Inclusion Criteria:  Adults aged 18 at the time of registration; Seasonal allergic rhinoconjunctivitis (AR) in the context of grass pollen allergy diagnosed on the basis of anamnesis cfr. ARIA guidelines and positive skin prick test and / or immunocap assay; Positive skin prick test (SPT) for grass pollen and / or the presence of specific IgE for grass pollen, confirmed by a medical specialist, measured at the start of the study: Soluprick SQ Phleum pratense pollen 10 HEP - ALK and / or IgE specific immunocap assay Phleum pratense (timothy grass) (g6); Body Mass Index in the range of 19-32 kg / m2; Instructed during screening and agreed not to use other probiotic products outside of the study during the study period; Signed the consent form.  Exclusion Criteria:  Antibiotic use at baseline and during the study; Pregnant women; Unstable / uncontrolled asthma (to be determined by investigator-physician); Sensitization to dust mites History of probiotic use in the past two weeks; Current diagnosis of cancer or immunosuppressive therapy within the past 6 months; Abnormalities of the oral mucosa; Acute and chronic infectious and inflammatory upper airway diseases (eg acute / chronic rhinosinusitis cfr. EPOS guidelines); Clinically significant bleeding disorder; Any other medical condition that, in the principal investigator's opinion, warrants exclusion from the trial; History of regular use (> 3 days out of 7) of tobacco products within the previous two weeks