title: Oral Administration ofLactobacillus plantarum299v Reduces Cortisol Levels in Human Saliva during Examination Induced Stress: A Randomized, Double-Blind Controlled Trial.
abstract: Objective. To clarify the effect ofLactobacillus plantarum299v on the salivary cortisol and salivary IgA levels in young adults under examination stress.Design. Forty-one students with an upcoming academic exam were included in a randomized double-blind, placebo-controlled study. The probiotic bacteria or the placebo product was administered in capsules once a day during 14 days. Saliva was collected and a perceived stress test was filled out at each sampling occasion. Saliva was collected for cortisol analysis by Electrochemiluminescence Immunoassay (ECLI) and salivary IgA was analysed by Enzyme-Linked Immunosorbent Assay (ELISA). Abundance of lactobacilli was evaluated by cultivation of saliva on selective medium and identification ofL. plantarum299v was done on randomly selected colonies by a random amplification of polymorphic DNA (RAPD) typing.Results. A significant difference in cortisol levels was found between the treatment group and the placebo group (P< 0.05), together with a significant increase in levels of lactobacilli in the treatment group compared with the placebo group (P< 0.001). No significant changes were found for salivary IgA.Conclusion. A probiotic bacterium with ability to reduce symptoms of irritable bowel syndrome (IBS) prohibited increased levels of the stress marker cortisol during the examination period. The registration number of the study is NCT02974894, and the study is registered at ClinicalTrials.gov.
authors.affiliation: Food Hygiene, Department of Food Technology, Engineering and Nutrition, Lund University, P.O. Box 124, 22100 Lund, Sweden.
authors.forename: Hannah
authors.initials: H
authors.lastname: Andersson
authors.affiliation: Food Hygiene, Department of Food Technology, Engineering and Nutrition, Lund University, P.O. Box 124, 22100 Lund, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Tullberg
authors.affiliation: Food Hygiene, Department of Food Technology, Engineering and Nutrition, Lund University, P.O. Box 124, 22100 Lund, Sweden.
authors.forename: Siv
authors.initials: S
authors.lastname: Ahrné
authors.affiliation: Faculty of Odontology, Malmö University, 205 06 Malmö, Sweden.
authors.forename: Kristina
authors.initials: K
authors.lastname: Hamberg
authors.affiliation: Probi AB, Ideon Gamma 1, 223 70 Lund, Sweden.
authors.forename: Irini
authors.initials: I
authors.lastname: Lazou Ahrén
authors.affiliation: Food Hygiene, Department of Food Technology, Engineering and Nutrition, Lund University, P.O. Box 124, 22100 Lund, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Molin
authors.affiliation: Faculty of Odontology, Malmö University, 205 06 Malmö, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Sonesson
authors.affiliation: Food Hygiene, Department of Food Technology, Engineering and Nutrition, Lund University, P.O. Box 124, 22100 Lund, Sweden.
authors.forename: Åsa
authors.identifier: 0000-0001-7584-5540
authors.initials: Å
authors.lastname: Håkansson