Evidence suggests that a gluten-free diet may increase the risk of metabolic abnormalities associated with cardiovascular disease in adults with Coeliac Disease (CeD). This 9-week, double-blind, placebo-controlled, randomised pilot study investigated the effects of a combined supplement containing probiotic Lactiplantibacillus plantarum ECGC 13110402 and plant sterols and stanols, on cardiometabolic biomarkers and gut microbiota diversity and composition in adults with CeD and hypercholesterolaemia. Blood lipid profiles and vitamin D concentrations were analysed, and gut microbiota was profiled via 16S rRNA amplicon sequencing. In the active group, significant reductions in total cholesterol, LDL-cholesterol, non-HDL cholesterol, and apolipoprotein B were observed at multiple time points during the treatment phase, with changes generally greater in magnitude compared with the placebo group. Vitamin D levels also increased in the active group during supplementation. Microbiota analysis revealed potentially beneficial changes in participants receiving the active formulation, including higher alpha diversity and higher proportions of Bifidobacterium spp., Christensenellaceae R-7 group, and Lachnospiraceae ND3007 group. Overall, this feasibility study provides exploratory findings that a combined Lactiplantibacillus plantarum ECGC 13110402-phytosterol formulation may support lipid management and beneficially modulate gut microbiota in adults with CeD, particularly for those seeking non-pharmacological approaches to improving cardiometabolic health biomarkers.
To investigate the effects of a chromium-enriched glucomannan-fructooligosaccharide complex (SB) on glycaemic and insulin responses, satiation, and hunger biomarkers in healthy adults. Using a double-blind, placebo-controlled, randomised crossover design, we assessed the acute impact of a single 3 g SB dose in 16 healthy adults (BMI 18.5–24.9 kg/m2) during a modified oral glucose tolerance test. On separate days, participants consumed 50 g dextrose or 50 g dextrose with 3 g SB (SBD). Blood glucose and insulin were analysed over 2.5 h. Hunger, fullness, and desire to eat were assessed via visual analogue scales. Additionally, the impact of SB on gastric viscosity was assessed in vitro. SBD intake significantly reduced the insulin concentration compared to dextrose alone at 45, 75, and 90 min post-intake. Additionally, SBD resulted in significantly greater fullness and a lower desire to eat at 75 min when compared to dextrose (p < 0.05). Although hunger increased over time for both interventions, SBD led to lower hunger, desire to eat, and food desire scores compared to dextrose at 150 min (p < 0.05). The viscosity of SB, even when combined with dextrose, was significantly higher compared to dextrose alone. These novel findings suggest that SB can modulate insulin response and influence appetite regulation, highlighting its potential use in weight management strategies.
Prebiotics are known for their health-promoting functions associated with the modulation of the colonic microbiota and the products of fermentation. Recently, single-pot syntheses of galactooligosaccharides in combination with steviol glycosides (mSG-GOS) have been developed. This work was conducted to evaluate their prebiotic effect by using faecal inoculum from healthy human donors during in vitro batch fermentations. Additionally, their relative sweetness was evaluated to determine their suitability as food ingredients. The results showed a significant growth (p < 0.05) of bacteria, including the genera Bifidobacterium, Bacteroides and Clos-tridium, and a corresponding increase in short-chain fatty acids (SCFA) in comparison to either positive and negative controls. The sweetness equivalence to 1 % w:v of SG-GOS was 0.8 % w:v when compared to sucrose. Considering the bacteria and organic acids analyses and their sweetness values of these new biosynthesized compounds, SG-GOS could act as a prebiotic sweetener with potential health benefits warranting further evaluation through human studies.
People with coeliac disease (CD) have a higher risk of developing cardiovascular disease (CVD), potentially due to inflammation. Probiotics can influence CVD risk through several mechanisms including modifying inflammation. We performed a systematic review of probiotic interventions in people with CD. In total, 4 databases were systematically searched for studies published up to March 2023. All outcomes, inclusive of any cardiovascular risk factors, were collated and reported. We screened 8084 articles and 11 publications reporting on 7 RCTs and 2 non-RCTs met the inclusion criteria for qualitative analysis. In total, 1 RCT and both non-RCTs were considered to have a high risk of bias. There was large heterogeneity between the studies and adherence to a gluten-free diet was only measured in two studies. No specific outcomes related to cardiovascular risk were reported. Two studies reported a significant reduction on serum TNF-α in children over time after probiotic supplementation. One study reported no significant change in intestinal permeability over a 3-week intervention. Currently there is insufficient evidence to advocate a positive impact of probiotics on inflammation in CD, due, in part, to the limited data on adherence to the gluten-free diet and active disease.
