Diet, gut microbiota and immune responses. Nat Immunol. 2011;12:5-9. [PMID: 21169997 DOI: 10.1038/ni0111-5]

Influence of systemic antibiotic therapy on the development and progression of induced apical periodontitis in Wistar rats

The aim of this study was to investigate the influence of systemic antibiotic therapy on the development and progression of induced apical periodontitis (AP) in Wistar rats. Fifty-six rats were submitted to pulp exposure of the lower left first molar for the induction of AP. On the same day, intraperitoneal antibiotic therapy was administered once a day, for 15 days, until euthanasia. The groups were formed according to the different treatments (n = 8): C-control; GEN-treated with gentamicin (10 mg/Kg); AC-treated with amoxicillin (100 mg/Kg); MZ-treated with metronidazole (40 mg/Kg); AMP-treated with ampicillin (100 mg/Kg); AMC group-treated with amoxicillin + clavulanic acid (100 mg/kg); CLI-treated with clindamycin (60 mg/kg). After euthanasia, the jaws were collected and processed for (1) histological and histometric analysis using hematoxylin and eosin staining, (2) analysis of collagen fibers using Picrosirius Red staining and (3) bacteriological analysis using Brown-Brenn staining. The data were analyzed statistically (p < 0.05). AP induction was confirmed in all groups. The AMC group had the lower intensity of inflammatory infiltrate (p = 0.028) and less periapical bone resorption compared to control (p = 0.006). Regarding collagen maturation, PSR staining revealed a predominance of mature collagen fibers in all groups. The AC and AMC groups had the lower amount of mature fibers and the highest amount of immature fibers, compared to all other groups (p < 0.001). All groups showed bacterial contamination; however, the AC and AMC groups showed a lower extent of bacterial contamination compared to the control (p < 0.001). It can be concluded that systemic antibiotic therapy influences the development and progression of induced AP.

The gut microbiota improves reproductive dysfunction in obese mice by suppressing the NLRP3/ASC/caspase-1 axis

Aim: To explore the complex relationship between gut microbiota, obesity-related male reproductive impairments, and the NLRP3 inflammasome.Methods: A high-fat diet was administered to induce obesity in a mouse model, fecal microbiota transplantation or a high-dietary fiber diet (HDFD) was administered for 5 weeks to evaluate changes in parameters related to reproductive capacity, NLRP3, gut microbiota composition and metabolites in mice.Results: A high-fat diet induces obesity and decreases reproductive capacity in male mice. Fecal microbiota transplantation and HDFD can improve reproductive capacity in obese mice by adjusting the gut microbiota population to suppress the NLRP3/ASC/caspase-1 axis, thereby reducing IL-1β levels.Conclusion: This study offers a potential treatment for obesity-induced reproductive dysfunction by targeting the gut microbiota and the NLRP3 inflammasome pathway.

Alginate oligosaccharide improves 5-fluorouracil-induced intestinal mucositis by enhancing intestinal barrier and modulating intestinal levels of butyrate and isovalerate

Chemotherapy-induced mucositis (CIM) is the typical side effect of chemotherapy. This study investigates the potential of alginate oligosaccharide (AOS) in ameliorating CIM induced by 5-fluorouracil (5-FU) in a murine model and its underlying mechanisms. AOS effectively mitigated body weight loss and histopathological damage, modulated inflammatory cytokines and attenuated the oxidative stress. AOS restored intestinal barrier integrity through enhancing expression of tight junction proteins via MLCK signaling pathway. AOS alleviated intestinal mucosal damage by inhibiting TLR4/MyD88/NF-κB signaling pathway, downregulating the pro-apoptotic protein Bax and upregulating the anti-apoptotic protein Bcl-2. Moreover, AOS significantly enriched intestinal Akkermansiaceae and increased the production of short-chain fatty acids (SCFAs), most notably butyrate and isovalerate. Pre-treatment with butyrate and isovalerate also alleviated 5-FU-induced CIM. In conclusion, AOS effectively mitigated CIM through strenghthening intestinal barrier, attenuating inflammation, and modulating gut microbiota and intestianl levels of butyrate and isovalerate. These finding indicate that AOS could be potentially utilized as a supplemental strategy for prevention or mitigation of CIM.

Effects of pregnancy and lactation prebiotics supplementation on infant allergic disease: A randomized controlled trial

BACKGROUND

Ingestion of prebiotics during pregnancy and lactation may have immunomodulatory benefits for the developing fetal and infant immune system and provide a potential dietary strategy to reduce the risk of allergic diseases.

OBJECTIVE

We sought to determine whether maternal supplementation with dietary prebiotics reduces the risk of allergic outcomes in infants with hereditary risk.

METHODS

We undertook a double-blind randomized controlled trial in which pregnant women were allocated to consume prebiotics (14.2 g daily of galacto-oligosaccharides and fructo-oligosaccharides in the ratio 9:1) or placebo (8.7 g daily of maltodextrin) powder from less than 21 weeks' gestation until 6 months postnatal during lactation. Eligible women had infants with a first-degree relative with a history of medically diagnosed allergic disease. The primary outcome was medically diagnosed infant eczema by age 1 year, and secondary outcomes included allergen sensitization, food allergy, and recurrent wheeze by age 1 year.

RESULTS

A total of 652 women were randomized between June 2016 and November 2021 (329 in the prebiotics group and 323 in the placebo group). There was no significant difference between groups in the percentage of infants with medically diagnosed eczema by age 1 year (prebiotics 31.5% [103 of 327 infants] vs placebo 32.6% [105 of 322 infants]; adjusted relative risk, 0.98; 95% CI, 0.77-1.23; P = .84). Secondary outcomes and safety measures also did not significantly differ between groups.

CONCLUSIONS

We found little evidence that maternal prebiotics supplementation during pregnancy and lactation reduces the risk of medically diagnosed infant eczema by age 1 year in infants who are at hereditary risk of allergic disease.

Dietary therapy of murine primary biliary cholangitis induces hepatocellular steatosis: A cautionary tale

BACKGROUND AND AIMS

There is increased interest in utilizing dietary interventions to alter the progression of autoimmune diseases. These efforts are driven by associations of gut microbiota/metabolites with levels of short-chain fatty acids (SCFAs). Propionate is a key SCFA that is commonly used as a food preservative and is endogenously generated by bacterial fermentation of non-digestible carbohydrates in the gut. A thesis has suggested that a diet rich in propionate and other SCFAs can successfully modulate autoimmunity. Herein, we investigated the effect of long-term administration of propionylated high-amylose resistant starches (HAMSP) on the course of murine primary biliary cholangitis.

MATERIALS AND METHODS

Groups of female ARE-Del mice were fed an HAMSP diet either before or after disease onset. A detailed immunobiological analysis was performed involving autoantibodies and rigorous T-cell phenotyping, including enumeration of T-cell subsets in the spleen, liver, intestinal intraepithelial lymphocytes and lamina propria by flow cytometry. Histopathological scores were used to assess the frequency and severity of liver inflammation and damage to hepatocytes and bile ducts.

RESULTS

Our results demonstrate that a long-term propionate-yielding diet re-populated the T-cell pool with decreased naïve and central memory T-cell subsets and an increase in the effector memory T cells in mice. Similarly, long-term HAMSP intake reduced CD4+CD8+ double-positive T cells in intraepithelial lymphocytes and the intestinal lamina propria. Critically, HAMSP consumption led to moderate-to-severe hepatocellular steatosis in ARE-Del mice, independent of the stage of autoimmune cholangitis.

CONCLUSIONS

Our data suggest that administration of HAMSP induces both regulatory and effector T cells. Furthermore, HAMSP administration resulted in hepatocellular steatosis. Given the interest in dietary modulation of autoimmunity and because propionate is widely used as a food preservative, these data have significant implications. This study also provides new insights into the immunological and pathological effects of chronic propionate exposure.

Immunostimulatory effects of dietary verjuice (Vitis vinifera) on immune response and transcription of immune-related genes in juvenile rainbow trout (Oncorhynchusmykiss)

The development of green aquaculture practices has led to the supplementation of fish diets with natural immunostimulants such as organic acids. This study aimed to assess the dietary effects of verjuice (VJ; unfermented unripe grapes; Vitis vinifera) on hematological parameters, skin mucosal immunity, transcriptional immune responses, and antibacterial serum activity against Aeromonas hydrophila in rainbow trout. The fish (51.0 ± 2.4 g) were randomly distributed into 15 tanks and fed ad-libitum thrice daily with diets containing different levels of VJ including 0 (control; VJ-0), 3 (VJ-3), 6 (VJ-6), 9 (VJ-9), and 12 (VJ-12) mL/kg VJ for 56 d. Results showed that immuno-hematological parameters (total white blood cells, neutrophils, and monocytes) were improved in VJ-added groups (P < 0.05). In addition, dietary VJ (9 mL/kg) modulated serum immunological parameters. Skin mucus immunology exhibited a notable increase in alkaline phosphatase, lysozyme activity, alkaline protease, total protein, total immunoglobulin, and esterase levels in VJ-9 group compared with those in the control group (P < 0.05). The mRNA expression of interleukin-1β, interleukin-6, interleukin-8, and immunoglobulin M were significantly higher in VJ-9 group than in the control (P < 0.05). Furthermore, the results of the antibacterial evaluation showed that A. hydrophila growth was significantly inhibited in the serum samples from VJ-3 to VJ-9 groups after the 56th day and in all VJ-treated groups after the 70th (P < 0.05). In conclusion, dietary VJ is a novel immunostimulant and the optimal dietary supplementation level of 6.65-7.46 mL/kg can effectively improve immune responses in rainbow trout.

