Cooked Black Turtle Beans Ameliorate Insulin Resistance and Restore Gut Microbiota in C57BL/6J Mice on High-Fat Diets

Postnatal Consumption of Black Bean Powder Protects against Obesity and Dyslipidemia in Male Adult Rat Offspring from Obese Pregnancies

The adverse influence of maternal obesity on offspring metabolic health throughout the life-course is a significant public health challenge with few effective interventions. We examined if black bean powder (BBP) supplementation to a high-calorie maternal pregnancy diet or a postnatal offspring diet could offer protection against the metabolic programming of metabolic disease risk in adult offspring. Female Sprague Dawley rats were randomly assigned to one of three diets (n = 10/group) for a 3-week pre-pregnancy period and throughout gestation and lactation: (i) a low-caloric control diet (CON); (ii) a high-caloric obesity-inducing diet (HC); or (iii) the HC diet with 20% black bean powder (HC-BBP). At weaning [postnatal day (PND) 21], one male pup from each dam was weaned onto the CON diet throughout the postnatal period until adulthood (PND120). In addition, a second male from the HC group only was weaned onto the CON diet supplemented with BBP (CON-BBP). Thus, based on the maternal diet exposure and offspring postnatal diet, four experimental adult offspring groups were compared: CON/CON, HC/CON, HC-BPP/CON, and HC/CON-BBP. On PND120, blood was collected for biochemical analysis (e.g., lipids, glycemic control endpoints, etc.), and livers were excised for lipid analysis (triglycerides [TG] and cholesterol) and the mRNA/protein expression of lipid-regulatory targets. Compared with the CON/CON group, adult offspring from the HC/CON group exhibited a higher (p < 0.05) body weight (BW) (682.88 ± 10.67 vs. 628.02 ± 16.61 g) and hepatic TG (29.55 ± 1.31 vs. 22.86 ± 1.85 mmol/g). Although maternal BBP supplementation (HC-BBP/CON) had little influence on metabolic outcomes, the consumption of BBP in the postnatal period (HC/CON-BBP) lowered hepatic TG and cholesterol compared with the other treatment groups. Reduced hepatic TG in the HC/CON-BBP was likely associated with lower postnatal BW gain (vs. HC/CON), lower mRNA and protein expression of hepatic Fasn (vs. HC/CON), and lower serum leptin concentration (vs. CON/CON and HC groups). Our results suggest that the postnatal consumption of a black-bean-powder-supplemented diet may protect male rat offspring against the programming of obesity and dyslipidemia associated with maternal obesity. Future work should investigate the bioactive fraction of BBP responsible for the observed effect.

Dietary pulses as a means to improve the gut microbiome, inflammation, and appetite control in obesity

A dysbiotic intestinal microbiome has been linked to chronic diseases such as obesity, which may suggest that interventions that target the microbiome may be useful in treating obesity and its complications. Appetite dysregulation and chronic systemic low-grade inflammation, such as that observed in obesity, are possibly linked with the intestinal microbiome and are potential therapeutic targets for the treatment of obesity via the microbiome. Dietary pulses (e.g., common beans) are composed of nutrients and compounds that possess the potential to modulate the gut microbiota composition and function which can in turn improve appetite regulation and chronic inflammation in obesity. This narrative review summarizes the current state of knowledge regarding the connection between the gut microbiome and obesity, appetite regulation, and systemic and adipose tissue inflammation. More specifically, it highlights the efficacy of interventions employing dietary common beans as a means to improve gut microbiota composition and/or function, appetite regulation, and inflammation in both rodent obesity and in humans. Collectively, results presented and discussed herein provide insight on the gaps in knowledge necessary for a comprehensive understanding of the potential of beans as a treatment for obesity while highlighting what further research is required to gain this understanding.

Protective Effects of White Kidney Bean (Phaseolus vulgaris L.) against Diet-Induced Hepatic Steatosis in Mice Are Linked to Modification of Gut Microbiota and Its Metabolites

Disturbances in the gut microbiota and its derived metabolites are closely related to the occurrence and development of hepatic steatosis. The white kidney bean (WKB), as an excellent source of protein, dietary fiber, and phytochemicals, has recently received widespread attention and might exhibit beneficial effects on a high-fat diet (HFD)-induced hepatic steatosis via targeting gut microbiota and its metabolites. The results indicated that HFD, when supplemented with WKB for 12 weeks, could potently reduce obesity symptoms, serum lipid profiles, and glucose, as well as improve the insulin resistance and liver function markers in mice, thereby alleviating hepatic steatosis. An integrated fecal microbiome and metabolomics analysis further demonstrated that WKB was able to normalize HFD-induced gut dysbiosis in mice, thereby mediating the alterations of a wide range of metabolites. Particularly, WKB remarkably increased the relative abundance of probiotics (Akkermansiaceae, Bifidobacteriaceae, and norank_f_Muribaculaceae) and inhibited the growth of hazardous bacteria (Mucispirillum, Enterorhabdus, and Dubosiella) in diet-induced hepatic steatosis mice. Moreover, the significant differential metabolites altered by WKB were annotated in lipid metabolism, which could ameliorate hepatic steatosis via regulating glycerophospholipid metabolism. This study elucidated the role of WKB from the perspective of microbiome and metabolomics in preventing nonalcoholic fatty liver disease, which provides new insights for its application in functional foods.

