Dietary calcium phosphate strongly impacts gut microbiome changes elicited by inulin and galacto-oligosaccharides consumption

Interactions between Dietary Antioxidants, Dietary Fiber and the Gut Microbiome: Their Putative Role in Inflammation and Cancer

The intricate relationship between the gastrointestinal (GI) microbiome and the progression of chronic non-communicable diseases underscores the significance of developing strategies to modulate the GI microbiota for promoting human health. The administration of probiotics and prebiotics represents a good strategy that enhances the population of beneficial bacteria in the intestinal lumen post-consumption, which has a positive impact on human health. In addition, dietary fibers serve as a significant energy source for bacteria inhabiting the cecum and colon. Research articles and reviews sourced from various global databases were systematically analyzed using specific phrases and keywords to investigate these relationships. There is a clear association between dietary fiber intake and improved colon function, gut motility, and reduced colorectal cancer (CRC) risk. Moreover, the state of health is reflected in the reciprocal and bidirectional relationships among food, dietary antioxidants, inflammation, and body composition. They are known for their antioxidant properties and their ability to inhibit angiogenesis, metastasis, and cell proliferation. Additionally, they promote cell survival, modulate immune and inflammatory responses, and inactivate pro-carcinogens. These actions collectively contribute to their role in cancer prevention. In different investigations, antioxidant supplements containing vitamins have been shown to lower the risk of specific cancer types. In contrast, some evidence suggests that taking antioxidant supplements can increase the risk of developing cancer. Ultimately, collaborative efforts among immunologists, clinicians, nutritionists, and dietitians are imperative for designing well-structured nutritional trials to corroborate the clinical efficacy of dietary therapy in managing inflammation and preventing carcinogenesis. This review seeks to explore the interrelationships among dietary antioxidants, dietary fiber, and the gut microbiome, with a particular focus on their potential implications in inflammation and cancer.

Calcium-rich dairy matrix protects better than mineral calcium against colonic luminal haem-induced alterations in male rats

The haemoglobin content in meat is consistently associated with an increased risk of colorectal cancer, whereas calcium may play a role as a chemopreventive agent. Using rodent models, calcium salts have been shown to prevent the promotion of haem-induced and red meat-induced colorectal carcinogenesis by limiting the bioavailability of the gut luminal haem iron. Therefore, this study aimed to compare impacts of dietary calcium provided as calcium salts or dairy matrix on gut homoeostasis perturbations by high haeminic or non-haeminic iron intakes. A 3-week intervention study was conducted using Fischer 344 rats. Compared to the ferric citrate-enriched diet, the haemoglobin-enriched diet led to increased faecal, mucosal, and urinary lipoperoxidation-related biomarkers, resulting from higher gut luminal haem iron bioavailability. This redox imbalance was associated to a dysbiosis of faecal microbiota. The addition of calcium to haemoglobin-enriched diets limited haem iron bioavailability and counteracted redox imbalance, with improved preventive efficacy when calcium was provided in dairy matrix. Data integration revealed correlations between haem-induced lipoperoxidation products and bacterial communities belonging to Peptococcaceae, Eubacterium coprostanoligenes group, and Bifidobacteriaceae. This integrated approach provides evidence of the benefits of dairy matrix as a dietary calcium vehicle to counteract the deleterious side-effects of meat consumption.

Utilization of diverse oligosaccharides for growth by Bifidobacterium and Lactobacillus species and their in vitro co-cultivation characteristics

Various approaches have been used to study the relationship between prebiotics and probiotics. The utilization of different carbohydrates by probiotics depends on the biochemical properties of the enzymes and substrates required by the microbial strain. However, few studies have systematically analyzed the ability of probiotics to utilize different prebiotics. Here, we investigated the effects of prebiotics from different manufacturers on the proliferation of 13 strains of the Lactobacillus group and the genus Bifidobacterium co-cultured in vitro. Inulin, fructose-oligosaccharide (FOS), and galactose-oligosaccharide (GOS) had broad growth-promoting effects. FOS significantly promoted the proliferation of B. longum. When strains from Lactobacillus group and Bifidobacterium were co-cultured, FOS caused each strain to proliferate cooperatively. GOS was effectively used by L. rhamnosus and L. reuteri for energy and growth promotion. L. casei and L. paracasei fully metabolized inulin; these strains performed better than other strains from Lactobacillus group and Bifidobacterium. Media containing a mixture of oligosaccharides had stronger effects on the growth of B. animalis subsp. lactis, L. acidophilus, and L. rhamnosus than media containing single oligosaccharides. Thus, different oligosaccharides had different effects on the growth of probiotics, providing a scientific basis for the use of synbiotics in health and related fields.

Nutritional Support: The Use of Antioxidants in Inflammatory Bowel Disease

The problem of treating inflammatory bowel disease continues to be a topic of great interest for researchers. Despite the complexity surrounding their treatment and strategies to prolong periods of remission, there is a promising exploration of various compounds that have potential in combating inflammation and alleviating symptoms. Selenium, calcium, magnesium, zinc, and iron are among these compounds, offering a glimpse of hope in the treatment of IBD. These essential minerals not only hold the promise of reducing inflammation in these diseases, but also show the potential to enhance immune function and possibly influence the balance of intestinal microflora. By potentially modulating the gut microbiota, they may help support overall immune health. Furthermore, these compounds could play a crucial role in mitigating inflammation and minimising complications in patients with IBD. Furthermore, the protective effect of these compounds against mucosal damage in IBD and the protective effect of calcium itself against osteoporosis in this group of patients are notable.