Yinchenhao Decoction mitigates intestinal impairment induced by high carbohydrate diet in largemouth bass (Micropterus salmoides): insights from inflammation, apoptosis, oxidative stress, tight junctions, and microbiota homeostasis

As a major source of energy, carbohydrates have a protein-saving effect. However, excessive consumption of carbohydrates can lead to the disruption of the intestinal barrier in fish, especially for carnivorous fish. Therefore, traditional Chinese medicine component Yinchenhao Decoction (YD), was used to detect the effect on intestinal barriers and microbial community equilibrium for largemouth bass in current research. In this research, a series of NC (normal carbohydrate diet) and HC (high carbohydrate diet) with graded YD treatments during 10 weeks feeding trial. Results suggested that 2% and 4% YD treatments significantly reduced gut inflammation and mucosal loss caused by HC. Compared with NC, HC significantly decreased the relative expression of intestinal tight junction-related genes (zo1, claudin1, claudin7, and occludin). However, with the application of YD, the expression of tight junction-related genes (zo1, claudin1, and claudin7) increased significantly (p < 0.05). Likewise, administration of YD significantly reduced elevated plasma diamine oxidase (DAO) activity caused by HC (p < 0.05). Additionally, YD significantly downregulated the mRNA expression of endoplasmic reticulum stress (ERS)-related genes (grp78, atf6, chopα, ire1, xbp1, and eifα) and pro-apoptosis genes (casp3, casp8, and bax) (p < 0.05), while upregulating the anti-apoptosis gene bcl2 (p < 0.05). Moreover, YD significantly increased the mRNA expression of antioxidant genes and the enzyme activities of CAT and GPX, while decreased MDA concentration significantly (p < 0.05). Whereas, YD markedly decreased the expression of pro-inflammatory genes (il1β, tnfα, il8, and nf-κB) and the immune enzymes activity (ACP and AKP) (p < 0.05) by up-regulating the expression of anti-inflammatory genes (ikb and il10). Notably, YD modulated the largemouth bass intestinal microbial community, enhanced the diversity and increased the abundance of probiotic microorganisms in the intestinal microbiota. In summary, YD supplementation in HC alleviated inflammation, apoptosis, oxidative stress, tight-junction injury, and microbiota disequilibrium in the intestine, which suggested that YD could be a valuable functional additive in aquaculture.

Lacticaseibacillus paracasei completely utilizes fructooligosacchrides in the human gut through β-fructosidase (FosE)

The fecal microbiota of two healthy adults was cultivated in a medium containing commercial fructooligosaccharides [FOS; 1-kestose (GF2), nystose (GF3), and 1F-fructofuranosylnystose (GF4)]. Initially, the proportions of lactobacilli in the two feces samples were only 0.42% and 0.17%; however, they significantly increased to 7.2% and 4.8%, respectively, after cultivation on FOS. Most FOS-utilizing isolates could utilize only GF2; however, Lacticaseibacillus paracasei strain Lp02 could fully consume GF3 and GF4 too. The FOS operon (fosRABCDXE) was present in Lc. paracasei Lp02 and another Lc. paracasei strain, KCTC 3510T, but fosE was only partially present in the non-FOS-degrading strain KCTC 3510T. In addition, the top six upregulated genes in the presence of FOS were fosABCDXE, particularly fosE. FosE is a β-fructosidase that hydrolyzes both sucrose and all three FOS. Finally, a genome-based analysis suggested that fosE is mainly observed in Lc. paracasei, and only 13.5% (61/452) of their reported genomes were confirmed to include it. In conclusion, FosE allows the utilization of FOS, including GF3 and GF4 as well as GF2, by some Lc. paracasei strains, suggesting that this species plays a pivotal role in FOS utilization in the human gut.

Alterations of mouse gut microbiome in alveolar echinococcosis

Alveolar echinococcosis (AE) may affect the composition of the host's gut microbiota, potentially disrupting the balance between the gut microbiota and metabolites. Metagenomics and untargeted metabolomics were employed to characterize changes in the gut microbiota and metabolites in mouse models infected with E. multilocularis. Pearson correlation coefficients were calculated to compare the distribution of microbiota and metabolites, revealing synergistic or mutually exclusive relationships. Functional outputs of the gut microbiota were explored using the CAZy database and six enzymes involved in carbohydrate metabolism were identified with statistically significant differential expression between infected and control groups. The resistome was characterized by identifying antibiotic resistance genes annotated in the Comprehensive Antibiotic Resistance Database from the metagenomes of the groups. Firmicutes are the main carrier of ARGs in the host gut with tetQ being most prevalent. Antibiotic efflux, inactivation and target modification were the principal mechanisms of resistance. Comparison and analysis of two sets of antibiotic metabolic pathways allowed the identification of enzyme reactions unique to infected mice. KEGG pathway overview shows phenazine biosynthesis involving phzG to be one of them. In conclusion, infection with AE in mice leads to an overall disruption of gut microbiota and metabolites with the involvement of enzymes related to carbohydrate metabolism. Furthermore, antibiotic-resistance genes may play a role in disease progression, offering potential insights into the relationship between antibiotic use in AE and treatment outcomes.

12,13-diHOME Promotes Inflammatory Macrophages and Epigenetically Modifies Their Capacity to Respond to Microbes and Allergens

Elevated infant fecal concentrations of the bacterial-derived lipid 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME) increase the risk for childhood atopy and asthma. However, the mechanisms by which this lipid contributes to disease development are largely unknown. We hypothesized that macrophages, which are key to both antimicrobial and antigen responses, are functionally and epigenetically modified by 12,13-diHOME leading to short- and long-term dysfunction with consequences for both antimicrobial and antigenic responses. Macrophages exposed to 12,13-diHOME are skewed toward inflammatory IL-1β highCD206low cells, a phenomenon that is further amplified in the presence of common microbial-, aero-, and food-allergens. These IL-1β highCD206low macrophages also exhibit reduced bacterial phagocytic capacity. In primary immune cell coculture assays involving peanut allergen stimulation, 12,13-diHOME promotes both IL-1β and IL-6 production, memory B cell expansion, and increased IgE production. Exposure to 12,13-diHOME also induces macrophage chromatin remodeling, specifically diminishing access to interferon-stimulated response elements resulting in reduced interferon-regulated gene expression upon bacterial lipopolysaccharide stimulation. Thus 12,13-diHOME reprograms macrophage effector function, B-cell interactions and promotes epigenetic modifications that exacerbate inflammatory response to allergens and mutes antimicrobial response along the interferon axis. These observations offer plausible mechanisms by which this lipid promotes early-life pathogenic microbiome development and innate immune dysfunction associated with childhood allergic sensitization.

Fasting-mimicking diet remodels gut microbiota and suppresses colorectal cancer progression

The progression of colorectal cancer is closely associated with diet. Fasting-mimicking diet (FMD) is a promising type of dietary intervention that have beneficial effects in the prevention and treatment of various cancers. We investigated the therapeutic effect of 4-day FMD against colorectal cancer in mice through immune cell analysis, microbiota composition analysis and anti-PD-1 treatment. These FMD cycles effectively suppressed colorectal cancer growth, reduced cell proliferation and angiogenesis, increased tumor-infiltration lymphocytes especially CD8+T cells. FMD stimulated protective gut microbiota, especially Lactobacillus. Supplementation of Lactobacillus johnsonii induced similar results as FMD intervention, which also suppressed tumor growth and increased CD45+ and CD8+ T cells. Additionally, FMD synthesizing with anti-PD-1 therapy effectively inhibited CRC progression. These findings suggest that Lactobacillus. johnsonii is necessary for the anticancer process of FMD in CRC. FMD through its effects on both gut microbiota and immune system, effectively suppressed colorectal cancer progression in mouse model.

Beneficial In Vitro Effects of Polysaccharide and Non-Polysaccharide Components of Dendrobium huoshanense on Gut Microbiota of Rats with Type 1 Diabetes as Opposed to Metformin

The extract of Dendrobium huoshanense, a traditional Chinese medicinal and food homologous plant belonging to the family Orchidaceae, was previously reported to have hypoglycemic and antioxidant effects. In this study, the direct effects of polysaccharide (DHP) and non-polysaccharide (NDHP) components of D. huoshanense, as well as its water extract (DHWE) were compared with that of metformin (an antidiabetic drug) on the gut microbiota (collected from fecal flora) of rats with streptozotocin-induced type 1 diabetes (T1D) using an in vitro fermentation method. The results showed that DHWE, DHP, and NDHP reduced pH and increased bacterial proliferation and short-chain fatty acid (SCFA) content in fermentation broth. DHWE, DHP, NDHP and metformin promoted the production of acetic and propionic acid, acetic acid, propionic acid and butyric acid, and propionic acid, respectively. DHWE, DHP, and NDHP reduced the abundance of Proteobacteria (subdominant pathogenic bacteria) and increased the abundance of Firmicutes (dominant beneficial gut bacteria). NDHP also reduced the abundance of Bacteroidetes (beneficial and conditional pathogenic). Metformin increased the abundance of Proteobacteria and reduced the abundance of Firmicutes and Bacteroidetes. At the genus level, NDHP promoted the proliferation of Megamonas and Megasphaera and decreased harmful bacteria (e.g., Klebsiella), and DHP increased the abundance of Prevotellaceae (opportunistic and usually harmless). By contrast, metformin increased the abundance of harmful bacteria (e.g., Citrobacter) and reduced the abundance of beneficial bacteria (e.g., Oscillospira). Our study indicates that DHWE, DHP, and NDHP are potentially more beneficial than metformin on the gut microbiota of T1D rats in vitro.

