Sapogenol is a Major Microbial Metabolite in Human Plasma Associated with High Protein Soy-Based Diets: The Relevance for Functional Food Formulations

Abstract

Legumes are a source of health-promoting macro- and micronutrients, but also contain numerous phytochemicals with useful biological activities, an example of which are saponins. Epidemiological studies suggest that saponins may play a role in protection from cancer and benefit human health by lowering cholesterol. Therefore, they could represent good candidates for specialised functional foods. Following the consumption of a soya-rich high-protein weight-loss diet (SOYA HP WL), the concentrations of Soyasaponin I (SSI) and soyasapogenol B (SSB) were determined in faecal samples from human volunteers (n = 10) and found to be between 1.4 and 17.5 mg per 100 g fresh faecal sample. SSB was the major metabolite identified in volunteers’ plasma (n = 10) after consumption of the soya test meal (SOYA MEAL); the postprandial (3 h after meal) plasma concentration for SSB varied between 48.5 ng/mL to 103.2 ng/mL. The metabolism of SSI by the gut microbiota (in vitro) was also confirmed. This study shows that the main systemic metabolites of soyasaponin are absorbed from the gut and that they are bioavailable in plasma predominantly as conjugates of sapogenol. The metabolism and bioavailability of biologically active molecules represent key information necessary for the efficient development of functional foods.

Soyasaponin ameliorates obesity and reduces hepatic triacylglycerol accumulation by suppressing lipogenesis in high‐fat diet‐fed mice

“…As mentioned in prior studies, soyasaponin A1 and I are the major components of group A and group B soyasaponins, respectively (Goda et al., 2002). Soyasapogenol is the plasma major metabolite after consumption of soybean diet (Neacsu et al., 2020). Reportedly, soyasaponin is converted to soyasapogenol by the human gut microbiota (Neacsu et al., 2020), which represents that the sugar chains of soyasaponin were removed in the intestine, and then absorbed in the form of soyasapogenol.…”

“…Soyasapogenol is the plasma major metabolite after consumption of soybean diet (Neacsu et al., 2020). Reportedly, soyasaponin is converted to soyasapogenol by the human gut microbiota (Neacsu et al., 2020), which represents that the sugar chains of soyasaponin were removed in the intestine, and then absorbed in the form of soyasapogenol. Additionally, in Caco‐2, a colon cell model, the absorption of soyasapogenol B is favored over that of soyasapogenol A (Chávez‐Santoscoy et al., 2013).…”

Physiologically Active Molecules and Functional Properties of Soybeans in Human Health—A Current Perspective

“…Soyasaponins are classified into group A (soyasapogenol A), group B (soyasapogenol B), or group E (soyasapogenol E) according to the non-saccharide segment ( Figure 10 A) [ 97 ]. A total of 11 different saponins, six from group A and five from group B, can be isolated from the hypocotyl of soybean [ 98 ]. The monosaccharides of soyasaponins are D-galactose, D-glucose, L-arabinose, L-rhamnose, D-xylose, and D-glucuronic acid.…”

Microbiota‐directed food formulation

“…In addition to macronutrients, other emerging targets for food formulation include the microbial metabolites of phytochemicals. An example of a specific molecule is the triterpenoid sapogenol, a known microbial metabolite that can be obtained from soya and has suggested anti‐inflammatory and hypercholesteraemic effects 10 . Another group of interest are the widely ubiquitous phenylpropanoid‐derived microbial metabolites.…”