Effect of a combination of inulin and polyphenol-containing adzuki bean extract on intestinal fermentation in vitro and in vivo

Adzuki and Mung Bean Sprouts Enriched with Probiotic Lactiplantibacillus plantarum 299v Improve Body Mass Gain and Antioxidant Status and Reduce the Undesirable Enzymatic Activity of Microbiota in Healthy Rats

Introducing and establishing new food requires a detailed evaluation of its safety, nutritional value and functionality, thus the control and probiotic-rich adzuki and mung bean sprouts were studied in an in vivo rats model. However, the total feed intake did not differ significantly between the groups, the highest body weight gain and body weight change were recorded in the control AIN diet. At the same time, the addition of legume sprouts caused a reduction of these parameters (up to 25% in the variant with probiotic-rich adzuki bean sprouts). There was no significant effect on serum morphology, except white blood cells (ca. 20% reduction in the control sprout-supplemented diets). Serum and liver antiradical properties were significantly elevated by consuming mung bean sprouts (no effect of the probiotics). The faecal lactic acid bacteria were already increased by the control sprouts (a 2.8- and 2.1-fold increase for adzuki and mung bean sprouts, respectively). The probiotic-rich sprouts further improved this parameter. The diets enriched with mung bean sprouts significantly decreased the urease (by ca. 65%) and β-glucuronidase activities (by ca. 30%). All the tested diets caused also a significant reduction of faecal tryptophanase activity (the effect was intensified by Lactiplantibacillus plantarum 299v). The functional components did not affect negatively the nutritional parameters and blood morphological characteristics. They improved also the antioxidant potential and significantly decreased the activities of colon cancer-related enzymes (urease and tryptophanase). The results confirmed that these new probiotic carriers may be a valuable, safe and functional element of a healthy diet.

Examination of Primary and Secondary Metabolites Associated with a Plant-Based Diet and Their Impact on Human Health

The consumption of plant-based diets has become a burgeoning trend, and they are increasingly consumed globally owing to their substantial energy intensity and dietetic advantages. Plants possess numerous bioactive components that have been recognized to exhibit manifold health-promoting assets. Comprehension of the synthesis of these primary and secondary metabolites by plants and their method of action against several chronic illnesses is a significant requirement for understanding their benefits to human health and disease prevention. Furthermore, the association of biologically active complexes with plants, humans, disease, medicine, and the underlying mechanisms is unexplored. Therefore, this review portrays various bioactive components derived from plant sources associated with health-promoting traits and their action mechanisms. This review paper predominantly assembles proposed plant-derived bioactive compounds, postulating valuable evidence aimed at perceiving forthcoming approaches, including the selection of potent bioactive components for formulating functional diets that are effective against several human disorders. This meticulous evidence could perhaps provide the basis for the advanced preemptive and therapeutic potential promoting human health. Hence, delivery opens possibilities for purchasers to approach the lucrative practice of plants as a remedy, produce novel products, and access new marketplaces.

Lowering glycemic levels via gastrointestinal tract factors: the roles of dietary fiber, polyphenols, and their combination

Dietary fiber (DF) and polyphenols (DP) are typical blood sugar-lowering components, and both play distinct yet interconnected roles in exerting their blood sugar-lowering effects. We comprehensively summarized the single and combined effects of DF and DP on blood glucose homeostasis through regulating the relevant factors in the upper gastrointestinal tract (UGT) and lower gastrointestinal tract (LGT). In the UGT, DF slowed down glucose metabolism by enhancing digesta viscosity and hindering enzyme-substrate interaction. DP primarily targeted enzymes and substrates. When combined, DP enhanced the adsorption capacity of DF for glucose. DF weakened DP's inhibitory effect on enzymes. Both DF and DP disrupted glucose intestinal uptake via physical or genomic modulation, but the co-consumption of DF and DP demonstrated a lower inhibitory effect on glucose uptake than DP alone. In the LGT, DF and DP showed synergistic or antagonistic effects on gut microbiota. Remarkably, whole foods exhibited potent prebiotic effects due to their compound-rich matrix, potentially enhancing glucose homeostasis and expanding dietary options for glucose regulation research.

