Synthesis Of Short-chain Fatty Acids Research Articles

A Comprehensive Review Exploring the Protective Role of Specific Commensal Gut Bacteria against Salmonella

Gut microbiota is a diverse community of microorganisms that constantly work to protect the gut against pathogens. Salmonella stands out as a notorious foodborne pathogen that interacts with gut microbes, causing an imbalance in the overall composition of microbiota and leading to dysbiosis. This review focuses on the interactions between Salmonella and the key commensal bacteria such as E. coli, Lactobacillus, Clostridium, Akkermansia, and Bacteroides. The review highlights the role of these gut bacteria and their synergy in combating Salmonella through several mechanistic interactions. These include the production of siderophores, which compete with Salmonella for essential iron; the synthesis of short-chain fatty acids (SCFAs), which exert antimicrobial effects and modulate the gut environment; the secretion of bacteriocins, which directly inhibit Salmonella growth; and the modulation of cytokine responses, which influences the host’s immune reaction to infection. While much research has explored Salmonella, this review aims to better understand how specific gut bacteria engage with the pathogen, revealing distinct defense mechanisms tailored to each species and how their synergy may lead to enhanced protection against Salmonella. Furthermore, the combination of these commensal bacteria could offer promising avenues for bacteria-mediated therapy during Salmonella-induced gut infections in the future.

Exploring the Multifaceted Therapeutic Potential of Probiotics: A Review of Current Insights and Applications.

The interplay between human health and the microbiome has gained extensive attention, with probiotics emerging as pivotal therapeutic agents due to their vast potential in treating various health issues. As significant modulators of the gut microbiota, probiotics are crucial in maintaining intestinal homeostasis and enhancing the synthesis of short-chain fatty acids. Despite extensive research over the past decades, there remains an urgent need for a comprehensive and detailed review that encapsulates probiotics' latest insights and applications. This review focusses on the multifaceted roles of probiotics in promoting health and preventing disease, highlighting the complex mechanisms through which these beneficial bacteria influence both gut flora and the human body at large. This paper also explores probiotics' neurological and gastrointestinal applications, focussing on their significant impact on the gut-brain axis and their therapeutic potential in a broad spectrum of pathological conditions. Current innovations in probiotic formulations, mainly focusing on integrating genomics and biotechnological advancements, have also been comprehensively discussed herein. This paper also critically examines the regulatory landscape that governs probiotic use, ensuring safety and efficacy in clinical and dietary settings. By presenting a comprehensive overview of recent studies and emerging trends, this review aims to illuminate probiotics' extensive therapeutic capabilities, leading to future research and clinical applications. However, besides extensive research, further advanced explorations into probiotic interactions and mechanisms will be essential for developing more targeted and effective therapeutic strategies, potentially revolutionizing health care practices for consumers.

Effects of Various Flavors of Baijiu on the Microbial Communities, Metabolic Pathways, and Flavor Structures of Dongbei Suancai.

This study aimed to assess the effects of Chinese Baijiu with different flavors as supplementary material on microbial communities and flavor formation during inoculated fermentation of Chinese Dongbei Suancai. The results showed that the addition of Fen flavor Baijiu significantly increased the relative abundance of Candida, Luzhou flavor Baijiu increased the relative abundance of Pedobacter and Hannaella, while Maotai flavor Baijiu increased the Chryseobacterium and Kazachstania. A total of 226 volatile metabolites were detected in Suancai fermented when adding different flavors of Baijiu. Furthermore, the significantly upregulated metabolites (p < 0.01) of Suancai after adding Baijiu increased by 328.57%, whereas the significantly downregulated metabolites decreased by 74.60%. Simultaneously, the addition of Baijiu promoted the synthesis and decomposition of amino acids and short-chain fatty acids in the early and middle stages of fermentation. Further, Maotai flavor Baijiu improved the diversification of metabolic pathways in the late stage of Suancai fermentation. The E-nose response showed that sulfur-organic, broad-alcohol, sulfur-chlor was the principal differential flavor in Suancai caused by adding Baijiu with different flavors. Simultaneously, Fen flavor Baijiu and Luzhou flavor Baijiu accelerated the formation of the Suancai flavor. These results indicated that Baijiu with different flavors had significant effects on the flavor formation of inoculated fermented Suancai.

