Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2025 Aug;80(8):2158-2166.
doi: 10.1111/all.16634. Epub 2025 Jun 27.

Effect of the Multi-Strain Probiotic SYN-53 in the Management of Allergic Rhinoconjunctivitis

Karl-Christian Bergmann  1   2   3 , Torsten Zuberbier  1   2   3
Affiliations
Randomized Controlled Trial

Effect of the Multi-Strain Probiotic SYN-53 in the Management of Allergic Rhinoconjunctivitis

Karl-Christian Bergmann et al. Allergy. 2025 Aug.

Abstract

Dysbiosis is increasingly linked to allergy development. This study evaluates the efficacy of the multi-strain probiotic SYN-53 in the management of allergic rhinoconjunctivitis (ARC). Eighty-four subjects with confirmed grass pollen allergy underwent up to three bi-weekly 3-day intake cycles with SYN-53 or placebo. After each cycle, subjects were exposed to grass pollen in an allergen exposure chamber. ARC symptoms were assessed using the Total Symptom Score (TSS) before and after each use of SYN-53. After one intake cycle, SYN-53 already showed a trend towards greater efficacy over placebo, which became significant after two cycles (ΔTSSMAX: -3.44 ± 0.42 vs. -1.87 ± 0.37; p = 0.0067), with 38% vs. 24% symptom relief. In subjects with moderate to severe symptoms, SYN-53 was already significantly superior after one single intake cycle and improved further after two cycles (ΔTSSMAX: -4.78 ± 0.51 vs. -2.43 ± 0.47; p = 0.0014), with 45% vs. 26% symptom relief. SYN-53 is effective in the management of ARC, highlighting the role of bacterial diversity and dosage in probiotic nutritional supplements.

Keywords: allergen exposure chamber; allergic rhinitis; allergic rhinoconjunctivitis; microbiome; probiotic.

PubMed Disclaimer

Conflict of interest statement

The European Centre for Allergy Research Foundation (ECARF) received reimbursement for participating as a study center. K.‐C.B. received honoraria for lectures from ALK, Allergopharma, Almirall, AstraZeneca, Bencard, Berlin‐Chemie, Chiesi, GSK, HAL, Mundipharma, Novartis, Sanofi, and Stallergenes during the last 5 years. T.Z. has received institutional funding for research and/or honoria for lectures and/or consulting from Amgen, AstraZeneca, AbbVie, ALK, Almirall, Astellas, Bayer Health Care, Bencard, Berlin Chemie, Blueprint Medicines, FAES, HAL, Henkel, Kryolan, Leti, L'Oreal, Meda, Menarini, Merck, MSD, Novartis, Pfizer, Sanofi, Stallergenes, Takeda, Teva and UCB, Uriach; in addition, he is a member of ARIA/WHO, DGAKI, ECARF, GA2LEN and WAO.

Figures

FIGURE 1
FIGURE 1
Timeline of the intake cycles and allergen exposures during the clinical study.
FIGURE 2
FIGURE 2
Overview and results of the intention‐to‐treat (ITT) population. (A) Overview of the subject flow (TSSMAX ≥ 3). (B) Difference in maximum Total Symptom Score (∆TSSMAX) in the ITT population after one, two and three intake cycles. ANCOVA analysis, values shown as mean ± SEM, n(placebo) = 47, n(intervention) = 37.
FIGURE 3
FIGURE 3
Overview and results of the subgroup analysis, with subject cluster TSSMAX ≥ 6. (A) Overview of the subject flow of cluster TSSMAX ≥ 6. (B) Difference in maximum Total Symptom Score (∆TSSMAX) in the cluster TSSMAX ≥ 6 after one, two and three intake cycles. ANCOVA analysis, values shown as mean ± SEM, n(placebo) = 33, n(intervention) = 28.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Pawankar R., “Allergic Diseases and Asthma: A Global Public Health Concern and a Call to Action,” World Allergy Organization Journal 7, no. 1 (2014): 12, 10.1186/1939-4551-7-12. - DOI - PMC - PubMed
    1. Savoure M., Bousquet J., Jaakkola J. J. K., Jaakkola M. S., Jacquemin B., and Nadif R., “Worldwide Prevalence of Rhinitis in Adults: A Review of Definitions and Temporal Evolution,” Clinical and Translational Allergy 12, no. 3 (2022): e12130, 10.1002/clt2.12130. - DOI - PMC - PubMed
    1. Blaiss M. S., Hammerby E., Robinson S., Kennedy‐Martin T., and Buchs S., “The Burden of Allergic Rhinitis and Allergic Rhinoconjunctivitis on Adolescents: A Literature Review,” Annals of Allergy, Asthma & Immunology 121, no. 1 (2018): 43–52, 10.1016/j.anai.2018.03.028. - DOI - PubMed
    1. Bousquet J., Anto J. M., Bachert C., et al., “Allergic Rhinitis,” Nature Reviews Disease Primers 6, no. 1 (2020): 95, 10.1038/s41572-020-00227-0. - DOI - PubMed
    1. Zuberbier T., Lotvall J., Simoens S., Subramanian S. V., and Church M. K., “Economic Burden of Inadequate Management of Allergic Diseases in the European Union: A GA(2) LEN Review,” Allergy 69, no. 10 (2014): 1275–1279, 10.1111/all.12470. - DOI - PubMed

Publication types

Grants and funding