Assessment of immune-modulating efficacy of two probiotic strains in healthy adults

INTERVENTION: Participants will be randomised to receive only one of the two probiotic strains or placebo. Prebiotics: Limosilactobacillus fermentum FNZ053 and Lactiplantibacillus plantarum FNZ042. These will be included in the capsules with the excipient maltodextrin and provide 1 X1010 CFU per capsule. Lactobacillus spp., one hundred million colony‐forming units (CFU), delivered in oral capsules, one capsule per day for 4 weeks. Adherence to the intervention will be monitored through questionnaire and study product return. CONDITION: immune health;gastrointestinal health; ; immune health ; gastrointestinal health Inflammatory and Immune System ‐ Normal development and function of the immune system Oral and Gastrointestinal ‐ Normal oral and gastrointestinal development and function PRIMARY OUTCOME: Participant immune status assessed by measuring serum proinflammatory cytokines (interkeukins)[Baseline, and 4 weeks after intervention commencement] SECONDARY OUTCOME: Bowel function will be measured using the daily bowel habit diary and Bristol Stool Scale [Daily for 4 weeks] Changes in appetite and food choices will be determined using weekly 3‐day food diary and dietary fructan frequency questionnaires[Weekly for 4 weeks of intervention] Changes in happiness will be measured daily using the Oxford Happiness Questionnaire[Daily for 4 weeks of intervention] Changes in the mood will be measured daily using the Profile of Mood States (POMS)[Daily for 4 weeks of intervention] Collection of stool samples for measuring markers of gut comfort and health[Beginning and end of 4 weeks of the intervention] Gastrointestinal comfort will be determined weekly using the Gastrointestinal Symptom Rating Scale (GSRS)[Weekly for 6 weeks (2 weeks run‐in, 4 weeks intervention)] Participant immune status assessed by measuring serum T cells[Baseline and 4 weeks after intervention commencement] INCLUSION CRITERIA: Healthy adults 18‐60 years