Cited by 103Probiotics and Fermented FoodsPediatric health and respiratory diseasesRespiratory viral infections research

Role of probiotics in stimulating the immune system in viral respiratory tract infections: A narrative review

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Lehtoranta, Liisa, Latvala, Sinikka, Lehtinen, Markus J.·2020·Nutrients

Abstract

Viral respiratory tract infection (RTI) is the most frequent cause of infectious illnesses including the common cold. Pharmacological solutions for treating or preventing viral RTIs are so far limited and thus several self-care products are available in the market. Some dietary supplements such as probiotics have been shown to modulate immune system function and their role in reducing the risk and the course of RTIs has been investigated extensively within the past decade. However, the mechanism of action and the efficacy of probiotics against viral RTIs remains unclear. We searched PubMed, Google Scholar, and Web of Knowledge for pre-clinical and clinical studies investigating the effect of probiotics on respiratory virus infections, immune response, and the course of upper and lower respiratory tract illness. The literature summarized in this narrative review points out that specific probiotic strains seem effective in pre-clinical models, through stimulating the immune system and inhibiting viral replication. Clinical studies indicate variable efficacy on upper respiratory illnesses and lack proof of diagnosed viral infections. However, meta-analyses of clinical studies indicate that probiotics could be beneficial in upper respiratory illnesses without specific etiology. Further studies aiming at discovering the mechanisms of action of probiotics and clinical efficacy are warranted.

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  • Probiotics and synbiotics can mediate the balance and diversity of the gut microbiota, which plays a significant role in the host's response to many viral infections.

    “Probiotics and synbiotics can mediate the balance and diversity of the gut microbiota, which plays a significant role in the host's response to many viral infections, either by promoting the attachment of viruses to host cells or by supporting antiviral immunity (such as interferons and innate immune activation).”

    From Comparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis (2025) · cites this paper as [7]

    Section 4.1 (page unavailable) says probiotics can temporarily change gut microbiota composition and influence immune responses, including through the gut–lung axis in respiratory tract infections. Sections 4.2–4.3 describe antiviral immune effects, including interferon activation. The copy does not establish the claim for synbiotics, changes in microbiota diversity, or viral infections broadly; it also does not describe microbiota promoting viral attachment to host cells. (LLM, conf=0.85)

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  • Antiviral cytokine responses such as IFN-γ, IL-2, IL-12, and IL-18 as well as improved antibody responses have been reported for probiotics.

    “Also antiviral cytokine responses such as IFN-γ, IL-2, IL-12, and IL-18 as well improved antibody responses have been reported (Lehtoranta et al., 2020).”

    From Viral Infections, the Microbiome, and Probiotics (2021) · cites this paper as Lehtoranta et al., 2020

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Authors
Lehtoranta, L., Latvala, S., & Lehtinen, M. J.
Affiliations
DuPont (Finland) (FI)
Corresponding author
Lehtoranta, Liisa
Venue
Nutrients
Publisher
MDPI AG
Published
2020-10-16
Volume
12
Issue
10
Pages
3163
ISSN
2072-6643 (ISSN-L)
OpenAlex
W3092694889
Cited by
103
References
89
Citations by year
2026: 7 · 2025: 14 · 2024: 11 · 2023: 22 · 2022: 21 · 2021: 26 · 2020: 1 · 2017: 1
FWCI
1.48
Type
journal article
Language
en
Open access
Locations
  • Nutrients (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Life Sciences › Agricultural and Biological Sciences › Food Science › Probiotics and Fermented Foods
  • Health Sciences › Health Professions › Emergency Medical Services › Pediatric health and respiratory diseases
  • Health Sciences › Medicine › Epidemiology › Respiratory viral infections research
Keywords
probiotics, respiratory viral infections, immune system stimulation, common cold, upper respiratory tract infection, lower respiratory tract infection, dietary supplements, viral replication inhibition, probiotic strains, self-care products
MeSH terms
Bifidobacterium, Humans, Immune System, Lactobacillus, Respiratory Tract Infections, Stimulation, Chemical, Virus Diseases, Virus Replication, Dietary Supplements, Probiotics, Immunomodulation

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