This study was conducted to investigate the sweetness intensity and the potential fecal microbiome modulation of galactooligosaccharides in combination with enzymatically modified mogrosides (mMV-GOS), both generated through a patented single-pot synthesis. Sweetness intensity was performed in vivo by trained sensory panelists. The impact on the human fecal microbiome was evaluated by in vitro pH-controlled batch fermentation, and bacterial populations and organic acid concentrations were measured by qPCR and GC-FID, respectively. Significant growth (p ≤ 0.05) during the fermentation at 10 h of bacterial populations includes Bifidobacterium (8.49 ± 0.44 CFU/mL), Bacteroides (9.73 ± 0.32 CFU/mL), Enterococcus (8.17 ± 0.42 CFU/mL), and Clostridium coccoides (6.15 ± 0.11 CFU/mL) as compared to the negative control counts for each bacterial group (7.94 ± 0.27, 7.84 ± 1.11, 7.52 ± 0.37, and 5.81 ± 0.08 CFU/mL, respectively) at the same time of fermentation. Likewise, the corresponding significant increase in production of SCFA in mMV-GOS at 10 h of fermentation, mainly seen in acetate (20.32 ± 2.56 mM) and propionate (9.49 ± 1.44 mM) production compared to a negative control at the same time (8.15 ± 1.97 and 1.86 ± 0.24 mM), is in line with a positive control (short-chain fructooligosaccharides; 46.74 ± 12.13 and 6.51 ± 1.91 mM, respectively) revealing a selective fermentation. In conclusion, these substrates could be considered as novel candidate prebiotic sweeteners, foreseeing a feasible and innovative approach targeting the sucrose content reduction in food. This new ingredient could provide health benefits when evaluated in human studies by combining sweetness and prebiotic fiber functionality.
Lactobacillus plantarum ECGC13110402 is a probiotic, selected for its high bile salt hydrolase and cholesterol reducing activity. This parallel, double-blind, placebo-controlled, randomized pilot study, investigated the cholesterol reducing capacity of L. plantarum ECGC13110402 in 16 hypercholesterolemic adults. Participants ingested 4 ×109 CFU encapsulated ECGC13110402 (active; n=8) or placebo (n=8), once daily, over 6 weeks, followed by a 3-week washout. Fasting blood samples were collected for blood lipid, liver function, and vitamin D analysis. After 6 weeks of L. plantarum ECGC 13110402 daily intake, biologically and statistically significant reductions were noted in TC by an average 34.6% (p=0.001), LDL-C by 28.4% (p=0.03), non-HDL-C by 17.6% (p=0.001) and apoB by 28.6% (p=0.008) compared to the placebo. No changes were observed in liver function biomarkers and vitamin D and no adverse effects were noted throughout the study. The findings of this study suggest that L. plantarum ECGC 13110402 can safely improve lipid profiles in dyslipidaemic individuals.
Luo Han Guo fruit extract (Siraitia grosvenorii), mainly composed of mogroside V (50%), could be considered a suitable alternative to free sugars; however, its commercial applications are limited by its unpleasant off-notes. In the present work, a central composite design method was employed to optimize the transglycosylation of a mogroside extract using cyclodextrin glucosyltransferases (CGTases) from three different bacteriological sources (Paenibacillus macerans, Geobacillus sp., and Thermoanaerobacter sp.) considering various experimental parameters such as maltodextrin and mogroside concentration, temperature, time of reaction, enzymatic activity, and pH. Product structures were determined by liquid chromatography coupled to a diode-array detector (LC-DAD), liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Sensory analysis of glucosylated mogrosides showed an improvement in flavor attributes relevant to licorice flavor and aftereffect. Consequently, an optimum methodology was developed to produce new modified mogrosides more suitable when formulating food products as free sugar substitutes.
An approach that combines weight loss with additional health benefits is very desirable. Glucomannan is a dietary fibre that expands in the stomach, creating the feeling of fullness, while chromium can regulate insulin response. Oligofructose is a non-digestible prebiotic fibre with well-established bifidogenic properties that may also have a role in regulating satiety and systemic inflammation. The aim of this 4-week pilot human intervention was to investigate the effect of agglomerated glucomannan, oligofructose and chromium, as part of a calorie restricted diet plan, on weight loss, satiety, satiation, mood and gut microbiota in 12 females (18–65 years, BMI 25–35 kg/m2). Significant reductions were observed in the anthropometric parameters and systolic blood pressure at the end of trial along with a positive impact on gut microbiota and food cravings. This pilot study suggests that this dietary combination, within an energy restricted, diet may be beneficial in managing obesity related health outcomes.
