Addressing the gut microbiome and implications for obesity

Identification of the gut microbiota as an environmental factor that modulates obesity and metabolic diseases has provided the medical and functional food industry with new targets to treat metabolic diseases. However, only limited knowledge about the mechanisms by which the gut microbiota contributes to these lifestyle diseases are known. The gut microbiota is involved in energy harvest from the diet, modulation of endocrine signalling, and promoting metabolic inflammation. This review will discuss how the gut microbiota is altered in obesity, some of the mechanisms by which it promotes disease development, and how pre- and probiotics may be used to improve metabolic diseases.     

Correlations between oligosaccharides in breast milk and the composition of the gut microbiome in breastfed infants

The composition of the microbiome in the early stages of life can directly affect the health of developing infants, and prior evidence suggests that human milk oligosaccharides (HMO) are critical regulators in the maintenance of a healthy gut microbiota in infants. Herein, we conducted an analysis of the gut microbiota of 1-mo-old breastfed infants from Jining and Harbin, China, and a corresponding analysis of the HMO profiles in samples of maternal breast milk. Quantification of HMO was conducted via liquid chromatography-mass spectrometry, and bacterial DNA sequencing was employed for characterization of the fecal microbiota. The abundances of total neutral oligosaccharides, lactodifucotetraose, lacto-N-fucopentaose I, and disialyl-lacto-N-tetraose were significantly increased in samples from the Jining group relative to the Harbin group. Bifidobacterium were the predominant microbial species in infants from both Harbin and Jining, with these levels being significantly higher in the former set. Correlation analyses evaluating microbes and 19 different HMO indicated that HMO were beneficial to the development of the gut microbiota in young infants. The predominance of Bifidobacterium in these microbial communities suggests that their ability to efficiently utilize HMO can contribute to the homeostasis of the gut microflora, with breast milk-derived HMO being critical to the shaping of the gut microbiota in breastfed infants.     

Understanding the gut microbiome of dairy calves: Opportunities to improve early-life gut health

Early gut microbiota plays a vital role in the long-term health of the host. However, understanding of these microbiota is very limited in livestock species, especially in dairy calves. Neonatal calves are highly susceptible to enteric infections, one of the major causes of calf death, so approaches to improving gut health and overall calf health are needed. An increasing number of studies are exploring the microbial composition of the gut, the mucosal immune system, and early dietary interventions to improve the health of dairy calves, revealing possibilities for effectively reducing the susceptibility of calves to enteric infections while promoting growth. Still, comprehensive understanding of the effect of dietary interventions on gut microbiota—one of the key aspects of gut health—is lacking. Such knowledge may provide in-depth understanding of the mechanisms behind functional changes in response to dietary interventions. Understanding of host–microbial interactions with dietary interventions and the role of the gut microbiota during pathogenesis at the site of infection in early life is vital for designing effective tools and techniques to improve calf gut health.     

Bidirectional interactions between dietary curcumin and gut microbiota

Abstract

Curcumin is a polyphenolic compound with a long history of use as an herbal remedy, dietary spice, and food-coloring agent. Despite curcumin possesses a wide range of biological and pharmacological activities, it exhibits extremely poor bioavailability, which makes its pharmacology intriguing and also hinders its clinical application. In recent years, there is ample evidence supporting the associations between the alteration of gut microbiota and many diseases. Interestingly, after oral administration, curcumin shows its preferential distribution and accumulation in the intestine. In view of the above aspects, we reviewed the updated knowledge regarding the bidirectional interactions between curcumin and gut microbiota from two perspectives: (1) gut microbiota regulation by curcumin and (2) curcumin biotransformation by digestive microbiota. Besides the study deals with 3 potential pharmacological implications: (1) identification of metabolites being more active and bioavaliable than parent curcumin; (2) assessment of contribution of gut microbiota regulation of curcumin to its pharmacological effects and (3) development of gut microbiota regulation-based disease prevention/treatment strategy for curcumin in view of its clinical safety. This review is important to deepen our understanding of the mechanisms of action of curcumin and to provide future directions about how to use this natural compound to combat human diseases.     