Ameliorative effect of an acidic polysaccharide from Phellinus linteus on ulcerative colitis in a DSS-induced mouse model

Phellinus linteus, a rare medicinal fungus, displays strong antitumor and anti-inflammatory activities because of its active metabolites, particularly polysaccharides. We investigated effects of P. linteus acidic polysaccharide (PLAP) on amelioration of dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in a mouse model, and associated mechanisms. PLAP treatment alleviated major UC symptoms (weight loss, reduced food intake, increased disease activity index), and ameliorated histopathological colon tissue damage, reduced levels of pro-inflammatory factors (TNF-α, IL-6, IL-1β), enhanced anti-inflammatory factor IL-10 level, reduced levels of oxidative stress-related enzymes iNOS and MPO, and enhanced expression of tight junction proteins (ZO-1, occludin, claudin-1). qPCR analysis revealed that PLAP downregulated phosphorylation levels of p65 and p38 and transcriptional level of TLR-4. High-throughput sequencing showed that PLAP restored gut microbiota diversity and species abundances in the UC model, and gas chromatographic analysis showed that it increased levels of beneficial short-chain fatty acids. Our findings indicate that PLAP has strong potential for development as an anti-UC agent based on its reduction of inflammation and oxidative stress levels, modulation of gut microbiota composition, and promotion of normal intestinal barrier function.

Dietary supplementation with inulin improves burn-induced skeletal muscle atrophy by regulating gut microbiota disorders

Inulin, as a prebiotic, could modulate the gut microbiota. Burn injury leads to gut microbiota disorders and skeletal muscle catabolism. Therefore, whether inulin can improve burn-induced muscle atrophy by regulating microbiota disorders remains unknown. This study aimed to clarify that inulin intake alleviates gut microbiota disorders and skeletal muscle atrophy in burned rats. Rats were divided into the sham group, burn group, prebiotic inulin intervention group, and pseudo-aseptic validation group. A 30% total body surface area (TBSA) third-degree burn wound on dorsal skin was evaluated in all groups except the sham group. Animals in the intervention group received 7 g/L inulin. Animals in the validation group received antibiotic cocktail and inulin treatment. In our study inulin intervention could significantly alleviate the burn-induced skeletal muscle mass decrease and skeletal myoblast cell apoptosis. Inulin intake increased the abundances of Firmicutes and Actinobacteria but decreased the abundance of Proteobacteria. The biosynthesis of amino acids was the most meaningful metabolic pathway distinguishing the inulin intervention group from the burn group, and further mechanistic studies have shown that inulin can promote the phosphorylation of the myogenesis-related proteins PI3K, AKT and P70S6K and activate PI3K/AKT signaling for protein synthesis. In conclusion, inulin alleviated burn induced muscle atrophy through PI3K/AKT signaling and regulated gut microbiota dysbiosis.

Prebiotic utilisation provides Lactiplantibacillus plantarum a competitive advantage in vitro, but is not reflected by an increased intestinal fitness

Synbiotics combine the concepts of probiotics and prebiotics to synergistically enhance the health-associated effects of both components. Previously, we have shown that the intestinal persistence of inulin-utilizing L. plantarum Lp900 is significantly increased in rats fed an inulin-supplemented, high-calcium diet. Here we employed a competitive population dynamics approach to demonstrate that inulin and GOS can selectively enrich L. plantarum strains that utilize these substrates for growth during in vitro cultivation, but that such enrichment did not occur during intestinal transit in rats fed a GOS or inulin-supplemented diet. The intestinal persistence of all L. plantarum strains increased irrespective of their prebiotic utilization phenotype, which was dependent on the calcium level of the diet. Analysis of fecal microbiota and intestinal persistence decline rates indicated that prebiotic utilization capacity did not selectively stimulate intestinal persistence in prebiotic supplemented diets. Moreover, microbiota and organic acid profile analyses indicate that the prebiotic utilizing probiotic strains are vastly outcompeted by the endogenous prebiotic-utilizing microbiota, and that the collective enhanced persistence of all L. plantarum strains is most likely explained by their well-established tolerance to organic acids.

Divergent metabolism of two lychee (Litchi chinensis Sonn.) pulp flavonols and their modulatory effects on gut microbiota: Discovery of hydroxyethylation in vitro colonic fermentation

Quercetin 3-O-rutinose-7-O-α-l-rhamnoside (QRR), a characteristic lychee pulp flavonoid, has been linked to diverse bioactivities involving microbial metabolism. By integrating colonic fermentation and mass spectrometry, the catabolites including 7-O-hydroxyethyl-isorhamnetin and 3'-amino-4'-O-methyl-7-O-hydroxyethyl-isorhamnetin were unprecedently identified and unique to QRR metabolism, relative to the structural analog quercetin 3-O-rutinoside (QR) metabolism. These above-described metabolites highlighted a special biotransformation hydroxyethylation in QRR catabolism. QRR was partially deglycosylated into quercetin 3-O-glucoside-7-O-α-l-rhamnoside potentially catalyzed by Bacteroides. QR was more directly degradable to aglycone during colonic fermentation than are QRR. Unlike with QR fermentation, equivalent QRR effectively upregulated concentrations of propionic and butyric acids that were highly relevant with Faecalibacterium and Coprococcus. After fermentation, the relative abundances of Bacteroides uniformis (0.03%) and Akkermansia muciniphila (0.13%) were only upregulated by QRR among all fermentation groups, leading to the enrichments of the corresponding genera. These results further reveal the relationship between flavonoid structures and metabolic characteristics.

