Food and Behaviour Research

Donate Log In

UK Nutrient Gaps and Impacts on Early Development with Dr Emma Derbyshire and TC Callis - BOOK HERE

Disrupting the Gut-Brain Axis: How Artificial Sweeteners Rewire Microbiota and Reward Pathways

Coccurello R (2025) Int J Mol Sci 26(20):10220 doi: 10.3390/ijms262010220 

Web URL: Read this research on PubMed

Abstract:

Artificial sweeteners, or non-caloric sweeteners (NCSs), are widely consumed as sugar substitutes to reduce energy intake and manage obesity. Once considered inert, accumulating evidence now shows that NCSs interact with host physiology, altering gut microbiota composition and neural circuits that regulate feeding.

This review synthesizes current knowledge on how NCSs disrupt the gut-brain axis (GBA), with particular focus on microbiota-mediated effects and neural reward processing.

In homeostatic regulation, NCS-induced dysbiosis reduces beneficial taxa such as
Akkermansia muciniphila and Faecalibacterium prausnitzii, diminishes short-chain fatty acid production, impairs gut barrier integrity, and promotes systemic inflammation. These changes blunt satiety signaling and favor appetite-promoting pathways.

Beyond homeostasis, NCSs also rewire hedonic circuits: unlike caloric sugars, which couple sweet taste with caloric reinforcement to robustly activate dopaminergic and hypothalamic pathways, NCSs provide sensory sweetness without energy, weakening reward prediction error signaling and altering neuropeptidergic modulation by orexin, neurotensin, and oxytocin.

Microbial disruption further exacerbates dopaminergic instability by reducing precursors and metabolites critical for reward regulation. Together, these top-down (neural) and bottom-up (microbial) mechanisms converge to foster maladaptive food seeking, metabolic dysregulation, and increased vulnerability to overeating.

Identifying whether microbiome-targeted interventions can counteract these effects is a key research priority for mitigating the impact of NCSs on human health.