Impact of a synbiotic food on the gut microbial ecology and metabolic profiles

Background  

The human gut harbors a diverse community of microorganisms which serve numerous important functions for the host wellbeing. Functional foods are commonly used to modulate the composition of the gut microbiota contributing to the maintenance of the host health or prevention of disease. In the present study, we characterized the impact of one month intake of a synbiotic food, containing fructooligosaccharides and the probiotic strains Lactobacillus helveticus Bar13 and Bifidobacterium longum Bar33, on the gut microbiota composition and metabolic profiles of 20 healthy subjects.     

Molecular analysis of autochthonous microbiota along the digestive tract of juvenile grouper Epinephelus coioides following probiotic Bacillus pumilus administration

Aims: To evaluate the diversity of dominant autochthonous microbiota along the digestive tract of juvenile Epinephelus coioides following the dietary administration of probiotic Bacillus pumilus for 60 days. Methods and Results: Polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE) with subsequently sequencing analysis was used to assess the gut microbiota. Generally similar DGGE patterns were observed in the foregut, midgut and hindgut of E. coioides, while the similarity dendrogram clearly revealed three different clusters depending on the three compartments of the GI tract. Dietary administration of B. pumilus stimulated its colonization in each compartment of the digestive tract. Samples collected from the probiotic group and the control group showed similar DGGE patterns, and no significant difference in the total number of bands and the Shannon index were detected between the probiotic group and the control group, suggested that B. pumilus exert no significant effect on the gut microbiota. However, various potentially beneficial bacteria, such as uncultured Bacillus sp. clone QJNY94‐like, Nitratireductor sp. YCSC5‐like, Methylobacterium hispanicum‐like and Microbacterium sp. YACS1‐like bacteria were stimulated by probiotic B. pumilus, while the potential harmful Staphylococcus saprophyticus‐like bacterium was depressed. Conclusions: Autochthonous gut microbiota of E. coioides was modulated to some degree, not significant, by probiotic B. pumilus, various potentially beneficial bacteria were selectively stimulated, while one potential harmful species was depressed. Significance and Impact of the Study: This work represents the first report that dietary administration of probiotic B. pumilus modulated the gut microbiota of E. coioides. These findings broaden our understanding of probiotic effects at the gut level, which is helpful in understanding the mechanisms that underpin host benefits.     

Membrane filter method to study the effects of Lactobacillus acidophilus and Bifidobacterium longum on fecal microbiota

A large number of commensal bacteria inhabit the intestinal tract, and interbacterial communication among gut microbiota is thought to occur. In order to analyze symbiotic relationships between probiotic strains and the gut microbiota, a ring with a membrane filter fitted to the bottom was used for in vitro investigations. Test strains comprising probiotic nitto strains (Lactobacillus acidophilus NT and Bifidobacterium longum NT) and type strains (L. acidophilus JCM1132^T and B. longum JCM1217^T) were obtained from diluted fecal samples using the membrane filter to simulate interbacterial communication. Bifidobacterium spp., Streptococcus pasteurianus, Collinsella aerofaciens, and Clostridium spp. were the most abundant gut bacteria detected before coculture with the test strains. Results of the coculture experiments indicated that the test strains significantly promote the growth of Ruminococcus gnavus, Ruminococcus torques, and Veillonella spp. and inhibit the growth of Sutterella wadsworthensis. Differences in the relative abundances of gut bacterial strains were furthermore observed after coculture of the fecal samples with each test strain. Bifidobacterium spp., which was detected as the dominant strain in the fecal samples, was found to be unaffected by coculture with the test strains. In the present study, interbacterial communication using bacterial metabolites between the test strains and the gut microbiota was demonstrated by the coculture technique. The detailed mechanisms and effects of the complex interbacterial communications that occur among the gut microbiota are, however, still unclear. Further investigation of these relationships by coculture of several fecal samples with probiotic strains is urgently required.     

