title: Specific probiotics and virological findings in symptomatic conscripts attending military service in Finland.
abstract: BACKGROUND
  Viral upper respiratory tract infections occur frequently among conscripts. Probiotics have reduced viral infections in children attending day care. Limited data are available on the effects of probiotics on the nasopharyngeal presence of respiratory viruses.
  
  
  OBJECTIVE
  To assess, whether probiotics could decrease nasopharyngeal occurrence of respiratory viruses in Finnish conscripts.
  
  
  METHODS
  In a randomized, double-blind, placebo-controlled 90- and 150-day intervention study, 239 nasopharyngeal swab samples were collected from 192 symptomatic conscripts receiving daily chewable probiotic tablet containing Lactobacillus rhamnosus GG and Bifidobacterium animalis ssp. lactis BB-12 (46.9%) or control tablet (53.1%) on visits to a garrison's health care center due to symptoms of infection. The presence of respiratory viruses was tested by PCR-methods, and viral findings were compared between the intervention groups.
  
  
  RESULTS
  184 (76.9%) nasopharyngeal samples were positive for at least one respiratory virus. Picornaviruses were the most common viruses and were detected in 155 (84.2%) of samples. Of these, 143 (92.3%) were rhinovirus-positive and 20 (12.9%) were enterovirus-positive. The control group had 83 (64%) and the probiotic group 72 (66%) picornavirus infections (p=0.79). Monthly distribution of picornaviruses showed that there were less picornavirus findings after 3 months in the probiotic group than in the control group (p=0.0069). However, probiotics did not reduce picornavirus occurrence in other months.
  
  
  CONCLUSIONS
  Overall, probiotics did not reduce viral occurrence in symptomatic conscripts. However, probiotics decreased the presence of picornaviruses after 3 months, which may imply that probiotics play a role against viruses causing common cold. Further investigations are necessary to clarify the mechanisms involved in order to target specific probiotics on specific respiratory viruses.
authors.affiliation: Centre for Military Medicine, Research and Development Department, Finnish Defense Forces, FI-00301 Helsinki, Finland; Institute of Biomedicine, Pharmacology, University of Helsinki, FI-00014 Helsinki, Finland. Electronic address: liisa.lehtoranta@helsinki.fi.
authors.forename: Liisa
authors.initials: L
authors.lastname: Lehtoranta
authors.affiliation: Centre for Military Medicine, Research and Development Department, Finnish Defense Forces, FI-00301 Helsinki, Finland.
authors.forename: Kim
authors.initials: K
authors.lastname: Kalima
authors.affiliation: Department of Public Health, Hjelt Institute, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Liang
authors.initials: L
authors.lastname: He
authors.affiliation: Department of Virology and Immunology, Helsinki University Central Hospital, Laboratory Services (HUSLAB), PO Box 400, FI-00029 Helsinki, Finland; Institute of Clinical Medicine, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Maija
authors.initials: M
authors.lastname: Lappalainen
authors.affiliation: Intestinal Viruses Unit, National Institute for Health and Welfare, FI-00271 Helsinki, Finland.
authors.forename: Merja
authors.initials: M
authors.lastname: Roivainen
authors.affiliation: Mehiläinen Ltd, FI-00260 Helsinki, Finland.
authors.forename: Mervi
authors.initials: M
authors.lastname: Närkiö
authors.affiliation: Institute of Clinical Medicine, University of Helsinki, FI-00014 Helsinki, Finland; Skin and Allergy Hospital, Helsinki University Central Hospital, FI-00029 Helsinki, Finland.
authors.forename: Mika
authors.initials: M
authors.lastname: Mäkelä
authors.affiliation: Centre for Military Medicine, Research and Development Department, Finnish Defense Forces, FI-00301 Helsinki, Finland.
authors.forename: Simo
authors.initials: S
authors.lastname: Siitonen
authors.affiliation: Institute of Biomedicine, Pharmacology, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Riitta
authors.initials: R
authors.lastname: Korpela
authors.affiliation: Institute of Clinical Medicine, University of Helsinki, FI-00014 Helsinki, Finland; Department of Otorhinolaryngology-Head and Neck Surgery, Helsinki University Central Hospital, FI-00029 Helsinki, Finland. Electronic address: anne.pitkaranta@helsinki.fi.
authors.forename: Anne
authors.initials: A
authors.lastname: Pitkäranta
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008889:Military Personnel; D009305:Nasopharynx / Q000821:virology; D019936:Probiotics; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D012621:Seasons; D055815:Young Adult
keywords: Conscript; Probiotic; Respiratory virus; Rhinovirus