Short-chain fructo-oligosaccharide administration dose-dependently increases fecal bifidobacteria in healthy humans

Polyphenolic Compounds: Orchestrating Intestinal Microbiota Harmony during Aging

In the aging process, physiological decline occurs, posing a substantial threat to the physical and mental well-being of the elderly and contributing to the onset of age-related diseases. While traditional perspectives considered the maintenance of life as influenced by a myriad of factors, including environmental, genetic, epigenetic, and lifestyle elements such as exercise and diet, the pivotal role of symbiotic microorganisms had been understated. Presently, it is acknowledged that the intestinal microbiota plays a profound role in overall health by signaling to both the central and peripheral nervous systems, as well as other distant organs. Disruption in this bidirectional communication between bacteria and the host results in dysbiosis, fostering the development of various diseases, including neurological disorders, cardiovascular diseases, and cancer. This review aims to delve into the intricate biological mechanisms underpinning dysbiosis associated with aging and the clinical ramifications of such dysregulation. Furthermore, we aspire to explore bioactive compounds endowed with functional properties capable of modulating and restoring balance in this aging-related dysbiotic process through epigenetics alterations.

Unraveling the microbiome-metabolome nexus: a comprehensive study protocol for personalized management of Behçet's disease using explainable artificial intelligence

The presented study protocol outlines a comprehensive investigation into the interplay among the human microbiota, volatilome, and disease biomarkers, with a specific focus on Behçet's disease (BD) using methods based on explainable artificial intelligence. The protocol is structured in three phases. During the initial three-month clinical study, participants will be divided into control and experimental groups. The experimental groups will receive a soluble fiber-based dietary supplement alongside standard therapy. Data collection will encompass oral and fecal microbiota, breath samples, clinical characteristics, laboratory parameters, and dietary habits. The subsequent biological data analysis will involve gas chromatography, mass spectrometry, and metagenetic analysis to examine the volatilome and microbiota composition of salivary and fecal samples. Additionally, chemical characterization of breath samples will be performed. The third phase introduces Explainable Artificial Intelligence (XAI) for the analysis of the collected data. This novel approach aims to evaluate eubiosis and dysbiosis conditions, identify markers associated with BD, dietary habits, and the supplement. Primary objectives include establishing correlations between microbiota, volatilome, phenotypic BD characteristics, and identifying patient groups with shared features. The study aims to identify taxonomic units and metabolic markers predicting clinical outcomes, assess the supplement's impact, and investigate the relationship between dietary habits and patient outcomes. This protocol contributes to understanding the microbiome's role in health and disease and pioneers an XAI-driven approach for personalized BD management. With 70 recruited BD patients, XAI algorithms will analyze multi-modal clinical data, potentially revolutionizing BD management and paving the way for improved patient outcomes.

Innovative Approaches for Maintaining and Enhancing Skin Health and Managing Skin Diseases through Microbiome-Targeted Strategies

The skin microbiome is crucial in maintaining skin health, and its disruption is associated with various skin diseases. Prebiotics are non-digestible fibers and compounds found in certain foods that promote the activity and growth of beneficial bacteria in the gut or skin. On the other hand, live microorganisms, known as probiotics, benefit in sustaining healthy conditions when consumed in reasonable quantities. They differ from postbiotics, which are by-product compounds from bacteria that release the same effects as their parent bacteria. The human skin microbiome is vital when it comes to maintaining skin health and preventing a variety of dermatological conditions. This review explores novel strategies that use microbiome-targeted treatments to maintain and enhance overall skin health while managing various skin disorders. It is important to understand the dynamic relationship between these beneficial microorganisms and the diverse microbial communities present on the skin to create effective strategies for using probiotics on the skin. This understanding can help optimize formulations and treatment regimens for improved outcomes in skincare, particularly in developing solutions for various skin problems.

Targeting microbiota to alleviate the harm caused by sleep deprivation

Sleep deprivation has become a common health hazard, affecting 37-58% of the population and promoting the occurrence and development of many diseases. To date, effective treatment strategies are still elusive. Accumulating evidence indicates that modulating the intestinal microbiota harbors significant potential for alleviating the deleterious impacts of sleep deprivation. This paper first reviews the effects of sleep deprivation on gastrointestinal diseases, metabolic diseases, and neuropsychiatric diseases, discussing its specific mechanisms of influence. We then focus on summarizing existing interventions, including probiotics, melatonin, prebiotics, diet, and fecal microbiota transplantation (FMT). Finally, we have discussed the advantages and limitations of each strategy. Compared with other strategies, probiotics showed a high potential in alleviating sleep deprivation-related hazards due to their reduced risk and high security. We suggest that future research should focus on the specific mechanisms by which probiotics mitigate the harms of sleep deprivation, such insights may unveil novel pathways for treating diseases exacerbated by insufficient sleep.

Preparation, Structural Characterisation, and Bioactivities of Fructans: A Review

Polysaccharides are important components of higher plants and have attracted increasing attention due to their many nutraceutical benefits in humans. Fructans, heterogeneous fructose polymers that serve as storage carbohydrates in various plants, represent one of the most important types of natural polysaccharides. Fructans have various physiological and therapeutic effects, which are beneficial to health, and have the ability to prevent or treat various diseases, allowing their wide use in the food, nutraceutical, and pharmaceutical industries. This article reviews the occurrence, metabolism, preparation, characterisation, analysis, and bioactivity of fructans. Further, their molecular weight, monosaccharide composition, linkages, and structural determination are described. Taken together, this review provides a theoretical foundation for further research into the structure-function relationships of fructans, as well as valuable new information and directions for further research and application of fructans in functional foods.

Gastrointestinal Effects and Tolerance of Nondigestible Carbohydrate Consumption

Nondigestible carbohydrates (NDCs) are food components, including nonstarch polysaccharides and resistant starches. Many NDCs are classified as dietary fibers by the US FDA. Because of their beneficial effects on human health and product development, NDCs are widely used in the food supply. Although there are dietary intake recommendations for total dietary fiber, there are no such recommendations for individual NDCs. NDCs are heterogeneous in their chemical composition and physicochemical properties-characteristics that contribute to their tolerable intake levels. Guidance on tolerable intake levels of different NDCs is needed because overconsumption can lead to undesirable gastrointestinal side effects, further widening the gap between actual and suggested fiber intake levels. In this review, we synthesize the literature on gastrointestinal effects of NDCs that the FDA accepts as dietary fibers (β-glucan, pectin, arabinoxylan, guar gum, alginate, psyllium husk, inulin, fructooligosaccharides and oligofructose, galactooligosaccharides, polydextrose, cellulose, soy fiber, resistant maltodextrin/dextrin) and present tolerable intake dose recommendations for their consumption. We summarized the findings from 103 clinical trials in adults without gastrointestinal disease who reported gastrointestinal effects, including tolerance (e.g., bloating, flatulence, borborygmi/rumbling) and function (e.g., transit time, stool frequency, stool consistency). These studies provided doses ranging from 0.75-160 g/d and lasted for durations ranging from a single-meal tolerance test to 28 wk. Tolerance was NDC specific; thus, recommendations ranged from 3.75 g/d for alginate to 25 g/d for soy fiber. Future studies should address gaps in the literature by testing a wider range of NDC doses and consumption forms (solid compared with liquid). Furthermore, future investigations should also adopt a standard protocol to examine tolerance and functional outcomes across studies consistently.

