Probiotics Effect on Mental Wellness

Improvement in mental wellbeing will be measured using the Oxford Happiness Questionnaire (OHQ).

The Oxford Happiness Inventory was devised as a broad measure of personal happiness. The OHQ has a total of 29 items. Each item is scored on a Likert scale from 1 to 6 (1=strongly disagree; 2=moderately disagree; 3=slightly disagree; 4=slightly agree; 5=moderately agree; 6=strongly agree). Some items are phrased positively and others negatively. Such that negative items (1, 3, 12, 13, 16, 18, 21 and 29) should be scored in reverse (Hills & Argyle, 2002). The total score is then divided by 29. Interpretation of the final score is as follows: A final score between 1 to 2 is considered "not happy"; between 2 and 3 is "somewhat unhappy"; between 3 and 4 is considered "Neutral"; 4 is "somewhat or moderately happy"; between 4 and 5 is "rather happy"; between 5 and 6 is "very happy"; 6 is "too happy".

Change in stress scores will be measured using the short version of the Depression, Anxiety, Stress Scale (DASS-21). Each item is scored from 0 to 3, with a score of 0 indicating that the statement did not apply or never. A score of 3 indicates that the statement applied very much or almost always. In DASS-21, items 1, 6, 8, 11, 12, 14 and 18 relate to measurement of stress. Given that DASS-21 is the short version of DASS-42, the total item score is multiplied by 2. The final total scores range from 0 (no stress) to 42 (extremely stressed). Scores ranging between 0-14 (stress) are considered normal. Scores above 14 are considered positive for stress.

Change in anxiety scores will be measured using the short version of the Depression, Anxiety, Stress Scale (DASS-21). Each item is scored from 0 to 3, with a score of 0 indicating that the statement did not apply or never. A score of 3 indicates that the statement applied very much or almost always. In DASS-21, items 2, 4, 7, 9, 15, 19 and 20 relate to measurement of anxiety. Given that DASS-21 is the short version of DASS-42, the total item score is multiplied by 2. The final total scores range from 0 (no anxiety) to 42 (extremely anxious). Scores ranging between 0-14 (stress) are considered normal. Scores above 14 are considered positive for anxiety.

Change in depression scores will be measured using the short version of the Depression, Anxiety, Stress Scale (DASS-21). Each item is scored from 0 to 3, with a score of 0 indicating that the statement did not apply or never. A score of 3 indicates that the statement applied very much or almost always. In DASS-21, items 3, 5, 10, 13, 16, 17, and 21 relate to measurement of depression . Given that DASS-21 is the short version of DASS-42, the total item score is multiplied by 2. The final total scores range from 0 (no depression ) to 42 (extremely depressed). Scores ranging between 0-14 (stress) are considered normal. Scores above 14 are considered positive for depression .

The saliva kit contains contains a 15 ml sterile plastic tube with lid and instructions. The instructions outline that the participant will need to self-collect the saliva sample before going to bed by spitting into the tube to fill up ½ of the tube. The collection process should take no more than 15-30 minutes total. The participant shall writ their name, the date, and the time of collection on the tube. The full sample volume will be used for measurement.