Inulin Supplementation Modulates the Hepatic Transcriptome, Metabolome, and Ferritin Content in Ovariectomized Rats

SCOPE

Liver is an important metabolic organ regulating whole-body homeostasis. This study aims to investigate how prebiotic-induced changes in the metabolic activity of the gut microbiome (GM) and dietary calcium depletion modulates the hepatic metabolome and transcriptome.

METHODS AND RESULTS

The serum metabolome, liver metabolome, and transcriptome are determined on samples from ovariectomized (OVX) rats fed a control diet (Control, n = 7), a control diet supplemented with 5% w/w inulin (Inulin, n = 7), or a calcium-deficient diet (CaDef, n = 7). Inulin fortification is associated with higher serum concentrations of acetate, 3-hydroxybutyrate, and reduced concentration of dimethyl sulfone, revealing that changes in the metabolic activity of the GM are reflected in circulating metabolites. Metabolomics also reveal that the inulin-fortified diet results in lower concentrations of hepatic glutamate, serine, and hypoxanthine while transcriptomics reveal accompanying effects on the hepatic expression of ferric iron binding-related genes. Inulin fortification also induces effects on the hepatic expression of genes involved in olfactory transduction, suggesting that prebiotics regulate liver function through yet unidentified mechanisms involving olfactory receptors.

CONCLUSION

Inulin ingestion impacts hepatic gene expression and is associated with an upregulation of ferritin synthesis-related genes and liver ferritin content.

Galacto-Oligosaccharides Alleviate LPS-Induced Immune Imbalance in Small Intestine through Regulating Gut Microbe Composition and Bile Acid Pool

Recent evidence suggests that the protective effect of gut microbiota on intestinal inflammation can be achieved through a microbe-bile acids (BAs) mechanism. Galacto-oligosaccharides (GOS) are a kind of prebiotic that alter gut microbiota composition. To verify whether GOS has a protective effect on intestinal inflammation through a microbe-BAs mechanism, this research was performed in a lipopolysaccharide (LPS) porcine model with the presence or absence of GOS. GOS prevented LPS-induced production of pro-inflammatory cytokines, the decrease of bacterial bile salt hydrolase-containing bacteria abundance, and the decrease of chendoxycholic acid (CDCA) level in piglets. Additionally, CDCA decreased LPS-induced production of pro-inflammatory cytokines, induced the expression of the takeda G-protein receptor 5 (TGR5), and its downstream cyclic adenosine monophosphate (cAMP) production in lamina propria-derived CD11b+ cells. The cAMP inhibitor eliminated the protective effect of CDCA on lamina propria-derived CD11b+ cells. These results suggested that GOS reduced the production of pro-inflammatory cytokines and inhibited NF-κB activation via microbe-BA-dependent TGR5-cAMP signaling in LPS-challenged piglets.

Identification of Gut Microbiota Profile Associated with Colorectal Cancer in Saudi Population

Colorectal cancer (CRC) is a significant global health concern. Microbial dysbiosis and associated metabolites have been associated with CRC occurrence and progression. This study aims to analyze the gut microbiota composition and the enriched metabolic pathways in patients with late-stage CRC. In this study, a cohort of 25 CRC patients diagnosed at late stage III and IV and 25 healthy participants were enrolled. The fecal bacterial composition was investigated using V3-V4 ribosomal RNA gene sequencing, followed by clustering and linear discriminant analysis (LDA) effect size (LEfSe) analyses. A cluster of ortholog genes' (COG) functional annotations and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were employed to identify enrichment pathways between the two groups. The findings showed that the fecal microbiota between the two groups varied significantly in alpha and beta diversities. CRC patients' fecal samples had significantly enriched populations of Streptococcus salivarius, S. parasanguins, S. anginosus, Lactobacillus mucosae, L. gasseri, Peptostreptococcus, Eubacterium, Aerococcus, Family XIII_AD3001 Group, Erysipelatoclostridium, Escherichia-Shigella, Klebsiella, Enterobacter, Alistipes, Ralstonia, and Pseudomonas (Q < 0.05). The enriched pathways identified in the CRC group were amino acid transport, signaling and metabolism, membrane biogenesis, DNA replication and mismatch repair system, and protease activity (Q < 0.05). These results suggested that the imbalance between intestinal bacteria and the elevated level of the predicated functions and pathways may contribute to the development of advanced CRC tumors. Further research is warranted to elucidate the exact role of the gut microbiome in CRC and its potential implications for use in diagnostic, prevention, and treatment strategies.

