Health Benefits and Side Effects of Short-Chain Fatty Acids

Systematically-designed mixtures outperform single fibers for gut microbiota support

Dietary fiber interventions to modulate the gut microbiota have largely relied on isolated fibers or specific fiber sources. We hypothesized that fibers systematically blended could promote more health-related bacterial groups. Initially, pooled in vitro fecal fermentations were used to design dietary fiber mixtures to support complementary microbial groups related to health. Then, microbial responses were compared for the designed mixtures versus their single fiber components in vitro using fecal samples from a separate cohort of 10 healthy adults. The designed fiber mixtures outperformed individual fibers in supporting bacterial taxa across donors resulting in superior alpha diversity and unexpected higher SCFA production. Moreover, unique shifts in community structure and specific taxa were observed for fiber mixtures that were not observed for single fibers, suggesting a synergistic effect when certain fibers are put together. Fiber mixture responses were remarkably more consistent than individual fibers across donors in promoting several taxa, especially butyrate producers from the Clostridium cluster XIVa. This is the first demonstration of synergistic fiber interactions for superior support of a diverse group of important beneficial microbes consistent across people, and unexpectedly high SCFA production. Overall, harnessing the synergistic potential of designed fiber mixtures represents a promising and more efficacious avenue for future prebiotic development.

Quantitative method for intestinal short chain fatty acids based on stable isotope labeling combined with liquid chromatography-mass spectrometry

Short chain fatty acids (SCFAs) are produced from the breakdown of dietary proteins and fiber by gut microbes, and they have a close relationship with the health and diseases of the host. However, due to the similar structures of SCFAs, the abundance of active molecules, the wide concentration range in biological samples, and the characteristics such as high polarity, poor chromatographic separation, and ionization performance, it is challenging to comprehensively and accurately quantify SCFAs. This study utilized a stable isotope-labeled carboxyl derivatization reagent d0-/d6-2,4-dimethoxy-6-piperazin-1-yl pyrimidine (d0-/d6-DMPP) to establish a new method for the wide-coverage quantification analysis of SCFAs using ultra-high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS), capable of detecting the content of 16 SCFAs. The method demonstrated low limits of detection (LODs) of 0.05-0.5 nmol/L and limits of quantification (LOQs) of 0.1-1.0 nmol/L, with excellent linearity (R² > 0.99), intra-day precision (RSD < 8.5 %), and inter-day precision (RSD < 7.8 %). Using this quantitative analysis method, we successfully quantified 16 SCFAs from the colonic contents of rats with 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced ulcerative colitis (UC) and Sini decoction (SND) intervention. It was found that after the interventional treatment with SND, the levels of 7 SCFAs in the colonic contents of rats with UC were significantly up regulated, including acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, 2-methylbutyric acid, and hexanoic acid, while 4 SCFAs were significantly down regulated, including 3-hydroxyisovaleric, 3-methyl-2-oxobutanoic acid, 3-methyl-2-oxovaleric acid, and 4-methyl-2-oxovaleric acid. These findings suggested that SND might exert its therapeutic effect on UC by regulating the metabolism of SCFAs. Overall, this study not only provides a new method for the analysis of SCFAs with high sensitivity and wide-coverage but also offers important scientific evidence for understanding the mechanism of SND against UC.

A Critical Review of Postbiotics as Promising Novel Therapeutic Agents for Clostridial Infections

Clostridial infections, known for their severity and rapid progression, present significant challenges in both clinical and veterinary fields. These bacteria, which can survive without oxygen and produce protective spores, cause many diseases, ranging from simple gastrointestinal disorders to severe and potentially fatal infections including botulism, tetanus, and gas gangrene. The rising occurrence of antibiotic-resistant strains and the repetitive character of some Clostridial illnesses, including Clostridioides difficile infections (CDI), highlight the immediate need for alternate treatment approaches. Postbiotics, which are metabolites derived from probiotics, are showing great potential as effective agents against these diseases. The current study offers a comprehensive investigation of the potential of postbiotics as therapeutic agents for treating Clostridial infections, including C. difficile, Clostridium perfringens, Clostridium botulinum, and Clostridium tetani. It also examines the processes by which postbiotics exert their effects. Preliminary investigations have shown that postbiotics have promising antibacterial and antibiofilm properties, indicating their potential as adjunct agents in methods for controlling microbial growth. Nevertheless, more study is required to thoroughly demonstrate their medicinal uses.

Bugs got milk? Exploring the potential of lactose as a prebiotic ingredient for the human gut microbiota of lactose-tolerant individuals

Milk consumption is important to help meet daily nutrient requirements. However, lactose-present in dairy products-has been associated with digestive discomfort in individuals who are lactose intolerant or have inadequate lactase activity. Yet, a new perspective on this dietary component has emerged: its potential as a prebiotic for the lactose-tolerant population. We hypothesized that ingestion of lactose may improve the microbial community structure and metabolism of the gut microbiota from healthy adults. First, we assessed the acute impact of lactose ingestion on the gut microbiota of adults using a short-duration in vitro batch colonic model. Subsequently, we employed a long-duration in vitro dynamic multivessel colonic model to evaluate the effects of lactose chronic ingestion. In both cases, a mixture of lactose/galactose/glucose was administered in a defined proportion to mimic lactose metabolism and galactose/glucose absorption in lactose-tolerant adults. The hypothesis was confirmed, as a modulatory prebiotic effect was revealed on the microbial community structure and metabolism of the microbiota upon treatments simulating the ingestion of three doses of lactose, equivalent to half a glass, one glass, and two glasses of cow's milk. The long-duration model confirmed this potential, increasing the relative abundance of the beneficial genera Lactobacillus, Akkermansia, and Faecalibacterium, while the usually detrimental genus Clostridium decreased. Additionally, the health-promoting microbial metabolites acetate, propionate, and lactate were increased. Therefore, lactose ingestion could positively modulate the gut microbiota in healthy lactose-tolerant adults, thereby promoting gut health and shedding light on the dietary benefits of consuming milk.

Canine-derived Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 combat aging by regulating gut microbiota

Old age raises the susceptibility of age-related disease in domestic dogs. Discovering effective anti-aging interventions is key for mitigating age-related disease and conserving "healthspan" in pet dogs. In this study, 2 bacterial strains were isolated from canine feces. After screening and identifying the strains, Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 were chosen to intervene during d-galactose-induced senescence in mice. We found that administering Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 improved the aging phenotype of mice, including an increase in antioxidant activity, a decrease in pro-inflammatory cytokines, and the restoration of intestinal and liver tissue damage. In addition, Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 lead to changes in the structure of intestinal microbiota in aging mice. Specifically, there was a decrease in the abundance of the Cyanobacteria and an increase in the abundance of Akkermansia and Lactobacillus. More importantly, there was a significant increase in acetic acid, a short-chain fatty acid, due to intervention with the 2 strains. This increase might be attributed to higher Akkermansia. We show that the modulation of gut microbiota and metabolism in aging mice may be a promising strategy through which Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 might exert their anti-aging effects.

