Administration of Inulin-Supplemented Gluten-Free Diet Modified Calcium Absorption and Caecal Microbiota in Rats in a Calcium-Dependent Manner

Effect of Lycium barbarum polysaccharide on osteoblast proliferation and differentiation in postmenopausal osteoporosis

OBJECTIVE

We aimed to investigate the effect of Lycium barbarum polysaccharide (LBP) on the proliferation and differentiation of osteoblasts in postmenopausal individuals with osteoporosis using in vitro cell experiments.

METHODS

We assessed the effect of long-term LBP consumption on the intestinal metabolites of individuals using a simulation of the human intestinal microbiota ecosystem. We also tested the capacity of LBP in proliferating MC3T3-E1 cells using the cell counting kit-8 (CCK-8) method and analyzed the effect of intestinal metabolites on the osteogenic differentiation of MC3T3-E1 cells by testing bone metabolism viability with relevant indicators.

RESULTS

The level of short-chain fatty acids (SCFAs) significantly increased (p < 0.05), and the concentrations of acetic acid, propionic acid, and butyric acid all showed an upward trend after the treatment using LBP. At appropriate concentrations, the fermentation supernatant can enhance osteoblast proliferation by significantly increasing the active expression of bone-alkaline phosphatase (B-ALP) and osteocalcin (OCN) in osteoblasts (p < 0.05).

CONCLUSION

By modulating the metabolites of intestinal microbiota, production of SCFAs, the prebiotic properties of LBP can enhance osteoblast differentiation through in vitro simulation experiment and cell-based assay.

Gut microbiota and obesity: an overview of microbiota to microbial-based therapies

The increasing prevalence of obesity and overweight is a significant public concern throughout the world. Obesity is a complex disorder involving an excessive amount of body fat. It is not just a cosmetic concern. It is a medical challenge that increases the risk of other diseases and health circumstances, such as diabetes, heart disease, high blood pressure and certain cancers. Environmental and genetic factors are involved in obesity as a significant metabolic disorder along with diabetes. Gut microbiota (GM) has a high potential for energy harvesting from the diet. In the current review, we aim to consider the role of GM, gut dysbiosis and significant therapies to treat obesity. Dietary modifications, probiotics, prebiotics, synbiotics compounds, using faecal microbiota transplant, and other microbial-based therapies are the strategies to intervene in obesity reducing improvement. Each of these factors serves through various mechanisms including a variety of receptors and compounds to control body weight. Trial and animal investigations have indicated that GM can affect both sides of the energy-balancing equation; first, as an influencing factor for energy utilisation from the diet and also as an influencing factor that regulates the host genes and energy storage and expenditure. All the investigated articles declare the clear and inevitable role of GM in obesity. Overall, obesity and obesity-relevant metabolic disorders are characterised by specific modifications in the human microbiota's composition and functions. The emerging therapeutic methods display positive and promising effects; however, further research must be done to update and complete existing knowledge.

The Effect of Copper Nanoparticles and a Different Source of Dietary Fibre in the Diet on the Integrity of the Small Intestine in the Rat

The aim of the study was to verify the hypothesis regarding the effect of recommended (6.5 mg/kg) or enhanced (13 mg/kg) level of CuNPs in the diet in combination with different types of dietary fibre—cellulose (control), inulin, pectin or psyllium—on selected biological parameters of intestinal integrity in rats. Rats were randomly divided into 10 groups. The first two groups were fed a control diet that contained cellulose, and a mineral mixture with standard or enhanced content of CuCO3. Experimental groups were fed a diet supplemented with CuNPs (6.5 or 13 mg/kg) and combined with different types of fibre (cellulose, pectin, inulin or psyllium). After the feeding period, blood and small intestine samples were collected for further analysis. Replacing CuCO3 by CuNPs in the diet positively reduced the level of lactic acid and apoptosis markers in the small intestine; however, it also resulted in the intensification of DNA oxidation. The most beneficial effect on DNA repair mechanisms is related to inulin, while pectin has the greatest ability to inhibit inflammatory processes that induce the apoptotic death of cells in the small intestine. Our results suggest that dietary fibre supplementation protects the small intestine against potentially harmful, oxidative effects of CuNPs by intensifying the intestinal barrier.