Dietary Fiber Intake and Gut Microbiota in Human Health

Dietary fiber is fermented by the human gut microbiota, producing beneficial microbial metabolites, such as short-chain fatty acids. Over the last few centuries, dietary fiber intake has decreased tremendously, leading to detrimental alternations in the gut microbiota. Such changes in dietary fiber consumption have contributed to the global epidemic of obesity, type 2 diabetes, and other metabolic disorders. The responses of the gut microbiota to the dietary changes are specific to the type, amount, and duration of dietary fiber intake. The intricate interplay between dietary fiber and the gut microbiota may provide clues for optimal intervention strategies for patients with type 2 diabetes and other noncommunicable diseases. In this review, we summarize current evidence regarding dietary fiber intake, gut microbiota modulation, and modification in human health, highlighting the type-specific cutoff thresholds of dietary fiber for gut microbiota and metabolic outcomes.

Rapamycin and inulin for third-dose vaccine response stimulation (RIVASTIM): Inulin - study protocol for a pilot, multicentre, randomised, double-blinded, controlled trial of dietary inulin to improve SARS-CoV-2 vaccine response in kidney transplant recipients

INTRODUCTION

Kidney transplant recipients (KTRs) are at an increased risk of hospitalisation and death from COVID-19. Vaccination against SARS-CoV-2 is our primary risk mitigation strategy, yet vaccine effectiveness in KTRs is suboptimal. Strategies to enhance vaccine efficacy are therefore required. Current evidence supports the role of the gut microbiota in shaping the immune response to vaccination. Gut dysbiosis is common in KTRs and is a potential contributor to impaired COVID-19 vaccine responses. We hypothesise that dietary fibre supplementation will attenuate gut dysbiosis and promote vaccine responsiveness in KTRs.

METHODS AND ANALYSIS

Rapamycin and inulin for third-dose vaccine response stimulation-inulin is a multicentre, randomised, prospective, double-blinded, placebo-controlled pilot trial examining the effect of dietary inulin supplementation prior to a third dose of COVID-19 vaccine in KTRs who have failed to develop protective immunity following a 2-dose COVID-19 vaccine schedule. Participants will be randomised 1:1 to inulin (active) or maltodextrin (placebo control), administered as 20 g/day of powdered supplement dissolved in water, for 4 weeks prior to and following vaccination. The primary outcome is the proportion of participants in each trial arm that achieve in vitro neutralisation of live SARS-CoV-2 virus at 4 weeks following a third dose of COVID-19 vaccine. Secondary outcomes include the safety and tolerability of dietary inulin, the diversity and differential abundance of gut microbiota, and vaccine-specific immune cell populations and responses.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Central Adelaide Local Health Network (CALHN) Human Research Ethics Committee (HREC) (approval number: 2021/HRE00354) and the Sydney Local Health District (SHLD) HREC (approval numbers: X21-0411 and 2021/STE04280). Results of this trial will be published following peer-review and presented at scientific meetings and congresses.

TRIAL REGISTRATION NUMBER

ACTRN12621001465842.

The Potential Role of Human Milk Oligosaccharides in Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is the most common gastrointestinal (GI) disorder in Western populations and therefore a major public health/economic concern. However, despite extensive research, psychological and physiological factors that contribute to the aetiology of IBS remain poorly understood. Consequently, clinical management of IBS is reduced to symptom management through various suboptimal options. Recent evidence has suggested human milk oligosaccharides (HMOs) as a potential therapeutic option for IBS. Here, we review literature concerning the role of HMOs in IBS, including data from intervention and in vitro trials. HMO supplementation shows promising results in altering the gut microbiota and improving IBS symptoms, for instance by stimulating bifidobacteria. Further research in adults is required into HMO mechanisms, to confirm the preliminary results available to date and recommendations of HMO use in IBS.

The genomes of chicory, endive, great burdock and yacon provide insights into Asteraceae palaeo-polyploidization history and plant inulin production

Inulin is an important reserve polysaccharide in Asteraceae plants, and is also widely used as a sweetener, a source of dietary fibre and prebiotic. Nevertheless, a lack of genomic resources for inulin-producing plants has hindered extensive studies on inulin metabolism and regulation. Here, we present chromosome-level reference genomes for four inulin-producing plants: chicory (Cichorium intybus), endive (Cichorium endivia), great burdock (Arctium lappa) and yacon (Smallanthus sonchifolius), with assembled genome sizes of 1.28, 0.89, 1.73 and 2.72 Gb, respectively. We found that the chicory, endive and great burdock genomes were shaped by whole genome triplication (WGT-1), and the yacon genome was shaped by WGT-1 and two subsequent whole genome duplications (WGD-2 and WGD-3). A yacon unique whole genome duplication (WGD-3) occurred 5.6-5.8 million years ago. Our results also showed the genome size difference between chicory and endive is largely due to LTR retrotransposons, and rejected a previous hypothesis that chicory is an ancestor of endive. Furthermore, we identified fructan-active-enzyme and transcription-factor genes, and found there is one copy in chicory, endive and great burdock but two copies in yacon for most of these genes, except for the 1-FEH II gene which is significantly expanded in chicory. Interestingly, inulin synthesis genes 1-SST and 1-FFT are located close to each other, as are the degradation genes 1-FEH I and 1-FEH II. Finally, we predicted protein structures for 1-FFT genes to explore the mechanism determining inulin chain length.