To improve flavor profiles, three cyclodextrin glucosyltransferases (CGTases) from different bacteriological sources, Paenibacillus macerans, Geobacillus sp. and Thermoanaerobacter sp., were used with an extract of steviol glycosides (SVglys) and rebaudioside A (RebA) as acceptor substrates in two parallel sets of reactions. A central composite experimental design was employed to maximize the concentration of glucosylated species synthesized, considering temperature, pH, time of reaction, enzymatic activity, maltodextrin concentration and SVglys/RebA concentration as experimental factors, together with their interactions. Liquid chromatography coupled to a diode-array detector (LC-DAD), liquid chromatography-mass spectrometry (LC-ESI-MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) were used to characterize and identify the chemical structures obtained along the optimization. To assess the impact on the sensory properties, a sensory analysis was carried out with a group of panelists that evaluated up to 16 sensorial attributes. CGTase transglucosylation of the C-13 and/or C-19 led to the addition of up to 11 glucose units to the steviol aglycone, which meant the achievement of enhanced sensory profiles due to a diminution of bitterness and licorice appreciations. The outcome herein obtained supposes the development of new potential alternatives to replace free sugars with low-calorie sweeteners with added health benefits.
Copra meal hydrolysate (CMH) is obtained by hydrolyzing defatted copra meal with β-mannanase from Bacillus circulans NT 6.7. In this study, we investigated the resistance of CMH to upper gastrointestinal tract digestion and the fecal fermentation profiles of CMH. Fecal slurries from four healthy human donors were used as inocula, and fructooligosaccharides (FOS) were used as a positive prebiotic control. Fecal batch cultures were performed at 37 °C under anaerobic conditions. Samples were collected at 0, 10, 24 and 34 h for bacterial enumeration via fluorescent in situ hybridization and organic acid (OA) analysis. In vitro gastric stomach and human pancreatic α-amylase simulations demonstrated that CMH was highly resistant to hydrolysis. Acetate was the main fermentation product of all the substrates. The proportions of acetate production of the total OAs from FOS, CMH and yeast mannooligosaccharides (MOS) after 34 h of fermentation did not significantly differ (69.76, 65.24 and 53.93%, respectively). At 24 h of fermentation, CMH promoted the growth of Lactobacillus and Bifidobacterium groups (P < 0.01) and did not significantly differ from the results obtained using FOS. The results of in vitro fecal fermentation of CMH indicate that CMH can promote the growth of beneficial bacteria.
Levan, a bacterial exopolysaccharide (EPS), has been suggested to have several biological activities, such as anti-tumour activity and lowering blood pressure. There has also been interest in its potential prebiotic activity. This study investigated the fermentation profile of a levan fraction from Erwinia sp. 10119 (average DP = 137) throughout a three-stage continuous gut model system, in which inulin HP (average DP = 40) was included as a comparison. Levan-type fructan was found to selectively stimulate the growth of Bifidobacterium and Eubacterium rectale - Clostridium coccoides group in all fermenter vessels, with significant (p < 0.05) increases in the concentration of both acetate and butyrate. The increases in Bifidobacterium population were significantly (p < 0.05) higher in the models treated with levan-type fructan (0.8–1.24 log cell/mL) compared to the models treated with inulin HP (0.62–0.7 log cell/mL), indicating a stronger bifidogenic effect of levan-type fructan and a prolonged persistence in the colon due to its higher DP.
