Comparison of Yacon (Smallanthus sonchifolius) Tuber with Commercialized Fructo-oligosaccharides (FOS) in Terms of Physiology, Fermentation Products and Intestinal Microbial Communities in Rats

Yacon-based product improves intestinal hypertrophy and modulates the production of glucagon-like peptide-1 in postmenopausal experimental model

AIMS

The progressive decline in estrogen level puts postmenopausal women at a higher risk of developing cardiometabolic diseases. Thus, we evaluated the potential beneficial effects of yacon-based product (YBP) on glycemic profile and intestinal health of postmenopausal rats.

METHODS

Eighty Wistar rats were randomized into 4 ovariectomized (OVX) groups or 4 celiotomized groups treated with a standard diet (SD) or diet supplemented with YBP at 6% of fructooligosaccharide (FOS)/inulin.

KEY FINDINGS

The continued consumption of YBP at 6% of FOS/inulin did not generate liver damage and gastrointestinal disorders. Rats fed with YBP displayed higher food consumption, but this did not increase the body weight gain, abdominal circumference and body fat percentual of OVX rats. Furthermore, we also found that the FOS/inulin fermentation present in the YBP resulted in cecum, ileum and colon crypts hypertrophy and increased the lactic acid levels in the cecal content. We observed an increase of glucagon-like peptide-1 (GLP-1) immunoreactive cells and there was no change in the glucose and insulin plasma levels of YBP-fed OVX rats.

SIGNIFICANCE

Our findings indicated that YBP when consumed previously and after the menopausal period has important effects on the morphology and function of intestinal mucous of rats and has potential to modulate indirectly the glycemic and insulinemic profiles, weight gain and body fat percentual in the hypoestrogenic period through metabolites produced in the fermentation process.

A Sustainable Wholesome Foodstuff; Health Effects and Potential Dietotherapy Applications of Yacon

A sustainable food supply is an ever-growing public and planetary health concern influenced by food culture, food practices, and dietary patterns. Globally, the consumption of plant foods that offer physiological and biochemical benefits is increasing. In recent years, products made from yacon (Smallanthus sonchifolius) tubers and leaves, e.g., in the form of syrup, powder, and herbal tea, have steadily emerged with scientific evidence to validate their possible health claims. Yacon was introduced to New Zealand in 1966, and its products can now be produced on a commercial scale. This paper reviews literature published mainly in the last 10 years concerning the health-related properties of yacon as a wholesome foodstuff and its bioactive components, e.g., fructooligosaccharides. Literature was sourced from Web of Science, PubMed, EBSCO Health, and Google Scholar up to June 2019. The potential markets for yacon in the field of food technology and new dietotherapy applications are discussed. Furthermore, the unique features of New Zealand-produced yacon syrup are introduced as a case study. The paper explores the scientific foundation in response to the growing public interest in why and how to use yacon.

Fructan-Enriched Diet Increases Bone Quality in Female Growing Rats at Calcium Deficiency

This study was designed to determine the effect of feeding female rats with low-calcium diet containing one of three fructan sources (Jerusalem artichoke, yacon, Beneo Orafti Synergy1), on selected bone parameters. Growing Wistar rats were fed modified AIN-93 G diet enriched in fructan sources (8%), added alone or as a strawberry sorbet ingredient. Two of eight groups were a validation model, where the positive control group was fed with recommended calcium dose in the diet (RCD), and negative one - with low calcium diet (LCD). After 12 weeks, femoral Ca content, bone densitometry, architecture and hardness were examined. The positive effects on femoral Ca content and cortical thickness, area and content in distal part of bone was observed after feeding animals diet enriched in Jerusalem artichoke sorbet. Beneficial action on other bone tomographic parameters (particularly trabecular volumetric bone mineral density) in this part of femur were associated mainly with the consumption of the diet with sorbet containing yacon. Our results showed an important role of diet containing frozen strawberry desserts enriched in fructan sources in the maintenance of healthy bones of growing organism. It may suggest possible synergisms between fructans and bioactive substances of strawberry.

Gut Microbiota in a Rat Oral Sensitization Model: Effect of a Cocoa-Enriched Diet

Increasing evidence is emerging suggesting a relation between dietary compounds, microbiota, and the susceptibility to allergic diseases, particularly food allergy. Cocoa, a source of antioxidant polyphenols, has shown effects on gut microbiota and the ability to promote tolerance in an oral sensitization model. Taking these facts into consideration, the aim of the present study was to establish the influence of an oral sensitization model, both alone and together with a cocoa-enriched diet, on gut microbiota. Lewis rats were orally sensitized and fed with either a standard or 10% cocoa diet. Faecal microbiota was analysed through metagenomics study. Intestinal IgA concentration was also determined. Oral sensitization produced few changes in intestinal microbiota, but in those rats fed a cocoa diet significant modifications appeared. Decreased bacteria from the Firmicutes and Proteobacteria phyla and a higher percentage of bacteria belonging to the Tenericutes and Cyanobacteria phyla were observed. In conclusion, a cocoa diet is able to modify the microbiota bacterial pattern in orally sensitized animals. As cocoa inhibits the synthesis of specific antibodies and also intestinal IgA, those changes in microbiota pattern, particularly those of the Proteobacteria phylum, might be partially responsible for the tolerogenic effect of cocoa.