RESUMEN

Mori folium, as a homologous drug-food, has hypoglycemic and lipid-lowering activity. Polysaccharides are the main bioactive ingredient of the Mori folium that exhibit diverse biological activities. In this study, a homogeneous polysaccharide (MP4) was purified and characterized from Mori folium. The changes of MP4 affected by saliva, simulated gastrointestinal juice, and human fecal fermentation, including physicochemical property or its bioactivity, were systematically investigated. Meanwhile, the influence of fermentation on the bioactivity were evaluated. The results showed that the backbone of MP4 is mainly composed of →4)-α-D-GalpA-(1→ residues. The molecular weight, the levels of reducing sugar content and free monosaccharides of MP4 exhibited no significant differences indicating that gastrointestinal digestion has a minimal effect on the physicochemical characteristics of MP4. However, during in vitro gut microbiota fermentation, MP4 are significantly degraded and utilized by gut microbiota, showing increased the production of short-chain fatty acids, notably acetic acid and propionic acid. The relative abundance of beneficial bacteria such as Bacteroidetes and Actinobacteria were significantly increased, whereas the levels of pathogenic bacteria such as Fusobacteria and Megamonas were significantly decreased, which changed the composition of the gut microbiota. The Firmicutes/Bacteroides ratio was also decreased significantly. Interestingly, after in vitro fermentation, the α-glucosidase inhibitory activity was increased, the lipase inhibitory activity and cholesterol adsorption activity was decreased. Correlation analysis showed that the relative abundance of some bacteria was significantly correlated with the bioactivities. These results provide a basis for the development of Mori folium polysaccharides as functional probiotic products.

RESUMEN

The production of short-chain fatty acids (SCFAs) through anaerobic fermentation of waste activated sludge (WAS) is commonly constrained by limited substrate availability, particularly for WAS with low organic content. Combining the hydrocyclone (HC) selection with alkali-thermal (AT) pretreatment is a promising solution to address this limitation. The results indicated that HC selection modified the sludge properties by enhancing the ratio of mixed liquid volatile suspended solids (MLVSS)/mixed liquid suspended solids (MLSS) by 19.0% and decreasing the mean particle size by 17.4%, which were beneficial for the subsequent anaerobic fermentation process. Under the optimal HC + AT condition, the peak value of SCFAs production reached 4951.9 mg COD/L, representing a 23.2% increase compared to the raw sludge with only AT pretreatment. Mechanism investigations revealed such enhancement beyond mechanical separation. It involved an increase in bound extracellular polymeric substances (EPS) through HC selection and the disruption of sludge spatial structure by AT pretreatment. Consequently, this combination pretreatment accelerated the transfer of particulate organics (i.e., bound EPS and intracellular components) to the supernatant, thus increasing the accessibility of WAS substrate to hydrolytic and acidifying bacteria. Furthermore, the microbial structure was altered with the enrichment of key functional microorganisms, probably due to the facilitation of substrate biotransformation and product output. Meanwhile, the activity of hydrolases and SCFAs-forming enzymes increased, while that of methanogenic enzymes decreased. Overall, this strategy successfully enhanced SCFAs production from WAS while reducing the environmental risks of WAS disposal.

Asunto(s)

Álcalis , Ácidos Grasos Volátiles , Fermentación , Aguas del Alcantarillado , Ácidos Grasos Volátiles/metabolismo , Anaerobiosis , Álcalis/química , Eliminación de Residuos Líquidos/métodos