Orally available dextran-aspirin nanomedicine modulates gut inflammation and microbiota homeostasis for primary colorectal cancer therapy

Reversing the aggravated immunosuppression hence overgrowth of colorectal cancer (CRC) caused by the gut inflammation and microbiota dysbiosis is pivotal for effective CRC therapy and metastasis inhibition. However, the low delivery efficiency and severe dose-limiting off-target toxicities caused by unsatisfied drug delivery systems remain the major obstacles in precisely modulating gut inflammation and microbiota in CRC therapy. Herein, a multifunctional oral dextran-aspirin nanomedicine (P3C-Asp) was utilized for oral treatment of primary CRC, as it could release salicylic acid (SA) while scavenging reactive oxygen species (ROS) and held great potential in modulating gut microbiota with prebiotic (dextran). Oral P3C-Asp retained in CRC tissues for over 12 h and significantly increased SA accumulation in CRC tissues over free aspirin (10.8-fold at 24 h). The enhanced SA accumulation and ROS scavenging of P3C-Asp cooperatively induced more potent inflammation relief over free aspirin, characterized as lower level of cyclooxygenase-2 and immunosuppressive cytokines. Remarkably, P3C-Asp promoted the microbiota homeostasis and notably increased the relative abundance of strengthening systemic anti-cancer immune response associated microbiota, especially lactobacillus and Akkermansia to 6.66- and 103- fold over the control group. Additionally, a demonstrable reduction in pathogens associated microbiota (among 96% to 79%) including Bacteroides could be detected. In line with our findings, inflammation relief along with enhanced abundance of lactobacillus was positively correlated with CRC inhibition. In primary CRC model, P3C-Asp achieved 2.1-fold tumor suppression rate over free aspirin, with an overall tumor suppression rate of 85%. Moreover, P3C-Asp cooperated with αPD-L1 further reduced the tumor weight of each mouse and extended the median survival of mice by 29 days over αPD-L1 alone. This study unravels the synergistic effect of gut inflammation and microbiota modulation in primary CRC treatment, and unlocks an unconventional route for immune regulation in TME with oral nanomedicine.

Genetic associations between gut microbiota and allergic rhinitis: an LDSC and MR analysis

Background

Several studies have suggested a potential link between allergic rhinitis (AR) and gut microbiota. In response, we conducted a meta-analysis of Linkage Disequilibrium Score Regression (LDSC) and Mendelian randomization (MR) to detect their genetic associations.

Methods

Summary statistics for 211 gut microbiota taxa were gathered from the MiBioGen study, while data for AR were sourced from the Pan-UKB, the FinnGen, and the Genetic Epidemiology Research on Aging (GERA). The genetic correlation between gut microbiota and AR was assessed using LDSC. The principal estimate of causality was determined using the Inverse-Variance Weighted (IVW) method. To assess the robustness of these findings, sensitivity analyses were conducted employing methods such as the weighted median, MR-Egger, and MR-PRESSO. The summary effect estimates of LDSC, forward MR and reverse MR were combined using meta-analysis for AR from different data resources.

Results

Our study indicated a significant genetic correlation between genus Sellimonas (Rg = -0.64, p = 3.64 × 10-5, Adjust_P = 3.64 × 10-5) and AR, and a suggestive genetic correlation between seven bacterial taxa and AR. Moreover, the forward MR analysis identified genus Gordonibacter, genus Coprococcus2, genus LachnospiraceaeUCG010, genus Methanobrevibacter, and family Victivallaceae as being suggestively associated with an increased risk of AR. The reverse MR analysis indicated that AR was suggestively linked to an increased risk for genus Coprococcus2 and genus RuminococcaceaeUCG011.

Conclusion

Our findings indicate a causal relationship between specific gut microbiomes and AR. This enhances our understanding of the gut microbiota's contribution to the pathophysiology of AR and lays the groundwork for innovative approaches and theoretical models for future prevention and treatment strategies in this patient population.

Quantitation of circulating short-chain fatty acids in small volume blood samples from animals and humans

BACKGROUND

The role of gut microbiota in human health has been intensively studied and more recently shifted from emphasis on composition towards function. Function is partly mediated through formed metabolites. Short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate as well as their branched analogues represent major products from gut fermentation of dietary fibre and proteins, respectively. Robust and high-throughput analysis of SCFAs in small volume blood samples have proven difficult. Major obstacles come from the ubiquitous presence of SCFAs that leads to contaminations and unstable analytical results because of the high volatility of these small molecules. Comprehensive and comparable data on the variation of SCFAs in blood samples from different blood matrices and mammal species including humans is lacking. Therefore, our aim was to develop and evaluate a stable and robust method for quantitation of 8 SCFAs and related fermentation products in small volume blood plasma samples and to investigate their variation in humans and different animal species.

RESULTS

Derivatization was a successful approach for measurement of SCFAs in biological samples but quenching of the derivatization reaction was crucial to obtain long-term stability of the derivatized analytes. In total 9 compounds (including succinic acid) were separated in 5 min. The method was linear over the range 0.6-3200 nM formic (FA), acetic (AA), 0.3-1600 nM propionic (PA), and 0.16-800 nM for butyric (BA)-, isobutyric (IBA)-, valeric (VA)-, isovaleric (IVA)-, succinic (SA) and caproic acid (CA). The precision ranged ≤12 % within days and ≤28 % between days (except for CA and VA) in three different plasma quality control (QC) samples (29 batches analyzed over 3 months). The extraction recovery was on average 94 % for the different SCFAs. Typical interquartile range (IQR) concentrations (μM) of SCFAs in human plasma samples were 168 μM (FA), 64 μM (AA), 2.2 μM (PA), 0.54 μM (BA), 0.66 μM (IBA), 0.18 μM (VA), 0.40 μM (IVA), and 0.34 μM (CA). In total, 55 samples per batch/day were successfully analyzed and in total 5380 human plasma samples measured over a 3-year timespan.

SIGNIFICANCE

The developed UHPLC-MS based method was suitable for measuring SCFAs in small blood volume samples and enabled robust quantitative data.

Manual therapy and exercise effects on inflammatory cytokines: a narrative overview

Background

Matching disease and treatment mechanisms is a goal of the Precision Medicine Initiative. Pro- and anti-inflammatory cytokines (e.g., Tumor Necrosis Factor-alpha, Transforming Growth Factor-beta, and Interleukin-2, 10, and 12) have gained a significant amount of interest in their potential role in persistent pain for musculoskeletal (MSK) conditions. Manual therapy (MT) and exercise are two guideline-recommended approaches for treating MSK conditions. The objective of this narrative overview was to investigate of the effects of MT and exercise on pro- and anti-inflammatory cytokines and determine the factors that lead to variability in results.

Methods

Two reviewers evaluated the direction and variabilities of MT and exercise literature. A red, yellow, and green light scoring system was used to define consistencies.

Results

Consistencies in responses were seen with acute and chronic exercise and both pro- and anti-inflammatory cytokines. Chronic exercise is associated with a consistent shift towards a more anti-inflammatory cytokine profile (Transforming Growth Factor-beta, and Interleukin-2 and 13, whereas acute bouts of intense exercise can transiently increase pro-inflammatory cytokine levels. The influence of MT on cytokines was less commonly studied and yielded more variable results.

Conclusion

Variability in findings is likely related to the subject and their baseline condition or disease, when measurement occurs, and the exercise intensity, duration, and an individual's overall health and fitness.

Propionic acid ameliorates cognitive function through immunomodulatory effects on Th17 cells in perioperative neurocognitive disorders

Background

Elderly patients undergoing surgery are prone to cognitive decline known as perioperative neurocognitive disorders (PND). Several studies have shown that the microglial activation and the decrease of short-chain fatty acids (SCFAs) in gut induced by surgery may be related to the pathogenesis of PND. The purpose of this study was to determine whether microglia and short-chain fatty acids were involved in cognitive dysfunction in aged rats.

Methods

Male wild-type Wistar rats aged 11-12 months were randomly divided into control group (Ctrl: Veh group), propionic acid group (Ctrl: PA group), exploratory laparotomy group (LP: Veh group) and propionic acid + exploratory laparotomy group (LP: PA group) according to whether exploratory laparotomy (LP) or PA pretreatment for 21 days was performed. The motor ability of the rats was evaluated by open field test on postoperative day 3 (POD3), and then the cognitive function was evaluated by Y-maze test and fear conditioning test. The expression of IL-1β, IL-6, RORγt and IL-17A mRNA in hippocampus was detected by RT-qPCR, the expression of IL-17A and IL-17RA in hippocampus was detected by Western blot, and the activation of microglia was detected by immunofluorescence.

