Impact of low-no-calorie sweeteners on the human gut microbiota ex vivo

Low-no-calorie sweeteners (LNCS) are used as sugar substitutes as part of strategies to reduce risk of chronic diseases related to high sugar intake (e.g., type 2 diabetes (T2D)). This study investigated how a range of sweeteners [tagatose (TA)/maltitol (MA)/sorbitol (SO)/stevia (ST)/sucralose (SU)/acesulfame K (ACK)] impact the gut microbiota of T2D subjects and healthy human adults using the ex vivo SIFR® technology (n=12). The cohort covered clinically relevant interpersonal and T2D-related differences. ACK/SU remained intact while not impacting microbial composition and metabolite production. In contrast, TA/SO and ST/MA were respectively readily and gradually fermented. ST and particularly TA/SO/MA increased bacterial density and SCFA production product-specifically: SO increased acetate (~Bifidobacterium adolescentis), whilst MA/ST increased propionate (~Parabacteroides distasonis). TA exerted low-specificity as it increased butyrate for healthy subjects, yet propionate for T2D subjects. Overall, LNCS exerted highly compound-specific effects stressing that results obtained for one LNCS cannot be generalized to other LNCS.