Glucan peptides, particularly those derived from beta-glucans found in oats, barley, and certain fungi, have been investigated for their potential benefits in metabolic syndrome. Metabolic syndrome is a cluster of conditions—including insulin resistance, dyslipidemia, hypertension, and central obesity—that together increase cardiovascular risk. Several clinical studies and meta-analyses have demonstrated that beta-glucans can improve components of metabolic syndrome, primarily by lowering LDL cholesterol and improving glycemic control. The mechanism involves the modulation of gut microbiota, delayed gastric emptying, and increased viscosity of intestinal contents, which slows carbohydrate absorption and enhances satiety.

For example, randomized controlled trials have shown that daily intake of beta-glucan-enriched foods can reduce fasting glucose and improve lipid profiles in individuals with metabolic syndrome or those at risk. The FDA has recognized oat beta-glucan for its cholesterol-lowering effects, which is a key aspect of managing metabolic syndrome. However, while the evidence is promising, it is not uniformly strong across all aspects of the syndrome (e.g., effects on blood pressure and abdominal obesity are less robust). "Glucan peptides" as a specific term is sometimes used interchangeably with beta-glucans in supplement marketing, but most research focuses on beta-glucan polysaccharides rather than peptide-conjugated forms.

In summary, there is moderate scientific support for the use of beta-glucans (and, by extension, glucan peptides if defined similarly) in supporting metabolic health, particularly for cholesterol and glucose management, though more high-quality research is needed.