Understanding the effects of dietary components on the gut microbiome and human health

Food Science and Biotechnology - The gut microbiome is the complex microbial ecosystem found in the gastrointestinal tract of humans and animals. It plays a vital role in host development,...     

Baby foods: formulations and interactions (a review)

Infant foods have a special place among food products mainly because of nutritional aspects and preparations methods. A great increase of baby foods incomes is predicted in near future. Formulation, handling, and storage of baby foods are important to keep nutritional quality and physicochemical properties of these foods. During storage some reactions and interactions occur which change physicochemical and nutritional properties of baby foods. Lactose crystallization, Maillard reaction, oxidation, and interactions between micronutrients and other components are the most important aspect of preparation and storage of baby foods. These reactions and interactions influence physical properties such as flowability of powder, solubility, and other functional properties. Controlling of storage conditions such as temperature and moisture content and oxygen quantity in headspace of product is required to keep product quality. In this paper the composition and interactions of baby foods between major components and their effect on nutritional quality of baby foods are explained.     

The effects of sorghum proanthocyanidins on digestive enzyme activity in vitro and in the digestive tract of chicken

The effects of sorghum grain proanthocyanidins (PAs) on the digestive enzyme activity of broiler chickens were investigated in vitro and in vivo using seven sorghum varieties grown in Zimbabwe. All seven sorghum varieties, classified as either high‐PA (DC‐75, Mutode, Red Swazi and Chirimaugute) or low‐PA (SV2, Brown Tsweta and Chibonda), were used to assess the PA–protein binding capacity and inhibition of trypsin and amylase in vitro. Three of the varieties (Chirimaugute, Chibonda and Brown Tsweta) were subsequently used in broiler diets to test the effects of PAs on the growth performance and digestive enzyme activity of 48 broiler chicks at 42 days of age. Protein precipitation and trypsin and amylase inhibition increased (P < 0.05) with an increase in level of PAs from the low‐PA varieties (by 1–10%) to the high‐PA varieties (by 40–70%). The activity of trypsin in the duodenal lumen of chicks fed the control diet was almost double that of chicks fed Chirimaugute. Amylase activity in the high‐PA group was lowered significantly (P < 0.01) relative to the control and low‐PA groups. The difference between in vitro and in vivo residual enzyme activities was 10–20% for amylase and 5–10% for trypsin. Chicks fed the high‐PA diet showed lower performance than chicks fed the control and low‐PA diets. Mean body weight gains were 59.9, 34.4, 57.3 and 61.4 (SE 4.02) g day⁻¹, final weights were 1936.4, 1363.3, 1773.2 and 1857.0 (SE 78.5) g and feed efficiencies were 1.85, 2.26, 1.65 and 2.13 (SE 0.014) for the control, Chirimaugute, Brown Tsweta and Chibonda groups respectively. The results indicate that PA–enzyme interaction, in addition to dietary protein–PA binding, contributes to the poor performance of chickens fed high‐PA sorghum diets. © 2000 Society of Chemical Industry     

Health benefits of whole grain: effects on dietary carbohydrate quality,the gut microbiome,and consequences of processing

Grains are important sources of carbohydrates in global dietary patterns. The majority of these carbohydrates, especially in refined-grain products, are digestible. Most carbohydrate digestion takes place in the small intestine where monosaccharides (predominantly glucose) are absorbed, delivering energy to the body. However, a considerable part of the carbohydrates, especially in whole grains, is indigestible dietary fibers. These impact gut motility and transit and are useful substrates for the gut microbiota affecting its composition and quality. For the most part, the profile of digestible and indigestible carbohydrates and their complexity determine the nutritional quality of carbohydrates. Whole grains are more complex than refined grains and are promoted as part of a healthy and sustainable diet mainly because the contribution of indigestible carbohydrates, and their co-passenger nutrients, is significantly higher. Higher consumption of whole grain is recommended because it is associated with lower incidence of, and mortality from, CVD, type 2 diabetes, and some cancers. This may be due in part to effects on the gut microbiota. Although processing of cereals during milling and food manufacturing is necessary to make them edible, it also offers the opportunity to still further improve the nutritional quality of whole-grain flours and foods made from them. Changing the composition and availability of grain carbohydrates and phytochemicals during processing may positively affect the gut microbiota and improve health.     