Common Bean Seeds Obtained by Plant Water Restriction Ameliorates Obesity-Associated Cardiovascular Risk and Insulin Resistance

The inclusion of beans in the diet has been recommended for obesity control. However, its beneficial effect varies depending on agroclimatic factors acting during plant development. The antiobesogenic capacity of Dalia bean (DB) seeds obtained by water restriction (WR) during the vegetative or reproductive stage of plant growth (50/100 and 100/50% of soil moisture in vegetative/reproductive stage, respectively), during the whole cycle (50/50), and well-watered plants (100/100) was researched. After phytochemical characterization, harvested beans from each experimental unit were pooled among treatments, based on a multivariate canonical discriminant analysis considering concentration of non-digestible carbohydrates (total, soluble and insoluble dietary fiber and resistant starch), phenolic compounds (total phenols, flavonoids, anthocyanins and condensed tannins) and total saponins, which showed no differences among replicas of each treatment. Obesity was induced in rats (UAZ-2015-36851) with a high fat diet (HFD) for four months. Afterwards, rats were fed with the HFD supplemented with 20% of cooked DB for three months. During treatment, 100/50 beans, improved blood triglycerides, cholesterol, and glucose, and alleviated early insulin resistance (IR) related to inhibition of lipase, α-amylase and -glucosidase activity. After sacrifice, a hypolipidemic capacity and atherogenic risk reduction was observed, especially from the 100/50 treatment, suggesting that intake of DB obtained from WR may prevent IR and dyslipidemia.

Microwaving released more polyphenols from black quinoa grains with hypoglycemic effects compared with traditional cooking methods

BACKGROUND

Polyphenols were reported to exhibit inhibitory effects on digestive enzymes to regulate carbohydrates and lipid digestion. However, different cooking methods might cause differences in the composition of polyphenols in cereal grains and thus further affect their activities.

RESULTS

The present study used boiling, roasting and microwaving to cook black quinoa and extracted polyphenols from them. Their total phenolic content (TPC) and total flavonoids content were determined, and phenolic composition was analyzed via high-performance liquid chromatography-mass spectrometry (HPLC-MS). Compared with other cooking methods, phenolic extract from microwaved black quinoa (PEM) showed the highest TPC value (about 2.64 mg GAE g^-1 ). Microwaving released more phenolic acids (ferulic acid and gallic acid) from black quinoa grains. PEM also exhibited the strongest antioxidant and α-glucosidase inhibitory activities. Lineweaver-Burk plots showed that PEM inhibited α-glucosidase in an uncompetitive mode, which was supported by circular dichroism analysis. PEM further reduced about 20.04% of digested starch in an in vitro digestion model and suppressed postprandial blood glucose increases (about 16.91% reduction) in vivo.

CONCLUSION

Collectively, our data suggested that microwaving could be an ideal method to cook quinoa in regards of its polyphenols in management of postprandial blood glucose. © 2022 Society of Chemical Industry.

Relandscaping the Gut Microbiota with a Whole Food: Dose–Response Effects to Common Bean

Underconsumption of dietary fiber and the milieu of chemicals with which it is associated is a health concern linked to the increasing global burden of chronic diseases. The benefits of fiber are partially attributed to modulation of the gut microbiota, whose composition and function depend on the amount and quality of microbiota-accessible substrates in the diet. However, not all types of fiber are equally accessible to the gut microbiota. Phaseolus vulgaris L., or common bean, is a food type rich in fiber as well as other prebiotics posing a great potential to positively impact diet-microbiota-host interactions. To elucidate the magnitude of bean’s effects on the gut microbiota, increasing doses of common bean were administered in macronutrient-matched diet formulations. The microbial communities in the ceca of female and male mice were evaluated via 16S rRNA gene sequencing. As the bean dose increased, the Bacillota:Bacteroidota ratio (formerly referred to as the Firmicutes:Bacteroidetes ratio) was reduced and α-diversity decreased, whereas the community composition was distinctly different between the diet groups according to β-diversity. These effects were more pronounced in female mice compared to male mice. Compositional analyses identified a dose-responsive bean-induced shift in microbial composition. With an increasing bean dose, Rikenellaceae, Bacteroides, and RF39, which are associated with health benefits, were enhanced. More taxa, however, were suppressed, among which were Allobaculum, Oscillospira, Dorea, and Ruminococcus, which are predominantly associated with chronic disease risk. Investigation of the origins of the dose dependent and biological sex differences in response to common bean consumption may provide insights into bean-gut microbiota-host interactions important to developing food-based precision approaches to chronic disease prevention and control.