Gluco and galacto-oligosaccharides in food: update on health effects and relevance in healthy nutrition

Urine Metabolomic Profile of Breast- versus Formula-Fed Neonates Using a Synbiotic-Enriched Formula

The aim of this study was to compare the urine metabolic fingerprint of healthy neonates exclusively breastfed with that of neonates fed with a synbiotic-enriched formula (Rontamil^® Complete 1) at four time points (the 3rd and 15th days of life and the 2nd and 3rd months). The determination of urine metabolic fingerprint was performed using NMR metabolomics. Multivariate data analyses were performed with SIMCA-P 15.0 software and R language. Non-distinct profiles for both groups (breastfeeding and synbiotic formula) for the two first time points (3rd and 15th days of life) were detected, whereas after the 2nd month of life, a discrimination trend was observed between the two groups, which was further confirmed at the 3rd month of life. A clear discrimination of the synbiotic formula samples was evident when comparing the metabolites taken in the first days of life (3rd day) with those taken in the 2nd and 3rd months of life. In both cases, OPLS-DA models explained more than 75% of the metabolic variance. Non-distinct metabolomic profiles were obtained between breastfed and synbiotic-formula-fed neonates up to the 15th day of life. Discrimination trends were observed only after the 2nd month of the study, which could be attributed to breastfeeding variations and the consequent dynamic profile of urine metabolites compared to the stable ingredients of the synbiotic formula.

Multiple reaction monitoring for identification and quantification of oligosaccharides in legumes using a triple quadrupole mass spectrometer

Raffinose family oligosaccharides are non-digestible compounds considered as dietary prebiotics with health-related properties. Hence, it is important to develop highly specific methods for their determination. An analytical method is developed in this study for oligosaccharide identification and quantification using liquid chromatography-tandem mass spectrometry equipped with a triple quadrupole analyser operating in Multiple Reaction Monitoring mode. Raffinose, stachyose and verbascose are separated in a 10-minute run and the method is validated over a broad concentration range, showing good linearity, accuracy, precision and high sensitivity. A low-cost, short eco-friendly procedure for oligosaccharide extraction from legumes, with a high recovery rate extraction, good repeatability and reproducibility is also proposed. No plant-matrix effects were demonstrated. The method applied to the screening of 28 different legumes revealed species-related traits for oligosaccharide distribution, highlighting Pisum sativum (9.22 g/100 g) as the richest source of these prebiotics and its suitability as a functional food ingredient.

Nutritional and antinutritional composition of fava bean (Vicia faba L., var. minor) cultivars

A dietary shift from resource-demanding animal protein to sustainable food sources, such as protein-rich beans, lowers the climate footprint of food production. In this study, we examined the nutrients and antinutrients in 15 fava bean varieties cultivated in Sweden to select varieties with high nutritional value. On a dry weight basis, the fava beans were analyzed for their content of protein (range 26-33%), amino acids (leucine range: 50.8-72.1 mg/g protein, lysine range: 44.8-74.8 mg/g protein), dietary fiber (soluble fraction range: 0.55-1.06%, insoluble fraction range: 10.7-16.0%), and iron (1.8-21.3 mg/100 g) and zinc contents (0.9-5.2 mg/100 g), as well as for the following antinutrients: lectin (0.8-3.2 HU/mg); trypsin inhibitor (1.2-23.1 TIU/mg) and saponin (18-109 µg/g); phytate (112-1,281 mg/100 g); total phenolic content (1.4-5 mg GAE/g); and vicine(403 µg/g - 7,014 µg/g), convicine (35.5 µg/g - 3,121 µg/g) and the oligosaccharides raffinose (1.1-3.9 g/kg), stachyose (4.4-13.7 g/kg) and verbascose (8-15 g/kg). The results indicate substantial differences between cultivars in relation to their contents of nutrients and antinutrients. Only one of the cultivars studied (Sunrise) have adequate estimated bioavailability of iron, which is of major concern for a diet in which legumes and grains serve as important sources of iron. The nutritional gain from consuming fava beans is significantly affected by the cultivar chosen as the food source.

Inclusion of limited amounts of extruded legumes plus cereal mixes in normocaloric or obesogenic diets for rats: effects on intestinal microbiota composition

BACKGROUND

Differences in the composition of the intestinal microbiota and energetic metabolism between lean and obese populations have been described. Legume consumption has been reported to modulate intestinal microbiota composition. However, to the best of our knowledge, no information can be found in the literature on the effects of consumption of diets containing extruded legume plus cereal mixes on the intestinal microbiota composition of rats. Our purpose was to evaluate the effects on lipids profile (see the accompanying paper) and intestinal microbiota composition (current paper) of incorporating this new food ingredient in normocaloric and obesogenic diets.

