High purity galacto-oligosaccharides enhance specific Bifidobacterium species and their metabolic activity in the mouse gut microbiome

Prebiotics are selectively fermented ingredients that result in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon the host health. The aim of this study was to evaluate the influence of a β (1–4) galacto-oligosaccharides formulation consisting of 90% pure GOS (GOS90), on the composition and activity of the mouse gut microbiota. Germ-free mice were colonized with microbiota from four pathogen-free wt 129 mice donors (SPF), and stools were collected during a feeding trial in which GOS90 was delivered orally for 14 days. Pyrosequencing of 16S rDNA amplicons showed that Bifidobacterium and specific Lactobacillus, Bacteroides and Clostridiales were more prevalent in GOS90-fed mice after 14 days, although the prebiotic impact on Bifidobacterium varied among individual mice. Prebiotic feeding also resulted in decreased abundance of Bacteroidales, Helicobacter and Clostridium. High-throughput quantitative PCR showed an increased abundance of Bifidobacterium adolescentis, B. pseudocatenulatum, B. lactis and B. gallicum in the prebiotic-fed mice. Control female mice showed a higher diversity (Phylogenetic Diversity PD = 15.1 ± 3.4 in stools and PD = 13.0 ± 0.6 in intestinal contents) than control males (PD = 7.8 ± 1.6 in stool samples and PD = 9.5 ± 1.0 in intestinal contents). GOS90 did not modify inflammatory biomarkers (IL-6, IL-12, IL-1β, IFN-γ and TNF-α). Decreased butyrate, acetate and lactate concentrations in stools of prebiotic fed mice suggested an increase in colonic absorption and reduced excretion. Overall, our results demonstrate that GOS90 is capable of modulating the intestinal microbiome resulting in expansion of the probiome (autochtonous commensal intestinal bacteria considered to have a beneficial influence on health)

Development of chitosan-coated agar-gelatin particles for probiotic delivery and targeted release in the gastrointestinal tract

This study reports the development of a novel and simple formulation for probiotic delivery using chitosan-coated agar-gelatin gel particles. This methodology involves the production of agar-gelatin particles by thermally treating a mixture of agar and gelatin solutions at high temperatures (121°C) and subsequently coating with chitosan. The particles were able to protect the probiotic strain Lactobacillus plantarum NCIMB 8826 during incubation for 2 hours in simulated gastric fluid (pH 2) as no statistically significant loss (P > 0.05) in cell concentration was observed, and also resist dissolution in simulated intestinal fluid (pH 7.2). Interestingly, this protection is related to the fact that the intense thermal treatment affected the physicochemical properties of agars, and resulted in the formation of a strong and tight polymer network, as indicated by the X-ray diffraction (XRD) analysis. Using an in vitro faecal batch fermentation model simulating the conditions of the distal part of the large intestine (pH 6.7-6.9), it was demonstrated by quantitative real time PCR that the majority of L. plantarum cells were released from the agar-gelatin particles within 30 to 48 hours. Overall, this work led to the development of a novel methodology for the production of probiotic containing particles which is simpler compared to current encapsulation technologies, and has a lot of potential to be used for the controlled release of probiotics and potentially other solid bioactives in the large intestine

Impact of 2′-fucosyllactose on gut microbiota composition in adults with chronic gastrointestinal conditions: batch culture fermentation model and pilot clinical trial findings