Faecalibacterium prausnitzii Is Associated with Disease Severity in MASLD but Its Supplementation Does Not Improve Diet-Induced Steatohepatitis in Mice

The gut microbiota plays an important role in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD). In this study, we aimed to evaluate the role of the butyrate-producing bacterium Faecalibacterium prausnitzii in MASLD and whether supplementation with butyrate-producing bacteria, in particular Faecalibacterium prausnitzii, can ameliorate diet-induced steatohepatitis in mice. The relative abundance of the genus Faecalibacterium and its most abundant strain Faecalibacterium prausnitzii was determined by 16S rRNA sequencing and quantitative polymerase chain reaction (qPCR), respectively, in 95 participants with MASLD and 19 healthy control subjects. Butyrate and butyrate-producing bacteria (Faecalibacterium prausnitzii and Coprococcus comes) were gavaged to C57BL/6 mice fed a steatohepatitis-inducing diet. The fecal relative abundance of Faecalibacterium and Faecalibacterium prausnitzii was decreased in subjects with MASLD versus healthy controls and lower in individuals with MASLD and stage 3-4 fibrosis versus those with stage 0-2 fibrosis. Sodium-butyrate supplementation improved hepatic steatosis in mice on high-fat diet (HFD). Gavage of various butyrate-producing bacteria including Faecalibacterium prausnitzii and Coprococcus comes isolated from humans did not improve HFD-induced liver disease in mice. Although the abundance of Faecalibacterium prausnitzii is associated with MASLD severity in humans, its gavage to mice does not improve experimental diet-induced liver disease.

Effects of NatureKnit™, a Blend of Fruit and Vegetable Fibers Rich in Naturally Occurring Bound Polyphenols, on the Metabolic Activity and Community Composition of the Human Gut Microbiome Using the M-SHIME® Gastrointestinal Model

This study evaluated the impact of a proprietary blend of fruit and vegetable fibers rich in naturally occurring bound polyphenols (commercially marketed as NatureKnitTM), compared to purified fibers (inulin and psyllium), on the human gut microbiome using the validated M-SHIME® gastrointestinal model. A short-term single-stage colonic M-SHIME® experiment (with fecal inoculum from three healthy human donors) was used to evaluate the test products compared to a negative control. Samples were assessed for pH, gas pressure, short-chain fatty acid (SCFA) production, lactate, and ammonium from 0 h to 48 h. Microbial community composition was assessed at 0 h (negative control only), 24 h, and 48 h (lumen) or 48 h (mucosal). All test products were fermented well in the colon as demonstrated by decreases in pH and increases in gas pressure over time; these changes occurred faster with the purified fibers, whereas NatureKnit™ demonstrated slow, steady changes, potentially indicating a gentler fermentation process. SCFA production significantly increased over the course of the 48 h experiment with all test products versus negative control. SCFA production was significantly greater with NatureKnit™ versus the purified fibers. Shifts in the microbial community composition were observed with all test products versus negative control. At the conclusion of the 48 h experiment, the absolute bacterial abundance and the richness of observed bacterial taxa in the lumen compartment was significantly greater with NatureKnit™ compared with inulin, psyllium, and negative control. Overall, NatureKnit™ demonstrated greater or similar prebiotic effects on study measures compared with established prebiotic fibers.

The Aging Immune System: A Critical Attack on Ischemic Stroke

Ischemic stroke caused by cerebrovascular embolism is an age-related disease with high rates of disability and mortality. Although the mechanisms of immune and inflammatory development after stroke have been of great interest, most studies have neglected the critical and unavoidable factor of age. As the global aging trend intensifies, the number of stroke patients is constantly increasing, emphasizing the urgency of finding effective measures to address the needs of elderly stroke patients. The concept of "immunosenescence" appears to explain the worse stroke outcomes in older individuals. Immune remodeling due to aging involves dynamic changes at all levels of the immune system, and the overall consequences of central (brain-resident) and peripheral (non-brain-resident) immune cells in stroke vary according to the age of the individual. Lastly, the review outlines recent strategies aimed at immunosenescence to improve stroke prognosis.

The Modulatory Role of Bioactive Compounds in Functional Foods on Inflammation and Metabolic Pathways in Chronic Diseases

Chronic diseases are major contributors to global morbidity and mortality. More than 70% of deaths worldwide are caused by chronic diseases, including cardiovascular diseases (CVDs), obesity, type 2 diabetes, and cancer. These diseases are characterised by chronic low-grade inflammation and metabolic dysregulation. Incorporating functional foods into daily diet has been suggested as a complementary strategy to promote health and lower the risk of non-communicable diseases. Functional foods, known as foods that confer health benefits beyond basic nutrition, have been reported to exhibit preventive and therapeutic benefits such as anti-inflammatory properties for human health. Therefore, the aim of this state-of-the-art review will synthesise the findings from recent and high-quality studies that investigated the modulatory role of some commonly reported bioactive active compounds, such as polyphenols, omega-3 fatty acids, probiotics, and prebiotics, in inflammation and metabolic pathways.

The association between dietary fiber intake and osteoarthritis: a cross-sectional study from the 1999-2018 U.S. National Health and Nutrition Examination Survey

OBJECTIVE

The relationship between dietary fiber intake and osteoarthritis (OA) remains unclear. This cross-sectional study, using data from the National Health and Nutrition Examination Survey (NHANES), aimed to examine the association between dietary fiber intake and OA.

METHODS

A cross-sectional analysis was conducted using NHANES data from 1999 to 2018 to assess the association between dietary fiber intake and OA. Univariate and multivariate weighted logistic regression models, along with restricted cubic spline (RCS) curves, were used to evaluate the relationship.

RESULTS

A total of 30,620 participants were included in this study, of whom 1,864 were diagnosed with OA, yielding a prevalence of 5.74%. Multivariate weighted logistic regression revealed a consistent inverse association between dietary fiber intake and OA (OR = 0.99, 95% CI: 0.97-0.99, P = 0.018). When dietary fiber was treated as a categorical variable, the highest quartile of intake (Q4) was associated with a 27% lower risk of OA compared to the lowest quartile (Q1) (OR = 0.73, 95% CI: 0.58-0.92, P = 0.007). The RCS analysis indicated a non-linear association between dietary fiber intake and OA risk (non-linear P = 0.013). The threshold effect interval suggested that dietary fiber intake in the range of 14.4-26.7 g was associated with a reduced risk of OA, while intake above this level did not provide significant additional protection.

CONCLUSION

The findings demonstrate a negative linear association between dietary fiber intake and OA risk. Increasing dietary fiber consumption may reduce the risk of OA, offering potential strategies for its prevention and management. Further studies are needed to confirm these findings.

Microbial effects of cold-pressed Sacha inchi oil supplementation in rats

Oil supplements have various benefits for metabolism, particularly Sacha inchi oil (SI), which is rich in polyunsaturated fatty acids (PUFAs) such as ω-3 and fat-soluble vitamins. However, the impacts of oil supplements on gut health remain unclear. The aim of this study was to compare the effects of an SI supplement with those of lard oil (LO), known for its high saturated fatty acid content, and a normal diet on gut health in male Sprague Dawley rats for 12 consecutive weeks. Fecal DNA was used to assess gut microbiota diversity and species abundance, diversity, and function prediction. Colon tissue from each rat was examined for colon crypt depth and histology. Rats administered the LO supplement exhibited higher dysbiosis than those administered the SI supplement, with the LO supplement influencing the relative abundance of various bacteria at the genus level. A KEGG analysis was conducted to examine the effects on metabolic pathways, revealing that the SI supplement promoted carbohydrate metabolism while reducing immune system activity. In contrast, the LO supplement increased replication, repair, and translation activities. A histological analysis of the colon tissues showed no significant alterations in crypt depth or lesions in all groups, indicating that neither supplement induced adverse structural changes in the gut. The results of this study suggest that SI supplementation modulates the gut microbiota, thereby enhancing gut health and metabolic function.