Proteomic comparison of the cytosolic proteins of three <Emphasis Type="Italic">Bifidobacterium longum</Emphasis> human isolates and <Emphasis Type="Italic">B. longum</Emphasis> NCC2705

Background  

Bifidobacteria are natural inhabitants of the human gastrointestinal tract. In full-term newborns, these bacteria are acquired from the mother during delivery and rapidly become the predominant organisms in the intestinal microbiota. Bifidobacteria contribute to the establishment of healthy intestinal ecology and can confer health benefits to their host. Consequently, there is growing interest in bifidobacteria, and various strains are currently used as probiotic components in functional food products. However, the probiotic effects have been reported to be strain-specific. There is thus a need to better understand the determinants of the observed benefits provided by these probiotics. Our objective was to compare three human B. longum isolates with the sequenced model strain B. longum NCC2705 at the chromosome and proteome levels.     

Modulation of gut mucosal microbiota as a mechanism of probiotics-based adjunctive therapy for ulcerative colitis

This was a pilot study aiming to evaluate the effects of probiotics as adjunctive treatment for ulcerative colitis (UC). Twenty-five active patients with UC were assigned to the probiotic (n = 12) and placebo (n = 13) groups. The probiotic group received mesalazine (60 mg kg⁻¹ day⁻¹) and oral probiotics (containing Lactobacillus casei Zhang, Lactobacillus plantarum P-8 and Bifidobacterium animalis subsp. lactis V9) twice daily for 12 weeks, while the placebo group received the same amounts of mesalazine and placebo. The clinical outcomes were assessed. The gut mucosal microbiota was profiled by PacBio single-molecule, real-time (SMRT) sequencing of the full-length 16S rRNA of biopsy samples obtained by colonoscopy. A significantly greater magnitude of reduction was observed in the UC disease activity index (UCDAI) in the probiotic group compared with the placebo group (P = 0.043), accompanying by a higher remission rate (91.67% for probiotic-receivers versus 69.23% for placebo-receivers, P = 0.034). The probiotics could protect from diminishing of the microbiota diversity and richness. Moreover, the gut mucosal microbiota of the probiotic-receivers had significantly more beneficial bacteria like Eubacterium ramulus (P < 0.05), Pediococcus pentosaceus (P < 0.05), Bacteroides fragilis (P = 0.02) and Weissella cibaria (P = 0.04). Additionally, the relative abundances of the beneficial bacteria correlated significantly but negatively with the UCDAI score, suggesting that the probiotics might alleviate UC symptoms by modulating the gut mucosal microbiota. Our research has provided new insights into the mechanism of symptom alleviation in UC by applying probiotic-based adjunctive treatment.     

Engineering bacterial thiosulfate and tetrathionate sensors for detecting gut inflammation

There is a groundswell of interest in using genetically engineered sensor bacteria to study gut microbiota pathways, and diagnose or treat associated diseases. Here, we computationally identify the first biological thiosulfate sensor and an improved tetrathionate sensor, both two‐component systems from marine Shewanella species, and validate them in laboratory Escherichia coli. Then, we port these sensors into a gut‐adapted probiotic E. coli strain, and develop a method based upon oral gavage and flow cytometry of colon and fecal samples to demonstrate that colon inflammation (colitis) activates the thiosulfate sensor in mice harboring native gut microbiota. Our thiosulfate sensor may have applications in bacterial diagnostics or therapeutics. Finally, our approach can be replicated for a wide range of bacterial sensors and should thus enable a new class of minimally invasive studies of gut microbiota pathways.     

Effects of yogurt and bifidobacteria supplementation on the colonic microbiota in lactose-intolerant subjects

