TABLE 2.
Summary of the articles in the scoping review1.
| Study type/Health status | Total number of studies | Age | Study design | ||||
|---|---|---|---|---|---|---|---|
| Observational study | Total | ≥18 y | <18 y | NR | Cross-sectional cohort | Prospective cohort | Other (retrospective, case-control) |
| All | 57 [13–69] | 47 [13–40, 48, 49, 51, 54–59, 61–69] | 7 [41–47] | 3 [50, 52, 53] | 47 [13–27, 29–40, 43–53, 55–58, 60, 63, 67–69] | 6 [28, 41, 42, 59, 61, 62] | 4 [54, 64–66] |
| Healthy | 39 [13–47, 63, 67–69] | 32 [13–40, 63, 67–69] | 7 [41–47] | 0 | 36 [13–27, 29–40, 43–47, 63, 67–69] | 3 [28, 41, 42] | 0 |
| With condition/disease2 | 10 [54–59, 61, 64–66] | 10 [54–59, 61, 64–66] | 0 | 0 | 4 [55–58] | 2 [59, 61] | 4 [54, 64–66] |
| NR health status | 8 [48–53, 60, 62] | 5 [48, 49, 51, 60, 62] | 0 | 3 [50, 52, 53] | 7 [48–53, 60] | 1 [62] | 0 |
| Interventional study | Total | ≥18 y | <18 y | NR | Crossover RCT | Parallel RCT | Other (incomplete randomization)4 |
| All | 28 [70–97] | 26 [70–93, 96, 95] | 2 [94, 95] | 0 | 12 [70, 71, 73, 74, 79, 82, 84–88, 96] | 13 [76–78, 80, 81, 83, 89–95] | 3 [72, 75, 97] |
| Healthy | 17 [71–74, 84–95, 97] | 15 [71–74, 84–93, 97] | 2 [94, 95] | 0 | 8 [71, 73, 74, 84–88] | 7 [89–95] | 2 [72, 97] |
| With condition/disease2 | 10 [70, 75–83]3 | 10 [70, 75–83] | 0 | 0 | 3 [70, 79, 82] | 6 [76–78, 80, 81, 83] | 1 [75] |
| NR health status | 1 [96] | 1 [96] | 0 | 0 | 1 [96] | 0 | 0 |
Age categories were divided based on reported subject inclusion, subject age range, and group mean age of each study. The age category “<18” also includes studies that recruited subjects aged both <18 and >18 y. The number of studies is reported in each cell, with references of studies included in square brackets.
With condition/disease: Ten observational studies had cohorts with certain diseases or health conditions [[54], [55], [56], [57], [58], [59], 61, [64], [65], [66]], including reactive hypoglycemia [54], cirrhosis [55], type 2 diabetes [58], metabolic syndrome [61], colorectal cancer [64], intestinal diseases (colon carcinoma, inflammatory bowel disease [56], Crohn’s disease or ulcerative colitis, irritable bowel syndrome [56, 65, 66]), or pregnancy [57, 59]. Among interventional studies, 10 studies were in cohorts with the following diseases or health conditions: Crohn’s disease [75], type 2 diabetes [76, 77], multiple sclerosis [78], chronic kidney disease [79], obesity with insulin resistance [80] or metabolic syndrome [81], chronic gastrointestinal disease [70], ischemic heart disease [82], or pregnancy [83].
One study [70] included all healthy subjects, except for 1 subject with chronic gastrointestinal disease.
One study [75] had all participants receive the same intervention (pre vs. post), thus the study was not categorized as crossover or parallel RCT; 2 studies [72, 97] included partial randomization, in which the intervention group was compared with a nonrandomly assigned comparison group. NR, not reported; RCT, randomized controlled trial.