Effect of Fructooligosaccharides Supplementation on the Gut Microbiota in Human: A Systematic Review and Meta-Analysis

Background: Numerous studies have investigated the effects of the supplementation of fructooligosaccharides (FOS) on the number of bacteria in the gut that are good for health, but the results have been inconsistent. Additionally, due to its high fermentability, supplementation of FOS may be associated with adverse gastrointestinal symptoms such as bloating and flatulence. Therefore, we assessed the effects of FOS interventions on the composition of gut microbiota and gastrointestinal symptoms in a systematic review and meta-analysis. Design: All randomized controlled trials published before 10 July 2022 that investigated the effects of FOS supplementation on the human gut microbiota composition and gastrointestinal symptoms and met the selection criteria were included in this study. Using fixed or random-effects models, the means and standard deviations of the differences between the two groups before and after the intervention were combined into weighted mean differences using 95% confidence intervals (CIs). Results: Eight studies containing 213 FOS supplements and 175 controls remained in this meta-analysis. Bifidobacterium spp. counts significantly increased during FOS ingestion (0.579, 95% CI: 0.444−0.714) in comparison with that of the control group. Subgroup analysis showed greater variation in Bifidobacterium spp. in adults (0.861, 95% CI: 0.614−1.108) than in infants (0.458, 95% CI: 0.297−0.619). The increase in Bifidobacterium spp. counts were greater in the group with an intervention duration greater than 4 weeks (0.841, 95% CI: 0.436−1.247) than an intervention time less than or equal to four weeks (0.532, 95% CI: 0.370−0.694), and in the group with intervention doses > 5 g (1.116, 95% CI: 0.685−1.546) the counts were higher than those with doses ≤ 5 g (0.521, 95% CI: 0.379−0.663). No differences in effect were found between FOS intervention and comparators in regard to the abundance of other prespecified bacteria or adverse gastrointestinal symptoms. Conclusions: This is the first meta-analysis to explore the effect of FOS on gut microbiota and to evaluate the adverse effects of FOS intake on the gastrointestinal tract. FOS supplementation could increase the number of colonic Bifidobacterium spp. while higher dose (7.5−15 g/d) and longer duration (>4 weeks) showed more distinct effects and was well tolerated.

Chemical Compounds of Berry-Derived Polyphenols and Their Effects on Gut Microbiota, Inflammation, and Cancer

Berry-derived polyphenols are bioactive compounds synthesized and secreted by several berry fruits. These polyphenols feature a diversity of chemical compounds, including phenolic acids and flavonoids. Here, we report the beneficial health effects of berry-derived polyphenols and their therapeutical application on gut-microbiota-related diseases, including inflammation and cancer. Pharmacokinetic investigations have confirmed the absorption, availability, and metabolism of berry-derived polyphenols. In vitro and in vivo tests, as well as clinical trials, showed that berry-derived polyphenols can positively modulate the gut microbiota, inhibiting inflammation and cancer development. Indeed, these compounds inhibit the growth of pathogenic bacteria and also promote beneficial bacteria. Moreover, berry-derived polyphenols exhibit therapeutic effects against different gut-microbiota-related disorders such as inflammation, cancer, and metabolic disorders. Moreover, these polyphenols can manage the inflammation via various mechanisms, in particular the inhibition of the transcriptional factor Nf-κB. Berry-derived polyphenols have also shown remarkable effects on different types of cancer, including colorectal, breast, esophageal, and prostate cancer. Moreover, certain metabolic disorders such as diabetes and atherosclerosis were also managed by berry-derived polyphenols through different mechanisms. These data showed that polyphenols from berries are a promising source of bioactive compounds capable of modulating the intestinal microbiota, and therefore managing cancer and associated metabolic diseases. However, further investigations should be carried out to determine the mechanisms of action of berry-derived polyphenol bioactive compounds to validate their safety and examinate their clinical uses.

Gastrointestinal Tolerance of Short-Chain Fructo-Oligosaccharides from Sugar Beet: An Observational, Connected, Dose-Ranging Study in Healthy Volunteers

Dietary fibres are important in the human diet with multiple health benefits. This study aimed to determine the gastrointestinal tolerance of short-chain fructo-oligosaccharides (scFOS), well-known prebiotic fibres, at doses up to 40 g/d. An observational, connected, dose-ranging trial was conducted in 116 healthy volunteers. During the first week, the participants were instructed to consume their usual diet. During the second week, half of the subjects consumed 15 g scFOS per day, and the other half consumed 20 g scFOS per day. For the third week, the scFOS dose was doubled for all subjects. Gastrointestinal symptom severity was reported daily, as well as stool consistency and frequency. The results show that scFOS are well tolerated up to 40 g/d; all reported symptoms remained very mild from a clinical perspective. Stool consistency stayed normal, between 3 and 5 on the Bristol stool scale, confirming that no diarrhoea appeared after scFOS intake. Stool frequency also remained within the normal range. In conclusion, scFOS intake is well tolerated up to 40 g/d in healthy subjects. Thanks to their short chains and unique composition, scFOS prebiotic fibres are much better tolerated than other types of inulin-type fructans with longer chains. The digestive tolerance of fibres should be considered when added to foods and beverages.

Inulin Improves Diet-Induced Hepatic Steatosis and Increases Intestinal Akkermansia Genus Level

Hepatic steatosis is characterized by triglyceride accumulation within hepatocytes in response to a high calorie intake, and it may be related to intestinal microbiota disturbances. The prebiotic inulin is a naturally occurring polysaccharide with a high dietary fiber content. Here, we evaluate the effect of inulin on the intestinal microbiota in a non-alcoholic fatty liver disease model. Mice exposed to a standard rodent diet or a fat-enriched diet, were supplemented or not, with inulin. Liver histology was evaluated with oil red O and H&E staining and the intestinal microbiota was determined in mice fecal samples by 16S rRNA sequencing. Inulin treatment effectively prevents liver steatosis in the fat-enriched diet group. We also observed that inulin re-shaped the intestinal microbiota at the phylum level, were Verrucomicrobia genus significantly increased in the fat-diet group; specifically, we observed that Akkermansia muciniphila increased by 5-fold with inulin supplementation. The family Prevotellaceae was also significantly increased in the fat-diet group. Overall, we propose that inulin supplementation in liver steatosis-affected animals, promotes a remodeling in the intestinal microbiota composition, which might regulate lipid metabolism, thus contributing to tackling liver steatosis.

The antagonistic activity of the synbiotic containing Lactobacillus acidophilus and pineapple residue FOS against pathogenic bacteria

Fructooligosaccharide is used widely in many foods and pharmaceutical industries and produced by using different ways such as extracting it from plants or producing it by using plants and microorganisms' enzymes. In a previous study, we extracted Fructosyltransferase (Ftase) enzyme from pineapple residue and produced FOS. In this study, we measured the antagonistic activity of two synbiotics, the first synbiotic containing Lactobacillus acidophilus and the produced FOS, the second synbiotic containing Lactobacillus acidophilus and standard FOS, against pathogenic bacteria (P. aeruginosa, E. coli, S. aureus and B cereus). The results showed that the antagonistic activity of both synbiotic types was very close, as there were no significant differences between them except in the antagonistic activity against S. aureus, there was a significant difference between the synbiotic containing the standard FOS, which was the highest in its antagonistic activity compared to the synbiotic containing the produced FOS in this study. The activity of the fructooligosaccharide (FOS) extracted from pineapple residue was evident in enhancing the activity of the probiotic bacteria (L. acidophilus), which had a major role in the production of acids and compounds that inhibited the pathogenic bacteria. The diameters of inhibition areas in the current study ranged between 19.33-28 mm, and E. coli was more susceptible to inhibition, followed by S. aureus, P. aeruginosa, and B. cereus, respectively.

