Satiety hormone secretion induced by a carob-based formulation (Csat®) after simulated gastrointestinal digestion and colonic fermentation in STC-1 cells

Csat® is a carob-derived based product standardized in galactomannans, inositols, and gallic acid, with potential applications in weight management and metabolic health. This study evaluated the effects of Csat® on satiety-related enteroendocrine signalling after simulated gastrointestinal digestion and colonic fermentation. A standardized INFOGEST in vitro digestion model was combined with batch colonic fermentation using human faecal inoculum, and the resulting fractions were tested in STC-1 cells to quantify glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK) secretion. Digestive stability of key bioactive compounds was assessed by HPLC-MS. Undigested Csat® did not stimulate hormone secretion, whereas gastric digestion induced the strongest enteroendocrine response, significantly increasing both GLP-1 and CCK release. The intestinal soluble phase maintained a moderate stimulatory effect. During colonic fermentation, galactomannans were extensively degraded, while pinitol remained stable and gallic acid showed variable recovery. Fermentation kinetics revealed active microbial metabolism, with early fermentation associated with the highest endocrine response. GLP-1 and CCK secretion peaked at 4 h fermentation and progressively declined at later stages. Overall, Csat® showed a marked phase-dependent endocrine activity, with gastrointestinal processing and early microbial fermentation generating the most bioactive fractions. These findings support the potential of Csat® to modulate satiety-related pathways through coordinated digestion- and microbiota-derived mechanisms.