Results

The PND rat model was successfully established by laparotomy. Compared with Ctrl: Veh group, the body weight of LP: Veh group decreased, the percentage of spontaneous alternations in Y maze decreased (P < 0.001), and the percentage of freezing time in contextual fear test decreased (P < 0.001). Surgery triggers neuroinflammation, manifested as the elevated levels of the inflammatory cytokines IL-1β (P < 0.001) and IL-6 (P < 0.001), the increased expression of the transcription factor RORγt (P = 0.0181, POD1; P = 0.0073, POD5)and major inflammatory cytokines IL-17A (P = 0.0215, POD1; P = 0.0071, POD5), and the increased average fluorescence intensity of Iba1 (P < 0.001, POD1; P < 0.001, POD5). After PA preconditioning, the recovery of rats in LP: PA group was faster than that in LP: Veh group as the body weight lost on POD1 (P = 0.0148) was close to the baseline level on POD5 (P = 0.1846), and they performed better in behavioral tests. The levels of IL-1β (P < 0.001) and IL-6 (P = 0.0035) inflammatory factors in hippocampus decreased on POD1 and the average fluorescence intensity of Iba1 decreased (P = 0.0024, POD1; P < 0.001, POD5), representing the neuroinflammation was significantly improved. Besides, the levels of RORγt mRNA (P = 0.0231, POD1; P = 0.0251, POD5) and IL-17A mRNA (P = 0.0208, POD1; P = 0.0071, POD5) in hippocampus as well as the expression of IL-17A (P = 0.0057, POD1; P < 0.001, POD5) and IL-17RA (P = 0.0388) decreased.

Conclusion

PA pretreatment results in reduced postoperative neuroinflammation and improved cognitive function, potentially attributed to the regulatory effects of PA on Th17-mediated immune responses.

Dupilumab therapy improves gut microbiome dysbiosis and tryptophan metabolism in Chinese patients with atopic dermatitis

BACKGROUND

Dupilumab has demonstrate its potential to orchestrate inflammatory skin microenvironment, enhance skin barrier and shift skin microbiome dysbiosis, collectively contributing to clinical improvement in patients with atopic dermatitis (AD). As the second genome of human body, growing evidence suggests that the gut microbiome might relate to the host response to treatments. Little is known about the association between dupilumab treatment and gut microbiome in AD patients.

OBJECTIVE

We aimed to characterize the gut microbiome among Chinese subjects with or without AD and determine the potential effect of dupilumab on the gut microbiome.

RESULTS

The 16 s rRNA gene sequencing was conducted on 48 healthy controls (HC), 44 AD patients and 27 AD patients who received dupilumab for 16 weeks. Prior to treatment, we identified the changed beta-diversity, increased Firmicutes/Bacteroidetes ratio, decreased Bifidobacterium and expanded Faecalibacterium among the AD patients compared to HC. After 16 weeks of dupilumab treatment, gut microbiome dysbiosis of the AD patients improved with reversed beta-diversity, closer bacterial connections, increased colonization of Bifidobacterium, Ruminococcus gnavus, and Coprococcus, which were negatively correlated with disease severity indicators. This shift was largely independent of the degree of clinical improvement. Bacterial function analysis revealed further metabolic alterations following dupilumab treatment, including up-regulated expression of genes involved in the indole pathway of tryptophan metabolism, corroborated by quantitative UHPLC-MS/MS analysis.

CONCLUSION

Dupilumab treatment tends to help shift the gut microbial dysbiosis in AD patients to a healthier state, along with improved intestinal tryptophan metabolism, suggesting the gut flora and its metabolites may mediate part of the synergistic therapeutic effects on the host.

Nutritional strategies to reduce intestinal cell apoptosis by alleviating oxidative stress

The gut barrier is the first line of defense against harmful substances and pathogens in the intestinal tract. The balance of proliferation and apoptosis of intestinal epithelial cells (IECs) is crucial for maintaining the integrity of the intestinal mucosa and its function. However, oxidative stress and inflammation can cause DNA damage and abnormal apoptosis of the IECs, leading to the disruption of the intestinal epithelial barrier. This, in turn, can directly or indirectly cause various acute and chronic intestinal diseases. In recent years, there has been a growing understanding of the vital role of dietary ingredients in gut health. Studies have shown that certain amino acids, fibers, vitamins, and polyphenols in the diet can protect IECs from excessive apoptosis caused by oxidative stress, and limit intestinal inflammation. This review aims to describe the molecular mechanism of apoptosis and its relationship with intestinal function, and to discuss the modulation of IECs' physiological function, the intestinal epithelial barrier, and gut health by various nutrients. The findings of this review may provide a theoretical basis for the use of nutritional interventions in clinical intestinal disease research and animal production, ultimately leading to improved human and animal intestinal health.

[Specific changes in gut microbiota and short-chain fatty acid levels in infants with cow's milk protein allergy]

OBJECTIVES

To explore the changes in gut microbiota and levels of short-chain fatty acids (SCFA) in infants with cow's milk protein allergy (CMPA), and to clarify their role in CMPA.

METHODS

A total of 25 infants diagnosed with CMPA at Children's Hospital Affiliated to Zhengzhou University from August 2019 to August 2020 were enrolled as the CMPA group, and 25 healthy infants were selected as the control group. Fecal samples (200 mg) were collected from both groups and subjected to 16S rDNA high-throughput sequencing technology and liquid chromatography-mass spectrometry to analyze the changes in gut microbial composition and metabolites. Microbial diversity was analyzed in conjunction with metabolites.

RESULTS

Compared to the control group, the CMPA group showed altered gut microbial structure and significantly increased α-diversity (P<0.001). The abundance of Firmicutes, Clostridiales and Bacteroidetes was significantly decreased, while the abundance of Sphingomonadaceae, Clostridiaceae_1 and Mycoplasmataceae was significantly increased in the CMPA group compared to the control group (P<0.001). Metabolomic analysis revealed reduced levels of acetic acid, butyric acid, and isovaleric acid in the CMPA group compared to the control group, and the levels of the metabolites were positively correlated with the abundance of SCFA-producing bacteria such as Faecalibacterium and Roseburia (P<0.05).

CONCLUSIONS

CMPA infants have alterations in gut microbial structure, increased microbial diversity, and decreased levels of SCFA, which may contribute to increased intestinal inflammation.

Immunologic derangement caused by intestinal dysbiosis and stress is the intrinsic basis of reactive arthritis

Reactive arthritis (ReA) is defined as arthritis resulting from infections in other body parts, such as the gastrointestinal and urogenital tracts. The primary clinical manifestations involve acute-onset and self-limiting asymmetric large joint inflammation in the lower limbs. Although bacterial or chlamydia infections have long been recognized as playing a pivotal role in its pathogenesis, recent studies suggest that antibiotic treatment may perpetuate rather than eradicate chlamydia within the host, indicating an involvement of other mechanisms in Reactive arthritis. Reactive arthritis is currently believed to be associated with infection, genetic marker (HLA-B27), and immunologic derangement. As an autoimmune disease, increasing attention has been given to understanding the role of the immune system in Reactive arthritis. This review focuses on elucidating how the immune system mediates reactive arthritis and explores the roles of intestinal dysbiosis-induced immune disorders and stress-related factors in autoimmune diseases, providing novel insights into understanding reactive arthritis.

Intestinal microbiota regulates the gut-thyroid axis: the new dawn of improving Hashimoto thyroiditis

Intestinal microbiota plays an indispensable role in the host's innate immune system, which may be related to the occurrence of many autoimmune diseases. Hashimoto thyroiditis (HT) is one of the most common autoimmune diseases, and there is plenty of evidence indicating that HT may be related to genetics and environmental triggers, but the specific mechanism has not been proven clearly. Significantly, the composition and abundance of intestinal microbiota in patients with HT have an obvious difference. This phenomenon led us to think about whether intestinal microbiota can affect the progress of HT through some mechanisms. By summarizing the potential mechanism of intestinal microflora in regulating Hashimoto thyroiditis, this article explores the possibility of improving HT by regulating intestinal microbiota and summarizes relevant biomarkers as therapeutic targets, which provide new ideas for the clinical diagnosis and treatment of Hashimoto thyroiditis.

Short-Chain Fatty Acid Production by Gut Microbiota Predicts Treatment Response in Multiple Myeloma

PURPOSE

The gut microbiota plays important roles in health and disease. We questioned whether the gut microbiota and related metabolites are altered in monoclonal gammopathies and evaluated their potential role in multiple myeloma and its response to treatment.

EXPERIMENTAL DESIGN

We used 16S rRNA sequencing to characterize and compare the gut microbiota of patients with monoclonal gammopathy of undetermined significance (n = 11), smoldering multiple myeloma (n = 9), newly diagnosed multiple myeloma (n = 11), relapsed/refractory multiple myeloma (n = 6), or with complete remission (n = 9). Short-chain fatty acids (SCFA) were quantified in serum and tested in cell lines. Relevant metabolites were validated in a second cohort of 62 patients.

RESULTS

Significant differences in alpha- and beta diversity were present across the groups and both were lower in patients with relapse/refractory disease and higher in patients with complete remission after treatment. Differences were found in the abundance of several microbiota taxa across disease progression and in response to treatment. Bacteria involved in SCFA production, including Prevotella, Blautia, Weissella, and Agathobacter, were more represented in the premalignant or complete remission samples, and patients with higher levels of Agathobacter showed better overall survival. Serum levels of butyrate and propionate decreased across disease progression and butyrate was positively associated with a better response. Both metabolites had antiproliferative effects in multiple myeloma cell lines.