Aims: Colonic metabolism of lactose may play a role in lactose intolerance. We investigated whether a 2‐week supplementation of Bifidobacterium longum (in capsules) and a yogurt enriched with Bifidobacterium animalis could modify the composition and metabolic activities of the colonic microbiota in 11 Chinese lactose‐intolerant subjects. Methods and Results: The numbers of total cells, total bacteria and the Eubacterium rectale/Clostridium coccoides group in faeces as measured with fluorescent in situ hybridization and the faecal β‐galactosidase activity increased significantly during supplementation. The number of Bifidobacterium showed a tendency to increase during and after supplementation. With PCR‐denaturing gradient gel electrophoresis, in subjects in which B. animalis and B. longum were not detected before supplementation, both strains were present in faeces during supplementation, but disappeared after supplementation. The degree of lactose digestion in the small intestine and the oro‐caecal transit time were not different before and after supplementation, whereas symptom scores after lactose challenge decreased after supplementation. Conclusions: The results suggest that supplementation modifies the amount and metabolic activities of the colonic microbiota and alleviates symptoms in lactose‐intolerant subjects. The changes in the colonic microbiota might be among the factors modified by the supplementation which lead to the alleviation of lactose intolerance. Significance and Impact of the Study: This study provides evidence for the possibility of managing lactose intolerance with dietary lactose (yogurt) and probiotics via modulating the colonic microbiota.     

Spirulina platensis alleviates chronic inflammation with modulation of gut microbiota and intestinal permeability in rats fed a high‐fat diet

Recent research suggested that taking a high‐fat diet (HFD) may lead to a gut microbiota imbalance and colon tissue damage. This would lead to increased intestinal permeability and consequent constant circulation of low‐grade inflammatory cytokines. Spirulina platensis can protect against HFD‐induced metabolic inflammation and can stimulate the growth of beneficial bacteria in in vitro stool cultures. However, it is unknown whether this beneficial effect acts on intestinal tissues. In this study, rats were fed a high‐fat diet fed with 3% S platensis for 14 weeks. We analysed endotoxin, the composition of the microbiota, inflammation and gut permeability. We found that S platensis decreased the bodyweight and visceral fat pads weight of the HFD‐fed rats. In addition, it lowered the levels of lipopolysaccharide and pro‐inflammatory cytokines in serum. Our results showed that S platensis could largely reduce the relative amount of Proteobacteria and the Firmicutes/Bacteroidetes ratio in faecal samples from HFD‐fed rats. S platensis significantly reduced intestinal inflammation, as shown by decreased expression of myeloid differentiation factor 88 (MyD88), toll‐like receptor 4 (TLR4), NF‐κB (p65) and inflammatory cytokines. S platensis also ameliorated the increased permeability and decreased expression of tight junction proteins in the intestinal mucosa, such as ZO‐1, Occludin and Claudin‐1. Therefore, in HFD‐induced gut dysbiosis rats, S platensis benefits health by inhibiting chronic inflammation and gut dysbiosis, and modulating gut permeability.     

The Effects of Limosilactobacillus reuteri LR-99 Supplementation on Body Mass Index,Social Communication,Fine Motor Function,and Gut Microbiome Composition in Individuals with Prader–Willi Syndrome: a Randomized Double-Blinded Placebo-Controlled Trial

Prader–Willi syndrome (PWS) is a rare genetic disorder associated with developmental delay, obesity, and neuropsychiatric comorbidities. Limosilactobacillus reuteri (Lactobacillus reuteri, Lact. reuteri) has demonstrated anti-obesity and anti-inflammatory effects in previous studies. In the present study, we aim to evaluate the effects of Lact. reuteri supplementation on body mass index (BMI), social behaviors, and gut microbiota in individuals with PWS. We conducted a 12-week, randomized, double-blind, placebo-controlled trial in 71 individuals with PWS aged 6 to 264 months (64.4 ± 51.0 months). Participants were randomly assigned to either receive daily Lact. reuteri LR-99 probiotic (6 × 10¹⁰ colony forming units) or a placebo sachet. Groupwise differences were assessed for BMI, ASQ-3, and GARS-3 at baseline, 6 weeks, and 12 weeks into treatment. Gut microbiome data was analyzed with the QIIME2 software package, and predictive functional profiling was conducted with PICRUSt-2. We found a significant reduction in BMI for the probiotic group at both 6 weeks and 12 weeks relative to the baseline (P < 0.05). Furthermore, we observed a significant improvement in social communication and interaction, fine motor function, and total ASQ-3 score in the probiotics group compared to the placebo group (P < 0.05). Altered gut microbiota was observed in the probiotic group to favor weight loss and improve gut health. The findings suggest a novel therapeutic potential for Lact. reuteri LR-99 probiotic to modulate BMI, social behaviors, and gut microbiota in Prader–Willi syndrome patients, although further investigation is warranted.

