Xylitol enhances synthesis of propionate in the colon via cross-feeding of gut microbiota

Abstract Background Xylitol, a white or transparent polyol or sugar alcohol, is digestible by colonic microorganisms and promotes the proliferation of beneficial bacteria and the production of short-chain fatty acids (SCFAs), but the mechanism underlying these effects remains unknown. We studied mice fed with 0%, 2% (2.17 g/kg/day), or 5% (5.42 g/kg/day) (weight/weight) xylitol in their chow for 3 months. In addition to the in vivo digestion experiments in mice, 3% (weight/volume) (0.27 g/kg/day for a human being) xylitol was added to a colon simulation system (CDMN) for 7 days. We performed 16S rRNA sequencing, beneficial metabolism biomarker quantification, metabolome, and metatranscriptome analyses to investigate the prebiotic mechanism of xylitol. The representative bacteria related to xylitol digestion were selected for single cultivation and co-culture of two and three bacteria to explore the microbial digestion and utilization of xylitol in media with glucose, xylitol, mixed carbon sources, or no-carbon sources. Besides, the mechanisms underlying the shift in the microbial composition and SCFAs were explored in molecular contexts. Results In both in vivo and in vitro experiments, we found that xylitol did not significantly influence the structure of the gut microbiome. However, it increased all SCFAs, especially propionate in the lumen and butyrate in the mucosa, with a shift in its corresponding bacteria in vitro. Cross-feeding, a relationship in which one organism consumes metabolites excreted by the other, was observed among Lactobacillus reuteri, Bacteroides fragilis, and Escherichia coli in the utilization of xylitol. At the molecular level, we revealed that xylitol dehydrogenase (EC 1.1.1.14), xylulokinase (EC 2.7.1.17), and xylulose phosphate isomerase (EC 5.1.3.1) were key enzymes in xylitol metabolism and were present in Bacteroides and Lachnospiraceae. Therefore, they are considered keystone bacteria in xylitol digestion. Also, xylitol affected the metabolic pathway of propionate, significantly promoting the transcription of phosphate acetyltransferase (EC 2.3.1.8) in Bifidobacterium and increasing the production of propionate. Conclusions Our results revealed that those key enzymes for xylitol digestion from different bacteria can together support the growth of micro-ecology, but they also enhanced the concentration of propionate, which lowered pH to restrict relative amounts of Escherichia and Staphylococcus. Based on the cross-feeding and competition among those bacteria, xylitol can dynamically balance proportions of the gut microbiome to promote enzymes related to xylitol metabolism and SCFAs.

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The Athlete and Gut Microbiome: Short-chain Fatty Acids as Potential Ergogenic Aids for Exercise and Training

International Journal of Sports Medicine ◽

10.1055/a-1524-2095 ◽

2021 ◽

Author(s):

Tindaro Bongiovanni ◽

Marilyn Ong Li Yin ◽

Liam Heaney

Keyword(s):

Fatty Acids ◽

Gut Microbiome ◽

Short Chain Fatty Acids ◽

Short Chain ◽

Future Research ◽

Immune Functions ◽

Additional Energy ◽

Chain Fatty Acids

AbstractShort-chain fatty acids (SCFAs) are metabolites produced in the gut via microbial fermentation of dietary fibers referred to as microbiota-accessible carbohydrates (MACs). Acetate, propionate, and butyrate have been observed to regulate host dietary nutrient metabolism, energy balance, and local and systemic immune functions. In vitro and in vivo experiments have shown links between the presence of bacteria-derived SCFAs and host health through the blunting of inflammatory processes, as well as purported protection from the development of illness associated with respiratory infections. This bank of evidence suggests that SCFAs could be beneficial to enhance the athlete’s immunity, as well as act to improve exercise recovery via anti-inflammatory activity and to provide additional energy substrates for exercise performance. However, the mechanistic basis and applied evidence for these relationships in humans have yet to be fully established. In this narrative review, we explore the existing knowledge of SCFA synthesis and the functional importance of the gut microbiome composition to induce SCFA production. Further, changes in gut microbiota associated with exercise and various dietary MACs are described. Finally, we provide suggestions for future research and practical applications, including how these metabolites could be manipulated through dietary fiber intake to optimize immunity and energy metabolism.