Gut Microbiota-Targeted Nutritional Interventions Improving Child Growth in Low- and Middle-Income Countries: A Systematic Review

The objective of this systematic literature review was to evaluate the efficacy of probiotic, prebiotic, and synbiotic interventions compared with control on improving growth outcomes of children living in low- and middle-income countries (LMICs). Probiotics had a beneficial effect on ≥1 of the growth outcomes in 5 out of the 11 included studies. Of these, 3 studies were conducted in undernourished children, 1 in healthy children, and 1 in children without a described health status. No effect of prebiotics on growth outcomes was seen in the 4 included studies. Synbiotics had a beneficial effect on growth outcomes in 3 out of 4 studies. Although a limited number of studies with high heterogeneity indicate that probiotics and synbiotics may have the potential to improve the growth of both undernourished and healthy children living in LMICs, more research is needed to confirm the observed effects. This review was registered at www.crd.york.ac.uk/prospero/ as CRD42020212998.

The Prebiotic Potential of Inulin-type Fructans: A Systematic Review

Inulin-type fructans (ITF), including short-chain fructooligosaccharides (scFOS), oligofructose, and inulin, are commonly used fibers that are widely regarded as prebiotic for their ability to be selectively utilized by the intestinal microbiota to confer a health benefit. However, the literature thus far lacks a thorough discussion of the evidence from human clinical trials for the prebiotic effect of ITF, including both effects on the intestinal microbiota composition as well as the intestinal and extraintestinal (e.g., glucose homeostasis, lipids, mineral absorption and bone health, appetite and satiety, inflammation and immune function, and body composition) benefits. Additionally, there is a lack of discussion regarding aspects such as the effect of ITF chain length on its intestinal and extraintestinal effects. The overall objective of this systematic review was to summarize the prebiotic potential of ITF based on the results of human clinical trials in healthy adult populations. Evidence from studies included in the current review suggest that ITF have a prebiotic effect on the intestinal microbiota, promoting the abundances of Bifidobacterium, Lactobacillus, and Faecalibacterium prausnitzii. Beneficial health effects reported following ITF intake include improved intestinal barrier function, improved laxation, increased insulin sensitivity, decreased triglycerides and an improved lipid profile, increased absorption of calcium and magnesium, and increased satiety. While there is some evidence for differing effects of ITF based on chain length, lack of direct comparisons and detailed descriptions of physicochemical properties limit the ability to draw conclusions from human clinical studies. Future research should focus on elucidating the mechanisms by which the intestinal microbiota mediates or modifies the effects of ITF on human health and the contribution of individual factors such as age and metabolic health to move towards personalization of prebiotic application.

Effect of inulin-type fructans on appetite in patients with type 2 diabetes: a randomised controlled crossover trial

The aim of the study was to investigate the effect of prebiotic fibres on appetite-regulating hormones, subjective feeling of appetite and energy intake in subjects with type 2 diabetes. Data presented are secondary outcomes of a study investigating the effect of prebiotics on glucagon-like peptide-1 and glycaemic regulation. We conducted a randomised and placebo-controlled crossover trial to evaluate the effects of 16 g/d of inulin-type fructans or a control supplement (maltodextrin) for 6 weeks in randomised order, with a 4-week washout period in-between, on appetite in thirty-five men and women with type 2 diabetes. Data were collected at visits before and after each treatment: plasma concentration of the satiety-related peptides ghrelin and peptide YY (PYY) were assessed during a standardised mixed meal. The subjective sensation of appetite was evaluated in response to an ad libitum lunch by rating the visual analogue scale. Twenty-nine individuals (twelve women) were included in the analyses. Compared to control treatment, the prebiotics did not affect ghrelin (P =0⋅71) or the ratings of hunger (P = 0⋅62), satiety (P = 0⋅56), fullness (P = 0⋅73) or prospective food consumption (P = 0⋅98). Energy intake also did not differ between the treatments. However, the response of PYY increased significantly after the control treatment with mean (sem) 11⋅1 (4⋅3) pg/ml when compared to the prebiotics -0⋅3 (4⋅3) pg/ml (P = 0⋅013). We observed no effect of inulin-type fructans on appetite hormones, subjective feeling of appetite or energy intake in patients with type 2 diabetes.

Supplementation of 1-Kestose Modulates the Gut Microbiota Composition to Ameliorate Glucose Metabolism in Obesity-Prone Hosts

Insulin resistance leads to the onset of medical conditions such as type 2 diabetes, and its development is associated with the alteration in the gut microbiota. Although it has been demonstrated that supplementation with prebiotics modulates the gut microbiota, limited evidence is available for effects of prebiotics on insulin resistance, especially for humans. We investigated the prebiotic effect of 1-kestose supplementation on fasting insulin concentration in obesity-prone humans and rats. In the preliminary study using rats, the hyperinsulinemia induced by high-fat diet was suppressed by intake of water with 2% (w/v) 1-kestose. In the clinical study using obese-prone volunteers, the fasting serum insulin level was significantly reduced from 6.5 µU/mL (95% CI, 5.5–7.6) to 5.3 (4.6–6.0) by the 12-week intervention with supplementation of 10 g 1-kestose/day, whereas it was not changed by the intervention with placebo (6.2 µU/mL (5.4–7.1) and 6.5 (5.5–7.6) before and after intervention, respectively). The relative abundance of fecal Bifidobacterium was significantly increased to 0.3244 (SD, 0.1526) in 1-kestose-supplemented participants compared to that in control participants (0.1971 (0.1158)). These results suggest that prebiotic intervention using 1–kestose may potentially ameliorate insulin resistance in overweight humans via the modulation of the gut microbiota. UMIN 000028824.

Tripartite relationship between gut microbiota, intestinal mucus and dietary fibers: towards preventive strategies against enteric infections

The human gut is inhabited by a large variety of microorganims involved in many physiological processes and collectively referred as to gut microbiota. Disrupted microbiome has been associated with negative health outcomes and especially could promote the onset of enteric infections. To sustain their growth and persistence within the human digestive tract, gut microbes and enteric pathogens rely on two main polysaccharide compartments, namely dietary fibers and mucus carbohydrates. Several evidences suggest that the three-way relationship between gut microbiota, dietary fibers and mucus layer could unravel the capacity of enteric pathogens to colonise the human digestive tract and ultimately lead to infection. The review starts by shedding light on similarities and differences between dietary fibers and mucus carbohydrates structures and functions. Next, we provide an overview of the interactions of these two components with the third partner, namely, the gut microbiota, under health and disease situations. The review will then provide insights into the relevance of using dietary fibers interventions to prevent enteric infections with a focus on gut microbial imbalance and impaired-mucus integrity. Facing the numerous challenges in studying microbiota-pathogen-dietary fiber-mucus interactions, we lastly describe the characteristics and potentialities of currently available in vitro models of the human gut.

Fiber in the ICU: Should it Be a Regular Part of Feeding?