In vitro colonic fermentation characteristics of barley-koji differ from those of barley

Barley-koji is prepared by inoculating barley, a beneficial prebiotic source, with the fungi Aspergillus luchuensis mut. kawachii. In this study, the prebiotic effects of barley-koji on human colonic microbiota were evaluated in vitro compared with barley, using pig feces. The enzyme-resistant fraction of following sample groups each were added to respective fermenters: cellulose, barley (Commander and β104), and barley-koji (Commander-koji and β104-koji). Short-chain fatty acid and ammonia-nitrogen production increased and decreased, respectively, in barley-koji and barley groups. Furthermore, the propionate concentration increased in the barley group, showing a positive correlation with the abundance of the genus Dialister. In the barley-koji group, however, acetate and n-butyrate concentrations increased during the early stages of incubation, and the relative abundance of the genus Megasphaera was higher than those of the other genera. Therefore, this study demonstrated that barley-koji might possess beneficial physiological properties for colonic fermentation, which differ from those of barley.

Restorative Effects of Inulin From Codonopsis pilosula on Intestinal Mucosal Immunity, Anti-Inflammatory Activity and Gut Microbiota of Immunosuppressed Mice

An inulin (CPPF), isolated from a traditional Chinese herbal medicine Codonopsis pilosula, was characterized and demonstrated with potential prebiotic activity in vitro before. Based on its non-digested feature, the intestinal mucosa and microbiota modulatory effects in vivo on immunosuppressed mice were investigated after oral administration of 200, 100 and 50 mg/kg of CPPF for 7 days. It was demonstrated that the secretions of sIgA and mucin 2 (Muc2) in ileum were improved by CPPF, and the anti-inflammatory activities in different intestine parts were revealed. The intestine before colon could be the target active position of CPPF. As a potential prebiotic substance, a gut microbiota restorative effect was also presented by mainly modulating the relative abundance of Eubacteriales, including Oscillibacter, unidentified Ruminococcus and Lachnospiraceae after high-throughput pyrosequencing of V4 region of 16S rRNA analysis. All these results indicated that this main bioactive ingredient inulin from C. pilosula was a medicinal prebiotic with enhancing mucosal immune, anti-inflammatory and microbiota modulatory activities.

Combined effects of BARLEYmax and cocoa polyphenols on colonic microbiota and bacterial metabolites in vitro

BARLEYmax, a barley variety, and cocoa polyphenols (CPPs) have been reported to affect bacterial metabolites in the colon. This study aimed to evaluate the combined effects of BARLEYmax and CPPs supplementation on fecal microbiota in vitro using pig feces for 48 h. The relative abundances of the family Clostridiaceae and the genus Clostridium and ammonia-nitrogen production were decreased by both BARLEYmax and CPP supplementation, and there was a positive correlation between their abundances and the ammonia-nitrogen concentration. Although acetate and n-butyrate production was decreased by CPP supplementation, their concentrations were maintained at a higher level in the BARLEYmax + CPP group than in the cellulose (control) and cellulose + CPP groups. Therefore, this study demonstrated that a combination of BARLEYmax and CPPs may be beneficial in maintaining higher short-chain fatty acid production and the elimination of potentially harmful factors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-021-00959-z.