CONCLUSIONS

We demonstrate that SCFAs metabolites and the gut microbiota associated with their production might have beneficial effects in disease evolution and response to treatment, underscoring its therapeutic potential and value as a predictor.

The Role of the Gut Microbiome and Microbial Dysbiosis in Common Skin Diseases

Dermatoses are an increasingly common problem, particularly in developed countries. The causes of this phenomenon include genetic factors and environmental elements. More and more scientific reports suggest that the gut microbiome, more specifically its dysbiosis, also plays an important role in the induction and progression of diseases, including dermatological diseases. The gut microbiome is recognised as the largest endocrine organ, and has a key function in maintaining human homeostasis. In this review, the authors will take a close look at the link between the gut-skin axis and the pathogenesis of dermatoses such as atopic dermatitis, psoriasis, alopecia areata, and acne. The authors will also focus on the role of probiotics in remodelling the microbiome and the alleviation of dermatoses.

Dietary betaine and/or TMAO affect hepatic lipid accumulation and glycometabolism of Megalobrama amblycephala exposed to a high-carbohydrate diet

A 12-week experiment was conducted to explore the effects of betaine and/or TMAO on growth, hepatic health, gut microbiota, and serum metabolites in Megalobrama amblycephala fed with high-carbohydrate diets. The diets were as follows: CD group (control diet, 28.5% carbohydrate), HCD group (high-carbohydrate diet, 38.2% carbohydrate), HBD group (betaine-added diet, 38.3% carbohydrate + 1.2% betaine), HTD group (TMAO-added diet, 38.2% carbohydrate + 0.2% TMAO), and HBT group (diet added with both betaine and TMAO, 38.2% carbohydrate + 1.2% betaine + 0.2% TMAO). The results showed that the hepatosomatic index (HSI); whole-body crude fat; hepatic lipid accumulation; messenger RNA expression levels of gk, fpbase, g6pase, ahas, and bcat; serum branched-chain amino acids (BCAAs); ratio of Firmicutes-to-Bacteroidetes; and abundance of the genus Aeromonas were all significantly increased, while the abundance levels of the genus Lactobacillus and phyla Tenericutes and Bacteroidetes were drastically decreased in the HCD group. Compared with the HCD group, the HSI; whole-body crude fat; hepatic lipid accumulation; expression levels of fbpase, g6pase, pepck, ahas, and bcat; circulating BCAA; ratio of Firmicutes-to-Bacteroidetes; and abundance levels of the genus Aeromonas and phyla Tenericutes and Bacteroidetes were significantly downregulated in the HBD, HTD, and HBT groups. Meanwhile, the expression levels of pk were drastically upregulated in the HBD, HTD, and HBT groups as well as the abundance of Lactobacillus in the HBT group. These results indicated that the supplementation of betaine and/or TMAO in high-carbohydrate diets could affect the hepatic lipid accumulation and glycometabolism of M. amblycephala by promoting glycolysis, inhibiting gluconeogenesis and biosynthesis of BCAA, and mitigating the negative alteration of gut microbiota. Among them, the combination of betaine and TMAO had the best effect.

Bacteroides and related species: The keystone taxa of the human gut microbiota

Microbial communities play a significant role in maintaining ecosystems in a healthy homeostasis. Presently, in the human gastrointestinal tract, there are certain taxonomic groups of importance, though there is no single species that plays a keystone role. Bacteroides spp. are known to be major players in the maintenance of eubiosis in the human gastrointestinal tract. Here we review the critical role that Bacteroides play in the human gut, their potential pathogenic role outside of the gut, and their various methods of adapting to the environment, with a focus on data for B. fragilis and B. thetaiotaomicron. Bacteroides are anaerobic non-sporing Gram negative organisms that are also resistant to bile acids, generally thriving in the gut and having a beneficial relationship with the host. While they are generally commensal organisms, some Bacteroides spp. can be opportunistic pathogens in scenarios of GI disease, trauma, cancer, or GI surgery, and cause infection, most commonly intra-abdominal infection. B. fragilis can develop antimicrobial resistance through multiple mechanisms in large part due to its plasticity and fluid genome. Bacteroidota (formerly, Bacteroidetes) have a very broad metabolic potential in the GI microbiota and can rapidly adapt their carbohydrate metabolism to the available nutrients. Gastrointestinal Bacteroidota species produce short-chain fatty acids such as succinate, acetate, butyrate, and occasionally propionate, as the major end-products, which have wide-ranging and many beneficial influences on the host. Bacteroidota, via bile acid metabolism, also play a role in in colonization-resistance of other organisms, including Clostridioides difficile, and maintenance of gut integrity.

Zanthoxylum bungeanum amides ameliorates nonalcoholic fatty liver via regulating gut microbiota and activating AMPK/Nrf2 signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum bungeanum Maxim. (Rutaceae) is a known herbal medicine with various bioactivities, including anti-obesity, lipid-lowering, learning & memory improving and anti-diabetes, and amides in Z. bungeanum (AZB) are considered as the major active agents for its bioactivities.

AIM OF THE STUDY

This research was carried out to uncover the anti-NAFL effect of AZB and its corresponding molecular mechanisms.

METHODS

The central composite design-response surface methodology (CCD-RSM) was utilized to optimize the AZB extraction process, and the anti-NAFL effect of AZB was investigated on high fat diet (HFD) fed mice (HFD mice). The levels of ROS in liver tissues were determined using laser confocal microscopy with DCFH-DA probe staining, and anti-enzymes (such as HO-1, SOD, CAT & GSH-PX) and MDA in liver tissues were measured using commercial detecting kits. GC-MS was used to determine the short-chain fatty acids (SCFAs) contents in feces and blood of mice. 16S high-throughput sequencing, western blotting (WB) assay and immunofluorescence (IF) were used to explore the intestinal flora changes in mice and the potential mechanisms of AZB for treatment of NAFL.

RESULTS

Our results showed AZB reduced body weight, alleviated liver pathological changes, reduced fat accumulation, and improved oxidative stress in HFD mice. In addition, we also found AZB improved OGTT and ITT, reduced TG, TC, LDL-C, whereas increased HDL-C in HFD mice. AZB increased total number of the species and interspecies kinship of gut microbiota and reduced the richness and diversity of gut microbiota in HFD mice. Moreover, AZB decreased the ratio of Firmicutes/Bacteroidota, whereas increased the abundance of Allobaculum, Bacteroides and Dubosiella in feces of HFD-fed mice. Furthermore, AZB increased the production of SCFAs, and up-regulated the phosphorylation of AMPK and increased the nuclear transcription of Nrf2 in liver of HFD mice.

CONCLUSION

Collectively, our results suggested AZB can improve NAFL, which could reduce body weight, reverse liver lesions and fat accumulation, improve oxidative stress in liver tissues of HFD mice. Furthermore, the mechanisms are related to increase of the abundance of high-producing bacteria for SCFAs (e.g. Allobaculum, Bacteroides and Dubosiella) to activate AMPK/Nrf2 signaling.

Nutritional regulation of microbiota-derived metabolites: Implications for immunity and inflammation

Nutrition profoundly shapes immunity and inflammation across the lifespan of mammals, from pre- and post-natal periods to later life. Emerging insights into diet-microbiota interactions indicate that nutrition has a dominant influence on the composition-and metabolic output-of the intestinal microbiota, which in turn has major consequences for host immunity and inflammation. Here, we discuss recent findings that support the concept that dietary effects on microbiota-derived metabolites potently alter immune responses in health and disease. We discuss how specific dietary components and metabolites can be either pro-inflammatory or anti-inflammatory in a context- and tissue-dependent manner during infection, chronic inflammation, and cancer. Together, these studies emphasize the influence of diet-microbiota crosstalk on immune regulation that will have a significant impact on precision nutrition approaches and therapeutic interventions for managing inflammation, infection, and cancer immunotherapy.

Plant biostimulants as natural alternatives to synthetic auxins in strawberry production: physiological and metabolic insights

The demand for high-quality strawberries continues to grow, emphasizing the need for innovative agricultural practices to enhance both yield and fruit quality. In this context, the utilization of natural products, such as biostimulants, has emerged as a promising avenue for improving strawberry production while aligning with sustainable and eco-friendly agricultural approaches. This study explores the influence of a bacterial filtrate (BF), a vegetal-derived protein hydrolysate (PH), and a standard synthetic auxin (SA) on strawberry, investigating their effects on yield, fruit quality, mineral composition and metabolomics of leaves and fruits. Agronomic trial revealed that SA and BF significantly enhanced early fruit yield due to their positive influence on flowering and fruit set, while PH treatment favored a gradual and prolonged fruit set, associated with an increased shoot biomass and sustained production. Fruit quality analysis showed that PH-treated fruits exhibited an increase of firmness and soluble solids content, whereas SA-treated fruits displayed lower firmness and soluble solids content. The ionomic analysis of leaves and fruits indicated that all treatments provided sufficient nutrients, with heavy metals within regulatory limits. Metabolomics indicated that PH stimulated primary metabolites, while SA and BF directly affected flavonoid and anthocyanin biosynthesis, and PH increased fruit quality through enhanced production of beneficial metabolites. This research offers valuable insights for optimizing strawberry production and fruit quality by harnessing the potential of natural biostimulants as viable alternative to synthetic compounds.

