Breath 13 CO 2 -evidence for a noninvasive biomarker to measure added refined sugar uptake.

Increased consumption of added sucrose and high-fructose corn syrup in the human diet has been associated with increasing incidence of obesity and metabolic disease. There are currently no reliable, objective biomarkers for added sugar intake that could be used in individuals or population settings. ¹³ C is a stable isotope of carbon, and measurement of blood ¹³ C content has been proposed as a marker of added sugar consumption. This study aimed to determine if breath ¹³ CO ₂ could represent an alternative, noninvasive biomarker to monitor added sugar intake. We undertook retrospective analyses of eight preclinical and human ¹³ C-breath studies to define baseline breath ¹³ CO ₂ characteristics. All samples were analyzed using isotope ratio mass spectrometry, and breath ¹³ CO ₂ was expressed as the delta value, δ expressed as parts per thousand (‰). All data are expressed as mean ± SEM, with statistical significance considered at P < 0.05. Breath δ ¹³ CO ₂ was significantly elevated in a cumulative manner in rats and mice that consumed a diet containing at least 15% sucrose. Mice fed an American rodent chow diet containing 50% sucrose and 15% corn starch had a significantly higher breath δ ¹³ CO ₂ compared with rodents consuming an Australian rodent chow diet. Furthermore, breath δ ¹³ CO ₂ was significantly increased in a dose-dependent manner in humans that ingested a bolus dose of sucrose. These findings suggest application for baseline breath δ ¹³ CO ₂ as a noninvasive biomarker for added sugar consumption, with broad application for longitudinal assessment of population sugar intake and obesity management strategies. NEW & NOTEWORTHY We have found that breath ¹³ CO ₂ is increased in rats and mice consuming diets high in sucrose. We also found that human breath ¹³ CO ₂ is increased in humans consuming increasing amounts of sucrose. Our collective findings suggest that breath ¹³ CO ₂ represents a potential marker of added dietary sugar consumption.