Lactobacillus reuteri supplements do not affect salivary IgA or cytokine levels in healthy subjects: A randomized, double-blind, placebo-controlled, cross-over trial.
OBJECTIVE
To evaluate the effect of daily ingestion of probiotic lactobacilli on the levels of secretory IgA (sIgA) and selected cytokines in whole saliva of healthy young adults.


METHODS
The study group consisted of 47 healthy adults (18-32 years) who volunteered for a randomized, double-blind, placebo-controlled, cross-over trial after informed consent. During intervention, the subjects ingested two lozenges per day containing two strains of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) or placebo lozenges. The intervention and wash-out periods were 3 weeks. Saliva samples were collected at baseline, immediately after each intervention period and 3 weeks post-intervention. ELISA was used to measure sIgA and luminex technology was used to measure the interleukins (IL)-1β, IL-6, IL-8 and IL-10. For statistical analyses a mixed ANOVA model was employed to calculate changes in the salivary outcome variables.


RESULTS
Forty-one subjects completed the study and reported a good compliance. No significant differences in the concentrations of salivary sIgA or cytokines were recorded between the L. reuteri and placebo interventions or between baseline and 3 weeks post-intervention levels. No side- or adverse effects were reported.


CONCLUSIONS
Supplementation with two strains of the probiotic L. reuteri did not affect sIgA or cytokine levels in whole saliva in healthy young adults. The results thereby indicate that daily oral supplementation with L. reuteri do not seem to modulate the salivary oral immune response in healthy young subjects (ClinicalTrials.gov NCT02017886).
a Department of Odontology, Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark ;
Mette Rose
MR
Jørgensen
a Department of Odontology, Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark ;
Mette Kirstine
MK
Keller
a Department of Odontology, Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark ;
Camilla
C
Kragelund
b Department of Cariology, Faculty of Odontology , Malmö University , Malmö , Sweden ;
Kristina
K
Hamberg
b Department of Cariology, Faculty of Odontology , Malmö University , Malmö , Sweden ;
Dan
D
Ericson
a Department of Odontology, Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark ;|c Institute for Inflammation Research, Department of Rheumatology and Spine Disease , Copenhagen University Hospital Rigshospitalet , Copenhagen , Denmark.
Claus Henrik
CH
Nielsen
a Department of Odontology, Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark ;
Svante
S
Twetman
D000293:Adolescent; D000328:Adult; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000032:analysis*; D016753:Interleukin-10 / Q000032:analysis; D053583:Interleukin-1beta / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D016209:Interleukin-8 / Q000032:analysis; D007378:Interleukins / Q000032:analysis*; D052200:Limosilactobacillus reuteri; D008297:Male; D010919:Placebos; D019936:Probiotics / Q000627:therapeutic use*; D012463:Saliva / Q000276:immunology* / Q000382:microbiology; D012471:Salivary Proteins and Peptides / Q000032:analysis; D055815:Young Adult
C508606:CXCL8 protein, human; C508609:IL10 protein, human; C508600:IL6 protein, human; D007071:Immunoglobulin A, Secretory; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D007378:Interleukins; D010919:Placebos; D012471:Salivary Proteins and Peptides; D016753:Interleukin-10
Clinical studies; immunoglobulins; interleukins; probiotics