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Prebiotic Wheat Bran Fractions Induce Specific Microbiota Changes
Abstract and Figures
Wheat bran fibers are considered beneficial to human health through their impact on gut microbiota composition and activity. Here, we assessed the prebiotic potential of selected bran fractions by performing a series of fecal slurry anaerobic fermentation experiments using aleurone as well as total, ultrafine, and soluble wheat bran (swb) as carbon sources. By combining amplicon-based community profiling with a fluorescent in situ hybridization (FISH) approach, we found that incubation conditions favor the growth of Proteobacteria such as Escherichia and Bilophila. These effects were countered in all but one [total wheat bran (twb)] fermentation experiments. Growth of Bifidobacterium species was stimulated after fermentation using ultrafine, soluble, and twb, in the latter two as part of a general increase in bacterial load. Both ultrafine and swb fermentation resulted in a trade-offbetween Bifidobacterium and Bilophila, as previously observed in human dietary supplementation studies looking at the effect of inulin-type fructans on the human gut microbiota. Aleurone selectively stimulated growth of Dorea and butyrate-producing Roseburia. All fermentation experiments induced enhanced gas production; increased butyrate concentrations were only observed following soluble bran incubation. Our results open perspectives for the development of aleurone as a complementary prebiotic selectively targeting colon butyrate producers. © 2018 D'hoe, Conterno, Fava, Falony, Vieira-Silva, Vermeiren, Tuohy and Raes.
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Supplementary resources (2)
Data
January 2018
Data
January 2018
... In multiple studies, the consumption of aleurone led to the stimulation of microbial activity (Bifidobacteria dorea and butyrate-producing Roseburia spp.) in the caecum and colon, thus leading to a higher yield of propionate and butyrate. These important short-chain fatty acids (SCFA) are renowned for their health benefits, namely in cancer prevention [57,74,75]. A decrease in health-detrimental bacteria, such as Bilophila, Escherichia and Parabacteroides, was also reported [75]. ...
... These important short-chain fatty acids (SCFA) are renowned for their health benefits, namely in cancer prevention [57,74,75]. A decrease in health-detrimental bacteria, such as Bilophila, Escherichia and Parabacteroides, was also reported [75]. ...
The wheat aleurone layer is, according to millers, the main bran fraction. It is a source of nutritionally valuable compounds, such as dietary fibres, proteins, minerals and vitamins, that may exhibit health benefits. Despite these advantages, the aleurone layer is scarce on the market, probably due to issues related to its extraction. Many processes exist with some patents, but a choice must be made between the quality and quantity of the resulting product. Nonetheless, its potential has been studied mainly in bread and pasta. While the nutritional benefits of aleurone-rich flour addition to bread agree, opposite results have been obtained concerning its effects on end-product characteristics (namely loaf volume and sensory characteristics), thus ensuing different acceptability responses from consumers. However, the observed negative effects of aleurone-rich flour on bread dough could be reduced by subjecting it to pre- or post-extracting treatments meant to either reduce the particle size of the aleurone’s fibres or to change the conformation of its components.
... In multiple studies, the consumption of aleurone led to the stimulation of microbial activity (Bifidobacteria dorea and butyrate-producing Roseburia spp.) in the caecum and colon, thus leading to a higher yield of propionate and butyrate. These important short chain fatty acids (SCFA) are renowned for their health benefits, namely in cancer prevention [57,69,70]. A decrease in health detrimental bacteria, such as Bilophila, Escherichia and Parabacteroides, was also reported [70]. ...
... These important short chain fatty acids (SCFA) are renowned for their health benefits, namely in cancer prevention [57,69,70]. A decrease in health detrimental bacteria, such as Bilophila, Escherichia and Parabacteroides, was also reported [70]. ...
The wheat aleurone layer is, according to millers, the main bran fraction. It is a source of nutritionally valuable compounds, such as dietary fibres, proteins, minerals and vitamins, that may exhibit health benefits. Despite these advantages, the aleurone layer is scarce on the market, probably due to issues related to its extraction. Many processes exist with some patents, but a choice must be made between the quality and quantity of the resulting product. Nonetheless, its potential has been studied mainly in bread and pasta. While the nutritional benefits of aleurone-rich flour addition to bread agree, opposite results have been obtained concerning its effects on end-product characteristics (namely loaf volume and sensory characteristics), thus ensuing different acceptability responses from consumers. However, the observed negative effects of aleurone-rich flour on bread dough could be reduced by subjecting it to pre- or post-extracting treatments meant to either reduce the particle size of the aleurone’s fibres or to change the conformation of its components.