RESULTS

Intestinal and fecal qPCR-based microbial composition of rats fed the extruded legumes plus cereal mixes differed (P < 0.05) from controls. Obesogenic diets did not affect bacterial counts. However, the inclusion of the extruded mixes reduced (P < 0.05) log₁₀ counts in some bacterial groups and increased (P < 0.05) counts of Lactobacilli, while others remained unaffected. PCoA at the genus level grouped together Lactobacillus reuteri, Akkermansia miciniphila and species from Parabacteroides, Prevotella, Rikenellaceae, and Lactobacillus with extruded legume plus cereal diets. Feeding on extruded legumes plus cereal mixes was associated with increased mRNA expression of the cytokines IL6 and TNF-α and decreased expression of TLR4.

CONCLUSIONS

Our results show that the inclusion in the feed of limited amounts of extruded legumes plus cereal mix, providing a diet that is closer to a normal human one, did modulate the intestinal microbiota composition. Taken together, these results point to the protective, health-promoting properties of extruded legume plus cereal mixes.

Nondigestible Oligosaccharides with Anti-Obesity Effects

Obesity has an important influence on health conditions, causing a multitude of complications and comorbidities, and drug therapy is considered to be one of the treatment strategies. Nowadays, there is increasing interest in the study of intestinal microbiota regulation of obesity; also, an increasing number of agricultural and sideline products have been found to have anti-obesity potential. In the present review, we summarize an overview of current known and potential anti-obesity oligosaccharides and their molecular structures. We describe their anti-obesity potential activity and the molecular structure associated with this activity, the regulation of intestinal microbiota composition and its mechanism of action, including regulation of the short-chain fatty acid (SCFA) pathway and altering bile acid (BA) pathway. This review will provide new ideas for us to develop new anti-obesity functional foods.

Protective effects of α-galacto-oligosaccharides against a high-fat/western-style diet-induced metabolic abnormalities in mice

In this study, we investigated the effects of a newly synthesized α-galacto-oligosaccharide mixture (α-GOSg), 0.5% in drinking water, on high-fat/western-style diet (HFWD)-induced metabolic abnormality in mice in a study of 13 weeks. Raffinose family oligosaccharides (RFOs) were included as a comparison. Mice treated with α-GOSg had significantly lower body weight and body fat (p < 0.05), while RFOs were less effective. Both α-GOSg and RFOs significantly reduced serum levels of total cholesterol and low-density lipoprotein cholesterol, alanine aminotransferase and liver lipids. However, only α-GOSg significantly decreased the histopathological score for liver steatosis and downregulated hepatic fatty acid synthesis gene acetyl CoA carboxylase-α. α-GOSg also significantly reduced the content of bile acids in the small intestine and significantly increased the abundance of gut Bifidobacterium and decreased the abundance of Clostridium leptum. These actions are proposed to be key mechanisms contributing to the beneficial health effects of α-GOSg.

Unexpected Potential of Iso-oligosaccharides in the Generation of Important Food Odorants

The generation of selected Maillard-derived odorants from iso-oligosaccharides (IOSs), namely, from isomaltose, isomaltotriose, isomaltulose, and melibiose, was studied and compared with that from other oligosaccharides (maltose, lactose, and panose) and monosaccharides (glucose, galactose, and fructose). The study was carried out in binary mixtures of sugar and amino acids (glycine, proline, and cysteine) and upon wafer baking. The results indicate that IOSs induce browning and generation of the majority of the monitored odorants, in particular 4-hydroxy-2,5-dimethyl-3(2 H)-furanone, 2,3-butanedione, 2-acetyl-1-pyrroline, 2-propionyl-1-pyrroline, 2-acetylthiazole, and 2-acetyl-2-thiazoline, far more than the other oligosaccharides and to a higher or similar degree to that of the monosaccharides. Plausible mechanisms, consistent with the yields obtained from individual sugars, were proposed for the formation of the studied compounds. This newly obtained data brought for the first time evidence about the extraordinary potential of IOSs in the formation of several potent food odorants.

Fermentability of a Novel Galacto-Oligosaccharide Mixture by Lactobacillus spp. and Bifidobacterium spp

