Tamarind Seed-Derived Xyloglucan Attenuates Insulin Resistance in Mice through Gut Microbiota

Xyloglucan (XG), a plant polysaccharide abundant in tamarind seeds, is FDA-approved for use as a food additive, stabilizer, thickener, or gelling agent. While its structural properties have been well-studied, its physiological effects remain unclear. This study employed a high-fat diet-induced insulin resistance mouse model to evaluate the effects of XG on metabolic disturbances, combining 16S rRNA sequencing and metabolomics to determine the role of gut microbiota. Results showed that XG intervention in HFD-fed mice improved glucose tolerance and liver function and reduced inflammation and oxidative stress, linked to altered carnitine and tryptophan metabolism. Gut microbiota analysis revealed selective enrichment of Bifidobacterium. Crucially, the benefit of XG was transferable via fecal microbiota transplantation but was abolished by antibiotic-induced microbiota depletion. This study demonstrates that tamarind seed-derived xyloglucan alleviates metabolic disturbances via a gut-microbiota-dependent mechanism, supporting its potential probiotic role in functional foods.