Effect of polyphenols isolated from purple sweet potato (Ipomoea batatas cv. Ayamurasaki) on the microbiota and the biomarker of colonic fermentation in rats fed with cellulose or inulin

A polyphenol-rich diet has been associated with various health benefits. This study assessed the effects of polyphenol/anthocyanin isolated from a purple sweet potato (Ipomoea batatas cv. Ayamurasaki) on colonic fermentation in cellulose- or inulin-fed rats. Male Fischer-344 rats were assigned to one of these experimental diets: 5% cellulose (CEL), 5% CEL + 1% purple sweet potato polyphenol extract (CELP), 5% inulin (INU), and 5% INU + 1% purple sweet potato polyphenol extract (INUP) in each diet. The purple sweet potato polyphenol extract (PSPP) increased the relative abundance of Dorea and reduced the relative abundances of Oscillospira and Bacteroides in cellulose- or inulin-fed rats, respectively. Besides, PSPP reduced the caecal iso-butyrate and pH in the cellulose-fed rats. Further, PSPP triggered an increase in the caecal mucin level when combined with cellulose and increased the caecal IgA level while reducing the indole production in both the cellulose- or inulin-fed rats. Finally, PSPP may have different effects on the intestinal fermentation properties depending on the fermentability of dietary fiber associated with it. Therefore, this study demonstrated that dietary inclusion of polyphenol/anthocyanin from purple sweet potato might confer positive health attributes to the host gut.

Grape Polyphenols Attenuate Diet-Induced Obesity and Hepatic Steatosis in Mice in Association With Reduced Butyrate and Increased Markers of Intestinal Carbohydrate Oxidation

A Western Diet (WD) low in fiber but high in fats and sugars contributes to obesity and non-alcoholic fatty liver disease (NAFLD). Supplementation with grape polyphenols (GPs) rich in B-type proanthocyanidins (PACs) can attenuate symptoms of cardiometabolic disease and alter the gut microbiota and its metabolites. We hypothesized that GP-mediated metabolic improvements would correlate with altered microbial metabolites such as short chain fatty acids (SCFAs). To more closely mimic a WD, C57BL/6J male mice were fed a low-fiber diet high in sucrose and butterfat along with 20% sucrose water to represent sugary beverages. This WD was supplemented with 1% GPs (WD-GP) to investigate the impact of GPs on energy balance, SCFA profile, and intestinal metabolism. Compared to WD-fed mice, the WD-GP group had higher lean mass along with lower fat mass, body weight, and hepatic steatosis despite consuming more calories from sucrose water. Indirect and direct calorimetry revealed that reduced adiposity in GP-supplemented mice was likely due to their greater energy expenditure, which resulted in lower energy efficiency compared to WD-fed mice. GP-supplemented mice had higher abundance of Akkermansia muciniphila, a gut microbe reported to increase energy expenditure. Short chain fatty acid measurements in colon content revealed that GP-supplemented mice had lower concentrations of butyrate, a major energy substrate of the distal intestine, and reduced valerate, a putrefactive SCFA. GP-supplementation also resulted in a lower acetate:propionate ratio suggesting reduced hepatic lipogenesis. Considering the higher sucrose consumption and reduced butyrate levels in GP-supplemented mice, we hypothesized that enterocytes would metabolize glucose and fructose as a replacement energy source. Ileal mRNA levels of glucose transporter-2 (GLUT2, SLC2A2) were increased indicating higher glucose and fructose uptake. Expression of ketohexokinase (KHK) was increased in ileum tissue suggesting increased fructolysis. A GP-induced increase in intestinal carbohydrate oxidation was supported by: (1) increased gene expression of duodenal pyruvate dehydrogenase (PDH), (2) a decreased ratio of lactate dehydrogenase a (LDHa): LDHb in jejunum and colon tissues, and (3) decreased duodenal and colonic lactate concentrations. These data indicate that GPs protect against WD-induced obesity and hepatic steatosis by diminishing portal delivery of lipogenic butyrate and sugars due to their increased intestinal utilization.

