Synthesis Of Short-chain Fatty Acids Research Articles

An Innovative Probiotic-Based Supplement to Mitigate Molecular Factors Connected to Depression and Anxiety: An In Vitro Study.

The gut-brain axis is a bidirectional relationship between the microbiota and the brain; genes related to the brain and gut synaptic formation are similar. Research on the causal effects of gut microbiota on human behavior, brain development, and function, as well as the underlying molecular processes, has emerged in recent decades. Probiotics have been shown in several trials to help reduce anxiety and depressive symptoms. Because of this, probiotic combinations have been tested in in vitro models to see whether they might modulate the gut and alleviate depression and anxiety. Therefore, we sought to determine whether a novel formulation might affect the pathways controlling anxiety and depression states and alter gut barrier activities in a 3D model without having harmful side effects. Our findings indicate that B. bifidum novaBBF7 10 mg/mL, B. longum novaBLG2 5 mg/mL, and L. paracasei TJB8 10 mg/mL may influence the intestinal barrier and enhance the synthesis of short-chain fatty acids. Additionally, the probiotics studied did not cause neuronal damage and, in combination, exert a protective effect against the condition of anxiety and depression triggered by L-Glutamate. All these findings show that probiotics can affect gut function to alter the pathways underlying anxiety and depression.

Milk-derived Lactobacillus with high production of short-chain fatty acids relieves antibiotic-induced diarrhea in mice.

Antibiotic-associated diarrhea (AAD) is a common side effect during antibiotic treatment, and this has warranted research into alternative protocols. In this study, we investigated the potential therapeutic effects of three cohorts, Lactobacillus plantarum KLDS 1.0386, Lactobacillus acidophilus KLDS 1.0901 and a mixed strain of both, on intestinal inflammation, the intestinal mucosal barrier, and microbial community in mice with ampicillin-induced diarrhea. The results showed that Lactobacillus inhibited the activation of the TLR4/NF-κB signaling pathway, decreased the expression of pro-inflammatory cytokines, increased the expression of anti-inflammatory cytokines in the murine intestine, and alleviated the intestinal barrier damage and inflammation induced by ampicillin. In addition, Lactobacillus ameliorates intestinal epithelial barrier damage by increasing the expression of tight junction proteins and aquaporins. After Lactobacillus treatment, the diversity of gut microbiota increased significantly, and the composition and function of gut microbiota gradually recovered. In the gut microbiota, Bacteroidetes and Escherichia Shigella related to the synthesis of short-chain fatty acids (SCFAs) were significantly affected by ampicillin, while Lactobacillus regulates the cascade of the microbial-SCFA signaling pathway, which greatly promoted the generation of SCFAs. Collectively, Lactobacillus showed better results in treating AAD, especially in mixed strains.

The Replacement of Fish Meal with Poultry By-Product Meal and Insect Exuviae: Effects on Growth Performance, Gut Health and Microbiota of the European Seabass, Dicentrarchus labrax.

This study addressed the urgent need for sustainable protein sources in aquaculture due to the depletion of marine resources and rising costs. Animal protein sources, particularly poultry by-product meal (PBM) and insect exuviae meal, were investigated as viable alternatives to fishmeal (FM). The research study confirmed the successful replacement of FM with a combination of PBM and insect exuviae meal (up to 50%) in the diet of European seabass without compromising growth, feed conversion, gut health, and liver fat content. In particular, growth was robust with both PBM formulations, with the 25% PBM diet showing better results. Histological examinations showed good gut and liver health, contradicting the concerns of previous studies. This paper emphasizes the importance of holistic analyzes that go beyond growth parameters and include histomorphological investigations. The results show that PBM in combination with insect/exuviae meal is well tolerated by seabass, which is consistent with reports in the literature of it mitigating negative effects on gut health. A detailed analysis of the microbiota revealed a decrease in the Firmicutes/Proteobacteria ratio due to an increase in potentially pathogenic bacteria. However, the formulation containing insect exuviae partially counteracted this effect by preserving the beneficial Lactobacillus and promoting the synthesis of short-chain fatty acids (SCFAs), particularly butyrate. Chitin-rich components from insect exuviae were associated with improved gut health, which was supported by the increased production of SCFAs, which are known for their anti-inflammatory properties. This paper concludes that a combination of PBM and insect/exuviae meal can replace up to 50% of FM in the diet of seabass, supporting sustainable aquaculture practices. Despite some changes in the microbiota, the negative effects are mitigated by the addition of insect exuviae, highlighting their potential as a prebiotic to increase fish productivity and contribute to a circular economy in aquaculture.