... Spore bacteria entering the human body can cause very serious disturbances in the functioning of the immune system, gastrointestinal tract, liver, respiratory system, and nervous system [18]. Even if spore bacteria do not cause rope disease, their presence in finished products is undesirable, since even a small amount of B. subtilis and B. licheniformis in food products can cause a mild form of foodborne disease [19]. In recent years, the spread of wheat bread disease caused by Bacillus has been observed [20]. ...
... Distinct diet patterns and consumption of specific substances induce alterations in the gut microbiota. It has increased the interest in evaluating the effects of several food components (e.g., dietary fiber, bioactive peptides, phenolic compounds, nutraceuticals, and botanicals) on the composition and metabolic activity of this microbiota (D'hoe et al. 2018;Martín-Peláez et al. 2017a, b;Menezes et al. 2021). In parallel, there have been efforts to advance in investigating the composition of the gut microbiota through the use of distinct experimental and methodological protocols developed Communicated by Erko Stackebrandt. ...
The increasing interest in the effects of the gut microbiota on host health has stimulated the investigation of the composition of this microbial community and the factors affecting these microorganisms. This review discusses the recent advances and progress applications in the use of the fluorescent in situ hybridization (FISH) coupled to flow cytometry (FC) technique (FISH-FC) in studies evaluating the gut microbiota published in the last 10 years, with particular emphasis on the effects of foods and dietary interventions. These studies have shown that FISH-FC technique is capable of detecting and quantifying several groups of bacteria found as part of the gut microbiota. FISH-FC can be considered an effective, versatile, and rapid technique to evaluate alterations in gut microbiota composition caused by different foods as assessed in studies in vitro, in vivo, and in clinical trials. Some specific probes have been most used to represent the general gut microbiota, such as those specific to Lactobacillus spp./Enterococcus spp., Bacteroidaceae/Prevotellaceae, Clostridium histolyticum, and Bifidobacterium spp. FISH-FC technique could have an important opportunity for application in studies with next-generation probiotics belonging to the gut microbiota. Optimizations of FISH-FC protocols could allow more discoveries about the gut microbiota, including the development of new probes targeting microorganisms still not explored, the analysis of individual portions of the intestine, and the proposition of novel quantitative approaches.
... On the contrary, early treatment of children with nephrotic syndrome boosts the number of SCFA-producing gut bacteria [40]. Daily use of whole wheat promotes the growth of intestinal microbiota, increases SCAF production, and improves gastrointestinal health [41,42]. ...
Introduction:
Nephrotic syndrome (NS) is a common chronic kidney disorder during childhood. The most important characteristic of this disease is proteinuria. The Persian medicine (PM) has important dietary recommendations for strengthening the kidney function and treatment of this disease. The aim of this study was to investigate the effect of a diet including PM recommendations and general principles of Western medicine.
Materials and methods:
Twenty children with nephrotic syndrome were randomly divided into intervention and control groups and monitored for one month. The control group received a diet based on the general principles of Western medicine. In the intervention group, in addition to the Western medicine diet, dietary recommendations of PM were also prescribed including the pomegranate (Cydonia oblonga mill.), quince (Cydonia oblonga mill.), and whole grains (wheat and barley). A 24-hour dietary questionnaire was applied and anthropometric and biochemical indices including spot urine protein (proteinuria), albumin (Alb), urea, creatinine (Cr), total cholesterol (TC), and triglyceride (TG) were measured before and after the study.
Results:
The amount of protein intake reduced significantly in the diet of both groups but the differences between the two groups were not significant. Proteinuria reduced significantly in both the Western and PM groups; however, proteinuria was significantly lower in the Persian medicine group compared to the control group. TC and Cr levels reduced significantly in the intervention group, although the changes were not significant compared to the control group.
Conclusion:
The results of this study showed that adding dietary recommendations of the Persian medicine to the general rules of the Western medicine diet reduced proteinuria and improved the combat against nephrotic syndrome.
Cereal bran consumption improves gastrointestinal and metabolic health. Unprocessed cereal brans have a limited shelf-life and the presence of anti-nutrient phytochemicals. In the present study, lipids and antinutrients (flavonoids, tannin,...
Antibiotics adversely affect intestinal communities and prebiotic fibers are effective to counteract the side effects of antibiotics. The effects of prebiotic fibers vary due to their molecular characteristics. This study compared the effects of three fibers with different fermentation rates on fecal microflora with the perturbance of antibiotics in vitro. The results showed that supplementation of the low-fermentable fiber (konjac glucomannan, KGM) enhanced the viability of several gut bacterial groups and increased the production of acetic acid and total SCFAs better than the high- (galactooligosaccharides, GOS) and moderate-fermentable fibers (inulin, INU) with antibiotic disturbance. The relative abundance of Bacteroidetes was significantly lowered after fermentation with GOS compared with KGM and INU in the presence of ampicillin. KGM fermentation also maintained the relative abundance of possible butyric acid producer Clostridium. These results suggest that low-fermentable carbohydrates confer better effects to relieve or counteract antibiotic influence on gut microbiome.
