Dietary fiber and gastrointestinal function

The purpose of the current study is to conduct a meta-analysis of published randomized controlled trials to explore the quantitative effect of quinoa supplementation on serum lipid concentrations.

Online databases, including Web of Science, Scopus, and PubMed, were systematically searched. A comprehensive literature review was performed based on English reports of randomized controlled trials of quinoa on lipid profiles in adults, which were published up to July 2020. Weighted mean differences (WMD) with a 95% confidence interval (CI) were assigned as the ultimate effects of using random models. Study quality was assessed by using the Cochran score, and a meta-analysis was conducted.

Five RCTs with eight intervention arms, including 291 participants, were selected for the present meta-analysis. The intervention period was between 4 and 12 weeks. The results showed doses higher than 50 g of quinoa consumption and duration more than six weeks of intervention significantly reduced serum triglyceride (TG) levels (WMD: −0.864 mg/dl; 95% CI: −1.286, −0.442, P < 0.001) and (WMD: −0.623 mg/dl; 95% CI: −1.015, −0.232, P = 0.002), respectively. In general, quinoa supplementation did not have a significant effect on concentrations of high-density lipoprotein cholesterol (HDL-C) levels (WMD: −0.145 mg/dl; 95% CI: −0.377, 0.086, P = 0.218), low-density lipoprotein cholesterol (LDL-C) levels, (WMD: 0.082 mg/dl; 95% CI: −0.150, 0.314, P = 0.489), and total cholesterol (TC) levels)WMD: − 0.036 mg/dl; 95% CI: − 0.267, 0.195, P = 0.759(.

This study reveals quinoa supplementation in doses higher than 50 g/day and the duration more than six weeks significantly reduced TG levels. However, further studies in this area are recommended to understand the potential mechanisms of quinoa on blood lipids.

The biomass from cereal side streams is rich in valuable components, such as hemicelluloses. Among the hemicelluloses, arabinoxylans and β-glucans are the most acknowledged for potential health benefits. Numerous publications discuss the potential to use purified forms of these hemicelluloses for various applications. However, as the purification of hemicelluloses may not be economically feasible to upscale, sustainable and cost-effective methods are needed to make their valorization more realistic for industrial applications. Co-components present in hemicellulose-rich fractions may also provide added functionality, such as flavonoid content and antioxidant capacity. This review provides an overview on the feasibility of sustainably upscaling hemicellulose extraction processes, focusing on by-products from different cereal streams. We describe the hemicelluloses’ physicochemical properties and provide various possible applications of pure and impure fractions from small scale to pilot and industrial scale. Furthermore, real case examples on the industrial utilization of cereal side streams are enclosed. This review provides pathways for future research for developing the hemicellulose extraction methods to obtain fractions with optimized purity, and offers suggestions to valorize them.

Human health depends on a population of microorganisms that inhabit the gut and contribute to homeostasis of the host, including nutrition, immunity and metabolism. Many of the organisms are interactive and mutually dependent, where the end-products for one organism become the fuel for another through substrate and metabolic cross-feeding. To optimise the gut microbiota using diet, the composition and functionality of the gut microbiota, including these interacting networks, must be understood. Microbial composition and functionality is affected by the structure of the energy input, which is primarily dietary fibre for the gut microbiota. The structure of dietary fibre has been reviewed by carbohydrate chemists, but knowledge of how dietary fibre structure affects the gut microbiota is limited.

The hierarchical structures of dietary fibre are reviewed, encompassing macrostructure, mesostructure and molecular structure, and how they are affected by food processing and digestion. These factors are considered in relation to their affects on microbial composition and functionality, to provide insight on the interactions between diet, the microbiota, and human health.

Food processing and digestion affect food structure, primarily through the removal of some soluble fractions and increased solubilisation of insoluble fractions. The provision of insoluble carbohydrates to the colon appears important for the sustenance of ‘keystone’ species that play a crucial role in stabilising the gut community. Further work is needed at the microbial strain level to understand the impact of increasing fibre solubility. This should be done in studies using well-characterised carbohydrates that consider the impact of food processing and digestion.