Complementary Feeding and Infant Gut Microbiota: A Narrative Review

Background: The complementary feeding period, spanning from 6 to 24 months of age, marks the transition from an exclusive liquid diet in infants to a dietary pattern requiring the introduction of solid foods to meet nutritional demands. Complementary feeding coincides with other critical development windows, including the maturation of the gut microbiome. However, the effects of specific solid foods on gut microbiota and the subsequent influence on health outcomes require further investigation. Methods: This narrative review analyzes published research from January 2004 to October 2024 and aims to summarize the current evidence of the effects of complementary feeding on the infant gut microbiota. Results: A total of 43 studies were included in this review. Overall, multiple studies reported an increase in alpha-diversity after solid food introduction. Bifidobacteriaceae is the predominant bacterial family during the first 6 months of life, shifting to Lachnospiraceae, Ruminococcaceae, and Clostridium spp. after the introduction of solid foods. The timing of solid food introduction may also influence gut microbiota, though results were inconclusive. The effect of individual dietary components on the gut microbiota was conflicting, with limited evidence to make inferences. Conclusions: Because of variations in study design, dietary intake quantification, and minimal follow-up, a lack of conclusive evidence exists describing the relationship between complementary feeding and gut microbiota outcomes in infants. Future research to describe these relationships should focus on the impact of individual foods on microbial diversity and maturation, as well as the relationship between microbiota and infant health outcomes.

The impact of regular sauerkraut consumption on the human gut microbiota: a crossover intervention trial

BACKGROUND

Sauerkraut is a fermented food that has been suspected to have a beneficial impact on the gut microbiome, but scientific evidence is sparse. In this crossover intervention trial with 87 participants (DRKS00027007), we investigated the impact of daily consumption of fresh or pasteurized sauerkraut for 4 weeks on gut microbial composition and the metabolome in a healthy study population.

RESULTS

Using shotgun metagenomic sequencing, we observed changes in single bacterial species following fresh and pasteurized sauerkraut consumption. More pronounced changes were observed in the pasteurized sauerkraut intervention arm. Only pasteurized sauerkraut consumption increased serum short-chain fatty acids (SCFAs).

CONCLUSIONS

The gut microbiome of healthy individuals is rather resilient to short-term dietary interventions even though single species might be affected by sauerkraut consumption. Video Abstract.

A Promising Approach for the Food Industry: Enhancing Probiotic Viability Through Microencapsulated Synbiotics

The role of prebiotics and probiotics in promoting gut health is increasingly recognized in food development and nutrition research. This study explored the enhancement of probiotic viability in the food industry through microencapsulated synbiotics, focusing on Lactiplantibacillus plantarum NCIMB 11974 with fructooligosaccharides (FOSs) and inulin as prebiotics. The effect of encapsulation in a chitosan-coated alginate matrix on probiotic survival under simulated gastrointestinal conditions showed a significant effect of 2% FOS concentration on the growth of Lactiplantibacillus plantarum NCIMB 11974. The optimization of microencapsulation parameters by the Taguchi method revealed a 2% sodium alginate concentration, a nozzle size of 200 µm, and a concentration of 0.4% chitosan solution as ideal, producing microcapsules with an estimated average diameter of 212 µm. Viability assessments in simulated gastric juice and simulated intestinal juice showed that chitosan-coated alginate microcapsules notably enhanced probiotic survival, achieving log 8 CFU mL-1 viability in both environments, a marked improvement over the uncoated variant. The study emphasizes the importance of microencapsulation, particularly by sodium alginate and chitosan, as a viable strategy to improve the survival and delivery of probiotics through the digestive system. By improving the stability and survivability of probiotics, microencapsulation promises to expand the use of synbiotics in various foods, contributing to the development of functional foods with health-promoting properties.

Modulation of microbiota composition and markers of gut health after in vitro dynamic colonic fermentation of plant sterol-enriched wholemeal rye bread

A human oral phase followed by a dynamic gastrointestinal digestion and colonic fermentation (simgi®) has been applied to wholemeal rye bread (WRB) and PS-enriched WRB (PS-WRB). The aim of this study was to evaluate the impact of these solid and high-fiber food matrices on the metabolism of PS, modulation of the microbiota and production of short-chain fatty acids (SCFA) and ammonium ion after a simulated chronic intake (5 days). In both breads, campesterol, campestanol, stigmasterol, β-sitosterol, sitostanol, Δ5-avenasterol, Δ5,24-stigmastadienol, Δ7-stigmastenol, and Δ7-avenasterol were identified, of which only β-sitosterol was metabolized to sitostenone after PS-WRB treatment. The presence of fiber in both breads exerted a prebiotic effect after fermentation by the increase in Firmicutes (Lactobacillus genus, maximum abundance of 89-99 %) and Actinobacteria (Bifidobacterium genus, maximum abundance of 30-31 %), reflected in an increase of SCFA content. The reduction of proteolytic activity confirmed by the decrease in ammonium ion contents is related to a reduction in the Proteobacteria phylum. Thus, PS-WRB could be considered as a healthy staple food choice since, besides the known hypocholesterolemic effect of PS, rye bread fiber preserves the beneficial microbiota and exerts a positive impact on markers of gut health.

Short-chain fatty acids and cancer

Short-chain fatty acids (SCFAs), derived from the diet and the microbiota, serve as crucial links between the diet, gut microbiota, metabolism, immunity, and cancer. They function as energy sources through β-oxidation and regulate macromolecular synthesis, G protein-coupled receptor (GPCR) and histone deacetylase (HDAC) activities, protein modifications, signaling pathways, and gene expression in cells within the tumor microenvironment, particularly in tumor and immune cells. The critical role of SCFAs in maintaining normal homeostasis and influencing tumor progression highlights the potential of targeting SCFA-mediated cellular processes for cancer prevention and treatment.

Dietary polysaccharides from dragon fruit pomace, a co-product of the fruit processing industry, exhibit therapeutic potential in high-fat diet-induced metabolic disorders

The increasing prevalence of metabolic disorders, often associated with high-fat diets (HFD), highlights the need for new therapeutic approaches, especially from natural sources. Dragon fruit pomace, a by-product of the fruit processing industry, is rich in polysaccharides with potential health benefits. This study investigates the effects of dragon fruit pomace-derived polysaccharides (PDPS) in alleviating HFD-induced metabolic dysfunction. Treatment with PDPS in mice fed a high-fat diet led to significant decreases in body weight increase, abdominal fat accumulation, total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) concentrations, along with a notable elevation in high-density lipoprotein cholesterol (HDL-C) concentrations. PDPS also improved glucose tolerance and prevented fat accumulation in the liver and adipose tissue. Additionally, PDPS exhibited anti-inflammatory properties, evidenced by reduced levels of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in the liver. Gut microbiota analysis indicated a shift toward beneficial bacteria, such as Romboutsia, Lachnospiraceae_NK4A136_group, Coriobacteriaceae_UCG-002, and Blautia. These findings suggest that PDPS may mitigate HFD-induced metabolic issues by enhancing lipid metabolism, glycemic control, and gut health, positioning it as a promising, sustainable functional ingredient for dietary interventions aimed at managing metabolic disorders.