Potential Health Benefits of Plant Food-Derived Bioactive Components: An Overview

Plant foods are consumed worldwide due to their immense energy density and nutritive value. Their consumption has been following an increasing trend due to several metabolic disorders linked to non-vegetarian diets. In addition to their nutritive value, plant foods contain several bioactive constituents that have been shown to possess health-promoting properties. Plant-derived bioactive compounds, such as biologically active proteins, polyphenols, phytosterols, biogenic amines, carotenoids, etc., have been reported to be beneficial for human health, for instance in cases of cancer, cardiovascular diseases, and diabetes, as well as for people with gut, immune function, and neurodegenerative disorders. Previous studies have reported that bioactive components possess antioxidative, anti-inflammatory, and immunomodulatory properties, in addition to improving intestinal barrier functioning etc., which contribute to their ability to mitigate the pathological impact of various human diseases. This review describes the bioactive components derived from fruit, vegetables, cereals, and other plant sources with health promoting attributes, and the mechanisms responsible for the bioactive properties of some of these plant components. This review mainly compiles the potential of food derived bioactive compounds, providing information for researchers that may be valuable for devising future strategies such as choosing promising bioactive ingredients to make functional foods for various non-communicable disorders.

Modulation of the human gut microbiota by phenolics and phenolic fiber-rich foods

The gut microbiota plays a prominent role in human health. Alterations in the gut microbiota are linked to the development of chronic diseases such as obesity, inflammatory bowel disease, metabolic syndrome, and certain cancers. We know that diet plays an important role to initiate, shape, and modulate the gut microbiota. Long-term dietary patterns are shown to be closely related with the gut microbiota enterotypes, specifically long-term consumption of carbohydrates (related to Prevotella abundance) or a diet rich in protein and animal fats (correlated to Bacteroides). Short-term consumption of solely animal- or plant-based diets have rapid and reproducible modulatory effects on the human gut microbiota. These alterations in microbiota profile by dietary alterations can be due to impact of different dietary macronutrients, carbohydrates, protein, and fat, which have diverse modulatory effects on gut microbial composition. Food-derived phenolics, which encompass structural variants of flavonoids, hydroxybenzoic acids, hydroxycinnamic acids, coumarins, stilbenes, ellagitannins, and lignans can modify the gut microbiota. Gut microbes have been shown to act on dietary fibers and phenolics to produce functional metabolites that contribute to gut health. Here, we discuss recent studies on the impacts of phenolics and phenolic fiber-rich foods on the human gut microbiota and provide an insight into potential synergistic roles between their bacterial metabolic products in the regulation of the intestinal microbiota.

In Vivo Colonic Fermentation of Sorghum (Sorghum bicolor L.): Important Correlations Observed among the Physiological Parameters of Cecum, Liver, Adipose Tissue and Fasting Serum Lipid Profile

High amylose corn starch (HAS), whole grain sorghum (S-Wh), refined sorghum (S-Rf) and α-corn starch (CON) diets were fed to animals for 1 mo aiming to examine the physiological effects of resistant starch inclusion in the diet from grains. HAS exhibited significantly lower feed intake, final body weight, serum lipid profile with significantly higher cecal parameters and short chain fatty acid (SCFA) contents. S-Wh group exhibited significantly higher body weight, feed intake and serum lipid parameters compared to other 3 groups. Cecal fermentation was not seemed to be prominent in the CON, S-Wh and S-Rf groups with respect to lower cecal parameters and SCFA contents. The cecal microbial compositions in HAS, S-Wh and CON/S-Rf exhibited 3 distinct clusters suggesting a significant effect of the cecal microbial composition on cecal parameters, SCFA contents and physiological parameters.

Effects of Raw Potato Starch with High Resistant Starch Levels on Cecal Fermentation Properties in Rats

The effects of potato starch, isolated from Snowden (SD) and Kitahime (KH) varieties, on cecal fermatation properties in rats were evaluated. In high-amylose cornstarch (HAS), SD and KH groups, cecal acetate and total short-chain fatty acid concentrations were increased and cecal pH was lowered compared to control (CON) group. Further, cecal immunoglobulin A levels were increased and cecal ammonia-nitrogen, p-cresol, skatole and indole concentrations were lowered in HAS, SD and KH groups compared to the CON group. Therefore, potato starch might possess beneficial intestinal fermentation properties.