РОЛЬ МИКРОБИОТЫ КИШЕЧНИКА И ОТДЕЛЬНЫХ ПРОДУКТОВ ИХ МЕТАБОЛИЗМА В РАЗВИТИИ ОЖИРЕНИЯ У ДЕТЕЙ

Abstract. Introduction. Obesity is one of the major problems in pediatrics worldwide. In recent years, the role of the gut microbiota in the development of various pathological conditions, including childhood obesity and its complications, has been increasingly discussed. We have presented the data characterizing changes in the gut microbiota in overweight patients and discussed their potential role in the development of this disease. Aim. To consider the key points of forming the intestinal microbiota in the neonatal period and the relationship of this process with the development of obesity in the subsequent years of the child’s life, the peculiarities of the microbiological landscape in obese patients, and the functional role of individual metabolites in its formation. Materials and Methods. A review of the scientific literature in the biomedical publication databases, such as PubMed, Medline, eLibrary, Google Scholar, and the Cochrane Library. Results and Discussion. Gut microbiota interact symbiotically with the human body, influencing metabolic activity and physiological characteristics. The microbiota formed at an early age are the basis of general health, but unfavorable influences on the processes of formation of the infant’s intestinal microbiota, such as non-physiological birth, artificial feeding, treatment with antibacterial drugs, can lead to the formation of pathological conditions. Metabolic processes in obese patients are particularly affected by qualitative changes in the intestinal microbiota and impaired synthesis of short-chain fatty acids. Excessive quantities of short-chain fatty acids produced by specific members of the gut microbiota represent an additional energy source and could lead to an energy imbalance, contributing to the development of obesity. Conclusions. Individual members of the gut microbiota can also be considered as predictors of obesity complications. Essential short-chain fatty acids are only a small part of the wide range of metabolites produced by gut bacteria, which also exert their influence on the metabolic and immune homeostasis of the human body.

Prospective association of the infant gut microbiome with social behaviors in the ECHO consortium

BackgroundIdentifying modifiable risk factors of autism spectrum disorders (ASDs) may inform interventions to reduce financial burden. The infant/toddler gut microbiome is one such feature that has been associated with social behaviors, but results vary between cohorts. We aimed to identify consistent overall and sex-specific associations between the early-life gut microbiome and autism-related behaviors.MethodsUtilizing the Environmental influences on Children Health Outcomes (ECHO) consortium of United States (U.S.) pediatric cohorts, we gathered data on 304 participants with fecal metagenomic sequencing between 6-weeks to 2-years postpartum (481 samples). ASD-related social development was assessed with the Social Responsiveness Scale (SRS-2). Linear regression, PERMANOVA, and Microbiome Multivariable Association with Linear Models (MaAsLin2) were adjusted for sociodemographic factors. Stratified models estimated sex-specific effects.ResultsGenes encoding pathways for synthesis of short-chain fatty acids were associated with higher SRS-2 scores, indicative of ASDs. Fecal concentrations of butyrate were also positively associated with ASD-related SRS-2 scores, some of which may be explained by formula use.LimitationsThe distribution of age at outcome assessment differed in the cohorts included, potentially limiting comparability between cohorts. Stool sample collection methods also differed between cohorts. Our study population reflects the general U.S. population, and thus includes few participants who met the criteria for being at high risk of developing ASD.ConclusionsOur study is among the first multicenter studies in the U.S. to describe prospective microbiome development from infancy in relation to neurodevelopment associated with ASDs. Our work contributes to clarifying which microbial features associate with subsequent diagnosis of neuropsychiatric outcomes. This will allow for future interventional research targeting the microbiome to change neurodevelopmental trajectories.

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.

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.

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.

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 &amp;lt; 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 &amp;lt; 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 &amp;lt; 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.