Snack Foods and Their Impact on the Immune Response Following Influenza Vaccination

ABSTRACT

ConditionImmune Response

InterventionDietary Supplement Intervention snack;Dietary Supplement Control snack

Primary outcome:Rates of seroconversion for =1 influenza virus strain

Criteria
Inclusion Criteria

1. Men or women, aged between 40-64 years

2. Body mass index (BMI) of 18.50 - 29.99 kg/m2

3. Individuals who regularly consume snacks (=2 per day, excluding fruit, vegetable, nut
and seed snacks)

4. Fibre intake <30 g/d

5. Willing to avoid receiving any vaccination (except for COVID-19 vaccination) from one
month prior to the baseline visit until completion of the 8-week intervention period

6. Willing to avoid receiving any COVID-19 vaccination/booster between week 2 and week 8
of the intervention period

7. Willing to discontinue use of prebiotics and probiotics during the trial

8. Willing to follow the protocol and provide consent

Exclusion Criteria

1. Allergy or intolerance to any intervention products

2. Dislike of any intervention products

3. Immunodeficiency/immunosuppression due to disease or medication, such as

- Chronic inflammatory disease or autoimmune disease (e.g., rheumatoid arthritis,
inflammatory bowel disease, psoriasis) or primary or secondary immunodeficiency
disease (e.g., HIV infection)

- Ongoing therapy with immunomodulators or immunosuppressants (e.g., chemotherapy,
oral corticosteroids, daily use of inhaled or nasal corticosteroids)

- Other immunodeficient state (e.g., asplenia).

4. Medical history of any of the following diabetes, major active psychiatric conditions
(e.g. schizophrenia), current eating disorder, alcohol abuse, active treatment for
cancer in the last year, severe neurological, endocrine, renal, cardiac or pulmonary
disease (or any other chronic medical condition), severe oesophagitis, gastritis or
duodenitis, active diverticulitis or intestinal/colonic strictures, Coeliac disease,
Crohn's disease or Ulcerative colitis, stem cell or organ transplant, gut resection
surgery, bleeding disorder, anaphylaxis or any other major or chronic condition known
to impact study outcome measures.

5. Ongoing use of antiviral agents, or any other drugs known to impact study outcome
measures

6. Use of immunoglobulins and/or any blood products within the three months prior to
vaccination

7. Ongoing use of anticoagulants (e.g., warfarin)

8. Antibiotic treatment in the month prior to the start of the study

9. Consumption of probiotics or prebiotic products within the four weeks prior to the
start of the study

10. History of severe adverse reaction and/or allergic reaction associated with the
influenza vaccine or any other vaccine

11. Known allergy or hypersensitivity to any component of the vaccine including sodium
chloride, potassium chloride, magnesium chloride hexahydrate, disodium phosphate
dihydrate, potassium dihydrogen phosphate; and possible trace residues
beta-propiolactone, cetyltrimethylammonium bromide, and polysorbate 80

12. Suffered from influenza illness in the six months prior to the start of the study

13. For participants recruited on or before 30/06/2023, exclusion criteria is already
vaccinated with any influenza vaccine licensed for the 2022/2023 season; For
participants recruited after 30/06/2023, exclusion criteria is already vaccinated
with any influenza vaccine licensed for the 2023/2024 season

14. Received any influenza vaccination within six months prior to the start of the study

15. Received any other vaccinations within one month prior to the start of the study
(except for COVID-19 vaccination)

16. Women who are pregnant, lactating or planning pregnancy

17. Ongoing alcohol, drug or medication abuse

18. Unexplained or unintentional weight loss in the past six months