Synergistic Effect of Retinoic Acid and Lactoferrin in the Maintenance of Gut Homeostasis

Lactoferrin (LF) is a glycoprotein that binds to iron ions (Fe2+) and other metallic ions, such as Mg2+, Zn2+, and Cu2+, and has antibacterial and immunomodulatory properties. The antibacterial properties of LF are due to its ability to sequester iron. The immunomodulatory capability of LF promotes homeostasis in the enteric environment, acting directly on the beneficial microbiota. LF can modulate antigen-presenting cell (APC) biology, including migration and cell activation. Nonetheless, some gut microbiota strains produce toxic metabolites, and APCs are responsible for initiating the process that inhibits the inflammatory response against them. Thus, eliminating harmful strains lowers the risk of inducing chronic inflammation, and consequently, metabolic disease, which can progress to type 2 diabetes mellitus (T2DM). LF and retinoic acid (RA) exhibit immunomodulatory properties such as decreasing cytokine production, thus modifying the inflammatory response. Their activities have been observed both in vitro and in vivo. The combined, simultaneous effect of these molecules has not been studied; however, the synergistic effect of LF and RA may be employed for enhancing the secretion of humoral factors, such as IgA. We speculate that the combination of LF and RA could be a potential prophylactic alternative for the treatment of metabolic dysregulations such as T2DM. The present review focuses on the importance of a healthy diet for a balanced gut and describes how probiotics and prebiotics with immunomodulatory activity as well as inductors of differentiation and cell proliferation could be acquired directly from the diet or indirectly through the oral administration of formulations aimed to maintain gut health or restore a eubiotic state in an intestinal environment that has been dysregulated by external factors such as stress and a high-fat diet.

Diet and the gut microbiota-immune axis in the context of perinatal mental health: Protocol for a prospective cohort study

BACKGROUND

Physiological and psychosocial changes experienced by women during the perinatal period may put them at risk for postpartum mental health disturbances. Accumulating evidence suggests that dietary patterns may influence mental health through the modulation of the gut microbiota and its effects on host immune activity. Thus, targeting the gut microbiota via dietary intake could serve as both a preventative and therapeutic strategy in improving perinatal mental health.

OBJECTIVES

Here, we present a protocol for a prospective cohort study that primarily aims to determine if diet quality during pregnancy is protective against postpartum depression severity. Secondary objectives will examine if microbiota- and blood-based inflammatory markers may be associated with the relationship between prenatal diet quality and postpartum depression severity, as well as with associations between additional dietary and mental health outcomes.

METHODS AND ANALYSIS

Dietary patterns and mental health symptoms will be documented in 100 pregnant women at 4 time points during pregnancy and postpartum. Participants will also provide stool and blood samples at the same time points to determine microbiota composition and predicted function and inflammatory factors, respectively. Stool microbiota will be analyzed using 16S ribosomal RNA gene sequencing and bioinformatics tools (QIIME 2/PICRUSt2). Inflammatory factors will be determined using high-sensitivity antibody-based immunoassays. Statistical analyses will include linear mixed models and hierarchical linear mixed effect models.

ETHICS

The study was approved by the Research Ethics Boards of the Royal Ottawa Health Care Group (#2022002) and of the University of Ottawa (#H-06-22-8013). Informed consent will be obtained from all participants before their enrollment.

DISCUSSION

Findings from this study will help develop evidence-based dietary recommendations and potential interventions for women susceptible to or suffering from postpartum mental health issues that are accessible, noninvasive, and have potential to play a role in prevention and treatment.

Game of microbes: the battle within - gut microbiota and multiple sclerosis

Multiple sclerosis (MS) is a chronic and progressive autoimmune disease of the central nervous system (CNS), with both genetic and environmental factors contributing to the pathobiology of the disease. While human leukocyte antigen (HLA) genes have emerged as the strongest genetic factor, consensus on environmental risk factors are lacking. Recently, trillions of microbes residing in our gut (microbiome) have emerged as a potential environmental factor linked with the pathobiology of MS as PwMS show gut microbial dysbiosis (altered gut microbiome). Thus, there has been a strong emphasis on understanding the factors (host and environmental) regulating the composition of the gut microbiota and the mechanism(s) through which gut microbes contribute to MS disease, especially through immune system modulation. A better understanding of these interactions will help harness the enormous potential of the gut microbiota as a therapeutic approach to treating MS.

Gut microbes in metabolic disturbances. Promising role for therapeutic manipulations?

The prevalence of overweight, obesity, type 2 diabetes, metabolic syndrome and steatotic liver disease is rapidly increasing worldwide with a huge economic burden in terms of morbidity and mortality. Several genetic and environmental factors are involved in the onset and development of metabolic disorders and related complications. A critical role also exists for the gut microbiota, a complex polymicrobial ecology at the interface of the internal and external environment. The gut microbiota contributes to food digestion and transformation, caloric intake, and immune response of the host, keeping the homeostatic control in health. Mechanisms of disease include enhanced energy extraction from the non-digestible dietary carbohydrates, increased gut permeability and translocation of bacterial metabolites which activate a chronic low-grade systemic inflammation and insulin resistance, as precursors of tangible metabolic disorders involving glucose and lipid homeostasis. The ultimate causative role of gut microbiota in this respect remains to be elucidated, as well as the therapeutic value of manipulating the gut microbiota by diet, pre- and pro- synbiotics, or fecal microbial transplantation.

Effects of the Addition of Crude Fibre Concentrate on Performance, Welfare and Selected Caecal Bacteria of Broilers

The study evaluated the effects of crude fibre concentrate supplementation on final body weight, mortality, feed conversion ratio, European Production Efficiency Factor, European Broiler Index, welfare parameters, colony-forming units of selected caecal bacteria (Enterobacteriaceae and lactic acid bacteria) and pH of broiler faeces and litter. The study comprised 990 Ross 308 male chicks divided into three groups, a control and two experimental groups, which were given crude fibre concentrate as a feed supplement. On the thirty-fifth day of rearing, the birds' welfare scores were evaluated, and 2 g of cecum was collected post-mortem from six chickens in each group. Subsequently, a series of ten-fold dilutions of the material was prepared, followed by cultures and measurement of pH in the faeces and litter. The inclusion of crude fibre concentrate resulted in a beneficial impact on the ultimate body mass (p ≤ 0.001), welfare standard (p ≤ 0.001), and quantity of colony-forming units of lactic acid bacteria (p ≤ 0.05) within the cecum. Furthermore, it had a positive influence on lowering the pH levels of both faeces and litter (p ≤ 0.05).

Causal analysis of the gut microbiota in differentiated thyroid carcinoma: a two-sample Mendelian randomization study

Objective: Numerous studies have highlighted an association between the gut microbiota (GM) and thyroid tumors. Employing Mendelian randomization methodology, we seek to elucidate the causal link between the gut microbiota and thyroid neoplasms. Methods: We procured data from the Mibiogen database encompassing 211 distinct gut microbiota taxa, alongside extensive genome-wide association studies (GWAS) summary data for differentiated thyroid carcinoma (DTC). Our principal analytical approach involved the application of the Inverse-Variance Weighted method (IVW) within the framework of Mendelian randomization. Simultaneously, we conducted sensitivity analyses to assess result heterogeneity, horizontal pleiotropy, and outcome stability. Results: IVW analysis revealed a dual role of the GM in thyroid carcinoma. The phylum Actinobacteria (OR, 0.249 [95% CI, 0.121-0.515]; p < 0.001) was associated with a decreased risk of DTC. Conversely, the genus Ruminiclostridium9 (OR, 11.276 [95% CI, 4.406-28.860]; p < 0.001), class Mollicutes (OR, 5.902 [95% CI, 1.768-19.699]; p = 0.004), genus RuminococcaceaeUCG004 (OR, 3.831 [95% CI, 1.516-9.683]; p = 0.005), genus Paraprevotella (OR, 3.536 [95% CI, 1.330-9.401]; p = 0.011), and phylum Tenericutes (OR, 5.902 [95% CI, 1.768-19.699]; p = 0.004) were associated with an increased risk of DTC. Conclusion: Our findings underscore that the presence of genus Ruminiclostridium9, class Mollicutes, genus RuminococcaceaeUCG004, genus Paraprevotella, and phylum Tenericutes is associated with an elevated risk of DTC, whereas the presence of the phylum Actinobacteria is linked to a decreased risk. These discoveries enhance our comprehension of the relationship between the GM and DTC.

Naringenin confers protection against experimental autoimmune encephalomyelitis through modulating the gut-brain axis: A multiomics analysis

Multiple sclerosis (MS) is a disease of the central nervous system that involves the immune system attacking the protective covering of nerve fibers. This disease can be influenced by both environmental and genetic factors. Evidence has highlighted the critical role of the intestinal microbiota in MS and its animal model, experimental autoimmune encephalomyelitis (EAE). The composition of gut microflora is mainly determined by dietary components, which, in turn, modulate host homeostasis. A diet rich in naringenin at 0.5% can effectively mitigate the severity of EAE in mice. However, there is little direct data on the impact of naringenin at optimal doses on EAE development, as well as its intestinal microbiota and metabolites. Our study revealed that 2.0% naringenin resulted in the lowest clinical score and pathological changes in EAE mice, and altered the gene expression profiles associated with inflammation and immunity in spinal cord tissue. We then used untargeted metabolomics and 16S rRNA gene sequences to identify metabolites and intestinal microbiota, respectively. Naringenin supplementation enriched gut microbiota in EAE mice, including increasing the abundance of Paraprevotellaceae and Comamonadaceae, while decreasing the abundance of Deltaproteobacteria, RF39, and Desulfovibrionaceae. Furthermore, the changes in gut microbiota affected the production of metabolites in the feces and brain, suggesting a role in regulating the gut-brain axis. Finally, we conducted a fecal transplantation experiment to validate that gut microbiota partly mediates the effect of naringenin on EAE alleviation. In conclusion, naringenin has potential immunomodulatory effects that are influenced to some extent by the gut microbiome.