Intestinal dysbiosis has been described in patients with certain gastrointestinal conditions including irritable bowel syndrome (IBS) and ulcerative colitis. 2′-fucosyllactose (2′-FL), a prebiotic human milk oligosaccharide, is considered bifidogenic and butyrogenic. To assess prebiotic effects of 2′-FL, alone or in combination with probiotic strains (potential synbiotics), in vitro experiments were conducted on stool from healthy, IBS, and ulcerative colitis adult donors. In anaerobic batch culture fermenters, Bifidobacterium and Eubacterium rectale-Clostridium coccoides counts, and short-chain fatty acids (SCFAs) including butyrate increased during fermentation with 2′-FL and some of the 2′-FL/probiotic combinations. In a subsequent open-label pilot trial, the effect of a 2′-FL-containing nutritional formula was evaluated in twelve adults with IBS or ulcerative colitis. Gastrointestinal Quality of Life Index (GIQLI) total and gastrointestinal symptoms domain scores, stool counts of Bifidobacterium and Faecalibacterium prausnitzii, and stool SCFAs including butyrate, increased after six weeks of intervention. Consistent with documented effects of 2′-FL, the batch culture fermentation experiments demonstrated bifidogenic and butyrogenic effects of 2′-FL during fermentation with human stool samples. Consumption of the 2′-FL-containing nutritional formula by adults with IBS or ulcerative colitis was associated with improvements in intra- and extra-intestinal symptoms, and bifidogenic and butyrogenic effects

Impact of short-chain galactooligosaccharides on the gut microbiome of lactose-intolerant individuals

Approximately 75% of the global human population are lactose malabsorbers. In a previous clinical trial, it was shown that feeding a high-purity galactooligosaccharide (>95% GOS) could improve symptoms of lactose-intolerant subjects, attaining lactose tolerance in a majority of subjects. To investigate the mechanism, we examined the microbiome of human subjects before and after GOS feeding. The results show a significant shift in the microbiome of responsive individuals, including lactose-fermenting microbes in their stools. The high-purity prebiotic GOS resulted in adaptive shifts in the microbiome and correlated with improvement in clinical symptoms

Raw and sous-vide-cooked red cardoon stalks (Cynara cardunculus L. var. altilis DC): (poly)phenol bioaccessibility, anti-inflammatory activity in the gastrointestinal tract, and prebiotic activity

The in vitro anti-inflammatory and prebiotic activity and the content and profile of bioaccessible (poly)phenols and catabolites of raw and sous-vide-cooked red cardoon (Cynara cardunculus L. var. altilis DC) were investigated during gastrointestinal (GI) digestion. Raw cardoon after in vitro GI digestion had 0.7% bioaccessible (poly)phenols, which protected against lipopolysaccharide-induced inflammation by counteracting IL-8, IL-6, TNF-α, and IL-10 secretions in differentiated Caco-2 cells. Contrarily, GI-digested sous vide cardoon showed higher (poly)phenol bioaccessibility (59.8%) and exerted proinflammatory effects in Caco-2 cells. (Poly)phenols were highly metabolized during the first 8 h of in vitro fermentation, and nine catabolites were produced during 48 h of fermentation. Colonic-fermented raw and sous-vide-cooked cardoon did not show anti-inflammatory activity in HT-29 cells but presented potential prebiotic activity, comparable to the commercial prebiotic FOS, by stimulating health-promoting bacteria such as Bifidobacterium spp. and Lactobacillus/Enterococcus spp. and by increasing the production of total SCFAs, especially acetate

Malnutrition and gut microbiota in children

Malnutrition continues to threaten the lives of millions across the world, with children being hardest hit. Although inadequate access to food and infectious disease are the primary causes of childhood malnutrition, the gut microbiota may also contribute. This review considers the evidence on the role of diet in modifying the gut microbiota, and how the microbiota impacts childhood malnutrition. It is widely understood that the gut microbiota of children is influenced by diet, which, in turn, can impact child nutritional status. Additionally, diarrhoea, a major contributor to malnutrition, is induced by pathogenic elements of the gut microbiota. Diarrhoea leads to malabsorption of essential nutrients and reduced energy availability resulting in weight loss, which can lead to malnutrition. Alterations in gut microbiota of severe acute malnourished (SAM) children include increased Proteobacteria and decreased Bacteroides levels. Additionally, the gut microbiota of SAM children exhibits lower relative diversity compared with healthy children. Thus, the data indicate a link between gut microbiota and malnutrition in children, suggesting that treatment of childhood malnutrition should include measures that support a healthy gut microbiota. This could be of particular relevance in sub-Saharan Africa and Asia where prevalence of malnutrition remains a major threat to the lives of millions