Poly(D,l-lactide-co-glycolide) particles are metabolised by the gut microbiome and elevate short chain fatty acids

The production of short chain fatty acids (SCFAs) by the colonic microbiome has numerous benefits for human health, including maintenance of epithelial barrier function, suppression of colitis, and protection against carcinogenesis. Despite the therapeutic potential, there is currently no optimal approach for elevating the colonic microbiome's synthesis of SCFAs. In this study, poly(D,l-lactide-co-glycolide) (PLGA) was investigated for this application, as it was hypothesised that the colonic microbiota would metabolise PLGA to its lactate monomers, which would promote the resident microbiota's synthesis of SCFAs. Two grades of spray dried PLGA, alongside a lactate bolus control, were screened in an advanced model of the human colon, known as the M-SHIME® system. Whilst the high molecular weight (Mw) grade of PLGA was stable in the presence of the microbiota sourced from three healthy humans, the low Mw PLGA (PLGA 2) was found to be metabolised. This microbial degradation led to sustained release of lactate over 48 h and increased concentrations of the SCFAs propionate and butyrate. Further, microbial synthesis of harmful ammonium was significantly reduced compared to untreated controls. Interestingly, both types of PLGA were found to influence the composition of the luminal and mucosal microbiota in a donor-specific manner. An in vitro model of an inflamed colonic epithelium also showed the polymer to affect the expression of pro- and anti-inflammatory markers, such as interleukins 8 and 10. The findings of this study reveal PLGA's sensitivity to enzymatic metabolism in the gut, which could be harnessed for therapeutic elevation of colonic SCFAs.

Effects of UV/H2O2 degradation on Moringa oleifera Lam. leaves polysaccharides: Composition, in vitro fermentation and prebiotic properties on gut microorganisms

Moringa oleifera Lam. leaves are a new raw food material rich in polysaccharides. These polysaccharides exhibit various biological properties, including antioxidant, hypoglycemic and immunoregulatory effects. However, the use of Moringa oleifera Lam. leaves polysaccharides (MOLP) may be limited by their large molecular weight (MW) and presence of numerous impurities, such as pigments. Research has indicated that degraded polysaccharides usually exhibit high biological activity because of changes in physical structure and chemical properties. In this study, we focused on the extraction of a degraded-modified fraction from MOLP using the Ultraviolet/ Hydrogen peroxide (UV/H2O2) method. Specifically, the physicochemical properties and glycosidic bond composition of a particular fraction (UV/H2O2 degraded Moringa oleifera Lam. leaves polysaccharides in 3 h called DMOLP-3) were investigated. In addition, in vitro simulated digestion experiments showed that DMOLP-3 was only partially degraded during gastrointestinal digestion, indicating that DMOLP-3 can be utilised by gut microorganisms. Furthermore, the prebiotic properties of MOLP and DMOLP-3 was studied using an in vitro faecal fermentation model. The results indicated that compared with MOLP, DMOLP-3 led to a decrease in both the colour and MW of the polysaccharides. In addition, this model exhibited enhanced solubility and antioxidant capabilities while also influencing the surface morphology. Moreover, DMOLP-3 can facilitate the proliferation of advantageous microorganisms and enhance the synthesis of short-chain fatty acids (SCFAs). These results provide valuable insights into the utilization of bioactive components in Moringa oleifera Lam. leaves for the intestinal health.

Crosstalk between glucagon-like peptide 1 and gut microbiota in metabolic diseases.

