Baseline characteristics
Figure 1 summarizes the enrolment and analysis in the clinical trial. The study included 52 individuals recruited from healthcare practices. The study population comprised 23% males and 77% females with the overall average age of the participants being 45.44 ± 13.67 years. The BMI was computed from the weight (lbs) and height (inches) of the participants. The average BMI of the population was 25.32 ± 5.95 (((lbs/inches2) *703)). The baseline FS-SSS score was 21 ± 14.27. The baseline characteristics for the study population have been given in Table 1.
Table 1. Baseline characteristics
Baseline characteristics
|
|
(N = 52)
|
Age
|
45.44 ± 13.67
|
Female, n (%)
|
40 (77)
|
Male, n (%)
|
12 (23)
|
Body mass index ((lbs/inches2) *703)
|
25.32 ± 5.95
|
FS–SSS
|
21 ± 14.27
|
Data is given as mean ± SD
Abbreviations: FS-SSS - Food Sensitivity - Symptom Severity Scale
Intervention outcomes
Food Sensitivity - Symptom Severity Scale (FS-SSS)
To assess the effectiveness of the elimination diet, we aimed to understand the weekly improvement in symptoms during the intervention. For this, the baseline FS-SSS scores were compared to those of weeks, 1,2,3, and 4, respectively. The difference in the FS-SSS scores medians of the baseline and week 1 was dramatic with their medians [(Q1), (Q3)] being, 19.5 [(9.75), (31.25)] and 13.5 [(4.75), (23.25)], respectively. On statistically assessing the baseline and week 1 FS-SSS scores, a significant difference was observed (z = 4.11, p < 0.05) (Table 2). After week 1, a gradual decrease in FS-SSS scores was seen in weeks, 2, 3, and 4. Their medians [(Q1), (Q3)] were 11 [(4), (19.25)], 7 [(2.75), (14.5)], and 6 [(2), (11)], respectively. Statistically significant differences in FS-SSS scores were noted between baseline and week 2 (z = 5.27, p < 0.05), week 3 (z = 5.76, p < 0.05), and week 4 (z = 5.61, p < 0.05), respectively (Table 2). The Friedman test enabled assessing the overall change in the FS-SSS scores across baseline to week 4 which was also found to be statistically significant (p < 0.05) (Table 3). Figure 2 is indicative of the reduction in mean FS-SSS scores during the intervention.
Table 2. Weekly improvement in symptoms assessed by the Wilcoxon Signed Rank Test
Weekly improvement in symptoms
|
|
(N = 52)
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|
|
|
|
|
|
|
Median
[(Q1), (Q3)]
|
Median
[(Q1), (Q3)]
|
p Value
|
|
Baseline
|
Week 1
|
|
FS - SSS
|
19.5
[(9.75), (31.25)]
|
13.5
[(4.75), (23.25)]
|
< 0.05*
|
|
|
|
|
|
Baseline
|
Week 2
|
|
FS - SSS
|
19.5
[(9.75), (31.25)]
|
11
[(4), (19.25)]
|
< 0.05*
|
|
|
|
|
|
Baseline
|
Week 3
|
|
FS - SSS
|
19.5
[(9.75), (31.25)]
|
7
[(2.75), (14.5)]
|
< 0.05*
|
|
|
|
|
|
Baseline
|
Week 4
|
|
FS - SSS
|
19.5
[(9.75), (31.25)]
|
6
[(2), (11)]
|
< 0.05*
|
*Statistically significant at α=0.05.
Abbreviations: FS-SSS - Food Sensitivity - Symptom Severity Scale
Table 3. Friedman Test analysis for overall improvement and effect of demographics on intervention outcomes
Friedman Test analysis for overall improvement and effect of demographics on intervention outcomes
|
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(N =52)
|
|
|
|
|
|
|
Baseline
FS-SSS
|
Week 1
FS-SSS
|
Week 2
FS-SSS
|
Week 3
FS-SSS
|
Week 4
FS-SSS
|
p Value
|
|
Median
[(Q1), (Q3)]
|
Median
[(Q1), (Q3)]
|
Median
[(Q1), (Q3)]
|
Median
[(Q1), (Q3)]
|
Median
[(Q1), (Q3)]
|
|
|
|
|
|
|
|
|
Overall improvement
|
19.5
[(9.75), (31.25)]
|
13.5
[(4.75), (23.25)]
|
11
[(4), (19.25)]
|
7
[(2.75), (14.5)]
|
6
[(2), (11)]
|
< 0.05*
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
BMI
|
|
|
|
|
|
|
Normal weight
|
14
[(6.5), (26.5)]
|
12
[(4), (19.5)]
|
9
[(4), (16.5)]
|
5
[(1.5), (14.5)]
|
6
[(1.5), (9.5)]
|
< 0.05*
|
Overweight
|
27
[(14), (37)]
|
17
[(6), (25)]
|
15
[(9), (20)]
|
9
[(5), (14)]
|
6
[(4), (11)]
|
< 0.05*
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Sex
|
|
|
|
|
|
|
Female
|
20.5
[(11.75), (35.25)]
|
16.5
[(5), (24.5)]
|
13
[(6), (20)]
|
9
[(4), (16.25)]
|
6
[(2.75), (11.5)]
|
< 0.05*
|
Male
|
10.5
[(4), (22.25)]
|
8.5
[(3.5), (13.25)]
|
6.5
[(1.75), (12.25)]
|
5
[(1), (9)]
|
5
[(1), (6.25)]
|
< 0.05*
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Age
|
|
|
|
|
|
|
18 - 45 years
|
24
[(12.5), (37)]
|
17
[(10), (25)]
|
12
[(8), (19.5)]
|
9
[(4.5), (18)]
|
6
[(4), (13)]
|
< 0.05*
|
46 years and above
|
14
[(5), (27)]
|
9
[(4), (19)]
|
9
[(2), (18)]
|
6
[(2), (13)]
|
6
[(1), (9)]
|
< 0.05*
|
Assessment was carried out by testing the FS-SSS scores from baseline to week 4.