Milk- and solid-feeding practices and daycare attendance are associated with differences in bacterial diversity, predominant communities, and metabolic and immune function of the infant gut microbiome

The development of the infant intestinal microbiome in response to dietary and other exposures may shape long-term metabolic and immune function. We examined differences in the community structure and function of the intestinal microbiome between four feeding groups, exclusively breastfed infants before introduction of solid foods (EBF), non-exclusively breastfed infants before introduction of solid foods (non-EBF), EBF infants after introduction of solid foods (EBF+S), and non-EBF infants after introduction of solid foods (non-EBF+S), and tested whether out-of-home daycare attendance was associated with differences in relative abundance of gut bacteria. Bacterial 16S rRNA amplicon sequencing was performed on 49 stool samples collected longitudinally from a cohort of 9 infants (5 male, 4 female). PICRUSt metabolic inference analysis was used to identify metabolic impacts of feeding practices on the infant gut microbiome. Sequencing data identified significant differences across groups defined by feeding and daycare attendance. Non-EBF and daycare-attending infants had higher diversity and species richness than EBF and non-daycare attending infants. The gut microbiome of EBF infants showed increased proportions of Bifidobacterium and lower abundance of Bacteroidetes and Clostridiales than non-EBF infants. PICRUSt analysis indicated that introduction of solid foods had a marginal impact on the microbiome of EBF infants (24 enzymes overrepresented in EBF+S infants). In contrast, over 200 bacterial gene categories were overrepresented in non-EBF+S compared to non-EBF infants including several bacterial methyl-accepting chemotaxis proteins (MCP) involved in signal transduction. The identified differences between EBF and non-EBF infants suggest that breast milk may provide the gut microbiome with a greater plasticity (despite having a lower phylogenetic diversity) that eases the transition into solid foods

Other Helicobacters, gastric and gut microbiota

The current article is a review of the most important and relevant literature published in 2016 and early 2017 on non-Helicobacter pylori Helicobacter infections in humans and animals, as well as interactions between H. pylori and the microbiota of the stomach and other organs. Some putative new Helicobacter species were identified in sea otters, wild boars, dogs, and mice. Many cases of Helicobacter fennelliae and Helicobacter cinaedi infection have been reported in humans, mostly in immunocompromised patients. Mouse models have been used frequently as a model to investigate human Helicobacter infection, although some studies have investigated the pathogenesis of Helicobacters in their natural host, as was the case for Helicobacter suis infection in pigs. Our understanding of both the gastric and gut microbiome has made progress and, in addition, interactions between H. pylori and the microbiome were demonstrated to go beyond the stomach. Some new approaches of preventing Helicobacter infection or its related pathologies were investigated and, in this respect, the probiotic properties of Saccharomyces, Lactobacillus and Bifidobacterium spp. were confirmed

Determination of the prebiotic activity of wheat arabinogalactan peptide (AGP) using batch culture fermentation

Purpose To test the prebiotic activity of wheat arabinogalactan-peptide (AGP), which is a soluble dietary fibre composed of arabinogalactan polysaccharide linked to a 15-residue peptide, which accounts for up to 0.4% of the dry weight of wheat flour. Methods The prebiotic activity of AGP prepared from white wheat flour was tested using in-vitro fermentation by colonic bacteria in automated pH controlled anaerobic stirred batch cultures and compared to fructooligosaccharide (FOS) and wheat flour arabinoxylan (AX). Bacterial populations were measured using fluorescence in-situ hybridisation (flow-FISH) and short-chain fatty acid (SCFA) concentrations were measured using HPLC. Results Fermentation of AGP resulted in a significant bifidogenic activity and increased concentrations of SCFAs, mainly acetate after 24 h of fermentation. Conclusions These results were comparable to those obtained with AX and confirm the prebiotic potential of AGP. Furthermore, fermentation of a mixture of AGP and AX was faster compared to the single substrates and more similar to FOS, indicating that combinations of fermentable carbohydrates with different structures are potentially more effective as prebiotics than single substrates