Effect of a multi-strain fermented milk on the gut microbiota recovery after Helicobacter pylori therapy : a randomised, controlled trial Eric Guillemard 1 , Marion Poirel 1 , Florent Schäfer 1 , Laurent Quinquis 1 , Caroline Rossoni 1 , Christian Keicher 2 , Frank Wagner 2 , Hania Szajewska 3 , Frédéric Barbut 4 , Muriel Derrien 1* Peter Malfertheiner 5, 6* 1 Danone Nutricia Research, Palaiseau, France, 2 Charité Research Organisation GmbH, Berlin, Germany, 3 Medical University of Warsaw, Department of Paediatrics, Poland, 4 INSERM S-1139, Université de Paris, France, 5 OVGU University, Magdeburg Clinic, Department of Gastroenterology, Hepatology and Infectious Diseases, Magdeburg, Germany, 6 LMU University Clinic, Department of Internal Medicine II, München, Germany. Study design Test product is a 7-strain fermented milk product containing L. paracasei CNCM I-1518, L. paracasei CNCM I-3689, L. rhamnosus CNCM I-3690 and yogurt strains. A randomised, double-blind, controlled trial was performed in 136 adults under 14-day H. pylori (Hp) treatment (pantoprazole, clarithromycin and amoxicillin), receiving the Test or Control product for 28 days (Fig. 1) . No difference between groups was observed for AAD Context & Objective • Proton pump inhibitors and antibiotics are known to alter gut microbiota, which alteration may be associated with long-term health effects. • The goal of this study is to assess the effects of a potential probiotic fermented dairy product on Antibiotic Associated Diarrhea (AAD) occurrence and on the gut microbiota in patients under H. pylori treatment Results Test product strains viability in feces • During and after Hp treatment, L. paracasei CNCM I-1518, L. paracasei CNCM I-3689, L. rhamnosus CNCM I-3690 were viable (assessed by PMA qPCR) • 2 weeks after last consumption, total (live and dead) and viable L. rhamnosus CNCM I-3690 were detected in 20% and 8% of subjects respectively Effect of product intervention on global gut microbiota Effect of product intervention on bacterial genera and SCFA • Hp-treatment induced a significant alteration in global gut microbiota, which partially recovered 28 days following cessation of treatment (D42) (Fig. 2A) • Intra-subject beta-diversity distance from baseline was lower (padj=0.02) (Fig.2B) in the Test as compared to Control group at D42 (V7) Conclusions In patients under Hp-treatment, the consumption of a multi-strain fermented milk can induce a modest but significant faster recovery of the microbiota composition and limit the increase of some Enterobacteriaceae A B Figure 1. Study design • Among differentially abundant genera between groups, some Enterobacteriaceae , Escherichia-Shigella (padj=0.0082) and Klebsiella (padj=0.013), were less abundant in the Test group (Fig. 2C and 2D) • Concentrations of SCFA (acetate, propionate and butyrate) were higher in the Test group (p=0.035) (Fig. 2E) Figure 2. Gut microbiota response to Hp treatment and product intervention. A. Principal Coordinate analysis (PcoA) based on Bray-Curtis dissimilarity. B Intra-subject distance to baseline of each subject in Test and Control groups across the study * p <0.05 ; ** p < 0.01; *** p < 0.001. C . Heatmap of differentially abundant at V7 (D42) within group. Red indicates higher fold-change and blue lower fold-change with regard to the reference (V2 or Control). D. Quantitative abundance of Klebsiella and Escherichia- Shigella E . Concentration of major SCFA (acetate, propionate, butyrate) * p <0.05 between groups from V4 to V6. C D E