Trial registration Chinese Clinical Trial Registry: ChiCTR1900022646

     

Effect of Encapsulation on Viability of <Emphasis Type="Italic">Bifidobacterium longum</Emphasis> CFR815j and Physiochemical Properties of Ice Cream

The health beneficial attributes of bifidobacteria and its safe association with the host gut has increased its significance as a probiotic. However delivering probiotic bifidobacteria with Minimum Biological Value (MBV) through product has always been a challenge. In the present study, an attempt was made to maintain the viability of native isolate of Bifidobacterium longum CFR 815j and deliver through ice-cream. B. longum CFR815j was microencapsulated in alginate starch capsules by emulsification followed by evaluation of bead stability in simulated gastrointestinal conditions. After incorporation in ice-cream, the effect on chemical properties, sensory parameters and meltdown characteristics of the product were also evaluated. Survival studies of B. longum revealed higher counts than 10⁷ in the product which is essential for probiotic bacteria to exhibit beneficial effect. Further, all the properties of this ice-cream were comparable to the regular ice-cream. Our studies conclude that encapsulation was able to maintain the requisite MBV of bifidobacteria in ice-cream without affecting the sensory characteristics.     

Cross‐effects of dietary probiotic supplementation and rearing temperature on antioxidant responses in European seabass [Dicentrarchus labrax (Linnaeus, 1758)] juveniles

Temperature modulates the metabolism in both fish and bacteria and therefore the effect of probiotic bacteria on its host may vary accordingly. The current study aim was to evaluate the effect of probiotic supplementation (Bacillus sp., Lactobacillus sp., Enterococcus sp., Pediococcus sp.) in juvenile seabass, Dicentrarchus labrax, when reared under different temperatures (17, 20 and 23°C). A control diet was tested against a probiotic‐supplemented diet, with a concentration of 3 × 10⁹ CFU probiotic/kg diet. Antioxidant responses (TG, GSH, GSSG, GR, CAT and GSTs) and lipid peroxidation (LPO) were evaluated after 70 days of dietary probiotic supplementation. An effect of temperature was observed on LPO, which increased significantly in fish reared at 17°C (p < .05) compared to the 20 and 23°C groups. Total glutathione (TG) was significantly higher in the probiotic treatments in fish reared at 17 and 20°C (p < .05). In addition, a probiotic temperature interaction was observed for TG, reduced glutathione (GSH) levels, and for reduction of the oxidized glutathione ratio (GSH/GSSG; p < .05). In conclusion, the current study showed a strong temperature effect on oxidative stress responses, with an anti‐oxidant role of dietary probiotic supplementation at different rearing temperatures.     

Top‐down systems biology integration of conditional prebiotic modulated transgenomic interactions in a humanized microbiome mouse model

Gut microbiome–host metabolic interactions affect human health and can be modified by probiotic and prebiotic supplementation. Here, we have assessed the effects of consumption of a combination of probiotics (Lactobacillus paracasei or L. rhamnosus) and two galactosyl‐oligosaccharide prebiotics on the symbiotic microbiome–mammalian supersystem using integrative metabolic profiling and modeling of multiple compartments in germ‐free mice inoculated with a model of human baby microbiota. We have shown specific impacts of two prebiotics on the microbial populations of HBM mice when co‐administered with two probiotics. We observed an increase in the populations of Bifidobacterium longum and B. breve, and a reduction in Clostridium perfringens, which were more marked when combining prebiotics with L. rhamnosus. In turn, these microbial effects were associated with modulation of a range of host metabolic pathways observed via changes in lipid profiles, gluconeogenesis, and amino‐acid and methylamine metabolism associated to fermentation of carbohydrates by different bacterial strains. These results provide evidence for the potential use of prebiotics for beneficially modifying the gut microbial balance as well as host energy and lipid homeostasis.     