Blocked conversion of Lactobacillus johnsonii derived acetate to butyrate mediates copper-induced epithelial barrier damage in a pig model

BACKGROUND

High-copper diets have been widely used to promote growth performance of pigs, but excess copper supplementation can also produce negative effects on ecosystem stability and organism health. High-copper supplementation can damage the intestinal barrier and disturb the gut microbiome community. However, the specific relationship between high-copper-induced intestinal damage and gut microbiota or its metabolites is unclear.

OBJECTIVE

Using fecal microbiota transplantation and metagenomic sequencing, responses of colonic microbiota to a high-copper diet was profiled. In addition, via comparison of specific bacteria and its metabolites rescue, we investigated a network of bacteria-metabolite interactions involving conversion of specific metabolites as a key mechanism linked to copper-induced damage of the colon.

RESULTS

High copper induced colonic damage, Lactobacillus extinction, and reduction of SCFA (acetate and butyrate) concentrations in pigs. LefSe analysis and q-PCR results confirmed the extinction of L. johnsonii. In addition, transplanting copper-rich fecal microbiota to ABX mice reproduced the gut characteristics of the pig donors. Then, L. johnsonii rescue could restore decreased SCFAs (mainly acetate and butyrate) and colonic barrier damage including thinner mucus layer, reduced colon length, and tight junction protein dysfunction. Given that acetate and butyrate concentrations exhibited a positive correlation with L. johnsonii abundance, we investigated how L. johnsonii exerted its effects by supplementing acetate and butyrate. L. johnsonii and butyrate administration but not acetate could correct the damaged colonic barrier. Acetate administration had no effects on butyrate concentration, indicating blocked conversion from acetate to butyrate. Furthermore, L. johnsonii rescue enriched a series of genera with butyrate-producing ability, mainly Lachnospiraceae NK4A136 group.

CONCLUSIONS

For the first time, we reveal the microbiota-mediated mechanism of high-copper-induced colonic damage in piglets. A high-copper diet can induce extinction of L. johnsonii which leads to colonic barrier damage and loss of SCFA production. Re-establishment of L. johnsonii normalizes the SCFA-producing pathway and restores colonic barrier function. Mechanistically, Lachnospiraceae NK4A136 group mediated conversion of acetate produced by L. johnsonii to butyrate is indispensable in the protection of colonic barrier function. Collectively, these findings provide a feasible mitigation strategy for gut damage caused by high-copper diets. Video Abstract.

Gut microbiome association with brain imaging markers, APOE genotype, calcium and vegetable intakes, and obesity in healthy aging adults

Introduction

Advanced age is a significant factor in changes to brain physiology and cognitive functions. Recent research has highlighted the critical role of the gut microbiome in modulating brain functions during aging, which can be influenced by various factors such as apolipoprotein E (APOE) genetic variance, body mass index (BMI), diabetes, and dietary intake. However, the associations between the gut microbiome and these factors, as well as brain structural, vascular, and metabolic imaging markers, have not been well explored.

Methods

We recruited 30 community dwelling older adults between age 55-85 in Kentucky. We collected the medical history from the electronic health record as well as the Dietary Screener Questionnaire. We performed APOE genotyping with an oral swab, gut microbiome analysis using metagenomics sequencing, and brain structural, vascular, and metabolic imaging using MRI.

Results

Individuals with APOE e2 and APOE e4 genotypes had distinct microbiota composition, and higher level of pro-inflammatory microbiota were associated higher BMI and diabetes. In contrast, calcium- and vegetable-rich diets were associated with microbiota that produced short chain fatty acids leading to an anti-inflammatory state. We also found that important gut microbial butyrate producers were correlated with the volume of the thalamus and corpus callosum, which are regions of the brain responsible for relaying and processing information. Additionally, putative proinflammatory species were negatively correlated with GABA production, an inhibitory neurotransmitter. Furthermore, we observed that the relative abundance of bacteria from the family Eggerthellaceae, equol producers, was correlated with white matter integrity in tracts connecting the brain regions related to language, memory, and learning.

Discussion

These findings highlight the importance of gut microbiome association with brain health in aging population and could have important implications aimed at optimizing healthy brain aging through precision prebiotic, probiotic or dietary interventions.

Effects of Menaquinone-7 on the Bone Health of Growing Rats under Calcium Restriction: New Insights from Microbiome-Metabolomics

Insufficient calcium intake during growth is a global public health concern. The aim of this study was to investigate the effects of dietary menaquinone-7 (MK-7) on bone accrual in growing Sprague-Dawley rats under calcium restriction. Following 13 weeks of treatment, various bone quality parameters, including microarchitecture, were measured. Fecal and cecal samples were subjected to microbiome (16S rRNA gene sequencing) analyses, while metabolomics analysis of the cecum and humerus samples was analyzed based on UHPLC-Q/TOF-MS. We found that calcium deficiency diminished the richness of the microbiome and disrupted microbiome composition, accompanied by an elevation in the relative abundance of Parasutterella. Furthermore, calcium insufficiency escalated the level of isovaleric acid and modified the metabolic profiles. MK-7 supplementation significantly increased the cortical thickness, cortical bone area, and the calcium content of the femur. Apart from improving bone calcium deposition and diminishing bone resorption, the mechanisms underlying the beneficial effects of MK on bone quality also involve the modulation of the host's metabolic pathways and the composition of gut microbiota. The gut-bone axis holds promise as an efficacious target for ameliorating calcium deficiency in children's bone quality, and MK-7 is a promising dietary supplement from this perspective.