RESUMEN

BACKGROUND: Obesity continues to be a major problem, despite known treatment strategies such as lifestyle modifications, pharmaceuticals, and surgical options, necessitating the development of novel weight loss approaches. The naturally occurring fatty acid, 10,12 conjugated linoleic acid (10,12 CLA), promotes weight loss by increasing fat oxidation and browning of white adipose tissue, leading to increased energy expenditure in obese mice. Coincident with weight loss, 10,12 CLA also alters the murine gut microbiota by enriching for microbes that produce short chain fatty acids (SCFAs), with concurrent elevations in fecal butyrate and plasma acetate. METHODS: To determine if the observed microbiota changes are required for 10,12 CLA-mediated weight loss, adult male mice with diet-induced obesity were given broad-spectrum antibiotics (ABX) to perturb the microbiota prior to and during 10,12 CLA-mediated weight loss. Conversely, to determine whether gut microbes were sufficient to induce weight loss, conventionally-raised and germ-free mice were transplanted with cecal contents from mice that had undergone weight loss by 10,12 CLA supplementation. RESULTS/CONCLUSION: While body weight was minimally modulated by ABX-mediated perturbation of gut bacterial populations, adult male mice given ABX were more resistant to the increased energy expenditure and fat loss that are induced by 10,12 CLA supplementation. Transplanting cecal contents from donor mice losing weight due to oral 10,12 CLA consumption into conventional or germ-free mice led to improved glucose metabolism with increased butyrate production. These data suggest a critical role for the microbiota in diet-modulated changes in energy balance and glucose metabolism, and distinguish the metabolic effects of orally delivered 10,12 CLA from cecal transplantation of the resulting microbiota.

RESUMEN

Short-chain fatty acids (SCFAs) - acetate, propionate, and butyrate - are important bacterial fermentation metabolites regulating many important aspects of human physiology. Decreases in the concentrations of any or multiple SCFAs are associated with various detrimental effects to the host. Previous research has broadly focused on gut microbiome produced SCFAs as a group, with minimal distinction between acetate, propionate, and butyrate independently, each with significantly different host effects. In this review, we comprehensively delineate the roles of these SCFAs with emphasis on receptor affinity, signaling pathway involvement, and net host physiologic effects. Butyrate is highlighted due to its unique role in gastrointestinal-associated functions, especially maintaining gut barrier integrity. Butyrate functions by promoting epithelial tight junctions, serving as fuel for colonocyte ATP production, and modulating the immune system. Interaction with the immune system occurs locally in the gastrointestinal tract and systemically in the brain. Investigation into research conducted on butyrate production pathways and specific bacterial players involved highlights a unique risk associated with use of gram-positive targeted antibiotics. We review and discuss evidence showing the relationship between the butyrate-producing gram-positive genus, Roseburia, and susceptibility to commonly prescribed, widely used gram-positive antibiotics. Considering gut microbiome implications when choosing antibiotic therapy may benefit health outcomes in patients.

Asunto(s)

Butiratos , Ácidos Grasos Volátiles , Microbioma Gastrointestinal , Humanos , Microbioma Gastrointestinal/fisiología , Ácidos Grasos Volátiles/metabolismo , Animales , Butiratos/metabolismo , Bacterias/metabolismo , Bacterias/clasificación , Bacterias/genética , Tracto Gastrointestinal/microbiología , Tracto Gastrointestinal/metabolismo , Antibacterianos

RESUMEN

Megasphaera elsdenii has been correlated with gas production by human faecal microbiota during fermentation. The objective of this study was to determine the role of M. elsdenii in gas production by the microbiome. Kidney beans and sweet potatoes were subjected to in vitro digestion and dialysis followed by fermentation with ten faecal microbiomes: three with detectable M. elsdenii (Me_D) and seven with no detectable M. elsdenii (Me_ND). Me_D microbiomes produced more gas than the Me_ND microbiomes (p < 0.001). Me_D microbiomes produced more gas during fermentation of sweet potatoes than kidney beans (p < 0.001), while the opposite was true for the Me_ND microbiomes (p < 0.001). Among amplicon sequence variants that were associated with gas production, M. elsdenii had the strongest association (p < 0.001). Me_D microbiomes consumed more acetate and produced more butyrate than Me_ND microbiomes (p < 0.001). Gas production by M. elsdenii was confirmed by fermentation of sweet potatoes and acetate with human and rumen M. elsdenii isolates. The human isolate produced gas on sweet potatoes and acetate. This study suggests that M. elsdenii may be involved in gas production during the fermentation of flatulogenic foods through utilisation of undigestible substrates or cross-feeding on acetate.