Bile acids, the products of concerted host and gut bacterial metabolism, have important signaling functions within the mammalian metabolic system and a key role in digestion. Given the complexity of the mega-variate bacterial community residing in the gastrointestinal tract, studying associations between individual bacterial genera and bile acid processing remains a challenge. Here, we present a novel in vitro approach to determine the bacterial genera associated with the metabolism of different primary bile acids and their potential to contribute to inter-individual variation in this processing. Anaerobic, pH-controlled batch cultures were inoculated with human fecal microbiota and treated with individual conjugated primary bile acids (500 μg/ml) to serve as the sole substrate for 24 h. Samples were collected throughout the experiment (0, 5, 10, and 24 h) and the bacterial composition was determined by 16S rRNA gene sequencing and the bile acid signatures were characterized using a targeted ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) approach. Data fusion techniques were used to identify statistical bacterial-metabolic linkages. An increase in gut bacteria associated bile acids was observed over 24 h with variation in the rate of bile acid metabolism across the volunteers (n = 7). Correlation analysis identified a significant association between the Gemmiger genus and the deconjugation of glycine conjugated bile acids while the deconjugation of taurocholic acid was associated with bacteria from the Eubacterium and Ruminococcus genera. A positive correlation between Dorea and deoxycholic acid production suggest a potential role for this genus in cholic acid dehydroxylation. A slower deconjugation of taurocholic acid was observed in individuals with a greater abundance of Parasutterella and Akkermansia. This work demonstrates the utility of integrating compositional (metataxonomics) and functional (metabonomics) systems biology approaches, coupled to in vitro model systems, to study the biochemical capabilities of bacteria within complex ecosystems. Characterizing the dynamic interactions between the gut microbiota and the bile acid pool enables a greater understanding of how variation in the gut microbiota influences host bile acid signatures, their associated functions and their implications for health.
This study investigates the sweetness properties and other sensory attributes of ten commercial and four novel prebiotics (4-galactosyl-kojibiose, lactulosucrose, lactosyl-oligofructosides and raffinosyl-oligofructosides) of high degree of purity and assesses the influence of their chemical structure features on sweetness. The impact of the type of glycosidic linkage by testing four sucrose isomers, as well as the monomer composition and degree of polymerization on sweetness properties were determined. Data from the sensory panel combined with principal component analysis (PCA) concludes that chain length was the most relevant factor in determining the sweetness potential of a carbohydrate. Thus, disaccharides had higher sweetness values than trisaccharides which, in turn, exhibited superior sweetness than mixtures of oligosaccharides having DP above 3. Furthermore, a weak nonsignificant trend indicated that the presence of a ketose sugar moiety led to higher sweetness. The novel prebiotics tested in this study had between 15 and 25% of relative sweetness, in line with other commercial prebiotics, and samples varied in their extent of off flavour. Therefore, these findings suggest a potential use for clean tasting prebiotics as partial sugar replacers, or in combination with high intensity sweeteners, to provide a well-balanced sweetness profile.
This work addresses the high-yield and fast enzymatic production of theanderose, a naturally occurring carbohydrate, also known as isomaltosucrose, whose chemical structure determined by NMR is alpha-D-glucopyranosyl-(1 -> 6)-alpha-D-glucopyranosyl-(1 -> 2)-beta-D-fructofuranose. The ability of isomaltose to act as an acceptor in the Bacillus subtilis CECT 39 levansucrase-catalyzed transfructosylation reaction to efficiently produce theanderose in the presence of sucrose as a donor is described by using four different sucrose:isomaltose concentration ratios. The maximum theanderose concentration ranged from 122.4 to 130.4 g L-1 was obtained after only 1 h and at a moderate temperature (37 degrees C), leading to high productivity (109.7-130.4 g L(-1)h(-1)) and yield (up to 37.3%) values. The enzymatic synthesis was highly regiospecific, since no other detectable acceptor reaction products were formed. The development of efficient and cost-effective procedures for the biosynthesis of unexplored but appealing oligosaccharides as potential sweeteners, such as theanderose, could help to expand its potential applications which are currently limited by their low availability.
Coronary heart disease (CHD) is one of the major causes of death and disability in industrialised countries, with elevated blood cholesterol an established risk factor. Total plasma cholesterol reduction in populations suffering from primary hypercholesterolemia may lower CHD incidence. This study investigated the cholesterol reducing capacity of Lactobacillus plantarum ECGC 13110402, a strain selected for its high bile salt hydrolase activity, in 49 normal to mildly hypercholesterolaemic adults. Primary efficacy outcomes included effect on blood lipids (total cholesterol (TC), low density lipoproteins (LDL-C), high density lipoproteins (HDL-C) and triacylgycerides (TAG), inflammatory biomarkers and occurrence/severity of gastrointestinal side effects to establish safety and tolerance of the intervention. Secondary outcomes included blood pressure, immune biomarkers, gut microbiota characterisation and metabonome changes. The study was run in a parallel, double blind, placebo controlled, randomised design in which the active group ingested 2x109 CFU encapsulated Lactobacillus plantarum ECGC 13110402 twice daily. Daily ingestion of the active treatment resulted in a statistically significant reduction in LDL-C in volunteers with baseline TC<5mM during the 0-12 week period (13.9%, P = 0.030), a significant reduction in TC in volunteers with baseline TC≥6mM in the 0-6 week period (37.6%, P = 0.045), a significant decrease in TAG (53.9% P = 0.030) and an increase in HDL-C (14.7%, P = 0.007) in the over 60 years population in the 6-12 week period. A statistically significant reduction in systolic blood pressure was also observed across the active study group in the 6-12-week period (6.6%, P = 0.003). No impact on gastrointestinal function and side effects was observed during the study. Similar to blood and urine metabonomic analyses, faecal metagenomics did not reveal significant changes upon active or placebo intake. The results of this study suggest that Lactobacillus plantarum ECGC 13110402 is a well-tolerated, natural probiotic, that may be used as an alternative or supplement to existing treatments to reduce cardiovascular risk.TRIAL REGISTRATION:Clinical trials.gov NCT03263104.