PURPOSE OF REVIEW

To highlight the controversy of fiber use in the current critical care nutrition guidelines; review the effect of fiber on the gut microbiota in the critically ill; and examine the data on fiber and outcomes in the intensive care setting.

RECENT FINDINGS

Fiber is increasingly recognized as a necessary component of colonic health and nutrition support. In critical illness there is a shift toward gut dysbiosis and immune dysregulation. Through fermentation and the generation of short-chain fatty acids, fiber has a role in maintaining intestinal homeostasis, immune function, and supporting commensal bacteria. In contrast to fermentable fiber, recent animal models suggest that non-fermentable fiber can also favorably alter intestinal homeostasis in a mechanism distinct from short chain fatty acids. In the critically ill, RCTs and meta-analyses suggest that soluble and mixed fiber supplemented enteral nutrition can reduce diarrhea and is well tolerated. Based on limited data, there may be benefits in reducing length of hospital stay, certain infections, and glucose metabolism. Nonetheless, the role of fiber enriched nutrition in critically ill patients is controversial as evident in the conflicting guidelines. Despite shortcomings in the literature, soluble and mixed fiber supplemented enteral nutrition is safe and beneficial in most hemodynamically stable intensive care patients. More research is necessary to determine optimal fiber composition.

Highlighting the Relevance of Gut Microbiota Manipulation in Inflammatory Bowel Disease

Two different conditions are included in inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC), being distinguished by chronic recurrence of gut inflammation in persons that are genetically predisposed and subjected to environmental causative factors. The normal structure of the gut microbiome and its alterations in IBD were defined in several microbial studies. An important factor in the prolonged inflammatory process in IBD is the impaired microbiome or "dysbiosis". Thus, gut microbiome management is likely to be an objective in IBD treatment. In this review, we analyzed the existing data regarding the pathophysiological/therapeutic implications of intestinal microflora in the development and evolution of IBD. Furthermore, the main effects generated by the administration of probiotics, prebiotics, fecal transplantation, and phytochemicals supplementation were analyzed regarding their potential roles in improving the clinical and biochemical status of patients suffering from Crohn's disease (CD) and ulcerative colitis (UC), and are depicted in the sections/subsections of the present paper. Data from the literature give evidence in support of probiotic and prebiotic therapy, showing effects such as improving remission rate, improving macroscopic and microscopic aspects of IBD, reducing the pro-inflammatory cytokines and interleukins, and improving the disease activity index. Therefore, the additional benefits of these therapies should not be ignored as adjuvants to medical therapy.

The metabolic profile of Bifidobacterium dentium reflects its status as a human gut commensal

BACKGROUND

Bifidobacteria are commensal microbes of the mammalian gastrointestinal tract. In this study, we aimed to identify the intestinal colonization mechanisms and key metabolic pathways implemented by Bifidobacterium dentium.

RESULTS

B. dentium displayed acid resistance, with high viability over a pH range from 4 to 7; findings that correlated to the expression of Na+/H+ antiporters within the B. dentium genome. B. dentium was found to adhere to human MUC2+ mucus and harbor mucin-binding proteins. Using microbial phenotyping microarrays and fully-defined media, we demonstrated that in the absence of glucose, B. dentium could metabolize a variety of nutrient sources. Many of these nutrient sources were plant-based, suggesting that B. dentium can consume dietary substances. In contrast to other bifidobacteria, B. dentium was largely unable to grow on compounds found in human mucus; a finding that was supported by its glycosyl hydrolase (GH) profile. Of the proteins identified in B. dentium by proteomic analysis, a large cohort of proteins were associated with diverse metabolic pathways, indicating metabolic plasticity which supports colonization of the dynamic gastrointestinal environment.

CONCLUSIONS

Taken together, we conclude that B. dentium is well adapted for commensalism in the gastrointestinal tract.

Medical Application of Substances Derived from Non-Pathogenic Fungi Aspergillus oryzae and A. luchuensis-Containing Koji

Although most fungi cause pathogenicity toward human beings, dynasties of the East Asian region have domesticated and utilized specific fungi for medical applications. The Japanese dynasty and nation have domesticated and utilized koji fermented with non-pathogenic fungus Aspergillus oryzae for more than 1300 years. Recent research has elucidated that koji contains medicinal substances such as Taka-diastase, acid protease, koji glycosylceramide, kojic acid, oligosaccharides, ethyl-α-d-glucoside, ferulic acid, ergothioneine, pyroglutamyl leucine, pyranonigrin A, resistant proteins, deferriferrichrysin, polyamines, Bifidobacterium-stimulating peptides, angiotensin I-converting enzyme inhibitor peptides, 14-dehydroergosterol, beta-glucan, biotin, and citric acid. This review introduces potential medical applications of such medicinal substances to hyperlipidemia, diabetes, hypertension, cardiovascular and cognitive diseases, chronic inflammation, epidermal permeability barrier disruption, coronavirus disease 2019 (COVID-19), and anti-cancer therapy.

Dietary phytochemicals that influence gut microbiota: Roles and actions as anti-Alzheimer agents

The last decide has witnessed a growing research interest in the role of dietary phytochemicals in influencing the gut microbiota. On the other hand, recent evidence reveals that dietary phytochemicals exhibit properties of preventing and tackling symptoms of Alzheimer's disease, which is a neurodegenerative disease that has also been linked with the status of the gut microbiota over the last decade. Till now, little serious discussions, however, have been made to link recent understanding of Alzheimer's disease, dietary phytochemicals and the gut microbiota together and to review the roles played by phytochemicals in gut dysbiosis induced pathologies of Alzheimer's disease. Deciphering these connections can provide insights into the development and future use of dietary phytochemicals as anti-Alzheimer drug candidates. This review aims at presenting latest evidence in the modulating role of phytochemicals in the gut microbiota and its relevance to Alzheimer's disease and summarizing the mechanisms behind the modulative activities. Limitations of current research in this field and potential directions will also be discussed for future research on dietary phytochemicals as anti-Alzheimer agents.

Dietary fibre in gastrointestinal health and disease

Epidemiological studies have consistently demonstrated the benefits of dietary fibre on gastrointestinal health through consumption of unrefined whole foods, such as wholegrains, legumes, vegetables and fruits. Mechanistic studies and clinical trials on isolated and extracted fibres have demonstrated promising regulatory effects on the gut (for example, digestion and absorption, transit time, stool formation) and microbial effects (changes in gut microbiota composition and fermentation metabolites) that have important implications for gastrointestinal disorders. In this Review, we detail the major physicochemical properties and functional characteristics of dietary fibres, the importance of dietary fibres and current evidence for their use in the management of gastrointestinal disorders. It is now well-established that the physicochemical properties of different dietary fibres (such as solubility, viscosity and fermentability) vary greatly depending on their origin and processing and are important determinants of their functional characteristics and clinical utility. Although progress in understanding these relationships has uncovered potential therapeutic opportunities for dietary fibres, many clinical questions remain unanswered such as clarity on the optimal dose, type and source of fibre required in both the management of clinical symptoms and the prevention of gastrointestinal disorders. The use of novel fibres and/or the co-administration of fibres is an additional therapeutic approach yet to be extensively investigated.

