1 Marißen J, et al. BMJ Open 2019;9:e032617. doi:10.1136/bmjopen-2019-032617 Open access Effcacy of Bifdobacterium longum, B. infantis and Lactobacillus acidophilus probiotics to prevent gut dysbiosis in preterm infants of 28+0–32+6 weeks of gestation: a randomised, placebo- controlled, double-blind, multicentre trial: the PRIMAL Clinical Study protocol Janina Marißen, 1 Annette Haiß, 1 Claudius Meyer, 2 Thea Van Rossum, 3 Lisa Marie Bünte, 1 David Frommhold, 4 Christian Gille, 5 Sybelle Goedicke-Fritz, 6 Wolfgang Göpel, 1 Hannes Hudalla, 7 Julia Pagel, 1 Sabine Pirr, 8 Bastian Siller, 1 Dorothee Viemann, 8 Maren Vens, 9 Inke König, 9 Egbert Herting, 1 Michael Zemlin, 6 Stephan Gehring, 2 Peer Bork, 3 Philipp Henneke, 10 Christoph Härtel, 1 for the PRIMAL consortium To cite: Marißen J, Haiß A, Meyer C, et al. Effcacy of Bifdobacterium longum, B. infantis and Lactobacillus acidophilus probiotics to prevent gut dysbiosis in preterm infants of 28+0–32+6 weeks of gestation: a randomised, placebo-controlled, double-blind, multicentre trial: the PRIMAL Clinical Study protocol. BMJ Open 2019;9:e032617. doi:10.1136/ bmjopen-2019-032617 ► Prepublication history and additional material for this paper are available online. To view these fles, please visit the journal online (http://dx.doi. org/10.1136/bmjopen-2019- 032617). JM and AH contributed equally. Received 27 June 2019 Revised 18 October 2019 Accepted 04 November 2019 For numbered affliations see end of article. Correspondence to Professor Christoph Härtel; christoph.haertel@uksh.de Protocol © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. ABSTRACT Introduction The healthy ‘eubiosis’ microbiome in infancy is regarded as the microbiome derived from term, vaginally delivered, antibiotic free, breastfed infants at 4–6 months. Dysbiosis is regarded as a deviation from a healthy state with reduced microbial diversity and defcient capacity to control drug-resistant organisms. Preterm infants are highly sensitive to early gut dysbiosis. Latter has been associated with sepsis and necrotising enterocolitis, but may also contribute to long-term health problems. Probiotics hold promise to reduce the risk for adverse short-term outcomes but the evidence from clinical trials remains inconclusive and none has directly assessed the effects of probiotics on the microbiome at high resolution. Methods and analysis A randomised, double blind, placebo-controlled study has been designed to assess the safety and effcacy of the probiotic mix of Bifdobacterium longum and infantis and Lactobacillus acidophilus in the prevention of gut dysbiosis in preterm infants between 28+0 and 32+6 weeks of gestation. The study is conducted in 18 German neonatal intensive care units. Between April 2018 and March 2020, 654 preterm infants of 28+0–32+6 weeks of gestation will be randomised in the frst 48 hours of life to 28 days of once daily treatment with either probiotics or placebo. The effcacy endpoint is the prevention of gut dysbiosis at day 30 of life. A compound defnition of gut dysbosis is used: (1) colonisation with multidrug-resistant organisms or gram- negative bacteria with high epidemic potential or (2) a signifcant deviation of the gut microbiota composition as compared with healthy term infants. Dysbiosis is determined by (1) conventional microbiological culture and (2) phylogenetic microbiome analysis by high-throughput 16S rRNA and metagenome sequencing. Persistence of dysbiosis will be assessed at 12-month follow-up visits. Side effects and adverse events related to the intervention will be recorded. Key secondary endpoint(s) are putative consequences of dysbiosis. A subgroup of infants will be thoroughly phenotyped for immune parameters using chipcytometry. Strengths and limitations of this study ► This is a large randomised, placebo-controlled, double-blind, multicentre study in a diverse popu- lation of preterm infants of 28+0–32+6 weeks of gestation at risk for gut dysbiosis. ► Effcacy of Bifdobacterium longum, B. infantis and Lactobacillus acidophilus probiotics on gut dysbiosis is studied by high-resolution DNA sequencing of the microbiome and thorough clinical and immunologi- cal phenotyping of infants. ► The study design allows to control for inherent dif- ferences among neonatal intensive care units, such as their microbial environment, and for the maternal microbiome in a subset of infants. ► The time window of enrolment is restricted to the frst 48 hours of life to assure that early development of the infant’s microbiome is targeted. ► The defnition of gut dysbiosis in preterm infants at day 28–30 of life is based on deviations compared with the microbiome of healthy term infants. on July 22, 2020 by guest. Protected by copyright. http://bmjopen.bmj.com/ BMJ Open: first published as 10.1136/bmjopen-2019-032617 on 21 November 2019. Downloaded from