多酚与蛋白质、消化酶相互作用的研究进展

近年来,随着人们对营养和功能性食品的需求逐渐增长,果奶、奶茶、可可奶和咖啡奶等含有乳蛋白和多酚的复合产品备受青睐,而复合体系中乳蛋白与多酚的相互作用及其对产品营养健康性的影响也成为目前的研究热点。消化道是影响食品营养健康特性发挥作用的重要场所,在消化环境食品多酚与乳蛋白、多酚与消化酶存在相互作用,它们之间的竞争性作用会影响乳蛋白的消化性和多酚的健康功能性,然而有关此方面的研究较少。因此,该文主要概述了国内外关于多酚和乳蛋白、多酚和消化酶间相互作用的研究进展,分析在消化环境中多酚功能性质的改变,以及研究乳蛋白与多酚复合体系蛋白消化性、抗氧化性和生物利用性的变化情况,以期为提高此类产品的营养和功能品质提供一定的指导依据。     

Breakdown of the soluble soybean antigen in the digestive tract of adult rats

Adult male Wistar rats received intragastrically a protein mixture containing 3H-labeled reserve protein of soy beans (PSB), the soy protein isolate 500-E of Ralston Purina Co (USA) being chosen as a protein source. Immunoreactive and TCA-precipitable 3H-PSB was determined in the stomach and small bowel content, 20 and 60 minutes after the administration. The experiment showed more complete inactivation of soy antigen as compared to chick ovalbumin (the authors' data), bovine serum albumin, chick ovomucoid and Kunitz trypsin inhibitor (the literature data). Basing on the results obtained, it is suggested that the soy reserve protein possesses low allergenic properties.     

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.     

Association between the gut microbiota and mineral metabolism

The aim of this review is to present the most recent scientific evidence of interactions between the intestinal microbiota and minerals, and the effect of this interaction on the health of the host. The Web of Science database from the years 2013–2017 on this topic was reviewed. Numerous in vitro studies have shown that iron significantly affects the intestinal microbiota. However, Bifidobacteriaceae are capable of binding iron in the large intestine, thereby limiting the formation of free radicals synthesized in the presence of iron, and thus reducing the risk of colorectal cancer. Animal studies have revealed that supplementation with probiotics, prebiotics and synbiotics has a significant effect on bone calcium, phosphate and bone metabolism. The dynamic interaction between microbiota and zinc was shown. Human studies have provided evidence of the influence of probiotic bacteria on parathormone, calcium and phosphate levels and thus on bone resorption. Recent studies have produced new information mainly on the impact of the intestinal bacteria on the metabolism of calcium and iron. From a scientific perspective, the most urgent fields that remain to be investigated are the identification of all human gut microbes and new therapies targeting the interaction between intestinal bacteria and minerals. © 2017 Society of Chemical Industry     

Reciprocal interactions between resveratrol and gut microbiota deepen our understanding of molecular mechanisms underlying its health benefits

BackgroundResveratrol is a stilbene-based phytochemical, which possesses multiple pharmacological activities. However, the low bioavalibility of resveratrol mystifies its pharmacology.Scope and approachWe discussed the reciprocal interactions of resveratrol with gut microbiota as investigated by in vitro, animal models as well as humans studies.Key findings and conclusionsThe first part described the current in vitro and in vivo evidence concerning the modulative effect of resveratrol on gut microbiota composition, particularly focusing on the involvement of gut microbiota modulation in the anti-diabetic, anti-obesity, and anti-atherosclerosis effects of resveratrol. The second part summarized the bioconversion of resveratrol by gut microbiota, and the identification of metabolites along with bacterial species as generators of these metabolites. This may not only help reconcile the bioavailability conundrum of resveratrol, but also provide directions to expedite its medical applications.     