Dose-Dependent Effects of Dietary Xylooligosaccharides Supplementation on Microbiota, Fermentation and Metabolism in Healthy Adult Cats

In order to investigate the effect and appropriate dose of prebiotics, this study evaluated the effect of two levels of xylooligosaccharides (XOS) in cats. Twenty-four healthy adult cats were divided into three groups: no-XOS control diet with 1% cellulose; low XOS supplementation (LXOS) with 0.04% XOS and 0.96% cellulose; and high XOS supplementation (HXOS) with 0.40% XOS and 0.60% cellulose. Both XOS groups increased blood 3-hydroxybutyryl carnitine levels and decreased hexadecanedioyl carnitine levels. Both XOS treatments displayed an increased bacterial abundance of Blautia, Clostridium XI, and Collinsella and a decreased abundance of Megasphaera and Bifidobacterium. LXOS groups increased fecal pH and bacterial abundance of Streptococcus and Lactobacillus, decreased blood glutaryl carnitine concentration, and Catenibacterium abundance. HXOS group showed a more distinct microbiome profile and higher species richness, and an increased bacterial abundance of Subdoligranulum, Ruminococcaceae genus (unassigned genus), Erysipelotrichaceae genus, and Lachnospiraceae. Correlations between bacterial abundances and blood and fecal parameters were also observed. In conclusion, XOS could benefit feline gut health by altering microbiota; its effects dependant on the dose. The higher-dose XOS increased bacterial populations that possibly promoted intestinal fermentation, while the lower dose altered populations of carbohydrate-metabolic microbiota and possibly modulated host metabolism. Low-dose prebiotics may become a trend in future studies.

Prebiotic effect of inulin-type fructans on faecal microbiota and short-chain fatty acids in type 2 diabetes: a randomised controlled trial

PURPOSE

Compared to a healthy population, the gut microbiota in type 2 diabetes presents with several unfavourable features that may impair glucose regulation. The aim of this study was to evaluate the prebiotic effect of inulin-type fructans on the faecal microbiota and short-chain fatty acids (SCFA) in patients with type 2 diabetes.

METHODS

The study was a placebo controlled crossover study, where 25 patients (15 men) aged 41-71 years consumed 16 g of inulin-type fructans (a mixture of oligofructose and inulin) and 16-g placebo (maltodextrin) for 6 weeks in randomised order. A 4-week washout separated the 6 weeks treatments. The faecal microbiota was analysed by high-throughput 16S rRNA amplicon sequencing and SCFA in faeces were analysed using vacuum distillation followed by gas chromatography.

RESULTS

Treatment with inulin-type fructans induced moderate changes in the faecal microbiota composition (1.5%, p = 0.045). A bifidogenic effect was most prominent, with highest positive effect on operational taxonomic units (OTUs) of Bifidobacterium adolescentis, followed by OTUs of Bacteroides. Significantly higher faecal concentrations of total SCFA, acetic acid and propionic acid were detected after prebiotic consumption compared to placebo. The prebiotic fibre had no effects on the concentration of butyric acid or on the overall microbial diversity.

CONCLUSION

Six weeks supplementation with inulin-type fructans had a significant bifidogenic effect and induced increased concentrations of faecal SCFA, without changing faecal microbial diversity. Our findings suggest a moderate potential of inulin-type fructans to improve gut microbiota composition and to increase microbial fermentation in type 2 diabetes.

TRIAL REGISTRATION

The trial is registered at clinicaltrials.gov (NCT02569684).

Comparison of the effects of soluble corn fiber and fructooligosaccharides on metabolism, inflammation, and gut microbiome of high-fat diet-fed mice

Dietary fibers are essential components of a balanced diet and have beneficial effects on metabolic functions. To gain insight into their impact on host physiology and gut microbiota, we performed a direct comparison of two specific prebiotic fibers in mice. During an 8-wk follow up, mice fed a high-fat diet (HFD) were compared with mice on a normal diet (basal condition, controls) and to mice fed the HFD but treated with one of the following prebiotics: fructooligosaccharides (FOS) or soluble corn fiber (SCF). Both prebiotic fibers led to a similar reduction of body weight and fat mass, lower inflammation and improved metabolic parameters. However, these health benefits were the result of different actions of the fibers, as SCF impacted energy excretion, whereas FOS did not. Interestingly, both fibers had very distinct gut microbial signatures with different short-chain fatty acid profiles, indicating that they do not favor the growth of the same bacterial communities. Although the prebiotic potential of different fibers may seem physiologically equivalent, our data show that the underlying mechanisms of action are different, and this by targeting different gut microbes. Altogether, our data provide evidence that beneficial health effects of specific dietary fibers must be documented to be considered a prebiotic and that studies devoted to understanding how structures relate to specific microbiota modulation and metabolic effects are warranted.

In Vitro Evaluation of Prebiotic Properties of a Commercial Artichoke Inflorescence Extract Revealed Bifidogenic Effects

: Background: Prebiotics used as a dietary supplement, stimulate health-related gut microbiota (e.g., bifidobacteria, lactobacilli, etc.). This study evaluated potential prebiotic effects of an artichoke aqueous dry extract (AADE) using in vitro gut model based on the Simulator of Human Intestinal Microbial Ecosystem (SHIME^®).

METHODS

Short-term colonic fermentations (48 h) of AADE, fructo-oligosaccharides (FOS), and a blank were performed. Microbial metabolites were assessed at 0, 6, 24, and 48 h of colonic incubation via measuring pH, gas pressure, lactate, ammonium, and short-chain fatty acids (SCFAs) levels. Community composition was assessed via targeted qPCRs.

RESULTS

After 24 and 48 h of incubation, bifidobacteria levels increased 25-fold with AADE (p < 0.05) and >100-fold with FOS (p < 0.05) compared to blank. Lactobacillus spp. levels only tended to increase with AADE, whereas they increased 10-fold with FOS. At 6 h, pH decreased with AADE and FOS and remained stable until 48 h; however, gas pressure increased significantly till the end of study. Acetate, propionate, and total SCFA production increased significantly with both at all time-points. Lactate levels initially increased but branched SCFA and ammonium levels remained low till 48 h.

CONCLUSION

AADE displayed prebiotic potential by exerting bifidogenic effects that stimulated production of health-related microbial metabolites, which is potentially due to inulin in AADE.

Comment on Experimental Determination of the Threshold Dose for Bifidogenic Activity of Dietary 1-Kestose in Rats. Foods 2020, 9, 4

Currently, our group is undertaking a program trying to evaluate the bifidogenic effect/activity of different prebiotics and their dose-effect relationships [...]

