The impact of quinoa bioactive compounds on gut health

By Hugo Francisco de SouzaReviewed by Benedette Cuffari, M.Sc.Mar 4 2024

In a recent study published in Frontiers in Nutrition, researchers review the beneficial impacts of Chenopodium quinoa and its bioactive compounds, particularly its effects on intestinal microflora.

Study: Progress in research on the effects of quinoa (Chenopodium quinoa) bioactive compounds and products on intestinal flora. Image Credit: Elena Schweitzer / Shutterstock.com

What is quinoa?

Quinoa is the common name of Chenopodium quinoa, a whole-grain crop belonging to the Amaranthaceae family. Quinoa is native to the South American Andes Mountains and can be found in three varieties differentiated by its white, black, or red color.

Quinoa is becoming increasingly popular, especially among health- and fitness-conscious individuals, as it is a rich source of protein, fat, vitamins, minerals, fiber, and other bioactive compounds.

Recent nutraceutical research using quinoa has discovered that its bioactive compounds can affect the body's production of short-chain fatty acids (SCFAs) and alter intestinal pH, both of which are significant determinants of intestinal health. Intestinal microbiota health has profound effects on the risk and progression of chronic diseases, including cardiovascular diseases, neurological conditions, and cancers.

Collating and discussing research on quinoa's health and clinical benefits can better inform medical practitioners, health-conscious individuals, and future researchers of the optimal ways to utilize this natural, safe, and cost-effective plant.

About the study

The present study reviewed 85 scientific publications evaluating the biochemical composition of quinoa, its nutritional benefits, and the efficacy of its bioactives in improving intestinal health. The individual roles of quinoa-derived saponins, polyphenolic compounds, polysaccharides, and biopeptides in improving gut microbiota outcomes were also discussed.

Saponins

Saponins, which are also known as triterpene glycosides, are bitter plant-derived secondary metabolites with a broad spectrum of biologically relevant functions.

Quinoa-derived saponins exhibit poor intestinal absorption and low bioavailability, thereby resulting in prolonged intestinal residence, which may allow these metabolites to be used by gut microbiota as a source of nutrition. Previous studies in rats have confirmed this interaction and shown that quinoa supplementation directly correlates with increasing gut microbial diversity.

Metabolomic studies have found that saponins obtained from quinoa digestion can improve the metabolism of some vitamins and alter the ammonia cycle. However, caution must be taken when deciding upon supplementation dosages, as high concentrations of quinoa-derived saponins have been shown to be toxic in rat models.

Polyphenolics

Quinoa consists of many polyphenolic compounds. For example, as compared to placebo, red junglefowl treated with 1% quinoa quercetin exhibited reduced population sizes of opportunistic pathogens and increased populations of the beneficial bacterial phylum Firmicutes. When combined with supplementation of quinoa-derived cellulose, quercetin further increased the number of goblet cells, directly contributing to improved intestinal immunity.

Quinoa polyphenols inhibit enzymes involved in the regulation of the digestive tract, thereby affecting the abundance of intestinal flora and improving the microenvironment of intestinal flora.”

Polysaccharides

Most quinoa-derived polysaccharides are prebiotics capable of increasing the proportion of beneficial probiotic Bifidobacteria and Collinsella bacteria. In combination with quinoa dietary fiber, quinia polysaccharides effectively modulate SCFA concentrations and reduce weight in high-fat diets (HFDs) characteristic in hyperlipidemia.

Bioactive peptides

In vivo studies using hypertensive rats (SHR) have shown that quinoa proteins contain numerous promising peptide precursors. While their mechanism of action remain unknown, these precursors have been shown to significantly reduce the blood pressure of SHR models, thus highlighting their application in cardiovascular research. These health benefits extend beyond blood pressure management, as some studies suggest the colorectal cancer applications of quinoa proteins.

Quinoa proteins have also been found to be a naturally occurring source of angiotensin-converting enzyme (ACE) inhibitory peptides, an additional cardiovascular benefit.

Flour containing quinoa protein can significantly enhance cecal microbial activity, the activities of α-glucosidase, β-glucosidase, and α-galactosidase, and the production of SCFAs in rats, while promoting a reduction in the pH of digesters, thereby indicating the favorable effects of these proteins on growth parameters and metabolism of intestinal flora.”

Conclusions

While research in the field remains in its infancy, a growing body of literature highlights the clinical and nutritional benefits of quinoa.

The bioactive components of quinoa have been shown to promote the abundance of probiotic bacteria while simultaneously inhibiting pathogens. Furthermore, quinoa-derived bioactive compounds have been shown to reduce intestinal pH and increase the production of SCFAs.