The use of probiotics has been one of the effective strategies to restructure perturbed human gut microbiota following a disease or metabolic disorder. One of the biggest challenges associated with the use of probiotic-based gut modulation strategies is to keep the probiotic cells viable and stable during the gastrointestinal transit. Biofilm-based probiotics delivery approaches have emerged as fascinating modes of probiotic delivery in which probiotics show significantly greater tolerance and biotherapeutic potential, and interestingly probiotic biofilms can be developed on food-grade surfaces too, which is ideal for the growth and proliferation of bacterial cells for incorporation into food matrices. In addition, biofilms can be further encapsulated with food-grade materials or with bacterial self-produced biofilms. This review presents a newly emerging and unprecedently discussed techniques for the safe delivery of probiotics based on biofilms and further discusses newly emerging prebiotic materials which target specific gut microbiota groups for growth and proliferation.
Together with proteins and fats, carbohydrates are one of the macronutrients in the human diet. Digestible carbohydrates, such as starch, starch-based products, sucrose, lactose, glucose and some sugar alcohols and unusual (and fairly rare) α-linked glucans, directly provide us with energy while other carbohydrates including high molecular weight polysaccharides, mainly from plant cell walls, provide us with dietary fibre. Carbohydrates which are efficiently digested in the small intestine are not available in appreciable quantities to act as substrates for gut bacteria. Some oligo- and polysaccharides, many of which are also dietary fibres, are resistant to digestion in the small intestines and enter the colon where they provide substrates for the complex bacterial ecosystem that resides there. This review will focus on these non-digestible carbohydrates (NDC) and examine their impact on the gut microbiota and their physiological impact. Of particular focus will be the potential of non-digestible carbohydrates to act as prebiotics, but the review will also evaluate direct effects of NDC on human cells and systems.
Objective
Contrary to the long-standing prerequisite of inducing selective (ie, bifidogenic) effects, recent findings suggest that prebiotic interventions lead to ecosystem-wide microbiota shifts. Yet, a comprehensive characterisation of this process is still lacking. Here, we apply 16S rDNA microbiota profiling and matching (gas chromatography mass spectrometry) metabolomics to assess the consequences of inulin fermentation both on the composition of the colon bacterial ecosystem and faecal metabolites profiles.
Design
Faecal samples collected during a double-blind, randomised, cross-over intervention study set up to assess the effect of inulin consumption on stool frequency in healthy adults with mild constipation were analysed. Faecal microbiota composition and metabolite profiles were linked to the study's clinical outcome as well as to quality-of-life measurements recorded.
Results
While faecal metabolite profiles were not significantly altered by inulin consumption, our analyses did detect a modest effect on global microbiota composition and specific inulin-induced changes in relative abundances of Anaerostipes, Bilophila and Bifidobacterium were identified. The observed decrease in Bilophila abundances following inulin consumption was associated with both softer stools and a favourable change in constipation-specific quality-of-life measures.
Conclusions
Ecosystem-wide analysis of the effect of a dietary intervention with prebiotic inulin-type fructans on the colon microbiota revealed that this effect is specifically associated with three genera, one of which (Bilophila) representing a promising novel target for mechanistic research.
Trial registration number
NCT02548247.
With the increasing amount of evidence linking certain disorders of the human body to a disturbed gut microbiota, there is a growing interest for compounds that positively influence its composition and activity through diet. Besides the consumption of probiotics to stimulate favorable bacterial communities in the human gastrointestinal tract, prebiotics such as inulin-type fructans (ITF) and arabinoxylan-oligosaccharides (AXOS) can be consumed to increase the number of bifidobacteria in the colon. Several functions have been attributed to bifidobacteria, encompassing degradation of non-digestible carbohydrates, protection against pathogens, production of vitamin B, antioxidants, and conjugated linoleic acids, and stimulation of the immune system. During life, the numbers of bifidobacteria decrease from up to 90 % of the total colon microbiota in vaginally delivered breast-fed infants to < 5 % in the colon of adults and they decrease even more in that of elderly as well as in patients with certain disorders such as antibiotic-associated diarrhea, inflammatory bowel disease, irritable bowel syndrome, obesity, allergies, and regressive autism. It has been suggested that the bifidogenic effects of ITF and AXOS are the result of strain-specific yet complementary carbohydrate degradation mechanisms within cooperating bifidobacterial consortia. Except for a bifidogenic effect, ITF and AXOS also have shown to cause a butyrogenic effect in the human colon, i.e., an enhancement of colon butyrate production. Butyrate is an essential metabolite in the human colon, as it is the preferred energy source for the colon epithelial cells, contributes to the maintenance of the gut barrier functions, and has immunomodulatory and anti-inflammatory properties. It has been shown that the butyrogenic effects of ITF and AXOS are the result of cross-feeding interactions between bifidobacteria and butyrate-producing colon bacteria, such as Faecalibacterium prausnitzii (clostridial cluster IV) and Anaerostipes, Eubacterium and Roseburia species (clostridial cluster XIVa). These kinds of interactions possibly favor the co-existence of bifidobacterial strains with other bifidobacteria and with butyrate-producing colon bacteria in the human colon.