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Short-Chain Fatty Acids Prevent Diabetic Nephropathy In Vivo and In Vitro

Diabetes ◽

10.2337/db18-92-or ◽

2018 ◽

Vol 67 (Supplement 1) ◽

pp. 92-OR ◽

Cited By ~ 1

Author(s):

WEI HUANG ◽

YONG XU ◽

YOUHUA XU ◽

LUPING ZHOU ◽

CHENLIN GAO

Keyword(s):

Fatty Acids ◽

Diabetic Nephropathy ◽

Short Chain Fatty Acids ◽

Short Chain ◽

Chain Fatty Acids

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Chemical composition and in vitro digestibility of some selected under-utilized tropical seeds as protein sources in ruminants’ diet

Bulletin of the National Research Centre ◽

10.1186/s42269-020-00430-9 ◽

2020 ◽

Vol 44 (1) ◽

Author(s):

Oluwatosin Bode Omotoso ◽

Mary Oluwafunmilayo Adeduntan ◽

Adebowale Noah Fajemisin

Keyword(s):

Short Chain Fatty Acids ◽

Nutritional Composition ◽

Metabolizable Energy ◽

In Vitro Digestibility ◽

Protein Sources ◽

Dry Matter Digestibility ◽

Supplementary Feed ◽

Monodora Myristica

Abstract Background The study highlighted the potential of three common and under-utilized tropical leguminous seeds (Tomentosa nilotica, Dioclea reflexa and Monodora myristica) to be used as supplementary feed to ruminant livestock. These seeds (their plants inclusive) are valuable sources of food and medicine for the prevention of illness and maintenance of human health. The medicinal properties of these seeds include antimicrobial, anti-inflammatory, anti-oxidant and immuno-stimulant. Trypsin inhibitors, which are common anti-nutritional factors in legumes and for monogastric animals, do not exert adverse effects in ruminants because they are degraded in the rumen. Hence, the crux of this study is to examine the effect of processing methods on the nutritional composition (proximate, fibre fractions, minerals, anti-nutrients) and in vitro digestibility of Tomentosa nilotica, Dioclea reflexa and Monodora myristica seeds and their suitability as feedstuff (protein sources) in small ruminant feed, particularly during off-season. Results From the results, raw Tomentosa nilotica and Monodora myristica have the highest crude protein (30.35% CP) and fat (22.40% EE), respectively. It is noteworthy that roasting best improve the mineral and significantly reduce the anti-nutrients observed in this study better compared to boiling and soaking methods. The highest organic matter digestibility, short-chain fatty acids, metabolizable energy and in vitro dry matter digestibility values were obtained in Dioclea reflexa compared to other test seeds. Roasting best improved the nutritive values, while Dioclea reflexa seed was rated highest for all the nutritional attributes and in vitro digestibility. Conclusions Dioclea reflexa could be incorporated in ruminants’ diet as protein source, particularly during the off-season, for improved ruminant production in Nigeria. However, in vivo study is therefore recommended to validate this report.

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Organization of the regulatory region of the yeast CYC7 gene: multiple factors are involved in regulation

Molecular and Cellular Biology ◽

10.1128/mcb.7.9.3252-3259.1987 ◽

1987 ◽

Vol 7 (9) ◽

pp. 3252-3259

Author(s):

T Prezant ◽

K Pfeifer ◽

L Guarente

Keyword(s):

Cytochrome C ◽

Regulatory Region ◽

Carbon Sources ◽

Binding Studies ◽

Multiple Factors ◽

Vitro Binding ◽

Genes Encoding ◽

Nonfermentable Carbon Source

Regulation of the CYC7 gene of Saccharomyces cerevisiae, encoding iso-2-cytochrome c, was studied. Expression was induced about 20-fold by heme and derepressed 4- to 8-fold by a shift from glucose medium to one containing a nonfermentable carbon source. Deletion analysis showed that induction by heme depends upon sequences between -250 and -228 (from the coding sequence) and upon the HAP1 activator gene, previously shown to be required for CYC1 expression (L. Guarente et al., Cell 36:503-511, 1984). Thus, HAP1 coordinates expression of CYC7 and CYC1, the two genes encoding isologs of cytochrome c in S. cerevisiae. HAP1-18, a mutant allele of HAP1, which increased CYC7 expression more than 10-fold, also acted through sequences between -250 and -228. In vitro binding studies showed that the HAP1 product binds to these sequences (see also K. Pfeifer, T. Prezant, and L. Guarente, Cell 49:19-28, 1987) and an additional factor binds to distal sequences that lie between -201 and -165. This latter site augmented CYC7 expression in vivo. Derepression of CYC7 expression in a medium containing nonfermentable carbon sources depended upon sequences between -354 and -295. The interplay of these multiple sites and the factors that bind to them are discussed.