Chitosan and its derivatives: A novel approach to gut microbiota modulation and immune system enhancement

Chitosan, a biopolymer derived from the deacetylation of chitin found in crustacean shells and certain fungi, has attracted considerable attention for its promising health benefits, particularly in gut microbiota maintenance and immune system modulation. This review critically examines chitosan's multifaceted role in supporting gut health and enhancing immunity, beginning with a comprehensive overview of its sources, chemical structure, and its dual function as a dietary supplement and biomaterial. Chitosan's prebiotic effects are highlighted, with a focus on its ability to selectively stimulate beneficial gut bacteria, such as Bifidobacteria and Lactobacillus, while enhancing gut barrier integrity and inhibiting the growth of pathogenic microorganisms. The review delves deeply into chitosan's immunomodulatory mechanisms, including its impact on antigen-presenting cells, cytokine profiles, and systemic immune responses. A detailed comparative analysis assesses chitosan's efficacy relative to other prebiotics and immunomodulatory agents, examining challenges related to bioavailability and metabolic activity. Beyond its role in gut health, this review explores chitosan's potential as a dual-action agent that not only supports gut microbiota but also fortifies immune resilience. It introduces emerging research on novel chitosan derivatives, such as chitooligosaccharides, and evaluates their enhanced bioactivity for functional food applications. Special attention is given to sustainability, with an exploration of alternative, plant-based sources of chitosan and their implications for both health and environmental stewardship. Also, the review identifies new research avenues, such as the growing interest in chitosan's role in the gut-brain axis and its potential mental health benefits through microbial interactions. By addressing these innovative areas, the review aims to shift the focus from basic health effects to chitosan's broader impact on public health. The findings encourage further exploration, particularly through human trials, and emphasize chitosan's untapped potential in revolutionizing health and disease management.

Integrative analysis of gut microbiota and fecal metabolites in cynomolgus monkeys with spontaneous type 2 diabetes mellitus

BACKGROUND

Accumulating evidence suggests that gut microbiota (GM) is clearly associated with the pathogenesis of type 2 diabetes mellitus (T2DM). However, the underlying mechanism of GM dysbiosis participates the onset of T2DM is not fully understood. The spontaneous T2DM cynomolgus monkeys are a powerful model for understanding the pathological mechanism of T2DM.

METHODS

Fecal samples were collected from 7 spontaneous T2DM cynomolgus monkeys and 7 healthy controls matched with similar age for multi-omics analysis, including shotgun metagenomic sequencing, untargeted metabolomics profiling, and targeted metabolomics focusing on short chain fatty acids (SCFAs). Lastly, the correlation network between differential gut microbial species and fecal metabolites was performed to explore the potential biomarkers of T2DM.

RESULTS

We found that 17 low-abundance species showed significant differences between the two groups. Analysis of gut microbial functions revealed that 16 KEGG pathways and 51 KEGG modules were significantly different in the two groups. Meanwhile, 276 fecal DEMs were identified, and these DEMs were enriched in the KEGG pathways, including Nucleotide metabolism, ABC transporters, Purine metabolism and so on. Lastly, Spearman correlation network analysis showed that the species of Anaerostipes_hadrus and Lachnoanaerobaculum_umeaense, and the metabolites including Glycerophospho-N-palmitoyl ethanolamine and 2-Hydroxycinnamic acid might serve as potential biomarkers of T2DM.

CONCLUSIONS

Our study provides novel insights into specific alterations in the GM composition, gene functions, and fecal metabolic profiles in spontaneous T2DM cynomolgus monkeys.

Role of the gut microbiome in psychological symptoms associated with inflammatory bowel diseases

The brain-gut axis constitutes the basis for the bidirectional communication between the central nervous system and the gastrointestinal tract driven by neural, hormonal, metabolic, immunological, and microbial signals. Alterations in the gut microbiome composition as observed in inflammatory bowel diseases can modulate brain function and emerging empirical evidence has indicated that interactions among the brain-gut microbiome-axis seem to play a significant role in the pathogenesis of both inflammatory bowel diseases and psychiatric disorders and their comorbidity. Yet, the immunological and molecular mechanisms underlying the co-occurrence of inflammatory bowel diseases and psychological symptoms are still poorly understood. The aim of this narrative review is to highlight contemporary empirical findings supporting a pivotal role of the gut microbiome in the pathophysiology of highly prevalent neuropsychiatric symptoms in inflammatory bowel diseases such as fatigue, depression, and anxiety. Finally, we focus on microbiome modulation as potential treatment option for comorbid neuropsychiatric symptoms in immune-mediated diseases and especially in inflammatory bowel diseases. High-quality clinical trials are required to clarify how microbiome modulation through dietary interventions or probiotic, prebiotic or synbiotic treatment can be used clinically to improve mental health and thus quality of life of patients with inflammatory bowel diseases.

Effects of Selected Food Additives on the Gut Microbiome and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

The purpose of this article is to present selected food additives as disruptors of normal intestinal homeostasis with a potential impact on the development of metabolic dysfunction-associated steatotic liver disease (MASLD). A comprehensive literature search was conducted in three major electronic databases: PubMed, ScienceDirect, and Google Scholar. MASLD is a prevalent liver condition that is closely related to the global rise in obesity. Its pathogenesis is multifactorial, with genetic, environmental, and metabolic factors playing a key role. The "multiple-hit" hypothesis suggests that a Western-style diet, rich in ultra-processed foods, saturated fats, and food additives, combined with low physical activity, contributes to obesity, which promotes lipid accumulation in the liver. Recent studies underscore the role of impaired intestinal homeostasis in the development of MASLD. Food additives, including preservatives, emulsifiers, and sweeteners, affect gut health and liver function. Selected preservatives inhibit pathogenic microorganisms but disrupt the intestinal microbiota, leading to changes in intestinal permeability and liver dysfunction. Some emulsifiers and thickeners can cause inflammation and alter the gut microbiome, contributing to liver steatosis. Furthermore, the use of sweeteners such as sucralose and aspartame has been linked to changes in liver metabolism and intestinal microbial composition, which in turn promotes metabolic disorders.

Bee Pollen Phytochemicals and Nutrients as Unequaled Pool of Epigenetic Regulators: Implications for Age-Related Diseases

Bee pollen is characterized by an exceptional diversity and abundance of micronutrients and bioactive phytochemicals. This richness remains very sparsely investigated, but accumulating evidence strongly supports a promising future for bee pollen in human nutrition and medicine. Epigenetic regulation is among the most compelling biomedical topics that remain completely untapped in bee pollen and bee derivative research. In our current research, we identified numerous ubiquitous compounds that are consistently present in this matrix, regardless of its botanical and geographical origins, and that have been well studied and documented as epigenetic regulators in recent years. Given the relative newness of both bee pollen biomedical research and epigenetic studies within nutritional, pharmaceutical, and medical sciences, this review aims to bridge these valuable fields and advance related experimental investigations. To the best of our knowledge, this is the first work that has aimed to comprehensively investigate the epigenetic modulatory potential of bee pollen compounds. Our findings have also unveiled several intriguing phenomena, such as a dual effect of the same compound depending on the cellular context or the effect of some compounds on the cross-generational heritability of epigenetic traits. Although experimental studies of epigenetic regulation by bee pollen as a whole or by its extract are still lacking, our current study clearly indicates that this research avenue is very promising and worth further investigations. We hope that our current work constitutes a foundational cornerstone of future investigations for this avenue of research.

