title: Evaluation ofLactobacillus coryniformisCECT5711 strain as a coadjuvant in a vaccination process: a randomised clinical trial in healthy adults.
abstract: BACKGROUND
  Although the effects of probiotics on the immune system have been extensively evaluated under disease states, their role in healthy situations remains unclear, since changes are hardly expected under immunological homeostasis. EFSA indicates that vaccination protocols could be used to evaluate the potential role of probiotics to improve the immune response against antigen challenges. The aim of the study was to evaluate the effect ofLactobacillus coryniformisCECT5711 (Lc) on the specific immunity of healthy volunteers undergoing vaccination with Hepatitis A virus (HAV).
  
  
  METHODS
  One hundred twenty-three healthy adults were randomised into three groups to follow a 6-week (wk) intervention and all received an intramuscular HAV vaccine 2 weeks after starting the intervention: 1) PRO1 received Lc for 2weeks (1 capsule/day; 3 × 109CFU/capsule) and placebo capsules after vaccination; 2) PRO2 received a daily capsule of Lc (3 × 109cfu/day) before and after the challenge; 3) Control group (C) received a daily placebo capsule before and after the vaccine. Blood samples were collected at the beginning (visit 1; V1) and after 2 (V2) and 6 weeks (V3) of the intervention. At each visit, lymphocyte subset counts and cytokine levels were analysed. Specific HAV antibodies were analysed at V1 and V3. To evaluate differences between groups, one-way ANOVA with Bonferroni post-hoc test were used regarding lymphocyte subset counts and specific HAV antibodies production, and Friedman test of related samples and Kendall concordance coefficient for cytokines production. Chi square test was used to analyse seroconversion rates.
  
  
  RESULTS
  Specific HAV antibodies were significantly higher in PRO1 (50.54 ± 29.57) compared to C (36.23 ± 16.45) (P= 0.017) and showed an intermediate value in PRO2 (41.61 ± 15.74). Seroconversion rates were similar in the three groups (97.3, 92.3 and 97.4% in C, PRO1 and PRO2 respectively). Memory T-helper lymphocytes increased in V3 vs. V1 (P= 0.032) in PRO2. No differences were found in cytokine concentrations.
  
  
  CONCLUSIONS
  Mixed results have been found regarding the usefulness of Lc supplementation to increase the antigen-specific antibody response to an immune challenge. Clinical trial registration number: EudraCT Number 2016-000183-42. Registered 19 January 2016. Retrospectively registered.
authors.affiliation: Immunonutrition Group (Metabolism and Nutrition Department) - Institute of Food Science, Technology and Nutrition, Spanish National Research Council (ICTAN-CSIC), José Antonio Novais St. 10, 28040 Madrid, Spain.
authors.forename: Noemí
authors.initials: N
authors.lastname: Redondo
authors.affiliation: Immunonutrition Group (Metabolism and Nutrition Department) - Institute of Food Science, Technology and Nutrition, Spanish National Research Council (ICTAN-CSIC), José Antonio Novais St. 10, 28040 Madrid, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Nova
authors.affiliation: Immunonutrition Group (Metabolism and Nutrition Department) - Institute of Food Science, Technology and Nutrition, Spanish National Research Council (ICTAN-CSIC), José Antonio Novais St. 10, 28040 Madrid, Spain.
authors.forename: Alina
authors.initials: A
authors.lastname: Gheorghe
authors.affiliation: Immunonutrition Group (Metabolism and Nutrition Department) - Institute of Food Science, Technology and Nutrition, Spanish National Research Council (ICTAN-CSIC), José Antonio Novais St. 10, 28040 Madrid, Spain.
authors.forename: Ligia Esperanza
authors.initials: LE
authors.lastname: Díaz
authors.affiliation: Immunonutrition Group (Metabolism and Nutrition Department) - Institute of Food Science, Technology and Nutrition, Spanish National Research Council (ICTAN-CSIC), José Antonio Novais St. 10, 28040 Madrid, Spain.
authors.forename: Aurora
authors.initials: A
authors.lastname: Hernández
authors.affiliation: Immunonutrition Group (Metabolism and Nutrition Department) - Institute of Food Science, Technology and Nutrition, Spanish National Research Council (ICTAN-CSIC), José Antonio Novais St. 10, 28040 Madrid, Spain.
authors.forename: Ascensión
authors.initials: A
authors.lastname: Marcos
keywords: Healthy Adults; Immune response; Lactobacillus coryniformis CECT5711; Probiotics; Vaccine