Modeling digestive tract absorption and desorption of lipophilic organic contaminants in humans

A model of the absorption and desorption of persistent lipophilic organic pollutants in the human gastrointestinal tract was formulated. The influence of the dietary intake of chemical, the chemical concentration in human tissue, the physical-chemical properties of the chemical, and the sorption properties of the feces on the predicted net mass transfer of chemical was explored and shown to be consistent with experimental observations. The model was parametrized and tested using a data set of approximately 800 measurements of net absorption/excretion of polychlorinated biphenyls, dibenzo-p-dioxins, and dibenzofurans that were obtained in experiments with 14 human volunteers. Overall good agreement was obtained between the predicted and measured values. The largest discrepancies were observed in cases of net excretion because the model was not able to account for the considerable individual and temporal variability in the sorption properties of the feces. In a sample model application, good agreement was found between concentrations of octachlorodibenzo-p-dioxin in blood measured in different age groups of the background population and values predicted by the model.     

Stability of calcium salts of phosphorylated sucrose in fluids of the digestive tract

Calcium salts of phosphorylated sucrose, in addition to having cariostatic properties, can serve as a source of calcium and phosphorus and partly satisfy the nutritional requirements of an organism. It has been proved that two such preparations, commercial Australian ‘Anticay’ and a Czech product, have similar properties. Calcium present in these preparations is dissociated partly in saliva and totally in gastric juice. Phosphorus is released only in the duodenum and small intestine. Calcium salts of phosphorylated sucrose are not hydrolysed by invertase.     

Chyme homeostasis in the gastroduodenal portion of the digestive tract under different nutritional diets

The concentration of chyme ingredients and volumetric velocity of the chyme transfer from the duodenum to the jejunum were investigated in experiments on normal preoperated dogs with fistulas implanted into the stomach, duodenum and jejunum after feeding different diets throughout the entire process of active digestion. It has been established that as a result of exchange between the medium filling the gastroduodenal part of the alimentary tract and blood, an enteral medium is formed in the duodenum, with the composition of this medium being relatively constant as regards the concentration and constituent ingredients. It has been also shown that the direction of the balanced flows of the nutrients depends on their concentration in the diet and that both immediate exchange of substances between the enteral and internal media, which is effected according to the concentration gradient, and regulatory alterations in the secretion are involved in homeostasis of the enteral medium.     

Absorption and digestive tract metabolism of 2-hydroxy-4-methylthiobutanoic acid in lambs

Anabolic availability of the hydroxyl methionine analog, 2-hydroxy-4-methylthiobutanoic acid (HMTBA), given as oral doses to lambs, was quantified both directly as appearance in the portal vein and as synthesis to Met by digestive tract tissues. Eight lambs, prepared with vascular catheters in the mesenteric and portal veins plus the aorta, received twice daily for 7 d either 0.46 g or 2 g of HMTBA. On d 7, [1-¹³C]HMTBA was supplied as 1 oral dose while [methyl-²H₃]Met was infused into the jugular vein. Peak absorption as HMTBA occurred 70 to 90 min after the oral dose. All digestive tract tissues converted HMTBA to Met, equivalent to 24% of the Met provided by the diet for the larger HMTBA dose. Overall, total availability of HMBTA averaged 17.9% of the dose (range 10.6 to 27.9%), with 12.5% (range 7 to 22%) as absorbed HMBTA and the remainder as Met synthesized by digestive tract tissues. Release of ¹³CO₂ into the portal vein accounted for another 23% of the dose. In all digestive tract tissues, the d-isomer was present in a smaller proportion than in the dose. In terms of whole-body kinetics, HMTBA loss from the plasma followed first-order kinetics, with a mean biological half-life of 76 min. Using this value, a simple model was devised to estimate HMTBA absorption based on peripheral plasma samples. When compared with direct measures of absorption, the model gave a slope of 0.81 (R² = 0.68) and offers a practical means to test HMTBA availability to animals.