Influence of Body Composition and Specific Anthropometric Parameters on SIBO Type

Abstract

Recent observations have shown that Small Intestinal Bacterial Overgrowth (SIBO)affects the host through various mechanisms. While both weight loss and obesity have been reported in the SIBO population due to alterations in the gut microbiome, very little is known about the influence of SIBO type on body composition. This study aimed to evaluate whether there is a link between the three types of SIBO: methane dominant (M+), hydrogen dominant (H+), and methane-hydrogen dominant (H+/M+) and specific anthropometric parameters. This observational study included 67 participants (W = 53, M = 14) with gastrointestinal symptoms and SIBO confirmed by lactulose hydrogen-methane breath tests (LHMBTs) using the QuinTron device. Participants underwent a body composition assessment by Bioelectrical Impedance Analysis (BIA) using the InBody Analyzer. In the H+/M+ group, body weight (p = 0.010), BMI (p = 0.001), body fat in kg (p = 0.009), body fat in % (p = 0.040), visceral fat (p = 0.002), and mineral bone content (p = 0.049) showed an inverse correlation with hydrogen (H₂) gas production. These findings suggest that body weight, BMI, body fat, and mineral bone content may be inversely linked to the production of hydrogen and the risk of hydrogen-methane SIBO.

Keywords: BMI; SIBO; body composition; body fat; breath test; dysbiosis; gut; hydrogen–methane.

Figure 1

Median H₂ and CH₄ concentration as area under the curve (ppm/min) in hydrogen-type, methane-type, hydrogen–methane-type SIBO by BMI classification (A,B), body fat range (C,D), visceral fat range (E,F). p value is for comparison of differences among the 3 groups, significance level of p = 0.05, values calculated with the use of non-parametric Kruskal–Wallis test, verified on the basis of Shapiro–Wilk test, a-b Bonferroni post-hoc test.

Figure 1

Median H₂ and CH₄ concentration as area under the curve (ppm/min) in hydrogen-type, methane-type, hydrogen–methane-type SIBO by BMI classification (A,B), body fat range (C,D), visceral fat range (E,F). p value is for comparison of differences among the 3 groups, significance level of p = 0.05, values calculated with the use of non-parametric Kruskal–Wallis test, verified on the basis of Shapiro–Wilk test, a-b Bonferroni post-hoc test.

Figure 2

Median H₂ concentration as area under the curve (ppm/min) in hydrogen–methane-type SIBO by body weight (A), BMI (B), body fat range (C,D), visceral fat range (E), mineral bone content (F), total body water (G). Pearson correlation between gas productions and anthropometric measures (p ≤ 0.05, r ≥ ±0.3). Red solid line-correlation line, red dotted line-confidence interval, blue circles-cases.

Figure 2

Median H₂ concentration as area under the curve (ppm/min) in hydrogen–methane-type SIBO by body weight (A), BMI (B), body fat range (C,D), visceral fat range (E), mineral bone content (F), total body water (G). Pearson correlation between gas productions and anthropometric measures (p ≤ 0.05, r ≥ ±0.3). Red solid line-correlation line, red dotted line-confidence interval, blue circles-cases.

Figure 2

Median H₂ concentration as area under the curve (ppm/min) in hydrogen–methane-type SIBO by body weight (A), BMI (B), body fat range (C,D), visceral fat range (E), mineral bone content (F), total body water (G). Pearson correlation between gas productions and anthropometric measures (p ≤ 0.05, r ≥ ±0.3). Red solid line-correlation line, red dotted line-confidence interval, blue circles-cases.