Acute and Chronic Effects of Ecologic Barrier© on Mood and Cognition

A standardised assessment of visuospatial working memory. The task comprises nine identical squares fixed in a random arrangement on a screen. Participants observe sequences of between two and nine blocks, which they then reproduce as accurately as possible. The dependent variable is the number of blocks pointed out in the correct order. Four versions of each sequence length are presented during the task. A novel sequence will be presented on each occasion, the order of which will be counterbalanced across participants.

Participants will be presented with a sequential list of 15 words, at a rate of 1 word per second. The participant will then have 60s to say out loud as many of these words as possible, with the resulting score recorded as a percentage of accuracy.

After a period of time subject are asked to recall as many words as possible from list A

Following the delayed word recall, words from list A, list B and novel words are displayed sequentially on the screen and participants are asked to indicate which words were from list A only.

This task requires executive function and sustained attention, and provides a measure of cognitive flexibility. Participants view a circle with 8 equally spaced radii 2 of which form a bold bisecting line. Numbers are chosen randomly from a set of 1-4 & 6-9 and displayed sequentially in a clockwise direction. A response of higher or lower than 5 is made for trials below the bold line, and even or odd for numbers above the line. Outcome measures include overall accuracy and reaction time (RT) on correct trials, as well as accuracy and RT on trials where there is a 'switch cost' from stimuli moving from below to above the bold line and vice versa.

This task measures executive function - specifically the ability to inhibit or withhold a response to no-go stimuli. Both a neutral block (white circles) and an emotional block (happy and fearful faces from the FACES database) are included here, in order to explore any additional influence of emotional stimuli on inhibitory responses. Outcome measures include accuracy and reaction time (RT). Accuracy and reaction times in the emotional blocks may also be correlated with responses to mood measures.

A validated questionnaire measure of cognitive reactivity. The LEIDS-r comprises of 34 items which the participant rate on a scale from 0-4 to indicate how strongly each statement applied to them when they are feeling somewhat sad.

A validated self-report measure of affective state. The PANAS comprises of two distinct affective states (positive and negative), as well as 11 individual affective states (fear, guilt, sadness, surprise, hostility, shyness, joviality, self-assurance, attentiveness, fatigue and serenity. Subjects use a likert scale from 1 - 5 to indicate how the word relates to how they are currently feeling. As this analysis is exploratory all affective states will be explored.

A well validated scale for assessing self-reported state and trait anxiety. In line with the study objectives, only the state items will be used to assess current feelings of anxiety in the participants. This includes 10 items which are rated using a 4-point likert scale.

A validated 10 item scale for self-reporting levels of perceived stress over the last month. Items are rated using a 5-point likert scale.

A validated, brief self report measure of depressive symptoms commonly used to assess sub-clinical levels of low mood. Items are responded to using a 4-point likert scale. Scores range from 0 to 60, with high scores indicating greater depressive symptoms.

16S rRNA sequencing for classification and quantification of faecal bacteria

The Montreal Cognitive Assessment (MoCA) is a short cognitive screening tool to indicate current cognitive status. It is similar to the Mini Mental State Examination, but more sensitive to Mild Cognitive Impairment. Results will not be used to screen for eligibility, but baseline MoCA score may be included as covariate.

The FFQ is a validated tool for gauging the average habitual dietary intake of micro and macronutrients of an individual in the UK, which is particularly important to explore in order to understand how the probiotic supplement may interact with diet and gut microbiome diversity. Data will be processed using the FETA software.