Parental report of clinical symptoms (percentile score - higher score reflects more/more severe symptoms)

1. Disruptive Behavior Indicator
2. Learning and Language Disorder Indicator
3. Mood Disorder Indicator
4. Anxiety Disorder Indicator
5. ADHD Indicator

Teacher report of clinical symptoms (percentile score - higher score reflects more/more severe symptoms)

1. Disruptive Behavior Indicator
2. Learning and Language Disorder Indicator
3. Mood Disorder Indicator
4. Anxiety Disorder Indicator
5. ADHD Indicator

Child self-report of clinical symptoms (percentile score - higher score reflects more/more severe symptoms)

1. Disruptive Behavior Indicator
2. Learning and Language Disorder Indicator
3. Mood Disorder Indicator
4. Anxiety Disorder Indicator
5. ADHD Indicator

Computerised test of visual working memory

• DMS Percent Correct (overall, for all delays, simultaneous, 0 sec delay, 4 sec delay, 12 sec delay). Range 0-100% - higher score reflects greater accuracy.
• DMS Mean & Median Correct Latency (overall, for all delays, simultaneous, 0 sec delay, 4 sec delay, 12 sec delay). Range 0-∞ ms - higher score reflects worse performance.
• DMS Correct Latency Standard Deviation. Range 0-∞ ms - higher score reflects worse performance.
• DMS Mean Choices to Correct response. Range 0-4 - higher score reflects worse performance.
• DMS Probability of Error Given Error. Range 0-1 - higher score reflects worse performance.

Record of sleep - used qualitatively to detect and remove artefacts from the data.

Parental report of child's sleep A Total Sleep Disturbances score is calculated as the sum of all CSHQ scored questions, and can range from 33 to 99. A higher score indicates more problematic sleep.

Week long retrospective sleep survey (Scores range from 13-39 with a higher score indicating more/more severe sleep difficulties).

Objective measure of sleep quality and daytime activity

• Mean activity during sleep. Range 0-∞. A higher score = less sound sleep (worse).
• Minutes spent awake during the down period. Range 0-∞. A higher score = less sound sleep (worse).
• Sleep latency (time taken to fall asleep). Range 0-∞. A higher score = more time taken to fall asleep (worse).
• Sleep efficiency (% down period spent asleep, after removing sleep latency). A higher score = better.
• Wake after sleep onset (minutes spent awake during the down period after removing sleep latency). Range 0-∞. A higher score = less sound sleep (worse).
• Sleep fragmentation (number of awakenings/ total minutes of sleep x 100) - Higher score = more fragmented sleep (worse).
• Mean daytime activity (0-∞) not necessarily worse or better.

Questionnaire to evaluate common gastrointestinal symptoms Total scores range from 15-105 (with higher scores reflecting more/more severe gastrointestinal symptoms).

Subscales:

1. Abdominal pain (abdominal pain, hunger pains and nausea). Range 3-21 - a high score reflects worse symptoms.
2. Reflux syndrome (heartburn and acid regurgitation). Range 3-21 - a high score reflects worse symptoms.
3. Diarrhoea syndrome (diarrhoea, loose stools and urgent need for defecation). Range 3-21 - a high score reflects worse symptoms.
4. Indigestion syndrome (borborygmus, abdominal distension, eructation and increased flatus). Range 3-21 - a high score reflects worse symptoms. Range 3-21 - a high score reflects worse symptoms.
5. Constipation syndrome (constipation, hard stools and feeling of incomplete evacuation). Range 3-21 - a high score reflects worse symptoms.

Analysis of bacterial strains and diversity within stool sample

Questionnaire to assess the acceptability of the diet to parents of the children taking part in the study Score range 6-42 (High score reflects more positive attitude to treatment)