RESUMEN

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory demyelination occurring in the central nervous system (CNS). Inulin is a common prebiotic that can improve metabolic disorders by modulating the gut microbiota. However, its capacity to affect CNS autoimmunity is poorly recognized. Experimental autoimmune encephalomyelitis (EAE) is a classical mouse model of MS. Herein, we found that oral administration of inulin ameliorated the severity EAE in mice, accompanied by reductions in inflammatory cell infiltration and demyelination in the CNS. These reductions were associated with decreased proportion and numbers of Th17 cells in brain and spleen. Consistent with the findings, the serum concentrations of IL-17, IL-6, and TNF-α were reduced in inulin treated EAE mice. Moreover, the proliferation of auto-reactive lymphocytes, against MOG35-55 antigen, was attenuated ex vivo. Mechanistically, inulin treatment altered the composition of gut microbiota. It increased Lactobacillus and Dubosiella whereas decreased g_Prevotellaceae_NK3B31_group at the genus level, alongside with elevated concentration of butyric acid in fecal content and serum. In vitro, butyrate, but not inulin, could inhibit the activation of MOG35-55 stimulated lymphocytes. Furthermore, fecal microbiota transplantation assay confirmed that fecal contents of inulin-treated normal mice had an ameliorative effect on EAE mice. In contrast, antibiotic cocktail (ABX) treatment diminished the therapeutic effect of inulin in EAE mice as well as the reduction of Th17 cells, while supplementation with Lactobacillus reuteri restored the amelioration effect. These results confirmed that the attenuation of inulin on Th17 cells and inflammatory demyelination in EAE mice was dependent on its modulation on gut microbiota and metabolites. Our findings provide a potential therapeutic regimen for prebiotic inulin supplementation in patients with multiple sclerosis.

Asunto(s)

Autoinmunidad , Encefalomielitis Autoinmune Experimental , Ácidos Grasos Volátiles , Microbioma Gastrointestinal , Inulina , Ratones Endogámicos C57BL , Esclerosis Múltiple , Prebióticos , Células Th17 , Animales , Microbioma Gastrointestinal/efectos de los fármacos , Inulina/administración & dosificación , Inulina/farmacología , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/microbiología , Células Th17/inmunología , Ratones , Prebióticos/administración & dosificación , Femenino , Ácidos Grasos Volátiles/metabolismo , Autoinmunidad/efectos de los fármacos , Esclerosis Múltiple/inmunología , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple/microbiología , Sistema Nervioso Central/inmunología , Bacterias/clasificación , Bacterias/aislamiento & purificación

RESUMEN

Inflammatory bowel disease (IBD) is an incurable, chronic disorder of the gastrointestinal tract whose incidence increases every year. Scientific research constantly delivers new information about the disease and its multivariate, complex etiology. Nevertheless, full discovery and understanding of the complete mechanism of IBD pathogenesis still pose a significant challenge to today's science. Recent studies have unanimously confirmed the association of gut microbial dysbiosis with IBD and its contribution to the regulation of the inflammatory process. It transpires that the altered composition of pathogenic and commensal bacteria is not only characteristic of disturbed intestinal homeostasis in IBD, but also of viruses, parasites, and fungi, which are active in the intestine. The crucial function of the microbial metabolome in the human body is altered, which causes a wide range of effects on the host, thus providing a basis for the disease. On the other hand, human genomic and functional research has revealed more loci that play an essential role in gut homeostasis regulation, the immune response, and intestinal epithelial function. This review aims to organize and summarize the currently available knowledge concerning the role and interaction of crucial factors associated with IBD pathogenesis, notably, host genetic composition, intestinal microbiota and metabolome, and immune regulation.