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Study on a Fermented Whole Wheat: Phenolic Content, Activity on PTP1B Enzyme and In Vitro Prebiotic Properties

Molecules ◽

10.3390/molecules24061120 ◽

2019 ◽

Vol 24 (6) ◽

pp. 1120 ◽

Cited By ~ 3

Author(s):

Diletta Balli ◽

Maria Bellumori ◽

Paolo Paoli ◽

Giuseppe Pieraccini ◽

Monica Di Paola ◽

...

Keyword(s):

Lactobacillus Reuteri ◽

Tyrosine Phosphatase ◽

Bacterial Species ◽

Food Ingredient ◽

Microbial Composition ◽

Acidic Hydrolysis ◽

Inhibitory Power ◽

Methyl Ferulate ◽

First Time

Fermented cereals, staple foods in Asia and Africa, are recently receiving a growing interest in Western countries. The object of this work is the characterization of a fermented wheat used as a food ingredient and dietary supplement. To this aim, the phenolic composition, the activity on protein tyrosine phosphatase 1B (PTP1B), an enzyme overexpressed in type-II diabetes, the in vitro prebiotic properties on Lactobacillus reuteri and the microbial composition were investigated. Basic and acidic hydrolysis were tested for an exhaustive recovery of bound phenols: the acidic hydrolysis gave best yields. Methyl ferulate and neocarlinoside were identified for the first time in wheat. The inhibitory power of the extracts of several batches were investigated on PTP1B enzyme. The product was not able to inhibit the enzyme, otherwise, for the first time, a complete inhibition was observed for schaftoside, a major C-flavonoid of wheat. The microbial composition was assessed identifying Lactobacillus, Enterococcus, and Pediococcus as the main bacterial species. The fermented wheat was a suitable substrate for the grown of L. reuteri, recognized for its health properties in the human gut. The proposed method for phenols is easier compared to those based on strong basic hydrolysis; our results assessed the bound phenols as the major fraction, differently from that suggested by the literature for fermented cereals.

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Application of Probiotic Yeasts on Candida Species Associated Infection

Journal of Fungi ◽

10.3390/jof6040189 ◽

2020 ◽

Vol 6 (4) ◽

pp. 189

Author(s):

Lohith Kunyeit ◽

Anu-Appaiah K A ◽

Reeta P. Rao

Keyword(s):

Combination Therapy ◽

Candida Species ◽

Short Chain Fatty Acids ◽

Candida Auris ◽

Protective Mechanisms ◽

Probiotic Yeast ◽

Life Threatening ◽

Candida Infections

Superficial and life-threatening invasive Candida infections are a major clinical challenge in hospitalized and immuno-compromised patients. Emerging drug-resistance among Candida species is exacerbated by the limited availability of antifungals and their associated side-effects. In the current review, we discuss the application of probiotic yeasts as a potential alternative/ combination therapy against Candida infections. Preclinical studies have identified several probiotic yeasts that effectively inhibit virulence of Candida species, including Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, Candida krusei and Candida auris. However, Saccharomyces cerevisiae var. boulardii is the only probiotic yeast commercially available. In addition, clinical studies have further confirmed the in vitro and in vivo activity of the probiotic yeasts against Candida species. Probiotics use a variety of protective mechanisms, including posing a physical barrier, the ability to aggregate pathogens and render them avirulent. Secreted metabolites such as short-chain fatty acids effectively inhibit the adhesion and morphological transition of Candida species. Overall, the probiotic yeasts could be a promising effective alternative or combination therapy for Candida infections. Additional studies would bolster the application of probiotic yeasts.

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Lactobacillus reuteri Ameliorates Intestinal Inflammation and Modulates Gut Microbiota and Metabolic Disorders in Dextran Sulfate Sodium-Induced Colitis in Mice

Nutrients ◽

10.3390/nu12082298 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2298

Author(s):

Gang Wang ◽

Shuo Huang ◽

Shuang Cai ◽

Haitao Yu ◽

Yuming Wang ◽

...

Keyword(s):