Gut microbiota exert influence on gastrointestinal mucosal permeability, bile acid metabolism, short-chain fatty acid synthesis, dietary fiber fermentation, and farnesoid X receptor/Takeda G protein-coupled receptor 5 (TGR5) signal transduction. The incretin glucagon-like peptide 1 (GLP-1) is mainly produced by L cells in the gut and regulates postprandial blood glucose. Changes in gut microbiota composition and function have been observed in obesity and type 2 diabetes (T2D). Meanwhile, the function and rhythm of GLP-1 have also been affected in subjects with obesity or T2D. Therefore, it is necessary to discuss the link between the gut microbiome and GLP-1. In this review, we describe the interaction between GLP-1 and the gut microbiota in metabolic diseases. On the one hand, gut microbiota metabolites stimulate GLP-1 secretion, and gut microbiota affect GLP-1 function and rhythm. On the other hand, the mechanism of action of GLP-1 on gut microbiota involves the inflammatory response. Additionally, we discuss the effects and mechanism of various interventions, such as prebiotics, probiotics, antidiabetic drugs, and bariatric surgery, on the crosstalk between gut microbiota and GLP-1. Finally, we stress that gut microbiota can be used as a target for metabolic diseases, and the clinical application of GLP-1 receptor agonists should be individualized.

Nonylphenol induces depressive behavior in rats and affects gut microbiota: A dose–dependent effect

Nonylphenol (NP), an endocrine disruptor absorbed through food intake, was investigated in this study for its potential dose-response relationship with the manifestation of depression-like behavior in rats. Based on this, the mechanisms of NP-induced depressive behavior, encompassing neurotransmitters, gut barrier function, inflammatory response, gut microbiota composition and metabolites were further explored. At medium and high NP doses, both mRNA and protein levels of zonula occludens protein-1 and claudin-1 were considerably downregulated, concomitant with an elevation in tumor necrosis factor-α and interleukin-1β expression in a dose-dependent effect, resulting in damage to the gut mucosa. Despite a minimal impact on behavior and gut barriers at low NP doses, alterations in gut microbiota composition were observed. During NP exposure, dose-dependent changes in the gut microbiota revealed a decline in microbial diversity linked to the synthesis of short-chain fatty acids. NP not only adversely affected the gut microbiota structure but also exacerbated central nervous system damage through the gut-brain axis. The accumulation of NP may cause neurotransmitter disturbances and inflammatory responses in the hippocampus, which also exacerbate depressed behavior in rats. Therefore, NP could exacerbate the inflammatory response in the hippocampus and colon by compromising intestinal barrier integrity, facilitating the proliferation of pathogenic bacteria, impairing butyrate metabolism, and perturbing neurotransmitter homeostasis, thus aggravating the depressive behavior of rats. It is noteworthy that the changes in these indicators were related to the NP exposure dose.

Identification and structural characterization of key prebiotic fraction of soluble dietary fiber from grapefruit peel sponge layer and its regulation effect on gut microbiota

In this study, the key prebiotic fraction of grapefruit peel sponge layer soluble dietary fiber (GSLSDF) was identified, and its structure characteristics and modulatory effect on intestinal microorganisms were investigated. Firstly, two fractions (GSLSDF-1 and GSLSDF-2) were isolated from GSLSDF, and the GSLSDF-1 showed a better prebiotic activity. Subsequently, GSLSDF-1 was found to have a low molecular weight and crystallinity, a loose and porous microstructure, and a high glucose content. Meanwhile, GSLSDF-1 was a dextran with a main chain linked by β-1, 4 glycosidic bonds and branched by a β-1, 6 glycosidic bonds. These structural characteristics were responsible for the favorable prebiotic activity of GSLSDF-1. Finally, the regulation effect of GSLSDF-1 on gut microbiota was analyzed in vitro fecal fermentation. Compared with the blank and GSLSDF groups, GSLSDF-1 could increase the relative abundances of Lactobacillus, Bacteroides, Bifidobacterium and Faecalibacterium coupled with decrease the relative abundances of Clostridium and Clostridioides. Furthermore, GSLSDF-1 promoted the production of short-chain fatty acids (SCFAs) by modulating the SCFAs synthesis pathway of intestinal microorganisms, while the NH3-N synthesis of intestinal microorganisms was inhibited by GSLSDF-1. Above results indicated that GSLSDF-1 was the key prebiotic fraction of GSLSDF, which could effectively optimize the intestinal microorganism composition.

[Changes in the synthesis of short-chain fatty acids under the influence of various factors in healthy people and patients with type 2 diabetes mellitus].