Inulin: properties and health benefits

Inulin, a soluble dietary fiber, is widely found in more than 36 000 plant species as a reserve polysaccharide. The primary sources of inulin, include Jerusalem artichoke, chicory, onion, garlic, barley, and dahlia, among which Jerusalem artichoke tubers and chicory roots are often used as raw materials for inulin production in the food industry. It is universally acknowledged that inulin as a prebiotic has an outstanding effect on the regulation of intestinal microbiota via stimulating the growth of beneficial bacteria. In addition, inulin also exhibits excellent health benefits in regulating lipid metabolism, weight loss, lowering blood sugar, inhibiting the expression of inflammatory factors, reducing the risk of colon cancer, enhancing mineral absorption, improving constipation, and relieving depression. In this review paper, we attempt to present an exhaustive overview of the function and health benefits of inulin.

Effects of inulin on calcium metabolism and bone health

Inulin, a dietary fibre found in the roots of many plants, has positive effects on health. It is particularly noteworthy due to its positive impact on calcium metabolism. Inulin has significant functions, such as improving calcium absorption through passive diffusion, bolstering calcium absorption via ion exchange and expanding the absorption surface of the colon by stimulating cell growth. In addition, inulin boosts calcium absorption by increasing calcium solubility, stimulating levels of calcium-binding protein expression and increasing useful microorganisms. It increases calbindin levels and stimulates transcellular active calcium transport. An inulin intake of least 8-10 g/day supports calcium absorption and total body bone mineral content/density in adolescents through its known mechanisms of action. It also significantly enhances calcium absorption and improves bone health in postmenopausal women and adult men. Sustained and sufficient inulin supplementation in adults has a positive effect on calcium metabolism and bone mineral density.

Roles of Gut Microbiome in Bone Homeostasis and Its Relationship with Bone-Related Diseases

Simple Summary

In recent years, there has been increasing evidence that communication between the skeletal system and the gut microbiome (GM) can influence bone health and that the GM is a key regulator of bone homeostasis. Here, we review the roles of GM in bone homeostasis. In addition, the relationship between GM composition and selected bone-related diseases (osteoporosis, osteoarthritis, rheumatoid arthritis, diabetes mellitus, obesity and bone cancer) is presented. It is also emphasized that a probiotic supplementation can play an important role in suppressing the symptoms of each of these diseases.

Abstract

The extended microbial genome—the gut microbiome (GM)—plays a significant role in host health and disease. It is able to influence a number of physiological functions. During dysbiosis, GM is associated with the development of various chronic diseases with impaired bone quality. In general, GM is important for bone homeostasis and can affect it via several mechanisms. This review describes the roles of GM in bone homeostasis through influencing the immune and endocrine functions, short-chain fatty acids production, calcium absorption and the gut–brain axis. The relationship between GM composition and several bone-related diseases, specifically osteoporosis, osteoarthritis, rheumatoid arthritis, diabetes mellitus, obesity and bone cancer, is also highlighted and summarized. GM manipulation may become a future adjuvant therapy in the prevention of many chronic diseases. Therefore, the beneficial effects of probiotic therapy to improve the health status of individuals with aforementioned diseases are provided, but further studies are needed to clearly confirm its effectiveness. Recent evidence suggests that GM is responsible for direct and indirect effects on drug efficacy. Accordingly, various GM alterations and interactions related to the treatment of bone-related diseases are mentioned as well.

Effects of Calcium Source, Inulin and Lactose on Gut-Bone Associations in an Ovarierectomized Rat Model

SCOPE

Osteoporosis poses a health challenge especially for postmenopausal women. This study aimed to explore nutritional strategies to counteract bone demineralization in ovarierectomized (OVX) rats.

METHODS AND RESULTS

OVX rats (n = 49) were fed with one of six different diets, where two different calcium sources (dairy calcium or calcium carbonate) were provided alone or in combination with either inulin (5%) or lactose (0.5%). In addition, a calcium-deficient diet was included. Calcium supplementation increased intestinal concentrations of short-chain fatty acids (SCFAs) and the abundance of fecal Acinetobacter and Propionibacterium. Accompanied with these effects, rats fed with calcium-fortified diets had higher bone mineral density, bone mineral content and femur mechanical strength, lower serum levels of bone markers and lower expression of calcium absorption-related genes (CaBP and Trpv6) compared with control. Inulin supplementation resulted in a markedly increased production of intestinal SCFAs, a decreased intestinal pH, an increased abundance of Allobaculum and Bifidobacterium, and an increased expression of Trpv6. Inulin and lactose showed beneficial effects on spine bone.