* Statistically significant at α=0.05
Abbreviations: FS-SSS - Food Sensitivity - Symptom Severity Scale
Food Sensitivity - Global Improvement Scale (FS-GIS)
The physician’s observations were gauged using the FS-GIS score for each participant. The score allowed the physician to report the participant’s response to the intervention by comparing his/her health status before and after the intervention. Of the total study population, 17.31% were rated with the score ‘1’ indicating substantial improvement. 36.53% received a score of ‘2’ and 30.77% received a score of ‘3’ indicating moderate and slight improvement, respectively. However, 9.62% of the participants received a score of ‘4’ showing no change while 5.77% received a score of ‘5’ indicating slightly worsened outcomes. No participants reported with the scores, ‘6’ and ‘7’ which were indicative of moderately and substantially worsened outcomes. Based on the score, overall, 84.61% of the population reported to have improved scores while the rest of the 15.39% of participants reported scores corresponding to no improvement or worsened conditions, accordingly. The distribution of the FS-GIS in the study population is represented in Figure 3.
Correlation between the Food Sensitivity - Symptom Severity Scale (FS-SSS) and Food Sensitivity - Global Improvement Scale (FS-GIS) scores
On analyzing the FS-SSS scores for each FS-GIS category, it was evident that FS-GIS scores coincided with the change in symptoms (Figure 4). FS-SSS scores in the ‘substantially improved -1’ category were seen to dramatically decrease from baseline to week 4. On the other hand, there appeared to be an exacerbation in symptoms in week 4 for the ‘slightly worse - 5’ category which justified the FS-GIS score (Figure 4).
Serological analysis
Antibody titers for food sensitivity are quantified on a scale from 0 to 30 for each food antigen. Titers ranging from 0 to 10 are classified as baseline antibody levels, 10 to 20 as moderately elevated, and 20 to 30 as highly elevated. These thresholds were established based on data from healthy individuals without gut issues who maintained a balanced diet and regular physical activity. In this study, the change in biomarkers was assessed by calculating the percent decrease between pre- and post-intervention values. The improvements in IgG and IgA values are summarized in Figure 5. Among the study participants, 96.15% exhibited improved IgG values, indicated by a reduction in IgG titers post-intervention. For IgA, 84.61% of participants showed a decrease in IgA titers following the intervention. Furthermore, when assessing the percent decrease in antibody titers relative to symptom improvement, 88.46% of participants showed symptomatic improvement, as indicated by the reduction in their FS-SSS scores from baseline to week 4 (Figure 5). Overall, 71.15% of the participants showed reductions in IgG, IgA, and FS-SSS values (Figure 5).
The above-mentioned values indicating changes in individual assessment parameters are also represented in the Venn diagram (Figure 6). This figure collectively elucidates the patterns of change across all assessment parameters including, IgG, IgA, FS-SSS, and FS-GIS values. It displays the absolute number of participants who experienced changes within each parameter (category) and their overlaps (sub-category) alongside the respective percentages. Percentages for each category and sub-category were calculated based on the total study population (N = 52). Between IgG titers and FS-SSS scores, 44 (84.61%) participants exhibited improvements, while 42 (80.76%) participants had improvements in IgG and FS-GIS values. Concurrent improvements in IgA and FS-SSS values, as well as IgA and FS-GIS values, were noted in 39 (75%) participants for each pair. Finally, 33 (63.46%) participants demonstrated improvements across all four parameters (Figure 6). A summary of the changes in IgG and IgA titers, FS-SSS values, and FS-GIS scores for each participant is provided in Supplementary Material, Table 1.