This study aimed to investigate the specific growth stimulation of certain desired intestinal bacteria by a novel galacto-oligosaccharide mixture, which was produced with a β-galactosidase from a potential probiotic Lactobacillus isolate that contained mainly oligosaccharides of β-1,3 and β-1,6 glycosidic linkages (termed Lb-GOS) using single-strain fermentations. The composition of this Lb-GOS mixture was 33.5% disaccharides, 60.5% trisaccharides, 4.8% tetrasaccharides, and 1.0% pentasaccharides with a negligible amount of monosaccharides, lactose, and lactobionic acid (0.3%). Eight Lactobacillus spp. strains and three Bifidobacterium spp. strains were used in single-strain fermentations to determine the fermentation activity scores of this Lb-GOS preparation compared to two commercially available prebiotic mixtures, 4′GOS-P and Vivinal GOS (V-GOS). The highest scores were obtained when L. reuteri Lb46 and the two Bifidobacterium strains, B. animalis subsp. lactis Bif1 and Bif3, were grown on these galacto-oligosaccharide mixtures. In addition, the Lb-GOS mixture was found to have higher fermentation activity scores; hence, it stimulated the growth of these probiotic strains more than 4′GOS-P and V-GOS, which may be attributed to the different glycosidic linkage types that are found in the Lb-GOS mixture compared to the other two commercial preparations. These findings suggested that the Lb-GOS mixture that is described in this work should be of interest for the formulations of new carbohydrate-based functional food ingredients.

A Galacto-Oligosaccharides Preparation Derived From Lactulose Protects Against Colorectal Cancer Development in an Animal Model

Colorectal cancer (CRC) is one of the most common neoplasias worldwide, and its incidence is increasing. Consumption of prebiotics is a useful strategy in order to prevent this important disease. These nutraceutical compounds might exert protective biological functions as antitumors. In order to test the chemopreventive effect of GOS-Lu (galacto-oligosaccharides derived from lactulose) prebiotic preparation against this cancer, an animal model (Rattus norvegicus F344) was used. In this model, two doses of azoxymethane (10 mg/kg) and two treatments with dextran sodium sulfate (DSS) were administered to the animals. Animals were fed for 20 weeks, and either control drinking water or drinking water containing 10% (w/w) GOS-Lu prebiotic preparation was provided to them. Animals were sacrificed after those 20 weeks, and their digestive tract tissues were analyzed. The results revealed a statistically significant reduction in the number of colon tumors in the GOS-Lu cohort with respect to control animals. Metagenomics sequencing was used for studying colon microbiota populations, revealing significant reductions in populations of pro-inflammatory bacteria families and species, and significant increases in interesting beneficial populations, such as Bifidobacterium. Therefore, oral administration of the prebiotic GOS-Lu preparation may be an effective strategy for preventing CRC.

Fermentation of non-digestible raffinose family oligosaccharides and galactomannans by probiotics

Due to their prebiotic potential indigestible oligosaccharides became a major focus of research interest. In this study the growth of selected probiotic strains including lactobacilli, bifidobacteria, Lactococcus lactis, Streptococcus salivarius ssp. thermophilus, Pediococcus ssp. and Enterococcus faecium with the, raffinose family oligosaccharides (RFOs) raffinose, stachyose and verbascose and galactomannan from guar bean Cyamopsis tetragonoloba (total guar carbohydrates, oligosaccharides (dp 2-4) and polysaccharides (dp > 5), obtained by size exclusion chromatography) were tested by means of turbidity measurements. RFOs were used by 75% of all strains, with some delay for the trisaccharide raffinose and the tetrasaccharide stachyose and a limited fermentation of the pentasaccharide verbascose. L. reuteri, P. pentosaceus and B. lactis HNO19™ were able to ferment not only raffinose and stachyose but also verbascose. Guar oligosaccharides were fermented by 15 out of 20 strains; P. acidilactici, L. acidophilus, L. rhamnosus GG and B. animalis ssp. lactis BB12 metabolized them comparably well as glucose or galactose. Isolated guar polysaccharides were not fermented whereas total guar carbohydrates were fermented by 7 strains, apparently caused by the oligosaccharide content. The findings of this study may be important for functional food products especially for indigestible oligosaccharides which may cause adverse effects in the gut when not cleaved.

Effects of α-Galactooligosaccharides from Chickpeas on High-Fat-Diet-Induced Metabolic Syndrome in Mice

The gut microbiota has the ability to modulate host energy homeostasis, which may regulate metabolic disorders. Functional oligosaccharide may positively regulate the intestinal microbiota. Therefore, effects of α-galactooligosaccharides (α-GOS) from chickpea on high-fat-diet (HFD)-induced metabolic syndrome and gut bacterial dysbiosis were investigated. After 6 weeks of intervention, HFD led to significant increases in levels of blood glucose, total cholesterol, triglyceride, glycated serum protein, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol of mice compared to normal-chow-fed mice. Meanwhile, all of the α-GOS-treated groups significantly decreased above parameters compared to the HFD group. HFD could significantly decrease the content of all bacteria, especially Bacteroides (9.82 ± 0.09 versus 10.3 ± 0.10; p < 0.05) and Lactobacillus (6.67 ± 0.18 versus 7.30 ± 0.24; p < 0.05), and a decrease in the production of short-chain fatty acids was also observed. Treatment with α-GOS significantly increased the number of Bifidobacterium (6.07 ± 0.23 of the low-dose treatment versus 5.65 ± 0.20 of the HFD group) and Lactobacillus (7.22 ± 0.16 of the low-dose treatment). It also significantly promoted the secretion of propionic and butyric acids. These results indicate that α-GOS from chickpeas may affect the metabolic disorders and gut bacterial ecosystem in a positive way.