The impact of common pharmaceutical excipients on the gut microbiota

INTRODUCTION

Increasing attention is being afforded to understanding the bidirectional relationships that exist between oral medications and the gut microbiota, in an attempt to optimize pharmacokinetic performance and mitigate unwanted side effects. While a wealth of research has investigated the direct impact of active pharmaceutical ingredients (APIs) on the gut microbiota, the interactions between inactive pharmaceutical ingredients (i.e. excipients) and the gut microbiota are commonly overlooked, despite excipients typically representing over 90% of the final dosage form.

AREAS COVERED

Known excipient-gut microbiota interactions for various classes of inactive pharmaceutical ingredients, including solubilizing agents, binders, fillers, sweeteners, and color additives, are reviewed in detail.

EXPERT OPINION

Clear evidence indicates that orally administered pharmaceutical excipients directly interact with gut microbes and can either positively or negatively impact gut microbiota diversity and composition. However, these relationships and mechanisms are commonly overlooked during drug formulation, despite the potential for excipient-microbiota interactions to alter drug pharmacokinetics and interfere with host metabolic health. The insights derived from this review will inform pharmaceutical scientists with the necessary design considerations for mitigating potential adverse pharmacomicrobiomic interactions when formulating oral dosage forms, ultimately providing clear avenues for improving therapeutic safety and efficacy.

Dietary Calcium and Risk of Microscopic Colitis

BACKGROUND

Microscopic colitis (MC) is an increasingly common cause of watery diarrhea particularly in older individuals. The role of diet in MC has received little study.

METHODS

We conducted a case-control study at a single institution enrolling patients referred for elective outpatient colonoscopy for diarrhea. Patients were classified as cases with MC or non-MC controls after a review of colon biopsies by 1 research pathologist. Study subjects were interviewed by a trained telephone interviewer using a validated food frequency questionnaire. Adherent microbes were evaluated from colonic biopsies using 16s rRNA sequencing.

RESULTS

The study population included 106 cases with MC and 215 controls. Compared with controls, the cases were older, better educated, and more likely to be female. Cases with MC had lower body mass index and were more likely to have lost weight. Subjects in the highest quartile of dietary calcium intake had a lower risk of MC compared with those in the lowest quartile (adjusted odds ratio 0.22, 95% confidence interval 0.07-0.76). The findings were not explained by dairy intake, body mass index, or weight loss. We found that dietary calcium intake had significant associations with the abundance of Actinobacteria and Coriobacteriales in the microbial community of colonic biopsies.

DISCUSSION

Compared with patients with diarrhea, cases with MC had a lower intake of dietary calcium. Diet can be associated with alterations in the gut microbiota and with luminal factors that could affect the risk of MC.

Polystyrene micro- and nanoparticles exposure induced anxiety-like behaviors, gut microbiota dysbiosis and metabolism disorder in adult mice

Plastics have been proven to be a potential threat to the ecosystem, and their toxicity mechanism is still uncertain. In the ecological environment, plastics can be degraded into microplastics (MPs) and nanoplastics (NPs), which can be contaminated and ingested through the food chain. MPs and NPs are associated with severe intestinal injury, intestinal microbiota disorder, and neurotoxicity, but it is still unclear whether MPs- and NPs-induced intestinal microbiota dysbiosis will affect the brain through the gut-brain axis. In the current study, we determined the effects of exposure to polystyrene (PS)-MPs and PS-NPs on anxiety-like behaviors and explored the underlying mechanisms. This study explored the behavioral effects of 30-day and 60-day exposure to PS-NPs and PS-MPs using the open field test (OFT) and elevated plus maze (EPM) test. Behavioral tests showed PS-NPs and PS-MPs treatment remarkedly induced anxiety-like behaviors compared with the control group. Using 16 S rRNA gene sequencing and untargeted metabolomics analyses, we observed that PS-MPs and PS-NPs exposure reduced the beneficial gut microbiota expression level, such as Lachnoclostridium and Lactobacillus, and increased the conditionally pathogenic bacteria expressions level, such as Proteobacteria, Actinobacteria, and Desulfovibrio. In addition, PS-NPs and PS-MPs reduce intestinal mucus secretion and increase intestinal permeability. The results of serum metabonomics suggested that the metabolic pathways, such as ABC transporter pathways, aminoacyl-tRNA biosynthesis, biosynthesis of amino acids, and bile secretion were enriched after PS-NPs and PS-MPs treatment. Besides, neurotransmitter metabolites were also altered by PS-NPs and PS-MPs. It is noteworthy that the correlation analysis showed that the disorder of intestinal microbiota was related to anxiety-like behaviors and neurotransmitter metabolites disorder. The regulation of intestinal microbiota may be a promising treatment strategy for PS-MPs- and PS-NPs-induced anxiety disorder.