Fermentation profiles of five enzymatically synthesized purified oligosaccharides (kojibiose, 4-galactosyl-kojibiose, lactulosucrose, and sets of lactosyl- (DP 4-6) and raffinosyl-oligofructosides (DP 4-7)) were studied using an in vitro batch-culture fermentation system inoculated with human faecal slurries, simulating the events in the distal colon. Selectivity index for bifidobacteria and lactobacilli was calculated for each oligosaccharide to obtain a comparative relationship between the growth of these beneficial bacteria with respect to the other bacterial groups studied. Results showed a strong bifidogenic effect for all oligosaccharides, with similar Bifidobacterium levels compared to those produced by well-established prebiotics such as lactulose and fructo-oligosaccharides. Accordingly, acetic acid was the most prevalent SCFA produced. Oligosaccharides sharing structural features such as monomer composition and type of glycosidic linkage were grouped by dendrogram analysis, thus, underlining the potential correlation between the structural features of prebiotic candidates and their impact on the composition and metabolism of the human faecal microbiota.
OBJECTIVE:The colonic microbiota ferment dietary fibres, producing short chain fatty acids. Recent evidence suggests that the short chain fatty acid propionate may play an important role in appetite regulation. We hypothesised that colonic delivery of propionate would increase peptide YY (PYY) and glucagon like peptide-1 (GLP-1) secretion in humans, and reduce energy intake and weight gain in overweight adults. DESIGN:To investigate whether propionate promotes PYY and GLP-1 secretion, a primary cultured human colonic cell model was developed. To deliver propionate specifically to the colon, we developed a novel inulin-propionate ester. An acute randomised, controlled cross-over study was used to assess the effects of this inulin-propionate ester on energy intake and plasma PYY and GLP-1 concentrations. The long-term effects of inulin-propionate ester on weight gain were subsequently assessed in a randomised, controlled 24-week study involving 60 overweight adults. RESULTS:Propionate significantly stimulated the release of PYY and GLP-1 from human colonic cells. Acute ingestion of 10 g inulin-propionate ester significantly increased postprandial plasma PYY and GLP-1 and reduced energy intake. Over 24 weeks, 10 g/day inulin-propionate ester supplementation significantly reduced weight gain, intra-abdominal adipose tissue distribution, intrahepatocellular lipid content and prevented the deterioration in insulin sensitivity observed in the inulin-control group. CONCLUSIONS:These data demonstrate for the first time that increasing colonic propionate prevents weight gain in overweight adult humans. TRIAL REGISTRATION NUMBER:NCT00750438.
This work evaluates the bifidogenic potential of substituted xylo-oligosaccharides (XOS) obtained from a lignocellulosic feedstock (corn straw). Autohydrolysis was used to selectively hydrolyse the xylan-rich hemicellulosic fraction and the soluble oligosaccharides were purified by gel filtration chromatography. Selected oligosaccharides fractions within the target ranges of polymerization degree (4-6 and 9-21, samples S1 and S2, respectively) were characterized and their bifidogenic potential was investigated by in vitro fermentations using human fecal inocula. Bacterial growth was assessed by fluorescent in situ hybridization (FISH). XOS consumption and short-chain fatty acids (SCFA) production were evaluated and compared with commercial oligosaccharides. Under the tested conditions, all the substrates were utilized by the microbiota, and fermentation resulted in increased bifidobacteria populations. Samples S1 and S2 increased bifidobacteria populations and the production profile of SCFA was similar for XOS samples and commercial oligosaccharides although XOS samples displayed the highest concentration of SCFA on longer fermentation times. (C) 2015 Elsevier Ltd. All rights reserved.
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.
Purpose of reviewEvidence 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 findingsRecent 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.SummaryManipulation 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.