Short-chain fatty acids (SCFAs) are an important link in the maintenance and normalization of some important body functions. Recently, the metabolic component of the SCFAs effects has also been actively studied; the effect on body weight, insulin resistance and glycemia is of particular interest in the context of the prevention and treatment of carbohydrate metabolism disorders. In this regard, it is relevant to study the characteristics of SCFAs' production in patients with impaired carbohydrate metabolism, mainly with type 2 diabetes mellitus (T2DM). The purpose of the research was to study the modern data on the synthesis peculiarities of SCFAs in healthy people and patients with impaired carbohydrate metabolism. Material and methods. The data of domestic and foreign literature presented in PubMed, Google Scholar, ResearchGate, Elsevier, eLibrary, CyberLeninka databases, published mainly over the past 10 years, have been analyzed. Results. According to the concept of the philometabolic nucleus, bacteria of certain species, which are of the greatest importance compared to the rest, are responsible for the synthesis of specific SCFAs. The gut microbiota (GM) has the property of plasticity - the ability to change its composition under the influence of various factors. Most studies describe the effect of GM and its metabolites on the carbohydrate metabolism, but an equally important aspect of this process is the effect of carbohydrate metabolism disorders on GM and its functional activity. In case of disorders of carbohydrate metabolism, some altered components of homeostasis negatively affect GM and its production of SCFAs. As a result, the total amount and variety of SCFAs decrease, which exacerbate the imbalance in relation to carbohydrate metabolism. There is evidence that in patients with T2DM, the concentration of butyrate, which has a positive effect on insulin resistance, body weight, fasting glycemia and postprandial glycemia, decreases. The concentration of propionate and acetate, which didn't show such a pronounced positive effect in studies on carbohydrate metabolism, on the contrary, increases. Conclusion. The production of SCFAs by GM representatives depends on many factors, such as nutrition, physical activity, medication intake and the presence of chronic diseases. Numerous studies have confirmed the difference in the characteristics of the production of SCFAs in patients with T2DM and healthy people. The study of the peculiarities of GM metabolism in patients with T2DM is a tool in understanding the basics of therapy and lifestyle correction in both patients with T2DM and healthy people in order to prevent disorders of carbohydrate metabolism.

Lactobacillus fermentum CKCC1858 and Lactobacillus plantarum CKCC1312 ameliorate the symptoms of ulcerative colitis in mouse model induced by dextran sulfate sodium

The objective of this study was to investigate the therapeutical action of Lactobacillus fermentum CKCC1858 and Lactobacillus plantarum CKCC1312 on ulcerative colitis (UC) and its mechanism. The results showed that L. fermentum CKCC1858 and L. plantarum CKCC1312 were able to relieve UC in DSS-induced mice, manifested in a noticeable increase in food intake, colon length, water intake and weight, and a marked decrease in histological scores and disease activity index. Further studies showed that L. fermentum CKCC1858 and L. plantarum CKCC1312 had the capacity to increase the level of mucin-2, zonula occludens-1 and interleukin-10, decrease the levels of interleukin-1β, interleukin-17A, interferon-γ, interleukin-6 and tumor necrosis factor-α, and regulated the genes correlated with immune. Simultaneously, we suggested that L. fermentum CKCC1858 and L. plantarum CKCC1312 possess the ability to alleviate UC via regulating the intestinal microbiome and genes expression, improving intestinal mucosa and promoting the synthesis of short-chain fatty acids.

Alterations of the gut microbiota and fecal short-chain fatty acids in women undergoing assisted reproduction.

The community structure of gut microbiota changes during pregnancy, which also affects the synthesis of short-chain fatty acids (SCFAs). However, the distribution of gut microbiota composition and metabolite SCFA levels are poorly understood in women undergoing assisted reproductive technology (ART). To evaluate the changes in gut microbiota composition and metabolic SCFAs in women who received assisted reproduction treatment. Sixty-three pregnant women with spontaneous pregnancy (SP) and nine with ART pregnancy were recruited to provide fecal samples. Gut microbiota abundance and SCFA levels were determined by 16S ribosomal RNA (rRNA) gene amplicon sequencing and gas chromatography-mass spectrometry (GC-MS). The ART group showed decreased alpha diversity (the species richness or evenness in a sample). The principal coordinates analysis (a method of analysing beta diversity) showed significant difference in gut microbiota between the ART group versus the SP group (unweighted UniFrac distance, R2=0.04, P=0.003). Proteobacteria, Blautia and Escherichia-Shigella were enriched in the ART group, whereas the relative abundance of beneficial intestinal bacteria Faecalibacterium was lower than in the SP group. Different modes of conception were associated with several SCFAs (valeric acid (r=-0.280; P=0.017); isocaproic acid (r=-0.330; P=0.005); caproic acid (r=-0.336; P=0.004)). Significantly different SCFAs between the two groups were synchronously associated with the differential gut microbiota. The diversity and abundance of gut microbiota and the levels of SCFAs in women undergoing ART decreased. The application of ART shaped the microbial composition and metabolism, which may provide critical information for understanding the biological changes that occur in women with assisted reproduction.