The Effects of the Mediterranean Diet on Health and Gut Microbiota

The Mediterranean Diet (MD) is plant-based and consists of multiple daily portions of vegetables, fruit, cereals, and olive oil. Although there are challenges with isolating the MD from the typical Mediterranean lifestyle and culture (including prolonged 'social' meals and siestas), much evidence supports the health benefits of the MD that include improved longevity, reduced metabolic risk of Diabetes Mellitus, obesity, and Metabolic Syndrome, reduced risk of malignancy and cardiovascular disease, and improved cognitive function. The MD is also associated with characteristic modifications to gut microbiota, mediated through its constituent parts (primarily dietary fibres, extra virgin olive oil, and polyunsaturated fatty acids [including ω-3]). These include enhanced growth of species that produce short-chain fatty acids (butyrate), such as Clostridium leptum and Eubacterium rectale, enhanced growth of Bifidobacteria, Bacteroides, and Faecalibacterium prausnitzii species, and reduced growth of Firmicutes and Blautia species. Such changes in gut microbiota are known to be associated favourably with inflammatory and oxidative status, propensity for malignancy and overall metabolic health. A key challenge for the future is to explore the extent to which the health benefits of the MD are mediated by such changes to gut microbiota. The MD confers both health and environmental benefits. Adoption of the MD should perhaps be encouraged and facilitated more generally and not just restricted to populations from Mediterranean regions. However, there are key challenges to this approach that include limited perennial availability of the constituent parts of the MD in some non-Mediterranean regions, intolerability of a high-fibre diet for some people, and potential cultural disconnects that juxtapose some traditional (including Western) diets with the MD.

An Elemental Diet Enriched in Amino Acids Alters the Gut Microbial Community and Prevents Colonic Mucus Degradation in Mice with Colitis

The role of dietary amino acids or intact proteins in the progression of colitis remains controversial, and the mechanism involving gut microbes is unclear. Here, we investigated the effects of an elemental diet (ED) enriched in amino acids and a polymeric diet enriched in intact protein on the pathogenesis of dextran sulfate sodium (DSS)-induced colitis in mice. Our results showed that the ED induced remission of colitis in mice. Notably, ED treatment reduced the abundance of the mucolytic bacteria Akkermansia and Bacteroides, which was attributed to decreased colonic protein fermentation. Consistently, the activities of mucolytic enzymes were decreased, leading to protection against mucus layer degradation and microbial invasion. Fecal microbiota transplantation from ED-fed mice reshaped microbial ecology and alleviated intestinal inflammation in recipient mice. The ED failed to induce remission of colitis in pseudogermfree mice. Together, our results demonstrate the critical role of the gut microbiota in the prevention of colitis by an ED. IMPORTANCE The prevalence of inflammatory bowel disease is rapidly increasing and has become a global burden. Several specific amino acids have been shown to benefit mucosal healing and colitis remission. However, the role of amino acids or intact proteins in diets and enteral nutrition formulas is controversial, and the mechanisms involving gut microbes remain unclear. In this study, we investigated the effects of an elemental diet (ED) enriched in amino acids and a polymeric diet enriched in intact protein on the pathogenesis of colitis in mice. The underlying mechanisms were explored by utilizing fecal microbiota transplantation and pseudogermfree mice. ED treatment reduced the abundance of mucolytic bacteria, thereby protecting the mucus layer from microbial invasion and degradation. For the first time, we convincingly demonstrated the critical role of gut microbiota in the effects of the ED. This study may provide new insights into the gut microbiota-diet interaction and its role in human health.

Intake of slow-digesting carbohydrates is related to changes in the microbiome and its functional pathways in growing rats with obesity induced by diet

INTRODUCTION

The main cause of insulin resistance in childhood is obesity, which contributes to future comorbidities as in adults. Although high-calorie diets and lack of exercise contribute to metabolic disease development, food quality rather than the quantity of macronutrients is more important than food density. The purpose of the present study was to examine the effects of changing the quality of carbohydrates from rapidly to slowly digestible carbohydrates on the composition of the gut microbiota and the profiles of the functional pathways in growing rats with obesity due to a high-fat diet (HFD).

METHODS

During the course of 4 weeks, rats growing on an HFD-containing carbohydrates with different digestive rates were fed either HFD-containing carbohydrates with a rapid digestion rate (OBE group) or HFD-containing carbohydrates with a slow digestion rate (OBE-ISR group). A non-obese group (NOB) was included as a reference, and rats were fed on a rodent standard diet (AIN93G). An analysis of gut microbiota was conducted using 16S rRNA-based metagenomics; a linear mixed-effects model (LMM) was used to determine changes in abundance between baseline and 4 weeks of treatment, and functional pathways were identified. Gut microbiota composition at bacterial diversity and relative abundance, at phylum and genus levels, and functional profiles were analyzed by integrating the Integrated Microbial Genomes (IMG) database.

RESULTS

The groups showed comparable gut microbiota at baseline. At the end of the treatment, animals from the ISR group exhibited differences at the phylum levels by decreasing the diversity of Fisher's index and Firmicutes (newly named as Bacillota), and increasing the Pielou's evenness and Bacteroidetes (newly named as Bacteroidota); at the genus level by increasing Alistipes, Bifidobacterium, Bacteroides, Butyricimonas, Lachnoclostridium, Flavonifractor, Ruminiclostridium 5, and Faecalibaculum and decreasing Muribaculum, Blautia, and Ruminiclostridium 9. Remarkably, relative abundances of genera Tyzzerella and Angelakisella were higher in the OBE group compared to NOB and OBE-ISR groups. In addition, some microbiota carbohydrate metabolism pathways such as glycolysis, glucuronic acid degradation, pentose phosphate pathway, methanogenesis, and fatty acid biosynthesis exhibited increased activity in the OBE-ISR group after the treatment. Higher levels of acetate and propionate were found in the feces of the ISR group compared with the NOB and OBE groups.

