Resistant starch (RS) is a type of dietary fiber that resists digestion in the small intestine and ferments in the large intestine, producing short-chain fatty acids (SCFAs) such as butyrate. There is a growing body of scientific evidence suggesting that resistant starch may support metabolic health, including aspects of metabolic syndrome—such as insulin resistance, impaired glucose tolerance, and dyslipidemia. Clinical studies and randomized controlled trials have shown that consumption of resistant starch can improve insulin sensitivity and lower postprandial glucose responses in both healthy individuals and those at risk for type 2 diabetes. Some studies also indicate modest improvements in lipid profiles and reductions in certain inflammatory markers. The proposed mechanisms include SCFA-mediated modulation of gut hormones, improved gut microbiota composition, and enhanced satiety.

However, results are mixed and the magnitude of effect is generally modest. Most supportive studies are of short duration and involve small sample sizes. Meta-analyses conclude that resistant starch shows promise for improving aspects of metabolic syndrome, especially glycemic control, but emphasize the need for larger, longer-term trials to confirm clinical relevance. Overall, the scientific evidence is moderate (3/5), suggesting potential benefit but not definitive proof for the use of resistant starch in metabolic syndrome management.