Food by-product valorisation in nutrients through spent brewer's yeast bioprocessing with Propionibacterium freudenreichii

This study investigated the potential of Propionibacterium freudenreichii to enhance the nutritional quality of spent brewer's yeast (SBY) by producing short-chain fatty acids (SCFAs) and vitamin B12 (B12). SBY was also evaluated as a growth medium for P. freudenreichii. Four SBY samples from different breweries were utilized and compared to microbiological yeast extract (YE). The tested SBY samples exhibited similar chemical compositions in terms of protein content, free amino acids (FAAs), SCFAs, carbohydrates, riboflavin, and cobalt, whereas YE was richer in most of these substances. However, P. freudenreichii growth was hindered by polyphenols in SBY, as evidenced by better growth in samples with lower polyphenol levels and the control sample (YE). SCFA synthesis was efficient in the SBY sample, resulting in 1.3 mg mL−1 of acetic acid and 1.70 mg mL−1 of propionic acid. Furthermore, P. freudenreichii fermentation increased essential free amino acids (FAAs) in all tested samples. SBY was found to be a suitable medium for supporting the production of the active form of B12, with a concentration of 25.2 ng mL−1. However, YE outperformed SBY as a medium for B12 synthesis, yielding a concentration of 214.3 ng mL−1 after fermentation. The results indicate that both SBY and YE can serve as one-component sustainable growth media, valorised with valuable compounds through P. freudenreichii fermentation. In conclusion, SBY offers a novel opportunity for the biotechnological synthesis of SCFAs, FAAs, and B12 through P. freudenreichii fermentation.

Changes of gut microbiota and short chain fatty acids in patients with Peutz–Jeghers syndrome

Peutz–Jeghers Syndromeis a rare autosomal dominant genetic disease characterized by gastrointestinal hamartomatous polyps and skin and mucous membrane pigmentation. The pathogenesis of PJS remains unclear; however, it may be associated with mutations in the STK11 gene, and there is currently no effective treatment available. The gut microbiota plays an important role in maintaining intestinal homeostasis in the human body, and an increasing number of studies have reported a relationship between gut microbiota and human health and disease. However, relatively few studies have been conducted on the gut microbiota characteristics of patients with PJS. In this study, we analyzed the characteristics of the gut microbiota of 79 patients with PJS using 16 S sequencing and measured the levels of short-chain fatty acids in the intestines. The results showed dysbiosis in the gut microbiota of patients with PJS, and decreased synthesis of short-chain fatty acids. Bacteroides was positively correlated with maximum polyp length, while Agathobacter was negatively correlated with age of onset. In addition, acetic acid, propionic acid, and butyric acid were positively correlated with the age of onset but negatively correlated with the number of polyps. Furthermore, the butyric acid level was negatively correlated with the frequency of endoscopic surgeries. In contrast, we compared the gut microbiota of STK11-positive and STK11-negative patients with PJS for the first time, but 16 S sequencing analysis revealed no significant differences. Finally, we established a random forest prediction model based on the gut microbiota characteristics of patients to provide a basis for the targeted diagnosis and treatment of PJS in the future.

PSXIV-14 Evaluation of Short-Chain Fatty Acids in Cattle Treated with the Natural Additive Fator P