The common approach to the multiplicity problem calls for controlling the familywise error rate (FWER). This approach, though, has faults, and we point out a few. A different approach to problems of multiple significance testing is presented. It calls for controlling the expected proportion of falsely rejected hypotheses — the false discovery rate. This error rate is equivalent to the FWER when all hypotheses are true but is smaller otherwise. Therefore, in problems where the control of the false discovery rate rather than that of the FWER is desired, there is potential for a gain in power. A simple sequential Bonferronitype procedure is proved to control the false discovery rate for independent test statistics, and a simulation study shows that the gain in power is substantial. The use of the new procedure and the appropriateness of the criterion are illustrated with examples.
Despite the accepted health benefits of consuming dietary fiber, little is known about the mechanisms
by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic mouse model, in which animals were colonized with a synthetic human gut microbiota composed of fully
sequenced commensal bacteria, we elucidated the functional interactions between dietary fiber, the
gut microbiota, and the colonic mucus barrier, which serves as a primary defense against enteric pathogens.
We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts
to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus
barrier. Dietary fiber deprivation, together with a fiber-deprived, mucus-eroding microbiota, promotes
greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium. Our
work reveals intricate pathways linking diet, the gut microbiome, and intestinal barrier dysfunction,
which could be exploited to improve health using dietary therapeutics.
Cross-feeding interactions were studied between selected strains of lactobacilli and/or bifidobacteria and butyrate-producing colon bacteria that consume lactate but are not able to degrade inulin-type fructans (ITF) in a medium for colon bacteria (supplemented with ITF as energy source and acetate when necessary). Degradation of oligofructose by Lactobacillus acidophilus IBB 801 and inulin by Lactobacillus paracasei 8700:2 and Bifidobacterium longum LMG 11047 resulted in the release of free fructose into the medium and the production of mainly lactate (lactobacilli) and acetate (B. longum LMG 11047). During bicultures of Lb. acidophilus IBB 801 and Anaerostipes caccae DSM 14662T on oligofructose, the latter strain converted lactate (produced by the former strain from oligofructose) into butyrate and gases, but only in the presence of acetate. During bicultures of Lb. paracasei 8700:2 and A. caccae DSM 14662T or Eubacterium hallii DSM 17630 on inulin, the butyrate-producing strains consumed low concentrations of lactate and acetate generated by inulin degradation by the Lactobacillus strain. As more acetate was produced during tricultures of Lb. paracasei 8700:2 and B. longum LMG 11047, which degraded inulin simultaneously, and A. caccae DSM 14662T or E. hallii DSM 17630, a complete conversion of lactate into butyrate and gases by these butyrate-producing strains occurred. Therefore, butyrate production by lactate-consuming, butyrate-producing colon bacterial strains incapable of ITF degradation, resulted from cross-feeding of monosaccharides and lactate by an ITF-degrading Lactobacillus strain and acetate produced by a Bifidobacterium strain.
Background:
Dysbiosis of the intestinal microbiota has been widely established in inflammatory bowel disease (IBD). There is significant clinical and genetic overlap between spondyloarthritis (SpA) and IBD. Importantly, up to half of all SpA patients exhibit microscopic signs of bowel inflammation, often bearing particular resemblance to early Crohn's disease, a subtype of IBD.
Objective:
To assess the relation between intestinal microbial composition, gut histology and disease activity markers in SpA.
Methods:
We used 16S rRNA amplicon sequencing to compare microbial composition in ileal and colonic biopsies of 27 SpA patients with (N = 14) or without (N = 13) microscopic bowel inflammation and 15 healthy controls (ileal = 15 and colonic = 06).