Dietary adzuki bean paste dose-dependently reduces visceral fat accumulation in rats fed a normal diet

The aim of this study was to evaluate the dose-dependent effect of adzuki bean (Vigna angularis) paste (ABP) on visceral fat accumulation in rats. ABP is a rich source of indigestible carbohydrates (18.5%) with fiber and resistant starch (RS) contents of 14.5% and 4.0%, respectively. Animals were fed one of the following diets, control (CON), 30% ABP or 58.9% ABP for 28 days. The daily dietary energy intake was lowered (p < 0.05) and reduced visceral fat accumulation and lower serum lipid levels were observed in ABP fed groups. ABP consumption dose-dependently increased (p < 0.05) the daily fecal lipid and fecal acidic sterol excretions. On the other hand, cecal content and fecal moisture content in the 58.9% ABP group were greater (p < 0.05) than the CON group, while there was no significant difference between the two ABP fed groups. Both 30% and 58.9% ABP diets had significantly (p < 0.05) higher contents of cecal acetic, propionic and n-butyric acids, and lowered cecal pH, independently of the ABP dose. Microbial community data of rats fed ABP diets exhibited higher alpha-diversities than the rats fed CON diet, based on the Shannon Index and the number of observed species index, where the two ABP groups exhibited a similar alpha diversity. The weighted UniFrac-based principal coordinate analysis plot of cecal microbial community data showed that the ABP had a substantial effect on the cecal microbial composition. Furthermore, cecal bacterial 16S rRNA gene sequencing revealed that the ABP supplemented diets decreased the ratio of Firmicutes to Bacteroidetes. These findings suggested that the cecal fermentation of fiber and RS in ABP, might have decreased the energy intake, altered the gut microbiota composition, increased fecal lipid output, and thereby reduced fat accumulation in rats.

Purple Sweet Potato Polyphenols Differentially Influence the Microbial Composition Depending on the Fermentability of Dietary Fiber in a Mixed Culture of Swine Fecal Bacteria

The prevalence of many chronic diseases which have been associated with poor nutrition may be reduced by the positive modulation of colonic microbiota. In this study, we assess the effects of purple sweet potato polyphenols (PSP) in a mixed culture of swine fecal bacteria during in vitro colonic fermentation using pig colonic digest. Jar fermenters were used to conduct a small scale in vitro colonic fermentation experiments under the anaerobic condition for 48 h. Jar fermenters were assigned to one of the following groups: Cellulose, cellulose + PSP, inulin, and inulin + PSP. The present study revealed that the polyphenolic content of purple sweet potato could modulate the colonic microbiota by differentially increasing the population of beneficial bacteria and decreasing the pathogenic bacteria depending on cellulose and inulin. Accordingly, PSP might be a material conducive for improving the conditions for the fermentation of partly-fermentable dietary fiber. Besides, PSP was also responsible for the drastic reduction of putrefactive products, especially p-cresol to a significant level. Our results suggest that PSP could alter the microbial composition depending upon the fermentability of dietary fiber and has the potential to maintain a stable and healthy colonic environment that will ultimately alleviate chronic diseases development and confer health benefits to the host.

Lactic acid fermentation of legume seed sprouts as a method of increasing the content of isoflavones and reducing microbial contamination

Legume seeds and sprouts are a rich source of phytoestrogens in the form of isoflavonoids. For the first time, lactic acid fermentation of four types of legume sprouts was used to increase the content of isoflavonoids and microbiological safety. After germination, the highest content of isoflavonoids was observed in the clover and chickpea sprouts, which amounted to 1.1 g/100 g dw., whereas the lactic acid fermentation allowed the increase to as much as 5.5 g/100 g dw. The most beneficial properties were shown by fermented chickpea sprouts germinated in blue light. During fermentation the number of lactic acid bacteria increased by 2 Log₁₀ CFU/mL (LU), whereas mold decreased by 1 LU, E. coli and Klebsiella sp. by 2 LU, Salmonella sp. and Shigella sp. did not occur after fermentation, similar to Staphylococcus epidermidis, while S. aureus and S. saprophyticus decreased by 3 LU and in some trials were not detected.