Immunology and probiotic impact of the newborn and young children intestinal microflora

Human body has developed a holistic defence system, which mission is either to recognize and destroy the aggressive invaders or to evolve mechanisms permitting to minimize or restore the consequences of harmful actions. The host immune system keeps the capital role to preserve the microbial intestinal balance via the barrier effect. Specifically, pathogenic invaders such as, bacteria, parasites, viruses and other xenobiotic invaders are rejected out of the body via barriers formed by the skin, mucosa and intestinal flora. In case physical barriers are breached, the immune system with its many components comes into action in order to fence infection. The intestine itself is considered as an “active organ” due to its abundant bacterial flora and to its large metabolic activity. The variation among different species or even among different strains within a species reflects the complexity of the genetic polymorphism which regulates the immune system functions. Additionally factors such as, gender, particular habits, smoking, alcohol consumption, diet, religion, age, gender, precedent infections and vaccinations must be involved. Hormonal profile and stress seems to be associated to the integrity microbiota and inducing immune system alterations. Which bacterial species are needed for inducing a proper barrier effect is not known, but it is generally accepted that this barrier function can be strongly supported by providing benefic alimentary supplements called functional foods. In this vein it is stressed the fact that early intestinal colonization with organisms such as Lactobacilli and Bifidobacteria and possibly subsequent protection from many different types of diseases. Moreover, this benefic microflora dominated but Bifidobacteria and Lactobacilli support the concept of their ability to modify the gut microbiota by reducing the risk of cancer following their capacity to decrease β-glucoronidase and carcinogen levels. Because of their beneficial roles in the human gastrointestinal tract, LAB are referred to as “probiotics”, and efforts are underway to employ them in modern nutrition habits with so-called functional foods. Members of Lactobacillus and Bifidobacterium genera are normal residents of the microbiota in the human gastrointestinal tract, in which they developed soon after birth. But, whether such probiotic strains derived from the human gut should be commercially employed in the so-called functional foods is a matter of debate between scientists and the industrial world. Within a few hours from birth the newborn develops its normal bacterial flora. Indeed human milk frequently contains low amounts of non-pathogenic bacteria like Streptococcus, Micrococcus, Lactobacillus, Staphylococcus, Corynebacterium and Bifidobacterium. In general, bacteria start to appear in feces within a few hours after birth. Colonization by Bifidobacterium occurs generally within 4 days of life. Claims have been made for positive effects of Bifidobacterium on infant growth and health. The effect of certain bacteria having a benefic action on the intestinal ecosystem is largely discussed during the last years by many authors. Bifidobacterium is reported to be a probiotic bacterium, exercising a beneficial effect on the intestinal flora. An antagonism has been reported between B. bifidum and C. perfringens in the intestine of newborns delivered by cesarian section. The aim of the probiotic approach is to repair the deficiencies in the gut flora and restore the protective effect. However, the possible ways in which the gut microbiota is being influenced by probiotics is yet unknown.     

Role ofBifidobacterium longum in the induction of apoptotic deletion in the human enterocyte-like Caco-2 cell line

Bifidobacterium longum is a probiotic, known for its beneficial effects to the human gut and even for its immunomodulatory and antitumor activities. Recently, many studies have stressed out the intimate relation between probiotic bacteria and the GIT mucosa and their influence on human cellular homeostasis. We focused on the apoptotic deletion of cancer cells induced byB. longum. This has been valuedin vitro, performing the incubation of threeB. longum strains with enterocyte-like Caco-2 cells, to evidence DNA fragmentation, a cornerstone of apoptosis. The three strains tested were defined for their adhesion properties using adhesion and autoaggregation assays. These features are considered necessary to select a probiotic strain. The three strains named B12, B18 and B2990 resulted respectively: “strong adherent”, “adherent” and “non adherent”. Then, bacteria were incubated with Caco-2 cells to investigate apoptotic deletion. Cocultures of Caco-2 cells withB. longum resulted positive in DNA fragmentation test, only when adherent strains were used (B12 and B18). These results indicate that the interaction with adherentB. longum can induce apoptotic deletion of Caco-2 cells, suggesting a role in cellular homeostasis of the gastrointestinal tract and in restoring the ecology of damaged colon tissues.     