Protective Role of Dietary Polyphenols in the Management and Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM), a serious metabolic disorder, is a worldwide health problem due to the alarming rise in prevalence and elevated morbidity and mortality. Chronic hyperglycemia, insulin resistance, and ineffective insulin effect and secretion are hallmarks of T2DM, leading to many serious secondary complications. These include, in particular, cardiovascular disorders, diabetic neuropathy, nephropathy and retinopathy, diabetic foot, osteoporosis, liver damage, susceptibility to infections and some cancers. Polyphenols such as flavonoids, phenolic acids, stilbenes, tannins, and lignans constitute an extensive and heterogeneous group of phytochemicals in fresh fruits, vegetables and their products. Various in vitro studies, animal model studies and available clinical trials revealed that flavonoids (e.g., quercetin, kaempferol, rutin, epicatechin, genistein, daidzein, anthocyanins), phenolic acids (e.g., chlorogenic, caffeic, ellagic, gallic acids, curcumin), stilbenes (e.g., resveratrol), tannins (e.g., procyanidin B2, seaweed phlorotannins), lignans (e.g., pinoresinol) have the ability to lower hyperglycemia, enhance insulin sensitivity and improve insulin secretion, scavenge reactive oxygen species, reduce chronic inflammation, modulate gut microbiota, and alleviate secondary complications of T2DM. The interaction between polyphenols and conventional antidiabetic drugs offers a promising strategy in the management and treatment of T2DM, especially in advanced disease stages. Synergistic effects of polyphenols with antidiabetic drugs have been documented, but also antagonistic interactions that may impair drug efficacy. Therefore, additional research is required to clarify mutual interactions in order to use the knowledge in clinical applications. Nevertheless, dietary polyphenols can be successfully applied as part of supportive treatment for T2DM, as they reduce both obvious clinical symptoms and secondary complications.

Study on the Effect of Radish Sprouts on Short-Chain Fatty Acids and Gut Microbial Diversity in Healthy Individuals

This study aimed to assess the impact of radish sprouts on the gut microbiota of healthy individuals. Radish sprout additives, subjected to short-term storage and steam treatment, were used to intervene in an in vitro culture of human gut microbiota. The influence of radish sprouts on the gut microbiota was evaluated by monitoring short-chain fatty acid (SCFA) content and proportion in the fermentation broth, and microbial diversity was assessed using 16S rDNA amplicon sequencing. The results indicated that the gut microbiota produced a substantial amount of SCFA within 48 h of fermentation, with a right-skewed distribution across all groups. The addition of both digestates enhanced Firmicutes diversity, while Bacteroidetes and Proteobacteria diversity remained stable between the control and fresh sprout groups. The 30 s steam treatment group showed an increase in Bacteroidetes and a decrease in Proteobacteria diversity. The abundance of Bacilli, Bacillaceae, and Bacillus was significantly higher in both the fresh and steam-treated groups compared to the control. Both fresh and steam-treated radish sprout digestates enriched gut microbiota diversity, with steam treatment showing superior effects. These findings suggest that radish sprout consumption may positively influence gut microbiota, with steam treatment potentially enhancing these benefits.

Therapeutic effects of composite probiotics derived from fermented camel milk on metabolic dysregulation and intestinal barrier integrity in type 2 diabetes rats

Background

In the Kazakh community of Xinjiang, China, fermented camel milk has been traditionally used to manage diabetes. This study evaluates the effects of composite probiotics derived from fermented camel milk (CPCM) on metabolic disturbances in a rat model of Type 2 diabetes (T2DM).

Methods

T2DM was induced in Wistar rats using streptozotocin. Experimental groups included a diabetic control, Metformin, and low- and high-dose CPCM. Measurements over 6 weeks included body weight (BW), fasting blood glucose (FBG), oral glucose tolerance test (OGTT), glycated hemoglobin (HbA1c), C-peptide (CP), lipid profiles, inflammatory markers, fecal short-chain fatty acids (SCFAs), and tight junction protein expression in colonic tissues.

Results

High-dose CPCM significantly increased BW by 22.2% (p < 0.05) and reduced FBG by 6.5 mmol/L (p < 0.001). The OGTT AUC decreased by 40.1% (p < 0.001), and HbA1c levels fell by 22.9% (p < 0.01). CP levels rose by 21.8% (p < 0.05). Lipid profiles improved: TC decreased by 40.0%, TG by 17.1%, and LDL-C by 30.4% (all p < 0.001). Fecal SCFAs, including acetate (75.4%, p < 0.001), methyl acetate (18.9%, p < 0.05), and butyrate (289.9%, p < 0.001), increased, with total SCFAs rising by 89.7% (p < 0.001). Inflammatory markers IL-1β (12.7%, p < 0.01), TNF-α (16.7%, p < 0.05), and IL-6 (17.3%, p < 0.01) were significantly reduced. Tight junction protein expression (ZO-1, occludin, claudin-1) and mucin (MUC2) in colonic tissues increased (p < 0.05). CPCM treatment also reduced serum total bile acids by 24.9%, while hepatic and fecal bile acids increased by 114.0% and 37.8% (all p < 0.001). CPCM lowered serum DAO, D-lactate, and LPS levels (all p < 0.001). mRNA levels of TGR5 and CYP7A1 in the liver, and TGR5 and FXR in the colon, were markedly elevated (all p < 0.001). Histological examinations revealed reduced pancreatic inflammation and hepatic steatosis, with restored colonic structure.

Conclusion

CPCM treatment significantly improved metabolic dysregulation in the T2DM rat model, reducing blood glucose and lipid levels, enhancing intestinal barrier function, and increasing insulin secretion. These findings highlight the therapeutic potential of CPCM in T2DM management and probiotics' role in metabolic health.

Whole pulse ingredient inclusion in macronutrient-balanced diets increased fecal concentrations of propionic acid but not total bile acids in healthy adult large-breed dogs after 20 weeks

This study investigated the effects of up to 45% inclusion of whole pulse ingredients in grain-free (GF) diets on the excretion of bile acids (BAs) and other fecal metabolites in healthy large-breed dogs. Twenty-eight adult Siberian Huskies were fed 1 of 4 experimental diets formulated to meet the same macronutrient profiles for 20 wk: 1) grain-inclusive diet with 45% corn (Ctl), 2) GF diet with 15% pulses (Pulse15), 3) GF diet with 30% pulses (Pulse30), 4) GF diet with 45% pulses (Pulse45). All diets included chicken meal and pea starch. Fecal samples were collected on weeks 2 and 19. Bile acids were analyzed using ultra-performance liquid chromatography-MRM/MS technology, while fecal metabolites were analyzed using Agilent HP1000 high-performance liquid chromatography. Bile acids and fecal metabolite data were analyzed using the PROC GLIMMIX procedure in SAS studios (SAS version 9.4, SAS Inst., Inc., Cary, NC). All means were separated using the Tukey-Kramer adjustment (significant when P < 0.05). After 20 wk of feeding, concentrations of lithocholic acid were greater in Pulse15 and Pulse30 than Ctl (P = 0.001), but all were similar to Pulse45. Concentrations of deoxycholic (P = 0.054), lithocholic (P = 0.001), total secondary (P = 0.022), and total BA (P = 0.045) tended to be linearly associated with dietary pulse inclusion. Dogs consuming Pulse30 had greater fecal propionic acid concentrations than Ctl (P = 0.017), but both were similar to Pulse15 and Pulse45. Total branched-chain fatty acids (P = 0.001) and iso-butyric acid (P < 0.0001) were greater in Ctl than in all pulse groups. Inversely, arabinose concentrations were greater in all pulse groups compared to Ctl (P = 0.001). In summary, diets with up to 45% inclusion of whole pulse ingredients do not increase total BA excretion but may contribute to greater short-chain fatty acids production.

