1. Dientamoeba fragilis: comparison of prevalence between gastroenteritis cases and healthy controls Multi-centre, case-control study (2010-2012; the Netherlands): Cases: N=1,542 stool samples from pts visiting their general practitioner because of gastrointestinal (GI) complaints Controls: N=1,203 stool samples from patients without GI complaints or from family or laboratory technicians Cases/controls: matched for age, month of sample collection, sex, region Sample analysis: multiplex real-time PCR Cases with D. fragilis have less diarrhoea than cases without D. fragilis: de Boer M. ECCMID 2014 abs. O051 1 of 2 Data from oral presentation

2. Difference between cases and controls remains if: –Only D. fragilis studied (no coinfection): Cases: 17.8%; Controls: 32.4% –Laboratory staff and family excluded from analysis (D. fragilis prevalence among 39 lab technicians in control group: 62%) Dientamoeba fragilis: comparison of prevalence between gastroenteritis cases and healthy controls A positive PCR finding of D. fragilis should be interpreted with caution, given the higher prevalence in controls than in gastroenteritis cases de Boer M. ECCMID 2014 abs. O051 2 of 2 Data from oral presentation

3. Lactobacilli and bifidobacteria: impact on prevention of antibiotic-associated diarrhoea (AAD) and C.difficile diarrhoea (CDD) PLACIDE study: multi-centre, double-blind RCT: N=2,941 inpatients ≥65 yr exposed to ≥1 oral or parenteral antibiotics: –Multi-strain preparation of lactobacilli and bifidobacteria (total 6x 10 10 organisms) 1x/day for 21 days: N=1,470 –Placebo: N=1,471 Allen SJ et al. Lancet 2013;382:1249-57 1 of 2

4. Lactobacilli and bifidobacteria: impact on prevention of antibiotic-associated diarrhoea (AAD) and C.difficile diarrhoea (CDD) Median duration of hospital admission: 4 days for both groups (P=0.87) Serious adverse events (SAE): 19.7% of participants; frequency similar in both groups; no SAE attributed to study participation Meta-analysis: current RCT + 4 additional RCTs in pts ≥65 yr: In inpatients ≥65 yr, a multi-strain preparation of lactobacilli and bifidobacteria does not seem to prevent occurrence of ADD or CDD Allen SJ et al. Lancet 2013;382:1249-57 2 of 2