Low concentration of lipopolysaccharide acts on MC3T3‐E1 osteoblasts and induces proliferation via the COX‐2‐independent NFκB pathway

The translocations of lipopolysaccharide (LPS) from the gut and its effects on bone healing are usually of clinical interest during bone fracture. As already widely stuided, Cyclooxygenase‐2 (COX‐2) is a key enzyme for prostaglandin E2 (PGE₂) production, which induces the nuclear factor kappa B (NFκB) activation and is beneficial to fracture healing. In order to know their roles in skeletal regeneration, mouse MC3T3‐E1 osteoblasts were treated with NFκB inhibitor BAY 11‐7082 and sc791 (a selective COX‐2 inhibitor), in the presence of LPS. Interestingly, LPS could induce osteoblasts proliferation through increasing NFκB activation and translocation. This induction was not related to COX‐2 expression, suggesting that LPS‐induced NFκB activiation is independent of COX‐2. It is possible that low concentration of LPS can act as a stimulating factor of the NFκB pathway in nonstimulated cells such as osteoblasts. COX‐2 is not necessary for the NFκB pathway during LPS‐induced proliferation of osteoblasts since sc791 had no effects on this induction. These studies provide insight into a potential mechanism by which LPS can affect bone tissue repair in the initial phase of inflammation. Copyright © 2009 John Wiley & Sons, Ltd.     

Probiotic Administration Increases Amino Acid Absorption from Plant Protein: a Placebo-Controlled,Randomized, Double-Blind,Multicenter, Crossover Study

The fate of dietary protein in the gut is determined by microbial and host digestion and utilization. Fermentation of proteins generates bioactive molecules that have wide-ranging health effects on the host. The type of protein can affect amino acid absorption, with animal proteins generally being more efficiently absorbed compared with plant proteins. In contrast to animal proteins, most plant proteins, such as pea protein, are incomplete proteins. Pea protein is low in methionine and contains lower amounts of branched-chain amino acids (BCAAs), which play a crucial role in muscle health. We hypothesized that probiotic supplementation results in favorable changes in the gut microbiota, aiding the absorption of amino acids from plant proteins by the host. Fifteen physically active men (24.2 ± 5.0 years; 85.3 ± 12.9 kg; 178.0 ± 7.6 cm; 16.7 ± 5.8% body fat) co-ingested 20 g of pea protein with either AminoAlta™, a multi-strain probiotic (5 billion CFU L. paracasei LP-DG® (CNCM I-1572) plus 5 billion CFU L. paracasei LPC-S01 (DSM 26760), SOFAR S.p.A., Italy) or a placebo for 2 weeks in a randomized, double-blind, crossover design, separated by a 4-week washout period. Blood samples were taken at baseline and at 30-, 60-, 120-, and 180-min post-ingestion and analyzed for amino acid content. Probiotic administration significantly increased methionine, histidine, valine, leucine, isoleucine, tyrosine, total BCAA, and total EAA maximum concentrations (Cmax) and AUC without significantly changing the time to reach maximum concentrations. Probiotic supplementation can be an important nutritional strategy to improve post-prandial changes in blood amino acids and to overcome compositional shortcomings of plant proteins. ClinicalTrials.gov Identifier: ISRCTN38903788

     

Resistance to Simulated Gastrointestinal Conditions and Adhesion to Mucus as Probiotic Criteria for Bifidobacterium longum Strains