Gut Microbiota ◽

Metabolic Disorders ◽

Dextran Sulfate ◽

Dextran Sulfate Sodium ◽

Lactobacillus Reuteri ◽

Intestinal Inflammation ◽

Intestinal Bacteria ◽

Ht 29

Lactobacillus reuteri, a commensal intestinal bacteria, has various health benefits including the regulation of immunity and intestinal microbiota. We examined whether L. reuteri I5007 could protect mice against colitis in ameliorating inflammation, modulating microbiota, and metabolic composition. In vitro, HT-29 cells were cultured with L. reuteri I5007 or lipopolysaccharide treatment under three different conditions, i.e., pre-, co- (simultaneous), and posttreatment. Pretreatment with L. reuteri I5007 effectively relieves inflammation in HT-29 cells challenged with lipopolysaccharide. In vivo, mice were given L. reuteri I5007 by gavage throughout the study, starting one week prior to dextran sulfate sodium (DSS) treatment for one week followed by two days without DSS. L. reuteri I5007 improved DSS-induced colitis, which was confirmed by reduced weight loss, colon length shortening, and histopathological damage, restored the mucus layer, as well as reduced pro-inflammatory cytokines levels. Analysis of 16S rDNA sequences and metabolome demonstrates that L. reuteri I5007 significantly alters colonic microbiota and metabolic structural and functional composition. Overall, the results demonstrate that L. reuteri I5007 pretreatment could effectively alleviate intestinal inflammation by regulating immune responses and altering the composition of gut microbiota structure and function, as well as improving metabolic disorders in mice with colitis.

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7 LACTOBACILLUS REUTERI SUPPRESSES PRO-INFLAMMATORY DRIVEN REACTIVE OXYGEN SPECIES IN VITRO IN HUMAN INTESTINAL EPITHELIAL CELLS AND IN VIVO IN A TNBS COLITIS MOUSE MODEL

Inflammatory Bowel Diseases ◽

10.1093/ibd/zaa010.106 ◽

2020 ◽

Vol 26 (Supplement_1) ◽

pp. S41-S41 ◽

Cited By ~ 1

Author(s):

Wenly Ruan ◽

Melinda Engevik ◽

Alexandra Chang-Graham ◽

Joseph Hyser ◽

James Versalovic

Keyword(s):

Reactive Oxygen Species ◽

Epithelial Cells ◽

Lactobacillus Reuteri ◽

Intestinal Inflammation ◽

Intestinal Epithelial Cells ◽

Oxygen Species ◽

Intestinal Epithelial ◽

Colitis Model

Abstract Background Reactive oxygen species (ROS) play a role in maintaining intestinal epithelial homeostasis and are normally kept at low levels via antioxidant compounds. Dysregulation of ROS can lead to intestinal inflammation and contribute to inflammatory bowel disease (IBD). Select gut microbes possess the enzymatic machinery to produce antioxidants whereas others can dysregulate levels of ROS. Our model microbe, Lactobacillus reuteri (ATCC PTA 6475), has been demonstrated to reduce intestinal inflammation in mice models. It contains the genes encoding two distinct GshA-like glutamylcysteine ligases. We hypothesize that L. reuteri can secrete γ-glutamylcysteine to suppress ROS, minimize NFκB activation and regulate secretion of e pithelial cytokines. Methods & Results Conditioned media from L. reuteri was analyzed via mass spectrometry to confirm the presence of γ-glutamylcysteine. All cysteine containing products including γ-glutamylcysteine were fluorescently tagged in the conditioned media and then incubated with HT29 cell monolayers as well as human jejunal enteroid (HJE) monolayers. γ-glutamylcysteine was demonstrated to enter intestinal epithelial cells based on microscopy. Next, a Thioltracker assay was used to show increased intracellular glutathione levels by L. reuteri secreted γ-glutamylcysteine. HT29 cells and HJEs were then treated with IL-1β or hydrogen peroxide, and L. reuteri metabolites as well as γ-glutamylcysteine significantly suppressed pro-inflammatory cytokine driven ROS and IL-8 production. L. reuteri secreted products also reduced activity of NFκB as determined by a luciferase reporter assay. γ-glutamylcysteine deficient mutants were generated by targeted mutagenesis of GshA genes, and these mutant L. reuteri strains had a diminished ability to suppress IL-8 production and ROS. To further test the role of L. reuteri secreted γ-glutamylcysteine in vivo, a 2,4,6-Trinitrobenzenesulfonic acid (TNBS)- induced mouse colitis model was used. Adolescent mice were orogavaged with PBS, L. reuteri, L. reuteri GshA2 mutant, or γ-glutamylcysteine for a week after which TNBS was rectally administered to induce colitis. We demonstrate that L. reuteri and γ-glutamylcysteine can suppress histologic inflammation compared to PBS control and L. reuteri GshA2 mutant groups. Conclusions Together these data indicate that L. reuteri secretes γ-glutamylcysteine which can enter the intestinal epithelial cells and modulate epithelial cytokine production. It acts via suppression of ROS and NFκB which then decreases IL-8 production. We are able to demonstrate this in vitro in both HT 29 cells and HJEs. We now also demonstrate this in vivo in a mouse colitis model. These experiments highlight a prominent role for ROS intermediates in microbiome-mammalian cell signaling processes involved in immune responses and intestinal inflammation.

