The purpose of this study is to investigate the cognitive and mood effects of a probiotic dietary supplement when taken daily for 42 days in healthy older adults aged 65+

Inclusion Criteria:

1. Male or female, aged ≥ 65 years
2. Willing and able to provide written and informed consent
3. Ability of the participant (in the Principal Investigator's opinion) to comprehend the full nature and purpose of the study including possible risks and side effects
4. Agreement to comply with the protocol and study restrictions
5. Available for all study visits
6. In good general health, self-reported and as judged by the Principal Investigator/Clinical advisor based on medical history
7. Fluent in written and spoken English
8. Participant is willing to maintain habitual diet (including caffeine and alcohol) and physical activity patterns throughout the study period
9. Has a bank account (required for payment)

Exclusion criteria:

1. Have any pre-existing significant acute or chronic co-existing medical condition / illness which contraindicates, in the Principal Investigator's judgement, entry to the study NOTE: the explicit exceptions to this are controlled (medicated) hypertension, arthritis, asthma, hay fever, high cholesterol and reflux-related conditions. There may be other, unforeseen, exceptions and these will be considered on a case-by-case basis; i.e. participants may be allowed to progess to screening if they have a condition/illness which would not interact with the active treatments or impede performance
2. History of dementia, stroke and other neurological conditions
3. Traumatic loss of consciousness in the last 12 months
4. History of epilepsy or Parkinson's disease
5. Anxiety, depression or any psychiatric disorder that the Principal Investigator believes would interfere with the objectives of the study and requiring treatment in the last 2 years
6. Currently taking (from day of screening onwards) or have previously taken (last 4 weeks prior to screening) prescription medications that the Principal Investigator believes would interfere with the objectives of the study, pose a safety risk or confound the interpretation of the study results such as psychoactive medication (anxiolytics, sedatives, hypnotics, anti-psychotics, anti-depressants, anti-convulsants, centrally acting corticosteroids, opioid pain relievers) NOTE: the explicit exceptions to this are hormone replacement treatments for female participants where symptoms are stable, those medications used in the treatment of arthritis, high blood pressure, high cholesterol and reflux-related conditions; and those taken 'as needed' in the treatment of asthma and hay fever. As above, there may be other instances of medication use which, where no interaction with the active treatments is likely, participants may be able to progress to screening
7. Currently taking (from day of screening onwards) medication or dietary supplements that the Principal Investigator believes would interfere with the objectives of the study, pose a safety risk or confound the interpretation of the study results such as: melatonin, vitamin E, multivitamins, B vitamin complex, ginkgo biloba, fish oil, St. John's Wort or other cognitive enhancing dietary or herbal supplements over the study period
8. Recent (within last 4 weeks prior to screening) or ongoing antibiotic therapy during the intervention period
9. Daily consumption of concentrated sources of probiotics and / or prebiotics within 2 weeks of screening and throughout the intervention period other than the provided study products (e.g., probiotic / prebiotic tablets, capsules, drops or powders), including yoghurt or yoghurt drinks
10. Have high blood pressure (systolic over 159 mm Hg or diastolic over 99 mm Hg)
11. Have a Body Mass Index (BMI) outside of the range 18.5-29.9 kg/m2
12. Have learning difficulties, dyslexia
13. Have a visual impairment that cannot be corrected with glasses or contact lenses (including colour-blindness)
14. Current smoker (use of nicotine replacement products, vaping, gum, patches etc)
15. Have a history of alcohol or drug abuse
16. Current misuse of alcohol, drug or prescription medications
17. Excessive caffeine intake (>500 mg per day)
18. Excessive alcohol consumption (drinking on 5 or more days a week or consuming > 6 units of alcohol in a single session on 5 or more days a week) for 3 weeks prior to screening and during the intervention period
19. Contraindication to any substance in the investigational product
20. Principal Investigator believes that the participant may be uncooperative and / or noncompliant and should therefore not participate in the study
21. Participant under legal or administrative supervision
22. Have food intolerances / sensitivities
23. Have any health condition that would prevent fulfilment of the study requirements
24. Are unable or unwilling to complete all the study assessments
25. Are currently participating in other clinical or nutrition intervention studies, or have in the past 4 weeks