Eight Bifidobacterium longum strains, including reported probiotic strains (commercial and noncommercial), collection strains, and laboratory isolates, were investigated for their ability to adhere to mucin as well as their ability to tolerate acid and bile. Strains could be discriminated based on their sensitivity at pH values of 2.0 to 2.5 and bile concentrations of 0.5% to 2.0%. B. longum NCC 2705, a strain known for its probiotic properties, showed the highest resistance to gastrointestinal conditions, whereas the commercial probiotic strains B. longum BB 536 and SP 07/3 were the least resistant. In parallel, the human isolate B. longum BIF 53 showed the highest adhesion to mucin, whereas the commercial probiotic strains B. longum W 11, BB 536, and SP 07/3 were the least adhesive. The bacterial adhesion to mucin of strains B. longum NCC 2705 and BIF 53 could be reduced by lysozyme, indicating that cell-wall components are involved in the adhesion process. These results showed that there is no obvious link between adhesion and resistance to gastrointestinal conditions and the probiotic status of the studied strains. This calls for a definition of conditions for in vitro tests that better predict the in vivo functionality of probiotic strains.     

Targeting the gut microbiota with resveratrol: a demonstration of novel evidence for the management of hepatic steatosis

Resveratrol is a natural polyphenol that has been reported to reduce the risk of obesity and nonalcoholic fatty liver disease (NAFLD). Recent evidence has demonstrated that the gut microbiota plays an important role in the protection against NAFLD and other metabolic diseases. The present study aimed to investigate the relationship between the gut microbiota and the beneficial effects of resveratrol on the amelioration of NAFLD in mice. We observed marked decreases in body weight and liver steatosis and improved insulin resistance in high-fat diet (HFD)-fed mice treated with resveratrol. Furthermore, we found that resveratrol treatment alleviated NAFLD in HFD-fed mice by improving the intestinal microenvironment, including gut barrier function and gut microbiota composition. On the one hand, resveratrol improved gut intestinal barrier integrity through the repair of intestinal mucosal morphology and increased the expression of physical barrier- and physiochemical barrier-related factors in HFD-fed mice. On the other hand, in HFD-fed mice, resveratrol supplementation modulated the gut bacterial composition. The resveratrol-induced gut microbiota was characterized by a decreased abundance of harmful bacteria, including Desulfovibrio, Lachnospiraceae_NK4A316_group and Alistipes, as well as an increased abundance of short-chain fatty acid (SCFA)-producing bacteria, such as Allobaculum, Bacteroides and Blautia. Moreover, transplantation of the HFDR-microbiota into HFD-fed mice sufficiently decreased body weight, liver steatosis and low-grade inflammation and improved hepatic lipid metabolism. Collectively, resveratrol would provide a potentially dietary intervention strategy against NAFLD through modulating the intestinal microenvironment.     

Reconstitution conditions for dried probiotic powders represent a critical step in determining cell viability

Aims: Resuscitation of dried cultures represents a critical control point in obtaining active and effective probiotic strains. This study examined the effects of various rehydration conditions on the viability of Bifidobacterium longum NCC3001 and Lactobacillus johnsonii La1. Methods and Results: Reconstitution conditions for these strains were optimized using a multivariate experimental design approach. Furthermore, using flow cytometry, the cell integrity was followed during reconstitution. By adjusting the pH, availability of a metabolizable sugar, reconstitution duration, powder matrix and ratio of powder to reconstitution solution, the recovery of Bif. longum NCC3001 and Lact. johnsonii La1 following reconstitution was increased eight‐ and two‐fold, respectively, over standard reconstitution in maximum recovery diluent. It was shown that pH had a significant effect on the recovery of Bif. longum NCC3001 and Lact. johnsonii La1. Conclusions: The recovery of dried probiotic cultures is greatly dependent on the reconstitution conditions. The maximum recovery of 11·7 ¹⁰log CFU g^?1Bif. longum NCC3001 was achieved at 30‐min reconstitution at pH 8, in the presence of 2%l ‐arabinose and a ratio of 1 : 100 of powder to diluent. Lact. johnsonii La1 showed highest recovery (9·3 ¹⁰log CFU g^?1) after reconstitution, when mixed with maltodextrin at pH 4. Significance and Impact of the Study: To achieve accurate viable probiotic numbers from dried probiotic cultures, the reconstitution conditions should be optimized for the strain used.