Nutritional well-being is the prerequisite condition for a sustainable improvement in human welfare. Human gut microbiota plays a magnificent role in balancing the condition of metabolic syndrome management. Currently, the gut microbiome mediated immune system is gaining attention for the treatment of several health ailments such as diabetes, gastrointestinal disorders, and malnourishment. Bioactive compounds from marine polysaccharides from seaweeds are found beneficial for enhancing the activity of gut microbes.

There were limited reviews in recent times to discuss the updates on extraction, purification and biological activities of dietary fibers using non-conventional methods. The present review inspects on the proximal and structural composition of seaweed polysaccharides and their methods of extraction and purification aspects. It also focuses on the immune modulating mechanisms of prebiotic-probiotic synergetic interaction by stimulating beneficial gut microbial activity and by the production of short-chain fatty acids. The mutual relationship between prebiotics and probiotics that leads to a healthy gut was targeted in the present review.

Marine seaweeds polysaccharides are the untapped bioresources to be explored for its biotherapeutic properties of dietary fibers. The practical complications on extracting polysaccharides by a single technique could be overcome by adopting the strategy of utilizing combinatorial extraction and purification techniques. Its prebiotic effect aids in the enhancement of gut microbial activity by exhibiting the properties of non-digestibility, fermentability, and pathogen inhibition potential. The impending benefits of dietary fiber from seaweed polysaccharides as prebiotics for formulating functional food ingredients along with probiotic microbes to exhibit immunomodulation applications. Therefore, intended human clinical trials should be carried out to evaluate and discover the probiotic-prebiotic relationship in the human gut, which could step out the research to the next level in the medicinal world.

Sugar industries generate a big amount of residues during the harvest and milling of sugarcane. Both sugarcane bagasse and tops are two of the main biomass sources that potentially become part of the environmental pollution. These fibers can be theoretically used to obtain added value products, but require effective methods to separate lignin from biomass. The present paper intends to evaluate the effects of a microwave process (600 W, 5 min) applied during alkaline treatments of sugarcane bagasse (SBC) and sugarcane tops (SCTs) to separate lignocellulosic compounds and use them as nutraceutical ingredients of human food such as chapatti-type fermented bread and noodle-type pasta. Two alkaline treatments using sodium hydroxide (NaOH) and hydrogen peroxide (H₂O₂) with concentrations of 15, 22.5, 30, 37.5 mmol were analyzed. The study found that the alkaline treatments assisted with microwave heating could remove lignin more efficiently than the traditional method (immersion). The assistance of the microwave process during alkaline treatments is an alternative to deconstruct the lignocellulosic structure. From the evaluated concentrations, the highest lignin removal was observed with NaOH (37.5 mmol) for both kinds of fibers. Hedonic responses suggest that the addition of 8 wt.% of treated fibers during the production of chapatti-type fermented bread (with SCB) or noodle-type pasta (with SCTs) is suitable for human consumption; additionally, dietary trends for lower digestibility were observed in the fortified food.

The treatment of agroindustrial residues is an alternative to waste management and obtain products with added value. In this article, we describe the confocal microscopy images, the microbiological data, policosanol content and color measurement linked to the paper “production of dietary fibers from sugarcane bagasse and sugarcane tops using microwave - assisted alkaline treatments”. The data contain photographs after elaboration of noodles-type pasta and chapatti-type fermented bread; the confocal laser scanning micrographs, before and after including sugarcane bagasse and sugarcane tops fibers in foods. Microbiological analyses of total coliforms, molds and yeasts, and aerobic mesophiles were also presented according to Mexican Standard NOM- 247-SSA1-2008 which confirmed that the food is safe for human consumption. The data provided in this article have not been previously published and are available to enable critical or extended analyses.