Asunto(s)

Disbiosis , Microbioma Gastrointestinal , Enfermedades Inflamatorias del Intestino , Metaboloma , Humanos , Enfermedades Inflamatorias del Intestino/microbiología , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/genética , Disbiosis/microbiología , Animales

RESUMEN

Introduction: Si-Ni-San (SNS), a traditional Chinese medicine, is effective in treating liver fibrosis with an unclear mechanism. Although disturbance of intestinal flora and the subsequent secretion of short-chain fatty acids (SCFAs) is suggested to be involved in the progression of liver fibrosis, whether SNS produces the anti-fibrosis effect through the regulation of intestinal flora and SCFAs remains unclear. Methods: In the current study, carbon tetrachloride (CCl4)-treated mice were dosed with SNS to examine the anti-fibrotic effects and the involved mechanism. Biochemical parameters, histological staining, and analyses of fibrotic gene expression were used to evaluate the anti-fibrotic effect of SNS, while intestinal flora and SCFA content were determined by 16S rRNA and LC-MS to evaluate the mechanism. Results: In vivo results showed that SNS improved liver function, reduced hepatocyte apoptosis and FFAR2/3 expression, and restored intestinal dysbiosis and reduced PA, BA, and IsA levels. In vitro experiments showed that PA, BA, and IsA exacerbated TNF-α-induced HepG2 apoptosis. Notably, the protective effects of SNS were compromised in pseudo-sterile mice. Discussion: In conclusion, our experimental results suggest that the disturbance in intestinal flora results in elevated SCFA levels, which further exacerbates hepatocyte apoptosis in liver fibrosis, while SNS suppresses CCl4-induced liver fibrosis at least partially by reinstating intestinal flora homeostasis and reducing SCFA levels.

RESUMEN

Short-chain fatty acids (SCFAs), a subset of organic fatty acids with carbon chains ranging from one to six atoms in length, encompass acetate, propionate, and butyrate. These compounds are the endproducts of dietary fiber fermentation, primarily catalyzed by the glycolysis and pentose phosphate pathways within the gut microbiota. SCFAs act as pivotal energy substrates and signaling molecules in the realm of animal nutrition, exerting a profound influence on the intestinal, immune system, and intestinal barrier functions. Specifically, they contibute to 60-70% of the total energy requirements in ruminants and 10-25% in monogastric animals. SCFAs have demonstrated the capability to effectively modulate intestinal pH, optimize the absorption of mineral elements, and impede pathogen invasion. Moreover, they enhance the expression of proteins associated with intestinal tight junctions and stimulate mucus production, thereby refining intestinal tissue morphology and preserving the integrity of the intestinal structure. Notably, SCFAs also exert anti-inflammatory properties, mitigating inflammation within the intestinal epithelium and strengthening the intestinal barrier's defensive capabilities. The present review endeavors to synthesize recent findings regarding the role of SCFAs as crucial signaling intermediaries between the metabolic activities of gut microbiota and the status of porcine cells. It also provides a comprehensive overview of the current literature on SCFAs' impact on immune responses within the porcine intestinal mucosa.

Asunto(s)

Ácidos Grasos Volátiles , Microbioma Gastrointestinal , Inmunidad Mucosa , Mucosa Intestinal , Animales , Ácidos Grasos Volátiles/metabolismo , Porcinos , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiología , Fenómenos Fisiológicos Nutricionales de los Animales

RESUMEN

Purpose: To determine whether green banana powder (GBP) and pineapple fibre powder (PFP) promote beneficial bacterial species, directly improve human gut health and modulate the gut microbiome and understand their utility as functional foods and dietary supplements. Methods: Over 14 days, 60 adults followed protocol requirements, completed food diaries and study questionnaires, avoided consuming supplements with prebiotics, probiotics or postbiotics, and ingested food containing 5 g of total daily fibre [placebo (10.75 g), GBP (10.75 g) or PFP (7.41 g)]. Participants' medical and baseline wellness histories, as well as stool samples, were collected at baseline, day 7 and 14. Stool DNA was processed for sequencing. Results: Dietary fibre and resistant starches (RS) in GBP and PFP promoted temporal increases in beneficial bacteria. GBP significantly elevated 7 species (F. prausnitzii, B. longum, B. bifidum, B. adolescentis, B. pseudocatenulatum, B. obeum, and R. inulinivorans), while PFP enriched 6 species (B. ovatus, B. cellulosilyticus, B. bifidum, B. intestinalis, R. inulinivorans, and E. siraeum). These bacteria, found to be deficient in younger adults, were promoted by both powders. PFP benefitted both genders aged 16-23, while GBP benefitted overweight/obese individuals, including females. GBP and PFP fiber and RS improved bowel regularity and health as well as metabolism by promoting histidine, branched-chain amino acids, short-chain fatty acids, and biotin production. The additional fiber caused "low" bloatedness and reduced "fairly bad" sleep disruptions, without affecting sleep durations. Conclusion: GBP and PFP supplementation increased beneficial bacteria and metabolites, improved host gut health, and present a valuable nutritional strategy for enhancing human health. Clinical trial registration: AMILI Institutional Review Board, Identifier 2023/0301.