CONCLUSION

The results of this study demonstrate that replacing rapidly digestible carbohydrates with slowly digestible carbohydrates within an HFD improve the composition of the gut microbiota. Consequently, metabolic disturbances associated with obesity may be prevented.

Comparison of composting factors, heavy metal immobilization, and microbial activity after biochar or lime application in straw-manure composting

Composting is an efficient way of disposing agricultural solid wastes as well as passivating heavy metals (HMs). Herein, equivalent (3%) biochar (BC) or lime (LM) were applied in rice straw and swine manure composting, with no additives applied as control group (CK). The results indicated that both the additives increased NO₃^--N content, organic matter degradation, humus formation, and HM immobilization in composting, and the overall improvement of lime was more significant. In addition, the additives optimized the bacterial community of compost, especially for thermophilic and mature phase. Lime stimulated the growth of Bacillus, Peptostreptococcus, Clostridium, Turicibacter, Clostridiaceae and Pseudomonas, which functioned well in HM passivation via biosorption, bioleaching, or promoting HM-humus formation by secreting hydrolases. Lime (3%) as additive is recommended in swine manure composting to promote composting maturity and reduce HM risk. The study present theoretical guidance in improving composting products quality for civil and industrial composting.

Colon cancer therapy with calcium phosphate nanoparticles loading bioactive compounds from Euphorbia lathyris: In vitro and in vivo assay

Amorphous calcium phosphate nanoparticles (ACP NPs) exhibit excellent biocompatibility and biodegradability properties. ACP NPs were functionalized with two coumarin compounds (esculetin and euphorbetin) extracted from Euphorbia lathyris seeds (BC-ACP NPs) showing high loading capacity (0.03% and 0.34% (w/w) for esculetin and euphorbetin, respectively) and adsorption efficiency (2.6% and 33.5%, respectively). BC-ACP NPs, no toxic to human blood cells, showed a more selective cytotoxicity against colorectal cancer (CRC) cells (T-84 cells) (IC50, 71.42 µg/ml) compared to non-tumor (CCD18) cells (IC50, 420.77 µg/ml). Both, the inhibition of carbonic anhydrase and autophagic cell death appeared to be involved in their action mechanism. Interestingly, in vivo treatment with BC-ACPs NPs using two different models of CRC induction showed a significant reduction in tumor volume (62%) and a significant decrease in the number and size of polyps. A poor development of tumor vasculature and invasion of normal tissue were also observed. Moreover, treatment increased the bacterial population of Akkermansia by restoring antioxidant systems in the colonic mucosa of mice. These results show a promising pathway to design innovative and more efficient therapies against CRC based on biomimetic calcium phosphate NPs loaded with natural products.

Glucose metabolism and glycosylation link the gut microbiota to autoimmune diseases

Carbohydrates serve as important energy sources and structural substances for human body as well as for gut microbes. As evidenced by the advances in immunometabolism, glucose metabolism and adenosine triphosphate (ATP) generation are deeply involved in immune cell activation, proliferation, and signaling transduction as well as trafficking and effector functions, thus contributing to immune response programming and assisting in host adaption to microenvironment changes. Increased glucose uptake, aberrant expression of glucose transporter 1 (e.g., GLU1), and abnormal glycosylation patterns have been identified in autoimmunity and are suggested as partially responsible for the dysregulated immune response and the modification of gut microbiome composition in the autoimmune pathogenesis. The interaction between gut microbiota and host carbohydrate metabolism is complex and bidirectional. Their impact on host immune homeostasis and the development of autoimmune diseases remains to be elucidated. This review summarized the current knowledge on the crosstalk of glucose metabolism and glycosylation in the host with intestinal microbiota and discussed their possible role in the development and progression of autoimmune diseases. Potential therapeutic strategies targeting glucose metabolism and glycosylation in modulating gut ecosystem and treating autoimmune diseases were discussed as well.

Chronic exposure to polyvinyl chloride microplastics induces liver injury and gut microbiota dysbiosis based on the integration of liver transcriptome profiles and full-length 16S rRNA sequencing data

Microplastics (MPs) have become harmful environmental pollutants, and their potential toxicity to organisms has attracted extensive attention. However, the effects of polyvinyl chloride MPs (PVC-MPs) on the liver and their associated mechanism in mice remain obscure. Here, male mice were exposed to 2-μm PVC-MPs (0.5 mg/day) for 60 days and then sacrificed, and their liver, blood and gut feces were subsequently collected for testing. The liver tissue and fecal samples were subjected to RNA sequencing and full-length 16S rRNA sequencing analysis, respectively. Our results showed that the levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the mice exposed to PVC-MPs were markedly higher than those in the control group, implying hepatic injury, as evidenced by hepatic histopathological changes. Moreover, the serum and hepatic triglyceride (TG) and total bile acid (TBA) levels were decreased after exposure to PVC-MPs. The RNA sequencing of mouse liver tissue identified a total of 1540 differentially expressed genes (DEGs) associated with 47 pathways, including the lipid metabolic pathway, oxidative stress, and the phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt) signaling pathway, and these DEGs were enriched in the mouse livers. The full-length 16S rRNA sequencing analysis of the gut microbiota in mouse fecal samples revealed that PVC-MPs exposure decreased the relative abundance of probiotics and increased the abundance of conditionally pathogenic bacteria. In conclusion, chronic PVC-MPs exposure causes hepatotoxicity and gut microbiota dysbiosis in mice, and these findings provide new insight into the potential risks of PVC-MPs to human health.

