Table 1 Review of primary literature on fructose breath tests and fructan breath tests

Fructose breath tests

 Fructose (A. 15 g fructose in 150 cc water; B. 25 g fructose in 250 cc water; C. 50 g fructose in 500 cc water; D. 50 g fructose in 125 cc water)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen, methane, or both; or successive rise of ≥ 5 ppm over baseline in 3 consecutive readings. Test duration of 4–6 h

0% (A), 10% (B), 80% (C), and 60% (D) in healthy patients (n = 20 each)

Rao et al., 2007 [20]

 Fructose (50 g fructose)

Hydrogen and methane

Hydrogen levels ≥ 20 ppm; methane levels ≥ 12 ppm; or sum of combined peaks ≥ 15 ppm. Test duration of 2–4 h

55% in IBS patients (n = 94), and 65% in IBS patients on fructose-reduced diet (n = 88)

Berg et al., 2013 [21]

 Fructose (25 g fructose in 200 cc water)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 2 h

16% in lactose intolerant patients (n = 279)

Schnedl et al., 2020 [22]

 Fructose (1 g/kg fructose up to maximum of 25 g)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 2.5 h

55% in patients with abdominal symptoms (n = 222)

Escobar et al., 2014 [23]

 Fructose (35 g in 300 cc water)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen; or ≥ 10 ppm over baseline methane twice in succession. Test duration of 5 h

45% in functional gastrointestinal disease patients (n = 1372)

Wilder-Smith et al., 2013 [24]

 Fructose (1 g/kg fructose up to maximum of 25 g)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 3 h

35% in pediatric patients with gastrointestinal symptoms (n = 323)

Kwiecień et al., 2021 [25]

 Fructose (35 g fructose in 300 cc water)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen; or ≥ 10 ppm over baseline methane. Test duration of 5 h

27% in functional gastrointestinal disease patients (n = 30)

Wilder-Smith et al., 2021 [26]

 Fructose (A. 50 g fructose, B. 25 g fructose)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 2 h

58% (A) and 19% (B) in healthy patients (n = 21)

Truswell et al., 1988 [27]

 Fructose (1 g/kg fructose up to maximum of 25 g)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 2 h

30% in pediatric patients with chronic abdominal pain (n = 118)

Posovszky et al., 2019 [28]

 Fructose (1 g/kg fructose up to maximum of 25 g)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen; rise of ≥ 5 to ≥ 12 ppm methane; or ≥ 10 to ≥ 15 ppm for hydrogen-plus-methane. Test duration of 3 h

50% in pediatric patient with abdominal symptoms (n = 54)

Hammer et al., 2021 [29]

 Fructose (1 g/kg fructose up to maximum of 25 g)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen; or ≥ 10 ppm over baseline methane. Test duration of 3 h

60% (by hydrogen), 35% (by methane) in pediatric patients with abdominal symptoms (n = 187)

Schneider et al., 2020 [30]

 Fructose (40 g fructose in 330 cc water)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 3 h

65% in healthy patients (n = 20), 70% in IBS patients (n = 30)

Skoog et al., 2008 [31]

 Fructose (1 g/kg fructose up to maximum of 50 g)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 3 h (symptoms monitored for 24 h)

68% in patients with abdominal pain (n = 31)

Ozaki et al., 2018 [32]

 Fructose (A. 50 g fructose in 150 cc water, B. 50 g fructose in 250 cc water, C. 25 g in 250 cc water)

Hydrogen and methane

Rise of ≥ 3 ppm over 3 consecutive breath samples from baseline; or ≥ 20 ppm over baseline hydrogen and/or methane. Test duration of

74% (A, n = 203), 70% (B, n = 33), 39% (C, n = 36) in patients with abdominal symptoms

Choi et al., 2003 [33]

 Fructose (1 g/kg fructose up to maximum of 50 g)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen and/or methane. Test duration of 5 h

59% in healthy pediatic patients (n = 34), 41% in pediatric patients with functional abdominal pain (n = 71)

Martínez-Azcona et al., 2019 [34]

 Fructose (25 g fructose in 250 cc water)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 2 h

14% in healthy Thai patients (n = 77)

Densupsoontorn et al., 2007 [35]

 Fructose (2 g/kg fructose up to maximum of 50 g)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration not reported

62% in pediatric patients with recurrent abdominal pain (n = 121)

Gijsbers et al., 2012 [36]

 Fructose (25 g fructose in 250 cc water)

Hydrogen and methane

Hydrogen and/or methane levels ≥ 20 ppm. Test duration of 5 h

35% in IBS patients (n = 90)

Melchior et al., 2014 [37]

 Fructose (A. 1 g fructose, B. 15 g fructose, C. 45 g fructose in 240 cc water)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 3 h

0% (A, n = 9), 3% (B, n = 10), 62% (C, n = 13) in pediatric patients with abdominal pain

Gomara et al., 2008 [38]

 Fructose (50 g fructose in 250 cc water)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 3 h

75% in obese African American patients (n = 16), 43% in obese Hispanic patients (n = 21)

Walker et al., 2012 [39]

 Fructose (25 g fructose in 200 cc water)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 2 h

24% in patients with abdominal symptoms (n = 341)

Enko et al., 2016 [40]

Fructan breath tests

 Fructan (10 g inulin dissolved in 100 cc water)

Hydrogen

Rise of ≥ 20 ppm over baseline hydrogen. Test duration of 3 h

19% in IBS patients (n = 21), 5% in healthy patients

Gutierrez et al., 2016 [41]

 Fructan (10 g fructan dissolved in 100 cc water)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen; or ≥ 15 ppm over baseline methane. Test duration of 3 h

64% in IBS patients (n = 102)

Leelasinjaroen et al., 2017 [42]

 Fructan (10 g fructan dissolved in 100 cc water)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen; or ≥ 15 ppm over baseline methane. Test duration of 3 h

58.3% in IBS patients (n = 24)

Yu et al., 2014 [43]

 Fructan (10 g fructan dissolved in 100 cc water)

Hydrogen and methane

Rise of ≥ 20 ppm over baseline hydrogen; or ≥ 15 ppm over baseline methane. Test duration of 3 h

77% in female IBS patients

Attaluri et al., 2009 [44]