Mechanisms of Action of Prebiotics and Their Effects on Gastro-Intestinal Disorders in Adults

In recent years, research has focused on the use of dietary fibers and prebiotics, since many of these polysaccharides can be metabolized by intestinal microbiota, leading to the production of short-chain fatty acids. The metabolites of prebiotic fermentation also show anti-inflammatory and immunomodulatory capabilities, suggesting an interesting role in the treatment of several pathological conditions. Galacto-oligosaccharide and short- and long-chain fructans (Fructo-oligosaccharides and inulin) are the most studied prebiotics, even if other dietary compounds seem to show the same features. There is an increasing interest in dietary strategies to modulate microbiota. The aim of this review is to explore the mechanisms of action of prebiotics and their effects on the principal gastro-intestinal disorders in adults, with a special focus on Galacto-oligosaccharides, Fructo-oligosaccharides, lactulose and new emerging substances which currently have evidence of prebiotics effects, such as xilooligosaccharides, soybean oligosaccharides, isomaltooligosaccharides, lactobionic acid, resistant starch and polyphenols.

Mechanisms of Action of Prebiotics and Their Effects on Gastro-Intestinal Disorders in Adults

In recent years, research has focused on the use of dietary fibers and prebiotics, since many of these polysaccharides can be metabolized by intestinal microbiota, leading to the production of short-chain fatty acids. The metabolites of prebiotic fermentation also show anti-inflammatory and immunomodulatory capabilities, suggesting an interesting role in the treatment of several pathological conditions. Galacto-oligosaccharide and short- and long-chain fructans (Fructo-oligosaccharides and inulin) are the most studied prebiotics, even if other dietary compounds seem to show the same features. There is an increasing interest in dietary strategies to modulate microbiota. The aim of this review is to explore the mechanisms of action of prebiotics and their effects on the principal gastro-intestinal disorders in adults, with a special focus on Galacto-oligosaccharides, Fructo-oligosaccharides, lactulose and new emerging substances which currently have evidence of prebiotics effects, such as xilooligosaccharides, soybean oligosaccharides, isomaltooligosaccharides, lactobionic acid, resistant starch and polyphenols.

Formation, nutritional value, and enhancement of characteristic components in black garlic: A review for maximizing the goodness to humans

Black garlic (BG) is essentially a processed food and obtained through the transformation of fresh garlic (FG) (Allium sativum L.) via a range of chemical reactions (including the Maillard reaction) and microbial fermentation. This review provides the up-to-date knowledge of the dynamic and complicated changes in major components during the conversion of FG to BG, including moisture, lipids, carbohydrates (such as sugars), proteins, organic acids, organic sulfur compounds, alkaloids, polyphenols, melanoidins, 5-hydroxymethylfurfural, vitamins, minerals, enzymes, and garlic endophytes. The obtained evidence confirms that BG has several advantages over FG in certain product attributes and biological properties (especially antioxidant activity), and the factors affecting the quality of BG include the type and characteristics of FG and processing technologies and methods (especially pretreatments, and processing temperature and humidity). The interactions among garlic components, and between garlic nutrients and microbes, as well as the interplay between pretreatment and main manufacturing process, all determine the sensory and nutritional qualities of BG. Before BG is marketed as a novel snack or functional food, more research is required to fill the knowledge gaps related to quantitative monitoring of the changes in metabolites (especially those taste-active and/or biological-active substances) during BG manufacturing to maximize BG's antioxidant, anticancer, antiobesity, anti-inflammatory, immunostimulatory, anti-allergic, hepatoprotective, cardioprotective and oxidative stress-/hangover syndrome-reducing functions, and beneficial effects on memory/nervous systems. Assessments of the quality, efficacy, and safety of BG should be performed considering the impacts of BG production conditions, postproduction handling, and intake methods.

Experimental Determination of the Threshold Dose for Bifidogenic Activity of Dietary 1-Kestose in Rats

1-Kestose is a non-digestible oligosaccharide consisting of glucose linked to two fructose units. While 1-kestose is not digested in the small intestine of mammals, it is fermented in the ceca and colon, where the growth of bifidobacteria is promoted. In the present study, we assessed the threshold dose of dietary 1-kestose that increased cecal bifidobacterial levels in rats. Rats were fed experimental diets containing 0% to 0.3% 1-kestose for four weeks. The levels of the genus Bifidobacterium and total gut bacteria were significantly increased in cecal samples of rats fed the 0.3% 1-kestose diet. Further, a significant correlation between the dose of 1-kestose and the levels of cecal Bifidobacterium and total gut bacteria was observed. The minimum dose of dietary 1-kestose to induce significant bifidogenic activity in rats was 0.3% by weight in the diet.

Targeting the gut microbiota for the treatment of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder that affects an estimated 11% of people across the world. IBS patients are one of the largest subgroups seen in gastroenterology clinics, exhibit a lesser quality of life, and take greater use of the healthcare system. The exact etiology of IBS remains uncertain. Alterations in the gut microbiome may characterize apotential mechanism in the pathogenesis of IBS. This hypothesis is paralleled by rodent models in which manipulation of the gut microbiota leads to disturbed physiological functions along the brain-gut axis. Recent research in IBS treatments has redirected its focus towards gu microbiome based therapeutics. In this review, we discuss potential roles of enteric bacteria in the pathogenesis of IBS and its comorbidities. We then explore the manipulation of the enteric microbiota by prebiotics, probiotics, antibiotics, dietary changes, and fecal microbiota transfer. We also discuss the positive and negative effects of these therapeutics on IBS symptoms.

In vitro approach to evaluate the fermentation pattern of inulin-rich food in obese individuals

Alterations of the gut microbiome have been associated with obesity and metabolic disorders. The gut microbiota can be influenced by the intake of dietary fibres with prebiotic properties, such as inulin-type fructans. The present study tested the hypothesis that obese individuals subjected for 12 weeks to an inulin-enriched v. inulin-poor diet have differential faecal fermentation patterns. The fermentation of cellulose and inulin hydrolysates of six different inulin-rich and inulin-poor vegetables of both groups was analysed in vitro on faecal inocula. The results showed that the microbiota from obese patients who received a fructan-rich diet for 3 weeks produces more gas and total SCFA compared with the microbiota taken from the same individuals before the treatment. Obese individuals fed with a low-fructan diet produce less gas and less SCFA compared with the treated group. The present study highlighted profound changes in microbiota fermentation capacity obtained by prebiotic intervention in obese individuals, which favours the production of specific bioactive metabolites.