RESUMEN

AIMS: Metformin has been attributed to cardiovascular protection even in the absence of diabetes. Recent observations suggest that metformin influences the gut microbiome. We aimed to investigate the influence of metformin on the gut microbiota and hypertensive target organ damage in hypertensive rats. METHODS: Male double transgenic rats overexpressing the human renin and angiotensinogen genes (dTGR), a model of angiotensin II-dependent hypertension, were treated with metformin (300 mg/kg/day) or vehicle from 4 to 7 weeks of age. We assessed gut microbiome composition and function using shotgun metagenomic sequencing and measured blood pressure via radiotelemetry. Cardiac and renal organ damage and inflammation were evaluated by echocardiography, histology, and flow cytometry. RESULTS: Metformin treatment increased the production of short-chain fatty acids (SCFA) acetate and propionate in feces without altering microbial composition and diversity. It significantly reduced systolic and diastolic blood pressure and improved cardiac function, as measured by end-diastolic volume, E/A, and stroke volume despite increased cardiac hypertrophy. Metformin reduced cardiac inflammation by lowering macrophage infiltration and shifting macrophage subpopulations towards a less inflammatory phenotype. The observed improvements in blood pressure, cardiac function, and inflammation correlated with fecal SCFA levels in dTGR. In vitro, acetate and propionate altered M1-like gene expression in macrophages, reinforcing anti-inflammatory effects. Metformin did not affect hypertensive renal damage or microvascular structure. CONCLUSION: Metformin modulated the gut microbiome, increased SCFA production, and ameliorated blood pressure and cardiac remodeling in dTGR. Our findings confirm the protective effects of metformin in the absence of diabetes, highlighting SCFA as a potential mediators.

RESUMEN

As a medicinal and edible homologous Chinese herb, Polygonatum sibiricum has been used as a primary ingredient in various functional and medicinal products. Damage to the intestinal mucosal barrier can lead to or worsen conditions such as type 2 diabetes and Alzheimer's disease. Traditional Chinese medicine and its bioactive components can help prevent and manage these conditions by restoring the integrity of the intestinal mucosal barrier. This review delves into the mode of action of P. sibiricum polysaccharide in disease prevention and management through the restoration of the intestinal barrier. Polysaccharide from P. sibiricum effectively treats conditions by repairing the intestinal mucosal barrier, offering insights for treating complex diseases and supporting the application of P. sibiricum in clinical settings.

RESUMEN

Diet plays a critical role in shaping the gut microbiome, which in turn regulates molecular activities in the colonic mucosa. The state and composition of the gut microbiome are key factors in the development of colorectal cancer. An altered gut microbiome, linked to weakened immune responses and the production of carcinogenic substances, is a significant contributor to colorectal cancer pathogenesis. Dietary changes that involve low-fiber and phytomolecule intake, coupled with higher consumption of red meat, can raise the risk of colorectal cancer. Salutary filaments, which reach the colon undigested, are metabolized by the gut microbiome, producing short-chain fatty acids. Short-chain fatty acids possess beneficial anti-inflammatory and antiproliferative properties that promote colon health. A well-balanced microbiome, supported by beneficial fibers and phytochemicals, can regulate the activation of proto-oncogenes and oncogenic pathways, thereby reducing cell proliferation. Recent research suggests that an overabundance of specific microbes, such as Fusobacterium nucleatum, may contribute to adverse changes in the colonic mucosa. Positive lifestyle adjustments have been demonstrated to effectively inhibit the growth of harmful opportunistic organisms. Synbiotics, which combine probiotics and prebiotics, can protect the intestinal mucosa by enhancing immune responses and decreasing the production of harmful metabolites, oxidative stress, and cell proliferation. This narrative review provides a concise understanding of evolving evidence regarding how diet influences the gut microbiome, leading to the restoration of the colonic epithelium. It underscores the importance of a healthy, plant-based diet and associated supplements in preventing colorectal cancer by enhancing gut microbiome health.