Effects of highland barley β-glucan on gut microbiota composition and metabolism in vitro fermentation

Highland barley β-glucan (HBG) has attracted increasing attention due to its excellent biological activities. However, the effects of HBG on gut flora and metabolites are unknown. Therefore, the effects of HBG on the gut microbiota during fermentation were analyzed by 16 s rRNA sequencing and untargeted metabolomics. The results showed that HBG could enrich microbial diversity, increase the abundance of beneficial bacteria, and inhibit the biology of pathogenic bacteria. In addition, HBG increased the content of short-chain fatty acids and decreased fermentation broth pH. Metabolomics analyses showed that HBG also increased the content of beneficial metabolites such as taurine and affected amino acid metabolism, among other pathways. This study lays the foundation for the application of HBG in functional foods.

Butyrate: A potential mediator of obesity and microbiome via different mechanisms of actions

Butyrate, a short-chain fatty acid, is a crucial product of gut microbial fermentation with significant implications for various metabolic and physiological processes. Dietary sources of butyrate are limited, primarily derived from the fermentation of dietary fibers by butyrate-producing gut bacteria. Butyrate exerts its effects primarily as a histone deacetylase (HDAC) inhibitor and through signaling pathways involving G protein-coupled receptors (GPCRs). Its diverse benefits include promoting gut health, enhancing energy metabolism, and potentially alleviating complications associated with obesity. However, the exact role of butyrate in obesity is still under investigation, with a limited number of human trials necessitating further research to determine its efficacy and safety profile. Moreover, butyrate impact on the gut-brain axis and its modulation of microbiome effect on behavior highlight its broader importance in regulating host physiology. A thorough understanding of the metabolic pathways and mechanisms of butyrate is essential for developing targeted interventions for metabolic disorders. Continued research is crucial to fully realize its therapeutic potential and optimize its clinical applications in human health. In summary, this review illuminates the multifaceted role of butyrate as a potential mediator of obesity and related metabolic changes.

16S rRNA Sequencing and Metabolomics to Analyze Correlation Between Fecal Flora and Metabolites of Squabs and Parent Pigeons

Intestinal microorganisms are essential for maintaining homeostasis, health, and development, playing a critical role in nutrient digestion, growth, and exercise performance in pigeons. In young pigeons, the gut microbiota is primarily acquired through pigeon milk, meaning the microbial composition of parent pigeons directly influences microbial colonization in squabs. However, research on the correlation between the gut microbial diversity of parent pigeons and their offspring remains scarce. This study investigates the fecal microbiota and metabolites of 10 pairs of parent pigeons and 20 squabs raised under a 2 + 2 system. Fecal samples were collected at 15 days of age, and differences in the microbiota and metabolites between the two groups were analyzed using 16S rRNA sequencing and LC-MS/MS. The results showed the following: (1) Squabs exhibited significantly lower α diversity, with a reduction in their Chao1 index and observed OTUs compared to the parent pigeons. (2) Firmicutes dominated the fecal microbiota in both groups, but parent pigeon feces showed a notably higher abundance of Proteobacteria. At the family level, 10 distinct families were identified, with 9 at the genus level and 4 at the species level. (3) A LEfSe analysis identified 16 significantly different bacterial species in the parent pigeons and 7 in the squabs. Functional gene abundance was highest in the metabolism, genetic information processing, and environmental information processing pathways. (4) An LC-MS/MS analysis in cationic mode identified 218 metabolites, with 139 upregulated and 79 downregulated in the squabs relative to the parents. These metabolites were primarily concentrated in five functional categories and enriched in 33 pathways, 2 of which showed significant differences. In conclusion, significant differences in both the α and β diversity of fecal microbiota were observed between squabs and parent pigeons, with similar bacterial species but marked differences in abundance. Metabolite analysis revealed greater richness in the parent pigeon feces. These findings suggest that future gut modulation using beneficial bacteria, such as probiotics, could potentially enhance host health based on microbial and metabolite compositions.

Broccoli, Artichoke, Carob and Apple By-Products as a Source of Soluble Fiber: How It Can Be Affected by Enzymatic Treatment with Pectinex® Ultra SP-L, Viscozyme® L and Celluclast® 1.5 L

Dietary fiber (DF), and especially soluble dietary fiber (SDF), is a nutrient of particular interest today because of its anti-inflammatory role and its ability to reduce cardiovascular risk. Therefore, the enhancement of SDF in foods using different techniques has become a promising field of research. In order to prove the possibility of increasing this SDF content, the effects of different commercial enzymes (Pectinex® Ultra SP-L, Viscozyme® L and Celluclast® 1.5 L) were tested on a variety of carob (CE), artichoke (ARE), apple (APE) and broccoli (BE) by-product extracts. Enzymatic treatment significantly affected SDF content in all by-products, showing the greatest increases for CE, ARE and APE using Celluclast® 1.5 L, while Viscozyme® L obtained the best results after application in BE. On the other hand, positive results were reported in the solubility, WHC and FAC of the by-products due to the enzymatic treatment, being increased in all extracts analyzed. Moreover, a general increase in antioxidant capacity (FRAP, ABTS and DPPH) was observed after enzymatic treatment. Finally, high yields were obtained after the application of the enzymatic processes, reaching values of 80-85% for each food by-product. These results evidenced a potential revalorization of carob, artichoke, apple and broccoli by-products after enzymatic treatment, improving its nutritional and physicochemical properties, revealing a possible application as a higher value-added ingredient.