Abstract The use of additives in the diet of ruminants consists of a management protocol that makes the livestock system more productive, sustainable and profitable. In practice, additives promote the balance of the microbial population, and improve the energy balance from food. The use of these compounds becomes advantageous as they reduce energy losses by methanogenic metabolic pathways, and the emission of enteric gases from ruminal fermentation. The short-chain fatty acids which are compounds resulting from rumen fermentation, constitute the main source of energy in the rumen, and therefore, the entire metabolic process can directly reflect the productivity performance of the cattle. Fator P is a natural additive composed of amino acids, minerals, probiotics, prebiotics and fatty acids, which was developed to meet current market needs. The aim of this study was to evaluate the synthesis of short-chain fatty acids from ruminal fluid collected from grazing animals treated with the Fator P additive over a period of 365 consecutive days. The ruminal metabolism work was conducted at Research Center of Premix (Patrocínio Paulista-SP, Brazil), using 3 cattle per treatment, which received a daily dose of 6 g of Fator P additive in the treated group, and 6 g of placebo in the control group. Ruminal fluid samples were collected weekly, and the analysis of short-chain fatty acids were carried out by the method of gas chromatography coupled to mass spectrometry. The results of the difference between means showed an increase of 15.2% (P < 0.0001) in the production of total fatty acids in the group treated with the natural additive Fator P compared with the control group. Notably, there was also an increase in the production of the three main AGCC: 13.3% for acetate (P < 0.0001); 14.7% for propionate (P = 0.0003); and 18.4% for butyrate (P = 0.0001; Table 1). Statistical analyzes were performed using the ANOVA test followed by the Tukey mean test (P < 0.05) in GraphPad PRISM Program 7.00 version. Therefore, the results indicate that the natural additive Fator P improves energy levels through the increase of short-chain fatty acids and directly reflects on the productivity indexes of the cattle. Furthermore, the product reduces the use of growth promoting antibiotics, improve intestine health, immune response of animals, carcass finishing, increase herd weight gain and milk production in a profitable and sustainable way for the cattle breeder.

Does postoperative pulmonary infection correlate with intestinal flora following gastric cancer surgery? - a nested case-control study.

The primary objective of this study was to investigate the potential correlation between gut microbes and postoperative pulmonary infection in gastric cancer patients. Additionally, we aimed to deduce the mechanism of differential functional genes in disease progression to gain a better understanding of the underlying pathophysiology. A nested case-control study design was utilized to enroll patients with gastric cancer scheduled for surgery at West China Hospital of Sichuan University. Patients were categorized into two groups, namely, the pulmonary infection group and the control group, based on the development of postoperative pulmonary infection. Both groups were subjected to identical perioperative management protocols. Fecal samples were collected 24 h postoperatively and upon pulmonary infection diagnosis, along with matched controls. The collected samples were subjected to 16S rDNA and metagenomic analyses, and clinical data and blood samples were obtained for further analysis. A total of 180 fecal specimens were collected from 30 patients in both the pulmonary infection and control groups for 16S rDNA analysis, and 3 fecal samples from each group were selected for metagenomic analysis. The study revealed significant alterations in the functional genes of the intestinal microbiome in patients with postoperative pulmonary infection in gastric cancer, primarily involving Klebsiella, Enterobacter, Ruminococcus, and Collinsella. During postoperative pulmonary infection, gut flora and inflammatory factors were found to be associated with the lipopolysaccharide synthesis pathway and short-chain fatty acid (SCFA) synthesis pathway. The study identified enriched populations of Klebsiella, Escherella, and intestinal bacteria during pulmonary infection following gastric cancer surgery. These bacteria were found to regulate the lipopolysaccharide synthesis pathway, contributing to the initiation and progression of pulmonary infections. Inflammation modulation in patients with postoperative pulmonary infection may be mediated by short-chain fatty acids. The study also revealed that SCFA synthesis pathways were disrupted, affecting inflammation-related immunosuppression pathways. By controlling and maintaining intestinal barrier function, SCFAs may potentially reduce the occurrence of pulmonary infections after gastric cancer surgery. These findings suggest that targeting the gut microbiome and SCFA synthesis pathways may be a promising approach for preventing postoperative pulmonary infections in gastric cancer patients.

Effects of different feeding patterns on the rumen bacterial community of tan lambs, based on high-throughput sequencing of 16S rRNA amplicons.