CONCLUSION

Calcium modulated gut microbiome composition and function. A pronounced effect of inulin on metabolic activity in the gastrointestinal tract was evident, and lactose supplementation decreased jejunal pH that might be associated with slightly enhanced bone mineralization. This article is protected by copyright. All rights reserved.

The Role of Depletion of Gut Microbiota in Osteoporosis and Osteoarthritis: A Narrative Review

Osteoporosis and osteoarthritis are common diseases in an aging society, are considered metabolic diseases, and affect the quality of life of older adults. In addition, the gut microbiome is considered an additional organ to regulate bone metabolism. In the past decade, people have been studying the relationship between gut microbiota and bone metabolism. The role and mechanism of the gut microbiota in regulating bone metabolism is very important to improve the development of osteoporosis and osteoarthritis. Depletion of the gut microbiota as a method of studying the role of the gut microbiota was provided strategies to enhance the role of the gut microbiota in regulating osteoporosis and osteoarthritis. In this review, we discuss how depletion of the gut microbiota affects osteoporosis and osteoarthritis.

Effect of Xylo-Oligosaccharides Supplementation by Drinking Water on the Bone Properties and Related Calcium Transporters in Growing Mice

Xylo-oligosaccharides (XOS), non-digestible oligosaccharides, have the potential to regulate intestinal microorganisms, and thus, improve host health, but little evidence exists for the prebiotic effects on bone health. This study evaluates the dose-response effect of XOS supplementation on bone properties, the morphology of the intestine, cecum pH, and cecum wall weight, as well as the related calcium transporters. Ninety-six 28-day-old male mice were randomized into one of four groups, fed the same commercial diet, and given different types of deionized water containing 0, 1, 2, or 4% XOS by concentration for 30 days. Eight mice were randomly selected to accomplish particular tasks every 10 days. No significant differences in serum Ca and P levels and growth performance were observed among the four studied groups. XOS intervention significantly decreased cecum pH and increased cecum wall weight in a dose-dependent manner. At the late growth stage, compared with 0% XOS, the bone mineral density (BMD) and bone-breaking strength in 4% XOS were significantly higher. The bone crystallinity with 4% XOS, measured by Raman spectrum, was significantly enhanced compared to that with 0% XOS during later growth. The villus height and villus height to crypt depth (VH:CD) were enhanced with an increase of XOS concentration during the later stage of growth. The expression of transient receptor potential vanillin receptor 6 (TRPV6) and Na⁺/Ca²⁺ exchanger 1 (NCX1) in the duodenum were enhanced by XOS supplementation. XOS exerted a positive influence on bone properties by decreasing the cecum pH, increasing the cecum wall and villus structure, and upregulating the expression of related calcium transporters.

Probiotics, Prebiotics and Other Dietary Supplements for Gut Microbiota Modulation in Celiac Disease Patients

To date, the only available treatment for celiac disease (CD) patients is a life-lasting gluten-free diet (GFD). Lack of adherence to the GFD leads to a significant risk of adverse health consequences. Food cross-contamination, nutritional imbalances, and persistent gastrointestinal symptoms are the main concerns related to GFD. Moreover, despite rigid compliance to GFD, patients struggle in achieving a full restoring of the gut microbiota, which plays a role in the nutritive compounds processing, and absorption. Pivotal studies on the supplementation of GFD with probiotics, such as Bifidobacterium and Lactobacilli, reported a potential to restore gut microbiota composition and to pre-digest gluten in the intestinal lumen, reducing the inflammation associated with gluten intake, the intestinal permeability, and the cytokine and antibody production. These findings could explain an improvement in symptoms and quality of life in patients treated with GFD and probiotics. On the other hand, the inclusion of prebiotics in GFD could also be easy to administer and cost-effective as an adjunctive treatment for CD, having the power to stimulate the growth of potentially health-promoting bacteria strains. However, evidence regarding the use of prebiotics and probiotics in patients with CD is still insufficient to justify their use in clinical practice.