The effect of demographics on intervention outcomes
In this study, the effect of BMI on symptoms was explored by categorizing the underweight (BMI<18.5) and normal weight (BMI=18.5–24.9) participants under the ‘Normal weight’ group while the overweight (BMI=25–29.9) and obese (BMI ≥ 30) participants were categorized under the ‘Overweight’ group. Statistical analysis revealed that changes in symptoms in the ‘Normal weight’ group between baseline and weeks, 1 (z = 3.04, p < 0.05), 2 (z = 3.95, p < 0.05), 3 (z = 4.33, p < 0.05), 4 (z = 4.05, p < 0.05), respectively were statistically significant. A similar observation was made for the ‘Overweight’ group when the change in symptoms was compared between baseline and weeks, 1 (z = 2.92, p < 0.05), 2 (z = 3.54, p < 0.05), 3 (z = 3.82, p < 0.05), 4 (z = 3.90, p < 0.05), respectively. Correspondingly, when assessed based on sex, the change in the FS-SSS scores between baseline and weeks, 1 (z = 3.72, p < 0.05), 2 (z = 4.79, p < 0.05), 3 (z = 5.13, p < 0.05), 4 (z = 5.00, p < 0.05), respectively, was statistically significant for females. However, for males, the change between baseline and week 1 was not significant (z = 1.43, p=0.15) while the change in symptoms between baseline and weeks 2 (z = 2.00, p < 0.05), 3 (z = 2.66, p < 0.05), 4 (z = 3.31, p < 0.05), respectively, was statistically significant. On conducting age-based analysis, the change in symptoms for the ‘18 - 45 years’ group between baseline and weeks, 1 (z = 2.81, p < 0.05), 2 (z = 3.80, p < 0.05), 3 (z = 4.18, p < 0.05), 4 (z = 4.11, p < 0.05), respectively was statistically significant. Similarly, statistically significant differences in symptoms between baseline and weeks, 1 (z = 3.27, p < 0.05), 2 (z = 3.61, p < 0.05), 3 (z = 3.96, p < 0.05), 4 (z = 3.90, p < 0.05), respectively were observed for the age group, ‘46 years and above.’ These results obtained from the Wilcoxon Signed Rank Test have been summarized in Table 4. The Friedman test assessed the effect of all the demographic parameters on the FS-SSS scores across the baseline to week 4. This statistical assessment revealed significant changes in symptoms for all parameters throughout the intervention (Table 3).
Table 4. Effect of demographics on intervention outcomes based on the Wilcoxon Signed Rank Test
Effect of demographics on intervention outcomes based on the Wilcoxon Signed Rank Test
|
|
(N = 52)
|
|
|
|
|
|
|
|
Baseline
FS-SSS
|
Week 1
FS-SSS
|
Week 2
FS-SSS
|
Week 3
FS-SSS
|
Week 4
FS-SSS
|
|
|
Median
[(Q1), (Q3)]
|
Median
[(Q1), (Q3)]
|
Median
[(Q1), (Q3)]
|
Median
[(Q1), (Q3)]
|
Median
[(Q1), (Q3)]
|
|
|
|
|
|
|
|
BMI
|
|
|
|
|
|
|
|
Normal weight
|
14
[(6.5), (26.5)]
|
12
[(4), (19.5)]
|
9
[(4), (16.5)]
|
5
[(1.5), (14.5)]
|
6
[(1.5), (9.5)]
|
|
p value†
|
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
|
|
|
|
|
|
|
|
Overweight
|
27
[(14), (37)]
|
17
[(6), (25)]
|
15
[(9), (20)]
|
9
[(5), (14)]
|
6
[(4), (11)]
|
|
p value†
|
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
|
|
|
|
|
|
|
Sex
|
|
|
|
|
|
|
|
Female
|
20.5
[(11.75), (35.25)]
|
16.5
[(5), (24.5)]
|
13
[(6), (20)]
|
9
[(4), (16.25)]
|
6
[(2.75), (11.5)]
|
|
p value†
|
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
|
|
|
|
|
|
|
|
Male
|
10.5
[(4), (22.25)]
|
8.5
[(3.5), (13.25)]
|
6.5
[(1.75), (12.25)]
|
5
[(1), (9)]
|
5
[(1), (6.25)]
|
|
p value†
|
|
0.15
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
|
|
|
|
|
|
|
Age
|
|
|
|
|
|
|
|
18 - 45 years
|
24
[(12.5), (37)]
|
17
[(10), (25)]
|
12
[(8), (19.5)]
|
9
[(4.5), (18)]
|
6
[(4), (13)]
|
|
p value†
|
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
|
|
|
|
|
|
|
|
46 years and above
|
14
[(5), (27)]
|
9
[(4), (19)]
|
9
[(2), (18)]
|
6
[(2), (13)]
|
6
[(1), (9)]
|
|
p value†
|
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
< 0.05*
|
|
|
|
|
|
|
|
† p values are from the Wilcoxon Signed Rank Test conducted by assessing the baseline FS-SSS scores with the scores from week 1,2,3,4, respectively.
* Statistically significant at α=0.05.
Abbreviations: FS-SSS - Food Sensitivity - Symptom Severity Scale
Quality of life
Due to low compliance with filling out the FS-QoL form, the analysis could only be conducted for a subset of the population. 47 participants from the study population completed the pre- and post-FS-QoL forms. Of the subset, 57% of participants experienced an improvement in their quality of life, as evidenced by a reduction in their FS-QoL scores after the intervention. However, 43% of participants did not experience an improvement in their quality of life indicated by their unchanged or increased FS-QoL scores at week 4. On conducting statistical analysis, it was observed that the difference in the pre-and post-test FS-QoL scores was not statistically significant (z = 1.82, p = 0.06).