The mutton quality of Chinese Tan lambs (Ovis aries) has declined as feeding patterns have shifted from pasturing to pen rationing. While pen-fed can enhance the growth performance of sheep, it falls short in terms of meat quality attributes such as meat color and tenderness. Furthermore, compared to pen-fed, pasture-fed husbandry increases the proportion of oxidative muscle fibers, decreases the proportion of glycolytic muscle fibers, and reduces LDH (lactate dehydrogenase) activity. Mutton quality is affected by fatty acids, and rumen microorganisms play a role in the synthesis of short-chain fatty acids, long-chain fatty acids, and conjugated linoleic acids. We used 16S rRNA sequencing to analyze the effects of two feeding patterns on the rumen bacteria of Tan lambs. In a randomized block design with 24 newborn Tan lambs, 12 lambs were fed by ewes in pasture and 12 were fed by pen-fed ewes. At 2 months, the biceps femoris and the longissimus dorsi were analyzed by gas chromatography for intramuscular fat content and fatty acids composition, and DNA in the rumen contents was extracted and used to analyze the structure of the bacterial community. Different feeding patterns had no significant effect on the intramuscular fat content of the biceps femoris and longissimus dorsi of the lambs, but there was a significant effect on fatty acids composition. The fatty acids c18:3n3 and c20:5n3 were significantly higher in the biceps femoris and longissimus dorsi of the pasture group than the pen-ration group. The alpha diversity of rumen bacteria was significantly greater in the pasture group compared to the pen-ration group. The ACE index, Chao1 index, Shannon index, and Simpson index were all notably higher in the pasture group than in the pen-ration group. Utilizing beta diversity analysis to examine the differences in rumen bacteria between the pasture group and pen-ration group, it was observed that the homogeneity of bacteria in the pasture group was lower than that in the pen-ration group. Furthermore, the diversity of rumen bacteria in the pasture group was greater than that in the pen-ration group. Twenty-one phyla were identified in the pasture group, and 14 phyla were identified in the pen-ration group. The dominant phyla in the pasture group were Bacteroidetes and Fibrobacteres; the dominant phyla in the pen-ration group were Proteobacteria and Bacteroidetes. The relative abundance of Proteobacteria was significantly higher in the pen-ration group than in the pasture group (p < 0.01). Diversity at the genus level was also higher in the pasture group, with 176 genera in the pasture group and 113 genera in the pen-ration group. The dominant genera in the pasture group were Prevotella_1, Rikenellaceae_RC9_gut_group, and Bacteroidales_BS11_gut_group_Na; the dominant genera in the pen-ration group were Prevotella_1, Prevotella_7, Succinivibrionaceae_UCG-001, and Succinivibrionaceae_NA. The rumen bacterial community of Tan sheep is significantly influenced by pen-ration and pasture-fed conditions, leading to variations in fatty acid content in the muscle, which in turn affects the flavor and nutritional value of the meat to some extent. Pasture-fed conditions have been shown to enhance the diversity of rumen bacterial community structure in Tan sheep, thereby increasing the nutritional value of their meat.

Metabolic potential of gut microbiota in helminth infections as a way to achieve bronchial asthma control

The aim of the review was to analyze modern experimental studies and clinical trials aimed at assessing metabolic activity of gut microbiota in bronchial asthma (BA) and helminth infections.Being one of the most common chronic heterogeneous respiratory diseases, bronchial asthma secures its place among global health problems of great socioeconomic importance. In recent years, a lot of data has been accumulated indicating that the state of gut microbiota is an important factor determining the state of human health and affecting immune mechanisms underlying the development of allergic diseases in childhood. Dysbiosis of gut microbiota is due not only to changes in its composition, but also to disturbances in its metabolism. In accordance with the “gut – lung axis” concept, maintaining healthy gut microbiota and correcting its disorders, including strategies aimed at activating synthesis of short-chain fatty acids in the intestine, may become a new way to prevent and treat chronic respiratory diseases in childhood. In turn, experimental and epidemiological studies have shown the immunomodulatory activity of helminths. It is assumed that their impact on the composition and function of gut microbiota is one of the mechanisms by which helminths influence the immune response of the host and the course of BA.

