning
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listerial betaine uptake system into the strain
Evaluating bile salt hydrolase to increase BA tolerance
Evaluating mucin degradation activity and translation ability
Designer (Genetically modified) probiotic strains
Metagenomics and metabonomics
Can more trials help?
 A RCT of 2000 neonates and a baseline incidence of 8% would
have to show a doubling of the incidence of NEC to overturn
the benefits shown in the trials completed to date. Such a
reversal of effects has never been demonstrated in clinical
medicine.
Barrington KJ, Arch Dis Child Educ Pract Ed 2011
 A RCT of ~ 4,500 neonates will have to show “no effect” (RR
= 1.0) in mortality after probiotic supplementation.
Economic analyses (↓ NEC by 50%)
NEC expenses: 10 to 15 million dollars/year in Australia
Probiotic cost: $30 to $70 per baby ($5000/year)
 Don’t forget the lifelong stress of parents caring for a child
with NDI after severe NEC