RESUMEN

Short-chain fatty acids (SCFAs) are essential molecules produced by gut bacteria that fuel intestinal cells and may also influence overall health. An imbalance of SCFAs can result in various acute and chronic diseases, including diabetes, obesity and colorectal cancer (CRC). This review delves into the multifaceted roles of SCFAs, including a brief discussion on their source and various gut-residing bacteria. Primary techniques used for detection of SCFAs, including gas chromatography, high-performance gas chromatography, nuclear magnetic resonance and capillary electrophoresis are also discussed through this article. This review study also compiles various synthesis pathways of SCFAs from diverse substrates such as sugar, acetone, ethanol and amino acids. The different pathways through which SCFAs enter cells for immune response regulation are also highlighted. A major emphasis is the discussion on diseases associated with SCFA dysregulation, such as anaemia, brain development, CRC, depression, obesity and diabetes. This includes exploring the relationship between SCFA levels across ethnicities and their connection with blood pressure and CRC. In conclusion, this review highlights the critical role of SCFAs in maintaining gut health and their implications in various diseases, emphasizing the need for further research on SCFA detection, synthesis and their potential as diagnostic biomarkers. Future studies of SCFAs will pave the way for the development of novel diagnostic tools and therapeutic strategies for optimizing gut health and preventing diseases associated with SCFA dysregulation.

Asunto(s)

Ácidos Grasos Volátiles , Microbioma Gastrointestinal , Humanos , Ácidos Grasos Volátiles/metabolismo , Animales , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Obesidad/metabolismo

RESUMEN

BACKGROUND: Gastrectomy is one of the main treatment modalities for gastric cancer (GC) and induces pathophysiological changes that significantly affect patients' postoperative recovery. In this study, we investigated the relationships between altered insulin resistance (IR), inflammation, and gut microbiota associated with gastrectomy. PATIENTS AND METHODS: This study was a single-center prospective cohort investigation involving 60 patients with GC who underwent gastrectomy between May 2023 and April 2024. Monitoring encompassed IR, inflammation, and nutrition-related markers via blood assays, while gut microbiota analysis employed high-throughput sequencing, and short-chain fatty acids (SCFAs) were examined through targeted metabolomics. The study is registered under the number ChiCTR2300075653. RESULTS: The patients exhibited a significant increase in post-gastrectomy IR markers (P < 0.001), accompanied by elevated inflammation markers (P < 0.001), and also showed decreased nutrition-related indicators (P < 0.001). Notable alterations were observed in the gut microbiota, including reductions in Bifidobacterium and Faecalibacterium, an increase in Streptococcus, and a noteworthy decrease in fecal butyrate. Patients with postoperative IR exhibited poorer inflammation markers (P < 0.05), nutritional indicators (P < 0.05), and postoperative recovery parameters (P < 0.05). Furthermore, significant negative correlations were observed between IR and Bifidobacterium, Faecalibacterium, as well as butyrate. CONCLUSIONS: Patients with GC post-gastrectomy displayed heightened IR, exacerbated inflammation, and compromised nutritional status. Disturbed gut microbiota and reduced fecal butyrate were observed. Gut microbiota and metabolite butyrate production may be predictors of postoperative IR and short-term outcomes in patients with GC.