The Association of Oral Microbiome Dysbiosis with Gastrointestinal Cancers and Its Diagnostic Efficacy

BACKGROUND

The second leading mortality cause in the world is cancer, making it a critical issue that impacts human health. As a result, scientists are looking for novel biomarkers for cancer detection. The oral microbiome, made up of approximately 700 species-level taxa, is a significant source for discovering novel biomarkers. In this review, we aimed to prepare a summary of research that has investigated the association between the oral microbiome and gastrointestinal cancers.

METHODS

We searched online scientific datasets including Web of Science, PubMed, Scopus, and Google Scholar. Eligibility criteria included human studies that reported abundances of the oral microbiome, or its diagnostic/prognostic performance in patients with gastrointestinal cancers.

RESULTS

Some phyla of the oral microbiome have a relationship with cancers. Some particular phyla of the oral microbiome that may be related to gastrointestinal cancers consist of Firmicutes, Actinobacteria, Bacteroidetes, Proteobacteria, and Fusobacteria. Changes in the abundances of Porphyromonas, Fusobacterium, Prevotella, and Veillonella are correlated with carcinogenesis, and may be used for distinguishing cancer patients from healthy subjects. Oral, colorectal, pancreatic, and esophageal cancers are the most important cancers related to the oral microbiome.

CONCLUSION

The results of this study may help future research to select bacteria as an early diagnostic or prognostic biomarker of gastrointestinal cancer. Given the current state of our knowledge, additional research is required to comprehend the multiplex processes underlying the role of bacterial microbiota upon cancer progression and to characterize the complex microbiota-host interaction network.

Diet-induced shifts in the gut microbiota influence anastomotic healing in a murine model of colonic surgery

Host diet and gut microbiota interact to contribute to perioperative complications, including anastomotic leak (AL). Using a murine surgical model of colonic anastomosis, we investigated how diet and fecal microbial transplantation (FMT) impacted the intestinal microbiota and if a predictive signature for AL could be determined. We hypothesized that a Western diet (WD) would impact gut microbial composition and that the resulting dysbiosis would correlate with increased rates of AL, while FMT from healthy, lean diet (LD) donors would reduce the risk of AL. Furthermore, we predicted that surgical outcomes would allow for the development of a microbial preclinical translational tool to identify AL. Here, we show that AL is associated with a dysbiotic microbial community characterized by increased levels of Bacteroides and Akkermansia. We identified several key taxa that were associated with leak formation, and developed an index based on the ratio of bacteria associated with the absence and presence of leak. We also highlight a modifiable connection between diet, microbiota, and anastomotic healing, potentially paving the way for perioperative modulation by microbiota-targeted therapeutics to reduce AL.

Fecal microbiota transplantation in the treatment of systemic lupus erythematosus: What we learnt from the explorative clinical trial

Systemic lupus erythematosus (SLE) is an autoimmune disease with the characterized presence of autoantibodies and resulting in multiple organ damage, which is incurable and can be lethal. The current treatments are limited and less progress has been made in drug discovery for the last few decades. Researches imply that gut dysbiosis exists in both patients and murine models with SLE, taking part in the pathogenesis of SLE through multiple mechanisms such as microbiota translocation and molecular mimicry. Intestinal interventions on the gut microbiome by fecal transplantations to reconstitute the gut-immunity homeostasis serve as a novel therapeutic option for SLE patients. Fecal microbiota transplantation (FMT), which is usually used in intestinal diseases, has been firstly demonstrated to be safe and efficient in recovering gut microbiota structure of SLE patients and reducing lupus activity in our recent clinical trial, which is the first trial testing FMT therapy in SLE treatment. In this paper, we reviewed the results of the single-arm clinical trial and made recommendations on FMT practice in SLE treatment including therapeutic indications, screening items and dosage regimen, trying to provide references for future study and clinical practice. We also came up with the unanswered questions that need to be solved by the ongoing randomized controlled trial as well as the future expectations for the intestinal intervention strategies of SLE patients.

Seasonal Variation of Gut Microbial Composition and Metabolism in Tibetan antelopes in Hoh Xil National Nature Reserve

The Tibetan antelope is an endangered species suffering from poaching and habitat fragmentation. The intestinal flora and metabolites play a crucial role in the physiological homeostasis of hosts, which are influenced by various environmental factors like seasonal variation. In this particular research, our main goal was to explore the alterations in the metabolism and gut microbiota of Tibetan antelopes between the cold season (XB) and warm season (DA), using untargeted metabolomics and 16S rRNA gene-sequencing analyses. The findings indicated that Tibetan antelopes had a higher alpha-diversity of intestinal microbes during the cold season than during the warm season. Principal co-ordinate analysis revealed notable seasonal discrepancies in the function and structure of intestinal microbes in Tibetan antelopes. The relative abundance of Firmicutes was significantly increased during the cold season compared to during the warm season. Furthermore, the Tibetan antelope's primary metabolic functions of the intestinal micro-organisms were significantly higher during the cold season. The untargeted metabolomics analysis results showed a total of 532 metabolites that were significantly different between the cold season and warm season groups. These metabolites were found to be enriched in a total of 62 metabolic pathways. Among the most significant pathways of enrichment were the purine metabolism and pyrimidine metabolism. The levels of related metabolites in those pathways were remarkably higher in the warm season compared to the cold season. The comprehensive analysis of 16S rRNA and the metabolome reveals there is a significant correlation between differential microbiota and differential metabolites. Therefore, the gut microbiota changes caused by seasonal changes influenced the metabolites as well. This research reveals the function of seasonal changes in the intestinal flora and metabolites in the adaptation of Tibetan antelopes to environmental fluctuations and supplies a theoretical basis for instructing the protection management of Tibetan antelopes.

Oral and intestinal dysbiosis in Parkinson's disease

The suspicion of an origin of Parkinson's disease (PD) at the periphery of the body and the involvement of environmental risk factors in the pathogenesis of PD have directed the attention of the scientific community towards the microbiota. The microbiota represents all the microorganisms residing both in and on a host. It plays an essential role in the physiological functioning of the host. In this article, we review the dysbiosis repeatedly demonstrated in PD and how it influences PD symptoms. Dysbiosis is associated with both motor and non-motor PD symptoms. In animal models, dysbiosis only promotes symptoms in individuals genetically susceptible to Parkinson's disease, suggesting that dysbiosis is a risk factor but not a cause of Parkinson's disease. We also review how dysbiosis contributes to the pathophysiology of PD. Dysbiosis induces numerous and complex metabolic changes, resulting in increased intestinal permeability, local and systemic inflammation, production of bacterial amyloid proteins that promote α-synuclein aggregation, as well as a decrease in short-chain fatty acid-producing bacteria that have anti-inflammatory and neuroprotective potential. In addition, we review how dysbiosis decreases the efficacy of dopaminergic treatments. We then discuss the interest of dysbiosis analysis as a biomarker of Parkinson's disease. Finally, we give an overview of how interventions modulating the gut microbiota such as dietary interventions, pro-biotics, intestinal decontamination and fecal microbiota transplantation could influence the course of PD.

Rapid and sensitive determination of free fatty acids based on in-source microdroplet-driven derivatization coupled with high-resolution mass spectrometry

Accurate and sensitive measurements of free fatty acids (FFAs) in biological samples are valuable for diagnosing and prognosing diseases. In this study, an in-source microdroplet derivation strategy combined with high-resolution mass spectrometry was developed to analyze FFAs in lipid extracts of biological samples directly. FFAs were rapidly derivated with 2-picolylamine (PA) in the microdroplet which is derived by electrospray. With the proposed method, twelve typical FFAs were determined reliably with high sensitivity and acceptable linearities (R2 ≥ 0.94). The LODs and LOQs for the twelve FFAs were 9-76 pg mL-1 and 30-253 pg mL-1, respectively. The developed method was applied to analyze the alteration of FFAs in liver and kidney samples of rats induced by perfluorooctane sulfonate (PFOS) exposure. The good results demonstrate that the established analysis technique is dependable and has promising applications in detecting FFAs associated with complex biological samples.

Host habitat rather than evolutionary history explains gut microbiome diversity in sympatric stickleback species

Host-associated microbiota can influence host phenotypic variation, fitness and potential to adapt to local environmental conditions. In turn, both host evolutionary history and the abiotic and biotic environment can influence the diversity and composition of microbiota. Yet, to what extent environmental and host-specific factors drive microbial diversity remains largely unknown, limiting our understanding of host-microbiome interactions in natural populations. Here, we compared the intestinal microbiota between two phylogenetically related fishes, the three-spined stickleback (Gasterosteus aculeatus) and the nine-spined stickleback (Pungitius pungitius) in a common landscape. Using amplicon sequencing of the V3-V4 region of the bacterial 16S rRNA gene, we characterised the α and β diversity of the microbial communities in these two fish species from both brackish water and freshwater habitats. Across eight locations, α diversity was higher in the nine-spined stickleback, suggesting a broader niche use in this host species. Habitat was a strong determinant of β diversity in both host species, while host species only explained a small fraction of the variation in gut microbial composition. Strong habitat-specific effects overruled effects of geographic distance and historical freshwater colonisation, suggesting that the gut microbiome correlates primarily with local environmental conditions. Interestingly, the effect of habitat divergence on gut microbial communities was stronger in three-spined stickleback than in nine-spined stickleback, possibly mirroring the stronger level of adaptive divergence in this host species. Overall, our results show that microbial communities reflect habitat divergence rather than colonisation history or dispersal limitation of host species.