Modeling Longitudinal Metabonomics and Microbiota Interactions in C57BL/6 Mice Fed a High Fat Diet

Longitudinal studies aim typically at following populations of subjects over time and are important to understand the global evolution of biological processes. When it comes to longitudinal omics data, it will often depend on the overall objective of the study, and constraints imposed by the data, to define the appropriate modeling tools. Here, we report the use of multilevel simultaneous component analysis (MSCA), orthogonal projection on latent structures (OPLS), and regularized canonical correlation analysis (rCCA) to study associations between specific longitudinal urine metabonomics data and microbiome data in a diet-induced obesity model using C57BL/6 mice. (1)H NMR urine metabolic profiling was performed on samples collected weekly over a period of 13 weeks, and stool microbial composition was assessed using 16S rRNA gene sequencing at three specific time periods (baseline, first week response, end of study). MSCA and OPLS allowed us to explore longitudinal urine metabonomics data in relation to the dietary groups, as well as dietary effects on body weight. In addition, we report a data integration strategy based on regularized CCA and correlation analyses of urine metabonomics data and 16S rRNA gene sequencing data to investigate the functional relationships between metabolites and gut microbial composition. Thanks to this workflow enabling the breakdown of this data set complexity, the most relevant patterns could be extracted to further explore physiological processes at an anthropometric, cellular, and molecular level.

Oligosaccharides composition in eight food legumes species as detected by high-resolution mass spectrometry

BACKGROUND

As probiotics, soy oligosaccharides have become popular as healthy foods to reduce disease risk. However, comprehensive information about oligosaccharides in different food legumes is limited.

RESULTS

In this study, eight oligosaccharides were well detected and quantified in different varieties of eight legume species using high-resolution mass spectrometry. It was determined that species could be distinguished by total content of oligosaccharides and their distribution modes. Among the studied species, Vigna unguiculata is a better resource of non-digestible oligosaccharides, while Vicia faba and black soybean (Glycine max) are at a disadvantage. Normally, stachyose predominates in non-digestible oligosaccharides, except in mung bean and broad bean, where verbascose predominates. For mung bean and green soybean, the seed coat should be taken into account for oligosaccharide consumption. The developed high-resolution mass spectrometry method greatly simplified the sample preparation process and permitted the identification of oligosaccharides without reference compounds.

CONCLUSION

This work involved extensive sample collecting and provided useful information for consumers. The developed method may be useful for rapid quantification of oligosaccharides in related foods.

Immunomodulatory activity in vitro and in vivo of verbascose from mung beans (Phaseolus aureus)

In the present study, the immunostimulatory activity of verbascose from mung beans (Phaseolus aureus) was evaluated by using in vitro cell models and in vivo animal models. The results of in vitro experiments showed that verbascose could enhance the ability of devouring neutral red of peritoneal macrophages and promote the release of nitric oxide and immune reactive molecules such as interleukin (IL)-6, IL-1β, interferon (IFN)-α, and IFN-γ. Treatment with verbascose at a dose of 200 μg/mL exhibited the best effects. For assay in vivo, administration of verbascose at a medium dose of 90 mg/kg body weight could significantly increase the index of spleen, activity of lysozyme in spleen and serum, hemolysin level in serum, and swelling rate of earlap in the delayed type of hypersensitivity (DTH) of immunosuppressed mice. All of the results suggested that verbascose had potent immunostimulatory activity and could be explored as a potential natural immunomodulatory agent in functional foods.

Biological significance of short-chain fatty acid metabolism by the intestinal microbiome

PURPOSE OF REVIEW

Evidence suggests that short-chain fatty acids (SCFAs) derived from microbial metabolism in the gut play a central role in host homeostasis. The present review describes the current understanding and physiological implications of SCFAs derived from microbial metabolism of nondigestible carbohydrates.

RECENT FINDINGS

Recent studies indicate a role for SCFAs, in particular propionate and butyrate, in metabolic and inflammatory disorders such as obesity, diabetes and inflammatory bowel diseases, through the activation of specific G-protein-coupled receptors and modification of transcription factors. Established prebiotics, such as fructooligosaccharides and galactooligosaccharides, which support the growth of Bifidobacteria, mainly mediate acetate production. Thus, recent identification of prebiotics which are able to stimulate the production of propionate and butyrate by benign saccharolytic populations in the colon is of interest.

SUMMARY

Manipulation of saccharolytic fermentation by prebiotic substrates is beginning to provide information on structure-function relationships relating to the production of SCFAs, which have multiple roles in host homeostasis.