Anesthesia and surgery induce cognitive dysfunction in elderly male mice: the role of gut microbiota

It is well known that the incidence of postoperative cognitive dysfunction (POCD) is high in elderly patients. The pathogenesis and therapeutic mechanisms of POCD, however, have not yet been completely elucidated. The effects of gut microbiota, particularly in terms of regulating brain function, have gradually attracted increasing attention. In this study, we investigated the potential role of gut microbiota in POCD in aged male mice and attempted to determine whether alterations in gut microbiota would be helpful in the diagnosis of POCD. POCD and non-POCD mice were classified by hierarchical cluster analysis of behavioral results. Additionally, α- and β-diversity of gut microbiota showed a differential profile between the groups. In total, 24 gut bacteria were significantly altered in POCD mice compared with those in non-POCD mice, in which 13 gut bacteria were significantly correlated with escape latency in the Morris water maze test (MWMT). Remarkably, receiver operating characteristic curves revealed that the Dehalobacteriaceae family and Dehalobacterium genus are potentially important bacteria for the diagnosis of POCD. These findings indicate that alterations in the composition of gut microbiota are probably involved in the pathogenesis of POCD in aged mice. Novel therapeutic strategies regulating specific gut bacteria may be helpful for the prevention and treatment of POCD.

Calcium Oxalate Nephrolithiasis and Gut Microbiota: Not just a Gut-Kidney Axis. A Nutritional Perspective

Recent studies have shown that patients with kidney stone disease, and particularly calcium oxalate nephrolithiasis, exhibit dysbiosis in their fecal and urinary microbiota compared with controls. The alterations of microbiota go far beyond the simple presence and representation of Oxalobacter formigenes, a well-known symbiont exhibiting a marked capacity of degrading dietary oxalate and stimulating oxalate secretion by the gut mucosa. Thus, alterations of the intestinal microbiota may be involved in the pathophysiology of calcium kidney stones. However, the role of nutrition in this gut-kidney axis is still unknown, even if nutritional imbalances, such as poor hydration, high salt, and animal protein intake and reduced fruit and vegetable intake, are well-known risk factors for kidney stones. In this narrative review, we provide an overview of the gut-kidney axis in nephrolithiasis from a nutritional perspective, summarizing the evidence supporting the role of nutrition in the modulation of microbiota composition, and their relevance for the modulation of lithogenic risk.

Bacupari (Garcinia brasiliensis) extract modulates intestinal microbiota and reduces oxidative stress and inflammation in obese rats

The objective of this study was to evaluate the effects of an ethanolic extract of the bark of bacupari (Garcinia brasiliensis - EEB) on the abundance of intestinal microbiota, concentration of short-chain fatty acids (SCFAs), oxidative stress, and inflammation in obese rats fed a high-fat diet (HFD). Male Wistar rats were divided into three groups: an HFD-fed obese control group, a group fed HFD plus EEB (BHFD) at a dose of 300 mg per animal per day (42 mg 7-epiclusianone and 10.76 mg morelloflavone), and a lean control group fed an AIN-93 M diet for 8 weeks. EEB decreased (p < 0.05) the abundance of organisms belonging to the phyla Firmicutes and Proteobacteria, and increased (p < 0.05) the concentration of propionic acid. Liver concentrations of malondialdehyde, nitric oxide, resistin, and p65 nuclear factor-kappa B p65(NF-κB) decreased (p < 0.05), while the expression of heat shock protein (HSP)72 and catalase increased (p < 0.05) with the consumption of EEB. Moreover, computational molecular modeling studies involving molecular docking between the main constituents of EEB, 7-epiclusianone and morelloflavone, and NF-κB suggested its inhibitory activity, thus corroborating the experimental results. The consumption of EEB may therefore be a promising strategy for the beneficial dietary modulation of the intestinal ecosystem, thereby countering oxidative stress and inflammation in obese rats. This activity is attributable to the presence of bioactive compounds that act individually or synergistically in the scavenging of free radicals or in the inflammatory process.