Short-chain fatty acids as a novel intervention for high-fat diet-induced metabolic syndrome

Metabolic syndrome (MetS) is driven by a complex interplay of genetic, lifestyle, and dietary factors, leading to weight gain, insulin resistance, dyslipidemia, and chronic inflammation. Gut microbiota dysbiosis has been recently recognized as a key contributor to MetS, leading to advancements in gut microbiome-based interventions to improve health outcomes. Considering the unique challenges associated with the use of pre/probiotics, short-chain fatty acids (SCFA), also known as postbiotics, have emerged as promising therapeutic agents due to their role in modulating host metabolism and physiology. Considering this, the aim of the current study was to explore the therapeutic potential of SCFA (butyrate, propionate, and acetate) supplementation against a high-fat diet (HFD)-induced experimental model of MetS in male Wistar rats. Alterations in body weight, lipid profile, histopathology, and adipose tissue accumulation were assessed to establish SCFA-mediated amelioration of experimental MetS. Further, the enzymatic (GPx, Catalase, GR, and GST) and non-enzymatic (LPO, total ROS, and Redox ratio were evaluated. The results indicated that SCFA supplementation could effectively mitigate key features of MetS. A significant reduction in body weight gain and fasting blood glucose levels, along with markedly lowered triglycerides, total cholesterol, and LDL levels, with partial restoration of HDL levels was observed following SCFA supplementation. SCFA administration also attenuated MetS-associated hepatic damage as studied by histopathological investigation and analysis of liver function marker enzyme activities. Such ameliorative effects of SCFA against HFD-induced MetS were owed to potential redox modulation studied using enzymatic and non-enzymatic oxidative stress markers. In conclusion, the study's outcomes show that SCFA supplementation could potentially be used against managing MetS. It underscores the therapeutic potential of SCFA by placing them as a novel gut microbiome-based dietary approach to improve metabolic health and reduce the risk of MetS-associated complications. However, more detailed mechanistic explorations are warranted in the future, leading to their beneficial role in MetS contributing to holistic health outcomes.

The Multifaceted Impact of Bioactive Lipids on Gut Health and Disease

Bioactive lipids have a multifaceted role in health and disease and are recognized to play an important part in gut immunity and disease conditions such as inflammatory bowel disease and colon cancer. Advancements in lipidomics, enabled by mass spectrometry and chromatographic techniques, have enhanced our understanding of lipid diversity and functionality. Bioactive lipids, including short-chain fatty acids, saturated fatty acids, omega-3 fatty acids, and sphingolipids, exhibit diverse effects on inflammation and immune regulation. Short-chain fatty acids like butyrate demonstrate anti-inflammatory properties, enhancing regulatory T cell function, gut barrier integrity, and epigenetic regulation, making them promising therapeutic targets for inflammatory bowel disease and colon cancer. Conversely, saturated fatty acids promote inflammation by disrupting gut homeostasis, triggering oxidative stress, and impairing immune regulation. Omega-3 lipids counteract these effects, reducing inflammation and supporting immune balance. Sphingolipids exhibit complex roles, modulating immune cell trafficking and inflammation. They can exert protective effects or exacerbate colitis depending on their source and context. Additionally, eicosanoids can also prevent pathology through prostaglandin defense against damage to epithelial barriers. This review underscores the importance of dietary lipids in shaping gut health and immunity and also highlights the potential use of lipids as therapeutic strategies for managing inflammatory conditions and cancer.

The moderating effect of dietary fiber intake on the association between sleep pattern and liver fibrosis in metabolic dysfunction-associated steatotic liver disease: a study from NHANES

BACKGROUND

Insufficient nocturnal sleep was associated with a higher risk of fibrosis in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Dietary fiber intake may improve the stimulate the secretion of sleep cytokines, inhibit the inflammatory pathway, contribute to regulating sleep disorders and alleviate liver fibrosis. The associations of dietary fiber intake, sleep patterns, with liver fibrosis remain unclear. The study aimed to explore the associations between dietary fiber, sleep, and liver fibrosis, as well as the moderating effect of dietary fiber intake between sleep patterns and liver fibrosis in MASLD patients.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) database spanning from 2017 to 2020, a cross-sectional study included participants with MASLD was performed to assess the relationship between sleep patterns, dietary fiber intake, and liver fibrosis. Weighted univariate and multivariate logistic regression models were used to examine the linear connection between sleep pattern, dietary fiber intake, and liver fibrosis. Restricted cubic spline (RCS) method was also performed to describe the nonlinear relationship. A two-part linear regression model was also used to estimate threshold effects. The moderating effect of dietary fiber intake was further investigated in different subgroups. All results were presented as odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Totally, 1343 MASLD patients were included for final analysis. Among them, 207 (15.41%) have liver fibrosis. Dietary fiber intake did not correlate significantly with sleep pattern in patients with MASLD (Spearman's r = -0.028, P = 0.1678). Poor sleep pattern was related to higher odds of liver fibrosis (OR = 3.23, 95%CI: 1.05-9.90), while dietary fiber intake ≥ 15 gm/day was associated with lower liver fibrosis risk (OR = 0.51, 95%CI: 0.32-0.83). On the association between sleep pattern and liver fibrosis stratified by dietary fiber intake revealed that poor sleep patterns (OR = 15.13, 95%CI: 4.40-52.01) remained associated with increased liver fibrosis risk among individuals with dietary fiber intake < 15 gm/day. No connection was observed between poor sleep patterns and liver fibrosis in MASLD patients with higher dietary fiber intake, with moderate dietary fiber supplementation beneficial in mitigating poor sleep patterns associated with liver fibrosis. The similar findings were also found in patients aged < 50 years old, ≥ 50 years old, females, those with and without CVD groups, hypertension, and dyslipidemia. Particularly, dietary fiber intake also moderates the relationship between sleep patterns and liver fibrosis in the F4 stage (OR = 13.26, 95%CI: 4.08-43.11).

CONCLUSION

Dietary fiber intake affects the relationship between sleep patterns and liver fibrosis in MASLD patients.

The effect of a new developed synbiotic yogurt consumption on metabolic syndrome components in adults with metabolic syndrome: a randomized controlled clinical trial

BACKGROUND

Studies have proposed that probiotic intake may ameliorate some of the clinical components of metabolic syndrome (MetS). This study aimed to determine the effects of a new developed synbiotic yogurt containing Lactobacillus plantarum, Lactobacillus pentosus, and Chloromyces marcosianos yeast on the components of MetS in adults with MetS.

METHODS

In this randomized, placebo-controlled, clinical trial, 44 participants were divided into two groups to receive 300 grams of synbiotic yogurt or regular yogurt daily for 12 weeks. Anthropometric measurements, blood pressure, and biochemical parameters evaluated before and after the intervention.

RESULTS

Daily consumption of synbiotic yogurt containing L. plantarum, L. pentosus, and C. marcosianos yeast in adults with MetS caused a significant decrease in the levels of fasting blood glucose (FBG) (p = 0.005), fasting insulin (p = 0.001), homeostatic model assessment for insulin resistance (HOMA-IR) index (p < 0.001), waist to hip ratio (WHR) (p = 0.02) and systolic blood pressure (p = 0.008) in the intervention group compared to the control group.

CONCLUSIONS

According to the findings of this study, daily consumption of the synbiotic yogurt was associated with improvements in insulin resistance, systolic blood pressure and WHR, which could be beneficial in patients with MetS.

The effects of AG1® supplementation on the gut microbiome of healthy adults: a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

This study aimed to examine the effect of a commercially available multi-ingredient powder (AG1Ⓡ) on the gut microbiome and assess the impact of AG1Ⓡ on GI tolerability and other clinical safety markers in healthy men and women.

METHODS

Using a double-blind, randomized, two-arm, placebo-controlled, parallel design, we examined a 4-week daily supplementation regimen of AG1Ⓡ vs. placebo (PL). Fifteen men and 15 women provided stool samples for microbiome analysis, questionnaires for digestive quality of life (DQLQ), and completed visual analog scales (VAS) and Bristol stool charts to assess stool consistency and bowel frequency before and after the 4-week intervention. Participant's blood work (CBC, CMP, and lipid panel) was also assessed before and after the 4-week intervention. Alpha diversity was determined by Shannon and Chao1 index scores and evaluated by a two-way ANOVA, beta diversity in taxonomic abundances and functional pathways was visualized using partial least squares-discriminant analyses and statistically evaluated by PERMANOVA. To identify key biomarkers, specific feature differences in taxonomic relative abundance and normalized functional pathway counts were analyzed by linear discriminant analysis (LDA) effect size (LEfSe). Questionnaires, clinical safety markers, and hemodynamics were evaluated by mixed factorial ANOVAs with repeated measures. This study was registered on clinicaltrials.gov (NCT06181214).