NMR-Based Metabolomics to Decipher the Molecular Mechanisms in the Action of Gut-Modulating Foods

Metabolomics deals with uncovering and characterizing metabolites present in a biological system, and is a leading omics discipline as it provides the nearest link to the biological phenotype. Within food and nutrition, metabolomics applied to fecal samples and bio-fluids has become an important tool to obtain insight into how food and food components may exert gut-modulating effects. This review aims to highlight how nuclear magnetic resonance (NMR)-based metabolomics in food and nutrition science may help us get beyond where we are today in understanding foods’ inherent, or added, biofunctionalities in relation to gut health.

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.

Different Dose of Sucrose Consumption Divergently Influences Gut Microbiota and PPAR-γ/MAPK/NF-κB Pathway in DSS-Induced Colitis Mice

Sugar reduction and sugar control are advocated and gaining popularity around the world. Sucrose, as the widely consumed ingredient in our daily diet, has been reported a relation to gastrointestinal diseases. However, the role of sucrose in inflammatory bowel disease remains controversial. Hence, our study aimed to elucidate the potential role of three doses of sucrose on DSS-induced colitis in C57BL/6 mice and the underlying mechanisms. The results showed that low-dose sucrose intervention alleviated colitis in mice, reducing the expression of inflammatory cytokines and repairing mucosal damages. In contrast, high-dose sucrose intervention exacerbated colitis. Furthermore, three doses of sucrose administration markedly altered gut microbiota composition. Notably, the low-dose sucrose restored microbial dysfunction and enhanced the production of short chain fatty acids (SCFAs). Specifically, the abundance of SCFAs-producing bacteria Faecalibaculum, Bacteroides, and Romboutsia were increased significantly in the LOW group. Consistently, PPAR-γ, activated by SCFAs, was elevated in the LOW group, thereby inhibiting the MAPK/NF-κB pathway. Together, our study demonstrates the differential effects of sucrose on colitis at different doses, providing a scientific basis for measuring and modifying the safe intake level of sugar and providing favorable evidence for implementing sugar reduction policies.

Growth Performance, Bone Development and Phosphorus Metabolism in Chicks Fed Diets Supplemented with Phytase Are Associated with Alterations in Gut Microbiota

Phosphorus pollution caused by animal husbandry is becoming increasingly problematic, especially where decreasing and non-renewable phosphorus resources are concerned. We investigated the growth performance, bone development, phosphorus metabolism and gut microbiota changes elicited by different phosphorus levels with/without phytase in chicks during the brooding period (1-42 d). Five-hundred-and-forty (540) egg-laying chickens were assigned to six groups (0.13% NPP, 0.29% NPP, 0.45% NPP, 0.13% NPP + P, 0.29% NPP + P and 0.45% NPP + P) according to a factorial design with three non-phytate phosphorus (NPP) levels (0.13, 0.29 and 0.45%) and two phytase (P) dosages (0 and 200 FTU/kg). Chicks fed with the diet with 0.13% NPP had the lowest body weight, average daily gain, shank length, average daily feed intake and highest ratio of feed to gain, while phytase supplementation was able to mitigate the adverse effects of low-phosphorus diets on growth performance. Moreover, phosphorus metabolism was affected by different dietary NPP and phytase levels. Thus, 0.13% NPP significantly reduced serum phosphorus, while phytase supplementation significantly increased serum phosphorus. Notably, phosphorus utilization in the 0.13% NPP group was significantly decreased and the phosphorus excretion ratio was increased. Phytase supplementation significantly improved phosphorus utilization by 43.79% and decreased phosphorus emission in the 0.13% NPP group but not in the 0.29% NPP or the 0.45% NPP group. Remarkably, the alpha diversity of gut microbiota was significantly decreased in the low-phosphorus group, while phytase supplementation increased alpha diversity and improved gut microbial community and function. The LEfSe analysis revealed that several differential genera (e.g., Bacteroides, norank_f__Clostridiales_vadinBB60_group and Eggerthella) were enriched in the different dietary NPP and phytase levels. Furthermore, correlations between differential genera and several crucial phenotypes suggested that the enrichment of beneficial bacteria with different levels of phosphorus and phytase promoted phosphorus utilization in the foregut and hindgut. In summary, low-phosphorus diets inhibited growth performance and bone development, decreased utilization of phosphorus and altered gut microbial structure and function in the brooding stage of chicks. Finally, phytase supplementation improves growth performance and bone development and decreases phosphorus emission, and the potential mechanisms may be associated with the reprogramming of gut microbiota.