Dietary Fructooligosaccharide and Glucomannan Alter Gut Microbiota and Improve Bone Metabolism in Senescence-Accelerated Mouse

Gut microbiota improved using prebiotics may delay the onset of senescence-related health problems. We hypothesized that prolonged intake of prebiotics delays senile osteoporosis. Forty-five male senescence-accelerated mouse prone 6 (SAMP6) aged four weeks were raised on 5% fructooligosaccharide (FOS), 5% glucomannan (GM), or a control diet for 31 weeks. Gut microbiota were identified using culture-dependent analytical methods. Mineral content in femoral bone was analyzed using atomic absorption spectrophotometry. Bone metabolism and inflammatory markers were measured using enzyme-linked immunosorbent assay. The numbers of Lactobacillus and Bacteroides in cecal contents were significantly higher in the FOS than in the control group ( p < 0.05); the number of Clostridium was significantly higher in the GM than in the control group ( p < 0.05). Calcium content was significantly higher in the femoral bones of the FOS group (30.5 ± 0.8 mg) than in the control group (27.5 ± 1.5 mg) ( p < 0.05). There was no difference between the GM (29.1 ± 2.0 mg) and control groups. During senescence, urinary deoxypyridinoline and serum high-sensitivity C-reactive protein levels significantly decreased in the FOS (1.2 ± 0.2 nmol/3 d and 80 ± 6.1 ng/100 mL) and GM groups (1.2 ± 0.2 nmol/3 d and 80 ± 6.1 ng/100 mL) compared with the control group (1.8 ± 0.5 nmol/3 d and 93 ± 7.4 ng/100 mL) ( p < 0.05). Thus, dietary FOS and GM modified gut microbiota and reduced bone resorption by reducing systemic inflammation in SAMP6.

Extra-Intestinal Manifestations of Coeliac Disease in Children: Clinical Features and Mechanisms

Celiac disease (CD) is a systemic autoimmune disease due to a dysregulated mucosal immune response to gluten and related prolamines in genetically predisposed individuals. It is a common disorder affecting ~1% of the general population, its incidence is steadily increasing. Changes in the clinical presentation have become evident since the 80s with the recognition of extra-intestinal symptoms like short stature, iron deficiency anemia, altered bone metabolism, elevation of liver enzymes, neurological problems. Recent studies have shown that the overall prevalence of extra-intestinal manifestations is similar between pediatric and adult population; however, the prevalence of specific manifestations and rate of improvement differ in the two age groups. For instance, clinical response in children occurs much faster than in adults. Moreover, an early diagnosis is decisive for a better prognosis. The pathogenesis of extra-intestinal manifestations has not been fully elucidated yet. Two main mechanisms have been advanced: the first related to the malabsorption consequent to mucosal damage, the latter associated with a sustained autoimmune response. Importantly, since extra-intestinal manifestations dominate the clinical presentation of over half of patients, a careful case-finding strategy, together with a more liberal use of serological tools, is crucial to improve the detection rate of CD.

Glutathione depleting drugs, antioxidants and intestinal calcium absorption

Glutathione (GSH) is a tripeptide that constitutes one of the main intracellular reducing compounds. The normal content of GSH in the intestine is essential to optimize the intestinal Ca²⁺ absorption. The use of GSH depleting drugs such as DL-buthionine-S,R-sulfoximine, menadione or vitamin K₃, sodium deoxycholate or diets enriched in fructose, which induce several features of the metabolic syndrome, produce inhibition of the intestinal Ca²⁺ absorption. The GSH depleting drugs switch the redox state towards an oxidant condition provoking oxidative/nitrosative stress and inflammation, which lead to apoptosis and/or autophagy of the enterocytes. Either the transcellular Ca²⁺ transport or the paracellular Ca²⁺ route are altered by GSH depleting drugs. The gene and/or protein expression of transporters involved in the transcellular Ca²⁺ pathway are decreased. The flavonoids quercetin and naringin highly abrogate the inhibition of intestinal Ca²⁺ absorption, not only by restoration of the GSH levels in the intestine but also by their anti-apoptotic properties. Ursodeoxycholic acid, melatonin and glutamine also block the inhibition of Ca²⁺ transport caused by GSH depleting drugs. The use of any of these antioxidants to ameliorate the intestinal Ca²⁺ absorption under oxidant conditions associated with different pathologies in humans requires more investigation with regards to the safety, pharmacokinetics and pharmacodynamics of them.