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The gut microbial metabolite trimethylamine N-oxide aggravates GVHD by inducing M1 macrophage polarization in mice

Blood ◽

10.1182/blood.2019003990 ◽

2020 ◽

Vol 136 (4) ◽

pp. 501-515 ◽

Cited By ~ 8

Author(s):

Kunpeng Wu ◽

Yan Yuan ◽

Huihui Yu ◽

Xin Dai ◽

Shu Wang ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Macrophage Polarization ◽

Short Chain Fatty Acids ◽

Inflammasome Activation ◽

Microbial Metabolites ◽

M1 Macrophage ◽

The Impact

Abstract The diversity of the human microbiome heralds the difference of the impact that gut microbial metabolites exert on allogenic graft-versus-host (GVH) disease (GVHD), even though short-chain fatty acids and indole were demonstrated to reduce its severity. In this study, we dissected the role of choline-metabolized trimethylamine N-oxide (TMAO) in the GVHD process. Either TMAO or a high-choline diet enhanced the allogenic GVH reaction, whereas the analog of choline, 3,3-dimethyl-1-butanol reversed TMAO-induced GVHD severity. Interestingly, TMAO-induced alloreactive T-cell proliferation and differentiation into T-helper (Th) subtypes was seen in GVHD mice but not in in vitro cultures. We thus investigated the role of macrophage polarization, which was absent from the in vitro culture system. F4/80+CD11b+CD16/32+ M1 macrophage and signature genes, IL-1β, IL-6, TNF-α, CXCL9, and CXCL10, were increased in TMAO-induced GVHD tissues and in TMAO-cultured bone marrow–derived macrophages (BMDMs). Inhibition of the NLRP3 inflammasome reversed TMAO-stimulated M1 features, indicating that NLRP3 is the key proteolytic activator involved in the macrophage’s response to TMAO stimulation. Consistently, mitochondrial reactive oxygen species and enhanced NF-κB nuclear relocalization were investigated in TMAO-stimulated BMDMs. In vivo depletion of NLRP3 in GVHD recipients not only blocked M1 polarization but also reversed GVHD severity in the presence of TMAO treatment. In conclusion, our data revealed that TMAO-induced GVHD progression resulted from Th1 and Th17 differentiation, which is mediated by the polarized M1 macrophage requiring NLRP3 inflammasome activation. It provides the link among the host choline diet, microbial metabolites, and GVH reaction, shedding light on alleviating GVHD by controlling choline intake.

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Probiotic properties of native Lactobacillus spp. strains for dairy calves

Beneficial Microbes ◽

10.3920/bm2017.0131 ◽

2018 ◽

Vol 9 (4) ◽

pp. 613-624 ◽

Cited By ~ 4

Author(s):

S. Fernández ◽

M. Fraga ◽

E. Silveyra ◽

A.N. Trombert ◽

A. Rabaza ◽

...

Keyword(s):

Lactobacillus Reuteri ◽

Bacterial Species ◽

Control Group ◽

Probiotic Properties ◽

Real Time Quantitative Pcr ◽

Treatment And Prevention ◽

Probiotic Strains ◽

Lactobacillus Spp

The use of native microorganisms with probiotic capacity is an alternative tool for the treatment and prevention of several diseases that affect animals, such as neonatal calf diarrhoea. The selection of probiotic strains within a collection is based on different in vitro and in vivo assays, which predict their potential. The aim of this study was to characterise a group of native Lactobacillus spp. strains isolated from faeces of healthy calves using an in vitro approach and to assess their ability to colonise the gastrointestinal tract (GIT) of calves. Native Lactobacillus spp. strains were evaluated on their capacity to survive low pH conditions and bile salts presence, biofilm formation and adhesion to both mucus and Caco-2 cells. Based on the in vitro characterisation, four strains (Lactobacillus johnsonii TP1.1, Lactobacillus reuteri TP1.3B, L. johnsonii TP1.6 and Lactobacillus amylovorus TP8.7) were selected to evaluate their capacity to colonise and persist in the GIT of calves. The assessment of enteric persistence involved an in vivo assay with oral administration of probiotics and quantification in faeces of the administered bacterial species with real-time quantitative PCR (qPCR). The study was conducted using 15 calves (1-month-old) which were divided into five groups of three animals, four of which were treated with four different selected strains and one was the control group. Strains TP1.3B and TP1.6 managed to persist in treated animals until ten days after the end of the administration period, indicating that they could be promising candidates for the design of probiotics for calves.

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