RESUMEN

Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycemia. Type 2 diabetes mellitus (T2DM) represents approximately 90 % of all DM cases and is primarily caused by an imbalance in blood glucose homeostasis due to inadequate insulin secretion or insulin resistance. This study explores the potential therapeutic effects of chitosan guanidine (CSG) on a T2DM mouse model. The findings reveal that CSG significantly enhances oral glucose tolerance (OGTT) and insulin sensitivity (ITT), reduces fasting blood glucose (FBG) levels, and suppresses the expression of proinflammatory cytokines in T2DM mice. These changes improve insulin resistance and diminish inflammation. Additionally, CSG markedly ameliorates lipid metabolism disorders, lowers total cholesterol (TC) and triglyceride (TG) levels, and inhibits hepatic fat accumulation. 16S rRNA and Spearman correlation analyses indicate that CSG promotes the relative abundance of probiotic genera such as Bacteroidota, Patescibacteria, Actinobacteria, and Cyanobacteria. These bacteria are positively correlated with short-chain fatty acids (SCFAs) and high-density lipoprotein cholesterol (HDLC) levels. Conversely, CSG reduces the relative abundance of pathogenic bacteria, including Proteobacteria and Ralstonia, leading to an improved intestinal microbial community composition in T2DM mice and alleviating T2DM symptoms. These results suggest that CSG holds significant potential as a non-insulin therapeutic agent for diabetes management.

RESUMEN

This paper presents an in vitro evaluation of antitumor properties through producing short-chain fatty acids and inducing interleukin 12. In addition, it offers the most important and functional probiotic properties of 24 Lactobacillus gasseri, Lactiplantibacillus plantarum, Lactobacillus acidophilus, and Limosilactobacillus fermentum strains isolated from humans, foods, and fermented foods. To this end, survival in an acidic environment (pH = 2.5), tolerance in bile salt, viability in the presence of pepsin-pancreatin, adhesion percentage, antibiotic resistance, auto-aggregation, and potential percentage of co-aggregation are studied in contact with three human intestinal pathogens. These pathogens are Escherichia coli O157: H7 NCTC 12900, Salmonella enterica subsp. enterica ATCC 13076, and Listeria monocytogenes ATTC 7644. Also, in vitro induction amount of IL-12 in mouse splenocytes is investigated to evaluate antitumor properties by 19 strains of L. gasseri and L. plantarum along with the development of short-chain fatty acids (SCFA) by 5 strains of L. fermentum and L. acidophilus. Gas Chromatography Flame Ionization Detector (GC-FID) and enzyme-linked immunosorbent assay (ELISA) were used to measure short-chain fatty acids and IL-12, respectively. All strains had high viability under acidic conditions. The highest levels of pancreatin and pepsin resistance were found in strains LF56, LF57, LF55, OF, and F and strains LF56, LF57, and A7, respectively. All strains except LF56 had high resistance to bile salts. L. gasseri 54C had the highest average adhesion score (hydrophobicity) of 62.9 % among 19 strains. Despite the susceptibility of different strains of L. plantarum to the tested antibiotics, M8 and M11, S2G, A7, LF55, LF57, and 5G were resistant to kanamycin and chloramphenicol, respectively. Also, 21G was resistant to ampicillin, LF56 to tetracycline and M8, and M11, LF56, and 21G to Erythromycin. In addition, L. gasseri showed moderate resistance to ampicillin, erythromycin, and tetracycline, while L. fermentum ATCC 9338 showed good resistance to ampicillin, erythromycin, and chloramphenicol. In this respect, L. plantarum LF56 and gasseri 54C had the highest average auto-aggregation and co-aggregation against three pathogenic bacteria, respectively. The highest and lowest levels of acetic acid as short-chain fatty acids were produced by L. fermentum 19SH isolated from Horre 41.62 and L. fermentum 21SH from fermented seeds 27.047, respectively. Moreover, L. fermentum, with the OF code of traditional-fermented food origin, produced the most isobutyric acid, butyric acid, and valeric acid, with values of 0.6828, 0.74165, and 0.49915 mmol, respectively. L. fermentum isolated from the human origin with code F produced the most isovaleric acid of 1.1874 mmol. All the tested strains produced good propionic acid except L. fermentum 21SH from fermented seeds. Among strains, L. plantarum M11 isolated from milk and L. gasseri 52B from humans had the highest in vitro induction of IL-12, which is probably related to their cell wall compositions and structure.