Oral Health Impact Profile in Celiac Patients: Analysis of Recent Findings in a Literature Review

The increment of recording atypical oral manifestation in young patients often related to systematic disease is today a challenge for the therapists. Sometime, the presence of tooth enamel lesions correlated with soft tissue lesions is just a symptom or a trigger sign for a deeper and undetermined disease. Recently, high impact has been developed toward the influence of the diet as a controlled and modifiable factor in patients affected by celiac pathologies. The celiac disease (CD) is a chronic immune-mediated disorder triggered by the ingestion of gluten that appears in genetically predisposed patients. Gluten is a proline-rich and glutamine-rich protein present in wheat (gliadin), barley (hordein), and rye (secalin). The gluten-free diet (GFD) seems to better influence the oral health status of the CD patients. For this reason, the main objective of this revision was to analyze the international data highlighting the relationship between celiac patients and the oral health impact profile. A comprehensive review of the current literature was conducted according to the PRISMA guidelines by accessing the NCBI PubMed database. Authors conducted the search of articles in the English language published from 2008 to 2018. The first analysis with filters recorded 67 manuscripts accordingly with the selected keywords. Finally, a number of 16 appropriate published papers were comprehended in the review. The studies were different in terms of the structure, findings, outcomes, and diet quality evaluation, and for this reason, it was not possible to accomplish a meta-analysis of the recorded data. This manuscript offers some observational evidence to justify the advantages of gluten-free diets related to a better oral health status in the patients involved.

Reproductive disorders, osteoporosis and secondary hyperparathyroidism with celiac disease

A clinical observation of a patient with celiac disease, aged 23, with severe form of osteoporosis, accompanied by atraumatic fractures bones, lameness, late onset of menstruation and pathology of pregnancy is described. It is emphasized that only a timely diagnosis celiac disease and timely prescribed treatment make it possible to avoid severe complications.

Prebiotics, Bone and Mineral Metabolism

Increasing interest in functional foods has driven discovery in the area of bioactive compounds. Prebiotics are non-digestible carbohydrate compounds that, when consumed, elicit health benefits and aid in the prevention and treatment of chronic diseases. While prebiotics have been shown to improve a number of chronic, inflammatory conditions, growing evidence exists for prebiotic effects on calcium metabolism and bone health. These novel dietary fibers have been shown to increase calcium absorption in the lower intestines of both preclinical and human models. Rodent models have also been imperative for understanding prebiotic effects on bone mineral density and measures of skeletal strength. Although fewer data are available for humans, bone-related prebiotic effects exist across the lifecycle, suggesting benefits for attainment of peak bone mass during adolescence and minimized bone resorption among postmenopausal women. These effects are thought to occur through prebiotic-microbe interactions in the large intestine. Current prebiotic mechanisms for improved mineral absorption and skeletal health include alterations in gut microbiota composition, production of short-chain fatty acids, altered intestinal pH, biomarker modification, and immune system regulation. While the majority of available data support improved mineral bioavailability, emerging evidence suggests alternate microbial roles and the presence of an intricate gut-bone signaling axis. Overall, the current scientific literature supports prebiotic consumption as a cost-effective and sustainable approach for improved skeletal health and/or fracture prevention. The goal of this review is to discuss both foundational and recent research in the area of prebiotics, mineral metabolism, and bone health.

The Effect of Oligofructose-Enriched Inulin on Faecal Bacterial Counts and Microbiota-Associated Characteristics in Celiac Disease Children Following a Gluten-Free Diet: Results of a Randomized, Placebo-Controlled Trial

Celiac disease (CD) is associated with intestinal microbiota alterations. The administration of prebiotics could be a promising method of restoring gut homeostasis in CD. The aim of this study was to evaluate the effect of prolonged oligofructose-enriched inulin (Synergy 1) administration on the characteristics and metabolism of intestinal microbiota in CD children following a gluten-free diet (GFD). Thirty-four paediatric CD patients (mean age 10 years; 62% females) on a GFD were randomized into two experimental groups receiving Synergy 1 (10 g/day) or placebo (maltodextrin; 7 g/day) for 3 months. The quantitative gut microbiota characteristics and short-chain fatty acids (SCFAs) concentration were analysed. In addition, side effects were monitored. Generally, the administration of Synergy 1 in a GFD did not cause any side effects. After the intervention period, Bifidobacterium count increased significantly (p < 0.05) in the Synergy 1 group. Moreover, an increase in faecal acetate and butyrate levels was observed in the prebiotic group. Consequently, total SCFA levels were 31% higher than at the baseline. The presented trial shows that Synergy 1 applied as a supplement of a GFD had a moderate effect on the qualitative characteristics of faecal microbiota, whereas it stimulated the bacterial metabolite production in CD children.