Diet Is Associated with Frailty in Lung Cancer: A Possible Role of Gut Microbiota

This study investigated the associations between diet and frailty in lung cancer patients and the potential role of the gut microbiota involved. We assessed dietary intake and frailty status in 231 lung cancer patients by 3-day, 24-h dietary recalls and Fried frailty criteria, respectively, and collected 50 fecal samples for next-generation sequencing. A total of 75 (32.5%) patients were frail, which might be related to significantly lower intake of energy, protein, carbohydrate, dietary fiber, niacin, leucine, some minerals, and a poorer dietary quality as indicated by the Chinese Healthy Eating Index (p < 0.05). Among these, carbohydrate (OR = 0.98; 95% CI 0.96-0.99; p = 0.010), calcium (OR = 0.99; 95% CI 0.99-1.00; p = 0.025), and selenium (OR = 1.03; 95% CI 1.00-1.06; p = 0.022) were all significantly associated with frailty. A multivariate logistic regression analysis showed that the mean risk of frailty was 0.94 times lower (95% CI 0.90-0.99; p = 0.009) among participants with higher CHEI scores. Additionally, the frail patients demonstrated significantly lower gut microbiota β diversity (p = 0.001) and higher relative abundance of Actinobacteriota (p = 0.033). Frailty in lung cancer patients might be associated with insufficient nutrients intake and a poor dietary quality through gut microbiota regulation.

Oral Microbiota: A New Insight into Cancer Progression, Diagnosis and Treatment

The polymorphic microbiome has been defined as one of the "Hallmarks of Cancer". Extensive studies have now uncovered the role of oral microbiota in cancer development and progression. Bacteria, fungi, archaea, and viruses in the oral cavity interact dynamically with the oral microenvironment to maintain the oral micro-ecological homeostasis. This complex interaction is influenced by many factors, such as maternal transmission, personal factors and environmental factors. Dysbiosis of oral microbiota can disturbed this host-microbiota interaction, leading to systemic diseases. Numerous studies have shown the potential associations between oral microbiota and a variety of cancers. However, the underlying mechanisms and therapeutic insights are still poorly understood. In this review, we mainly focus on the following aspects: (1) the factors affect oral microbiota composition and function; (2) the interaction between microenvironment and oral microbiota; (3) the role of multi-kingdom oral microbiota in human health; (4) the potential underlying mechanisms and therapeutic benefits of oral microbiota against cancer. Finally, we aim to describe the impact of oral microbiota on cancer progression and provide novel therapeutic insights into cancer prevention and treatment by targeting oral microbiota.

The role of the Mediterranean diet in modulating the gut microbiome: A review of current evidence

The Mediterranean diet (MedDiet) is recognized as one of the United Nations Educational, Scientific and Cultural Organization Intangible Cultural Heritage assets associated with lower rates of cardiometabolic diseases; lower prevalence of cancer, Alzheimer's disease, depression, and onset of inflammatory bowel disease; and more generally low-grade inflammation and mortality risks. Beyond being an input source of beneficial micronutrients, it recently has been discovered that the MedDiet plays a role in a more complex human microbiome-mediated mechanism. An interesting hypothesis suggests a bidirectional relationship between the MedDiet and the gut microbiome, where gut microbiota assembly and biosynthetic capacity are responsive to the diet; in return, the microbiome-reachable nutrients shape and modulate the microbiome toward a characteristic probiotic state. It can be speculated that that primary health benefits of the MedDiet exerted via the gut microbiome are mediated by the bioactive compounds transformed by the microbiome. Furthermore, it is possible that additional probiotic properties of the organisms promoted by diet adherence have secondary benefits. As more detailed omic-based studies take place, more evidence on the MedDiet as a core generic probiotic microbiome modulation strategy surface. However, individual-specific microbiome compositions might impose personal variations on the diet outcome. Therefore, a prospective strategy of a fine-tuned precision nutrition approach might deliver optimized benefits of the MedDiet.

Contribution of the microbiome for better phenotyping of people living with obesity

Obesity has reached epidemic proportion worldwide and in all ages. Available evidence points to a multifactorial pathogenesis involving gene predisposition and environmental factors. Gut microbiota plays a critical role as a major interface between external factors, i.e., diet, lifestyle, toxic chemicals, and internal mechanisms regulating energy and metabolic homeostasis, fat production and storage. A shift in microbiota composition is linked with overweight and obesity, with pathogenic mechanisms involving bacterial products and metabolites (mainly endocannabinoid-related mediators, short-chain fatty acids, bile acids, catabolites of tryptophan, lipopolysaccharides) and subsequent alterations in gut barrier, altered metabolic homeostasis, insulin resistance and chronic, low-grade inflammation. Although animal studies point to the links between an "obesogenic" microbiota and the development of different obesity phenotypes, the translational value of these results in humans is still limited by the heterogeneity among studies, the high variation of gut microbiota over time and the lack of robust longitudinal studies adequately considering inter-individual confounders. Nevertheless, available evidence underscores the existence of several genera predisposing to obesity or, conversely, to lean and metabolically health phenotype (e.g., Akkermansia muciniphila, species from genera Faecalibacterium, Alistipes, Roseburia). Further longitudinal studies using metagenomics, transcriptomics, proteomics, and metabolomics with exact characterization of confounders are needed in this field. Results must confirm that distinct genera and specific microbial-derived metabolites represent effective and precision interventions against overweight and obesity in the long-term.

Understanding the impact of radical changes in diet and the gut microbiota on brain function and structure: rationale and design of the EMBRACE study

BACKGROUND

Bariatric surgery leads to profound changes in gut microbiota and dietary patterns, both of which may interact to impact gut-brain communication. Though cognitive function improves postsurgery, there is a large variability in outcomes. How bariatric surgery-induced modifications in the gut microbiota and dietary patterns influence the variability in cognitive function is still unclear.

OBJECTIVES

To elucidate the associations between bariatric surgery-induced changes in dietary and gut microbiota patterns with cognition and brain structure.

SETTING

University hospital.

METHODS

A total of 120 adult patients (≥30 years) scheduled to undergo a primary bariatric surgery along with 60 age-, sex-, and body mass index-matched patients on the surgery waitlist will undergo assessments 3-months presurgery and 6- and 12-month postsurgery (or an equivalent time for the waitlist group). Additionally, 60 age-and sex-matched nonbariatric surgery eligible individuals will complete the presurgical assessments only. Evaluations will include sociodemographic and health behavior questionnaires, physiological assessments (anthropometrics, blood-, urine-, and fecal-based measures), neuropsychological cognitive tests, and structural magnetic resonance imaging. Cluster analyses of the dietary and gut microbiota changes will define the various dietary patterns and microbiota profiles, then using repeated measures mixed models, their associations with global cognitive and structural brain alterations will be explored.

RESULTS

The coordinating study site (Centre intégré universitaire de santé et de services sociaux du Nord-de-l'Île-de-Montréal, QC, Canada), provided the primary ethical approval (Research Ethics Board#: MP-32-2022-2412).

CONCLUSIONS

The insights generated from this study can be used to develop individually-targeted neurodegenerative disease prevention strategies, as well as providing critical mechanistic information.

Food Processing and Risk of Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Several studies have been published on the association between food processing and risks of Crohn's disease (CD) and ulcerative colitis (UC), with some variability in results. We performed a systematic literature review and meta-analysis to study this association.

METHODS

From PubMed, Medline, and Embase until October 2022, we identified cohort studies that studied the association between food processing and the risk of CD or UC. Risk of bias of the included studies was assessed by the Newcastle-Ottawa scale. We computed pooled hazard ratios (HRs) and 95% confidence intervals (CIs) using random-effects meta-analysis based on estimates and standard errors.

RESULTS

A total of 1,068,425 participants were included (13,594,422 person-years) among 5 cohort studies published between 2020 and 2022. Four of the 5 included studies were scored as high quality. The average age of participants ranged from 43 to 56 years; 55%-83% were female. During follow-up, 916 participants developed CD, and 1934 developed UC. There was an increased risk for development of CD for participants with higher consumption of ultra-processed foods compared with those with lower consumption (HR, 1.71; 95% CI, 1.37-2.14; I2 = 0%) and a lower risk of CD for participants with higher consumption of unprocessed/minimally processed foods compared with those with lower consumption (HR, 0.71; 95% CI, 0.53-0.94; I2 = 11%). There was no association between risk of UC and ultra-processed foods (HR, 1.17; 95% CI, 0.86-1.61; I2 = 74%) or unprocessed/minimally processed foods (HR, 0.84; 95% CI, 0.68-1.02; I2 = 0%).

CONCLUSIONS

Higher ultra-processed food and lower unprocessed/minimally processed food intakes are associated with higher risk of CD but not UC.