RESUMEN

The human gastrointestinal microbiota, densely populated with a diverse array of microorganisms primarily from the bacterial phyla Bacteroidota, Bacillota, and Actinomycetota, is crucial for maintaining health and physiological functions. Dietary fibers, particularly pectin, significantly influence the composition and metabolic activity of the gut microbiome. Pectin is fermented by gut bacteria using carbohydrate-active enzymes (CAZymes), resulting in the production of short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate, which provide various health benefits. The gastrointestinal microbiota has evolved to produce CAZymes that target different pectin components, facilitating cross-feeding within the microbial community. This review explores the fermentation of pectin by various gut bacteria, focusing on the involved transport systems, CAZyme families, SCFA synthesis capacity, and effects on microbial ecology in the gut. It addresses the complexities of the gut microbiome's response to pectin and highlights the importance of microbial cross-feeding in maintaining a balanced and diverse gut ecosystem. Through a systematic analysis of pectinolytic CAZyme production, this review provides insights into the enzymatic mechanisms underlying pectin degradation and their broader implications for human health, paving the way for more targeted and personalized dietary strategies.

RESUMEN

The gut microbiota constitutes a complex ecosystem, comprising trillions of microbes that have co-evolved with their host over hundreds of millions of years. Over the past decade, a growing body of knowledge has underscored the intricate connections among diet, gut microbiota, and human health. Bioactive polysaccharides (BPs) from natural sources like medicinal plants, seaweeds, and fungi have diverse biological functions including antioxidant, immunoregulatory, and metabolic activities. Their effects are closely tied to the gut microbiota, which metabolizes BPs into health-influencing compounds. Understanding how BPs and gut microbiota interact is critical for harnessing their potential health benefits. This review provides an overview of the human gut microbiota, focusing on its role in metabolic diseases like obesity, type II diabetes mellitus, non-alcoholic fatty liver disease, and cardiovascular diseases. It explores the basic characteristics of several BPs and their impact on gut microbiota. Given their significance for human health, we summarize the biological functions of these BPs, particularly in terms of immunoregulatory activities, blood sugar, and hypolipidemic effect, thus providing a valuable reference for understanding the potential benefits of natural BPs in treating metabolic diseases. These properties make BPs promising agents for preventing and treating metabolic diseases. The comprehensive understanding of the mechanisms by which BPs exert their effects through gut microbiota opens new avenues for developing targeted therapies to improve metabolic health.

Asunto(s)

Microbioma Gastrointestinal , Enfermedades Metabólicas , Polisacáridos , Humanos , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/fisiología , Polisacáridos/farmacología , Enfermedades Metabólicas/microbiología , Enfermedades Metabólicas/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/microbiología , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Diabetes Mellitus Tipo 2/microbiología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Animales , Obesidad/microbiología , Obesidad/tratamiento farmacológico , Obesidad/metabolismo

RESUMEN

Fermentation-derived short-chain fatty acids (SCFA)4 are potential mediators of the health benefits associated with dietary fiber intake. SCFA affect physiological processes locally in the gut and on distant organs via the systemic circulation. Since SCFA are used as energy source for colonocytes and substrate for the liver metabolism, their concentrations in the systemic circulation are low. Therefore, quantification of systemic SCFA requires sensitive analytical techniques. This article covers the optimization and validation of a gas chromatography-mass spectrometry method to measure systemic SCFA concentrations following derivatization with 2,4-difluoroaniline (DFA)5 and extraction in ethyl acetate. Sample preparation was optimized by varying the amount of DFA, coupling agent 1,3-dicyclohexylcarbodiimide, ethyl acetate and sodium bicarbonate, which is used to quench derivatization. In addition, evaporation of the samples using a vacuum concentrator resulted in less contamination, notably of acetate, compared to drying with N2 gas. The method showed excellent linearity with coefficient of variation (R2) > 0.99 and a good precision (relative standard deviation < 20 %) and accuracy. Finally, systemic concentrations of SCFA in human plasma samples could successfully be determined.