Results:
Intestinal inflammation status was strongly associated with the mucosal microbiota profile of SpA patients. The bacterial community composition of inflamed biopsies clustered separate from that of non-inflamed biopsies (PERMANOVA p < 0.05; Hierarchical clustering on Bray-Curtis distances). Interestingly, we revealed a positive correlation between the abundance of the genus Dialister and the Ankylosing Spondylitis Disease Activity Score (ASDAS) (correlation coefficient rho = 0.62, FDR-corrected q-value < 0.01). This finding was further supported by the low frequency of Dialister observed in non-inflamed SpA samples and healthy controls.
Conclusion:
We observed a significant difference in intestinal microbial composition of SpA patients with versus without microscopic gut inflammation. Moreover, we were able to identify Dialister as a potential microbial marker of disease activity in SpA. This article is protected by copyright. All rights reserved.
Little is known about how colonic transit time relates to human colonic metabolism and its importance for host health, although a firm stool consistency, a proxy for a long colonic transit time, has recently been positively associated with gut microbial richness. Here, we show that colonic transit time in humans, assessed using radio-opaque markers, is associated with overall gut microbial composition, diversity and metabolism. We find that a long colonic transit time associates with high microbial richness and is accompanied by a shift in colonic metabolism from carbohydrate fermentation to protein catabolism as reflected by higher urinary levels of potentially deleterious protein-derived metabolites. Additionally, shorter colonic transit time correlates with metabolites possibly reflecting increased renewal of the colonic mucosa. Together, this suggests that a high gut microbial richness does not per se imply a healthy gut microbial ecosystem and points at colonic transit time as a highly important factor to consider in microbiome and metabolomics studies.
Despite recent progress, the organization and ecological properties of the
intestinal microbial ecosystem remain under-investigated. Here, using a manually
curated metabolic module framework for (meta-)genomic data analysis, we studied
species–function relationships in gut microbial genomes and microbiomes.
Half of gut-associated species were found to be generalists regarding overall
substrate preference, but we observed significant genus-level metabolic
diversification linked to bacterial life strategies. Within each genus,
metabolic consistency varied significantly, being low in Firmicutes genera and
higher in Bacteroides. Differentiation of fermentable substrate
degradation potential contributed to metagenomic functional repertoire variation
between individuals, with different enterotypes showing distinct
saccharolytic/proteolytic/lipolytic profiles. Finally, we found that
module-derived functional redundancy was reduced in the low-richness
Bacteroides enterotype, potentially indicating a decreased
resilience to perturbation, in line with its frequent association to dysbiosis.
These results provide insights into the complex structure of gut
microbiome-encoded metabolic properties and emphasize the importance of
functional and ecological assessment of gut microbiome variation in clinical
studies.
Prebiotic inulin-type fructans (ITF) display a bifidogenic and butyrogenic effect. Four bifidobacterial strains (Bifidobacterium breve Yakult, Bifidobacterium adolescentis LMG 10734, Bifidobacterium angulatum LMG 11039T, and Bifidobacterium longum subsp. longum LMG 11047), displaying different ITF degradation capacities, were each grown in cocultivation with Faecalibacterium prausnitzii DSM 17677T, an ITF-degrading butyrate-producing colon bacterium, as to unravel their cross-feeding interactions. These coculture fermentations were performed in a medium for colon bacteria, whether or not including acetate (necessary for the growth of F. prausnitzii DSM 17677T and whether or not provided through cross-feeding), supplemented with oligofructose or inulin as the sole energy source. Bifidobacterium breve Yakult did not degrade oligofructose, resulting in the production of high concentrations of butyrate by F. prausnitzii DSM 17677T through oligofructose degradation. The degradation of oligofructose by B. adolescentis LMG 10734 and of oligofructose and inulin by B. angulatum LMG 11039T and B. longum LMG 11047 resulted in the production of acetate, which was cross-fed to F. prausnitzii DSM 17677T, enabling the latter strain to degrade oligofructose and inulin. Slow preferential degradation of the short chain length fractions of oligofructose (intracellularly) by B. adolescentis LMG 10734 enabled substantial oligofructose degradation by F. prausnitzii DSM 17677T. However, fast non-preferential degradation of all chain length fractions of oligofructose (extracellularly) and efficient degradation of the short chain length fractions of inulin by B. angulatum LMG 11039T and B. longum LMG 11047 made it impossible for F. prausnitzii DSM 17677T to compete for the available substrate. These results indicate that cross-feeding interactions between bifidobacteria and acetate-depending, butyrate-producing colon bacteria can be either a pure commensal or beneficial relationship between these bacteria, or can be dominated by competition, depending on the ITF degradation capacities of the bifidobacterial strains involved.