A prospective randomized, double-blind, placebo-controlled, dose-response relationship study to investigate efficacy of fructo-oligosaccharides (FOS) on human gut microflora

Fructo-oligosaccharides (FOS), a prebiotic supplement, is known for its Bifidogenic capabilities. However, aspects such as effect of variable quantities of FOS intake on gut microbiota, and temporal dynamics of gut microbiota (transitioning through basal, dosage, and follow-up phases) has not been studied in detail. This study investigated these aspects through a randomized, double-blind, placebo-controlled, dose-response relationship study. The study involved 80 participants being administered FOS at three dose levels (2.5, 5, and 10 g/day) or placebo (Maltodextrin 10 g/day) during dosage phase. Microbial DNA extracted from fecal samples collected at 9 intervening time-points was sequenced and analysed. Results indicate that FOS consumption increased the relative abundance of OTUs belonging to Bifidobacterium and Lactobacillus. Interestingly, higher FOS dosage appears to promote, in contrast to Maltodextrin, the selective proliferation of OTUs belonging to Lactobacillus. While consumption of prebiotics increased bacterial diversity, withdrawal led to its reduction. Apart from probiotic bacteria, a significant change was also observed in certain butyrate-producing microbes like Faecalibacterium, Ruminococcus and Oscillospira. The positive impact of FOS on butyrate-producing bacteria and FOS-mediated increased bacterial diversity reinforces the role of prebiotics in conferring beneficial functions to the host.

Feeding of 1-Kestose Induces Glutathione-S-Transferase Expression in Mouse Liver

Functional food ingredients, including prebiotics, have been increasingly developed for human health. The improvement of the human intestinal environment is one of their main targets. Fructooligosaccarides (FOS) are oligosaccharide fructans that are well studied and commercialized prebiotics. 1-Kestose, one of the components of FOS, is considered to be a key prebiotic component in FOS. However, to our knowledge, no studies have been reported on the physiological efficacy of 1-Kestose regarding its anti-oxidative activity. In the present study, we examined the effects of dietary 1-Kestose on gene expression of antioxidative enzymes in the liver, kidney and epididymal adipose tissue of mice by quantitative RT-PCR (qRT-PCR). We demonstrated that a 1-Kestose-rich diet increased mRNA and enzymatic activity levels of glutathione-S-transferase (GST) in mouse liver. These results suggest the possibility that dietary 1-Kestose as a prebiotic may enhance antioxidative activity in mice.

Moderately high-protein enteral formula improved retinol-binding protein in tube-fed patients: A multicentre open study

Background:

Long-term inadequate dietary consumption may increase the possibility of malnutrition, morbidity and mortality. Enteral nutrition (EN) is a beneficial support that could help to maintain nutritional status and gut function.

Aim:

Our aim was to evaluate the effect of moderately high-protein enteral formula containing fibre on nutritional status, and its safety.

Method:

A total of 23 tube-feeding-dependent adult patients were included in this multicentre, open-label study. The patients were fed with the study formula for 7–12 days or equal to the required nutritional support period, during which we performed physical examinations and assessed nutritional status. The primary endpoint was the statistical difference in nutritional status after the treatment, and the secondary outcome was the desirable safety profile.

Results:

A significant improvement in cumulative energy balance after intervention was observed (p = 0.008). However, the differences in nutritional status, weight and BMI before and after the intervention do not reach statistical significance. Retinol-binding protein (RBP), a marker for nutritional status, increased from baseline levels. Few cases of diarrhoea and constipation had been reported during the study as a safety concern.

Conclusions:

This study investigated the efficacy and safety of an enteral feed formulation containing fibre. The patients were nourished with the studied formulation via tube feeding for a short period without serious adverse events. After the intervention, the significant increase in cumulative energy balance was observed. However, an extended period of the intervention may be required to attain the significance in other indicators for nutritional status.

In healthy adults, resistant maltodextrin produces a greater change in fecal bifidobacteria counts and increases stool wet weight: a double-blind, randomized, controlled crossover study

Dietary fiber stimulates the growth of potentially beneficial bacteria (eg, bifidobacteria), yet most Americans do not meet daily fiber recommendations. Resistant maltodextrin (RMD), a fermentable functional fiber, may help individuals meet total fiber recommendations and potentially increase bifidobacteria. It was hypothesized that fecal bifidobacteria counts/ng fecal DNA would increase after adding 25 g RMD to inadequate fiber diets of healthy adults. In this double-blind, controlled crossover study, 51 participants (26.3 ± 6.8 years, mean ± SD) were randomized to consume 0, 15, and 25 g RMD daily for 3 weeks followed by a 2-week washout. Participants collected all stools for 2 days at weeks 0 and 3 of each intervention for stool wet weight (WW) measurements and fecal bifidobacteria counts. Weekly 24-hour dietary recalls assessed total fiber intake. Only 25 g RMD resulted in a change (final minus baseline) in bifidobacteria that was significant compared with 0 g (0.17 ± 0.09 vs -0.17 ± 0.09 log₁₀[counts], respectively, mean ± SEM, P = .008). Stool WW increased only with 25 g (150 ± 11 vs baseline 121±11 g/d; P = .011). Mean daily total fiber intake (including RMD) was significantly higher (both P< .001) with 15 g (17.8 ± 0.6 g/1000 kcal or 4184 kJ) and 25 g (25.3 ± 1.1 g/1000 kcal) compared with 0 g RMD (8.4±0.4 g/1000 kcal). Mean daily total fiber intakes exceeded recommendations (14 g/1000 kcal) with 15 and 25 g of RMD, and 25 g RMD increased fecal bifidobacteria counts and stool WW, suggesting health benefits from increasing total fiber intake.

The Relationship between Habitual Dietary Intake and Gut Microbiota in Young Japanese Women

Recent studies have shown that dietary content affects the health of the host by changing the gut microbiota. However, little is known about the association of microbiota composition with habitual diet in Japanese people. Here, we aimed to clarify the relationship between the fecal microbiota and habitual dietary intake of micronutrients, macronutrients and food groups in healthy young Japanese women. Analysis of fecal microbiota was performed by the terminal restriction fragment length polymorphism (T-RFLP) method, and a dietary survey was conducted over three consecutive days using a weighed food record method. T-RFLP pattern analysis divided the subjects into two clusters, where cluster A group had a high relative abundance of Bacteroides and Clostridium cluster IV, and cluster B group had a high relative abundance of Bifidobacterium and Lactobacillales. Cluster A group also had lower intakes of iron and vitamin K and higher intakes of mushrooms and snacks than cluster B group. Analysis of Spearman rank correlations found several significant relationships between fecal microbiota and intake of nutrients and food groups. Bifidobacterium was correlated with iron intake, and Clostridium cluster XI was negatively correlated with intakes of cholesterol and eggs. These results suggest that dietary habits may strongly affect Bifidobacterium, Bacteroides and Clostridium abundance in the gut microbiota of young Japanese women. This is the first study to show relationships between fecal microbiota and habitual dietary intake in Japanese people. Accumulation of results from similar studies will help to elucidate the relationships between dietary intake and diseases in Japanese people.