Lignin intervention protected against Pb-induced oxidative stress and hypercholesterolemia via reducing Pb bioaccumulation and regulating gut microbiota in hamster

The widespread environmental heavy metal, Pb, is renowned for inducing irreversible damage to human health. Lignin, an original fiber, emerges as a promising natural candidate for mitigating lead toxicity owing to its exceptional adsorption capacity and biocompatibility. In this study, we conducted an investigation into the potential therapeutic effects of lignin derived from the bamboo (Dendrocalamus Latiforus) shoot shell (BSS-AAL) in alleviating Pb-induced oxidative stress and hypercholesterolemia in hamsters. Our findings demonstrated the remarkable ability of BSS-AAL to reduce Pb accumulation by 27–40% in plasma and 13–84% in tissues. Furthermore, BSS-AAL exerted reparative effects on the antioxidant system, evidenced by substantial reductions in plasma total cholesterol levels by at least 35% and hepatic cholesterol levels by an impressive 66%. Intervention with BSS-AAL also led to favorable alterations in the richness of key microbial genera, including norank_f__Erysipelotrichaceae, unclassified_f__Atopobiaceae, and norank_f__Eubacteriaceae, which are associated with modulating malonaldehyde accumulation, hepatic cholesterol 3-hydroxy-3-methylglutaryl coenzyme A reductase activity, as well as short chain fatty acids synthesis. These findings substantiated BSS-AAL played a vital role in effectively modulating Pb-induced oxidative stress and hypercholesterolemia by reducing Pb accumulation and favorably influencing gut microbiota.

[Relationships between microbiome and neurodegeneration].

Neurodegenerative diseases are often associated with changes in the (gut) microbiome. Based on studies in Parkinson's disease (PD) and Alzheimer's disease (AD), an overview of the current evidence of microbial changes and their possible role in the development of these diseases is given. Analysis, summary, and evaluation of the current literature on (gut) microbiome and neurodegeneration. Numerous studies have shown dysbiotic changes in the gut microbiome of PD and AD patients compared to healthy individuals, some of which might occur even in the prodromal phase. Specifically, these patients show areduction in bacteria involved in the synthesis of short-chain fatty acids. These microbial alterations have been associated with systemic inflammation and acompromised integrity of the intestinal barrier and blood-brain barrier. Bacterial molecules such as lipopolysaccharides may play an important role in these changes. Additionally, the bacterial protein curli, found on the surface of e.g., Escherichia coli, has been shown in vitro and in animal models to promote the misfolding of α-synuclein, thus suggesting acrucial pathomechanism. Moreover, certain oral bacteria appear to be more prevalent in AD patients and may contribute to the pathogenesis of AD. Neurodegenerative diseases are associated with dysbiosis of the (gut) microbiome, which can have diverse systemic effects; however, it remains unclear whether this dysbiosis is acause or aconsequence of the diseases. Further investigation of this (prodromal) microbial imbalance could reveal new approaches for targeted therapeutic manipulation of the microbiome to modify and prevent these diseases.

Percarbonate-strengthened ferrate pretreatment for enhancing short-chain fatty acids production from sewage sludge

Sewage sludge management poses a pressing environmental challenge, demanding the implementation of sustainable solutions to facilitate resource recovery. Short-chain fatty acids (SCFAs) serve as valuable chemicals and renewable energy sources, underscoring the importance of maximizing their production to achieve sustainable waste management. Therefore, this study proposes a novel and green strategy, i.e., percarbonate-strengthened ferrate pretreatment to enhance SCFAs synthesis from sewage sludge, because percarbonate could activate ferrate oxidation through providing (bi) carbonate and hydrogen peroxide. Results show that percarbonate largely reduces the required ferrate dosage for fermentation improvement, and their combination exhibits obvious synergistic effects on SCFAs accumulation and sludge reduction. Under the optimal pretreatment conditions, SCFAs production is promoted to 3670.2 mg COD/L, representing a remarkable increase of 5512.4 %, 156.0 % or 395.1 % compared to the control, percarbonate alone or ferrate alone, respectively. Mechanism explorations demonstrate that percarbonate-strengthened ferrate pretreatment significantly enhances sludge solubilization, elevates substrate biodegradability, and alters the physiochemical properties of sludge to favor organics fermentation. The synergistic effects on solid organics release and sludge properties can be attributed to the combined mechanisms of enhanced oxidation and alkaline hydrolysis. Further investigations on metabolic pathways reveal that the combination substantially improves key enzyme activities associated with hydrolysis and SCFAs formation, while severely inhibits that of SCFAs consumption. These findings are further supported by the functional genes coding relevant enzymes. Moreover, the combination alters microbial structures and compositions, leading to the screening and enrichment of key microbes that facilitate SCFAs accumulation. This innovative strategy holds significant promise in advancing sewage sludge management towards a more circular and resource-efficient paradigm.