RESULTS

AG1Ⓡ supplementation enriched two probiotic taxa (Lactobacillus acidophilus and Bifidobacterium bifidum) that likely stem from the probiotics species that exist in the product, as well as L. lactis CH_LC01 and Acetatifactor sp900066565 ASM1486575v1 while reducing Clostridium sp000435835. Regarding community function, AG1Ⓡ showed an enrichment of two functional pathways while diminishing none. Alternatively, the PL enriched six, but diminished five functional pathways. Neither treatment negatively impacted the digestive quality of life via DQLQ, bowel frequency via VAS, or stool consistency via VAS and Bristol. However, there may have been a greater improvement in the DQLQ score (+62.5%, p = 0.058, d = 0.73) after four weeks of AG1Ⓡ supplementation compared to a reduction (-50%) in PL. Furthermore, AG1Ⓡ did not significantly alter clinical safety markers following supplementation providing evidence for its safety profile.

CONCLUSIONS

AG1Ⓡ can be consumed safely by healthy adults over four weeks with a potential beneficial impact in their digestive symptom quality of life.

Linking reproductive tract microbiota to premature ovarian insufficiency: Pathophysiological mechanisms and therapies

Over the past decade, research on the human microbiota has become a hot topic. Among them, the female reproductive tract (FRT) also has a specific microbiota that maintains the body's health and dynamic balance, especially in the reproductive aspect. When the FRT ecosystem is dysregulated, changes in immune and metabolic signals can lead to pathological and physiological changes such as chronic inflammation, epithelial barrier disruption, changes in cell proliferation and apoptosis, and dysregulation of angiogenesis and metabolism, thereby causing disruption of the female endocrine system. Premature ovarian insufficiency (POI), a clinical syndrome of ovarian dysfunction, is primarily influenced by immune, genetic, and environmental factors. New evidence suggests that dysbiosis of the FRT microbiota and/or the presence of specific bacteria may contribute to the occurrence and progression of POI. This influence occurs through both direct and indirect mechanisms, including the regulation of estrogen metabolism. The use of probiotics or microbiota transplantation to regulate the microbiome has also been proven to be beneficial in improving ovarian function and the quality of life in women with premature aging. This article provides an overview of the interrelationships and roles between the FRT microbiome and POI in recent years, to fully understand the risk factors affecting female reproductive health, and to offer insights for the future diagnosis, treatment, and application of the FRT microbiome in POI patients.

An exploration of fibre intake and bowel function in a sample of adults at an Irish university campus

BACKGROUND

Bowel dysfunction can significantly impair quality of life. Adequate fibre intake is associated with good bowel health but intakes have been reported to be low in Ireland.

AIM

This study aimed to gather data on fibre intake and bowel habits in a cohort of adults at a university campus in Dublin, Ireland.

METHODS

An online questionnaire was developed by adapting validated tools to assess habitual fibre intake and bowel function. The questionnaire was circulated through mailing lists and advertised via QR codes on campus in February/March 2023. Data was analysed using SPSS, p < 0.05 was considered statistically significant.

RESULTS

In total, 275 valid responses were received. Low fibre intakes (< 19 g/day) were found in 50.5% of participants. A significantly higher proportion of males had low fibre intake compared to females (62.2% vs 44.8%, p = 0.039). Nearly a third (30.2%) of respondents experienced mild symptoms of bowel dysfunction, and 13.1% experienced moderate to severe symptoms. An inverse relationship was observed between fibre intake (g/day) and bowel dysfunction (p = 0.033).

CONCLUSIONS

In this cohort, low fibre intakes and some degree of bowel dysfunction were prevalent. Public health campaigns to increase fibre intake could prove to be a cost-effective way to improve bowel function and health amongst adults in Ireland.

Use of Different Synbiotic Strategies to Improve Gut Health in Dogs

This study evaluated the effects of two synbiotic strategies on the intestinal microbiota and immune response in Beagle dogs. Twelve dogs were subjected to a crossover design with three diets: a control diet (CON), a diet supplemented with fiber and B. velezensis DSM 15544 (SYN), and the SYN diet with added porcine plasma (SYN+). Over three periods of seven weeks, fecal samples were analyzed for digestibility, short-chain fatty acids (SCFA), fecal markers, and microbiome composition, while blood samples were assessed for biochemical parameters, leucocytic counts including CD4/CD8 lymphocyte populations, and phagocytic activity. Both SYN and SYN+ diets increased the fecal volume without affecting the consistency and slightly reduced the organic matter and energy digestibility, while increasing SCFA concentrations and reducing branched-chain fatty acids. A microbiome analysis revealed no changes in the alpha diversity, but significant shifts in the beta diversity, with increases in beneficial taxa such as Faecalibacterium prausnitzii and reductions in potentially harmful bacteria like Prevotella copri. Immune response indicators showed increased fecal IgA and higher blood leukocyte counts, particularly lymphocytes and neutrophils, in the SYN diet group. Overall, both synbiotic strategies positively modulated the microbiota and immune response, though the addition of porcine plasma did not confer additional benefits.

Industrial diet intervention modulates the interplay between gut microbiota and host in semi-stray dogs

BACKGROUND

The gut microbiota and derived metabolites play a key role in regulating host physiology. Diet is identified as a key regulatory factor of the microbiota composition and, potentially, of subsequent functionalities. Demonstrating the role of diet may be complex as most human studies are cross-sectional and dietary intervention is often accompanied by hygienic changes. The objective of the present study was to investigate the impact of an industrial diet on the modulation of the microbiota and targeted functionalities using a canine "natural" model.

RESULTS

We carried out a controlled dietary trial in a cohort of Tunisian semi-stray dogs. We made a transition from a natural diet to an industrial kibble diet and monitored the composition of the fecal microbiota, the concentration of short-chain fatty acids (SCFA) and bile acids (BAs), and protease activities. We demonstrated that dietary change significantly decreased fecal primary bile acids levels and protease activities. Interestingly, correlation analyses demonstrated that variation of specific microbial genera were associated with modulated physiological parameters.

CONCLUSIONS

Our study reveals that an industrial diet induces beneficial changes in microbial composition and functions characterised by increased diversity, synthesis of SCFA and secondary bile acids production, stressing the key role of the diet-microbiota-dog crosstalk.

Curcumin Mitigates Gut Dysbiosis and Enhances Gut Barrier Function to Alleviate Metabolic Dysfunction in Obese, Aged Mice

The gut microbiome plays a critical role in maintaining gut and metabolic health, and its composition is often altered by aging and obesity. This study aimed to investigate the protective effects of curcumin on gut dysbiosis, gut barrier integrity, and bile acid homeostasis in aged mice fed a high-fat, high-sugar diet (HFHSD). Eighteen- to twenty-one-month-old male C57BL/6 mice were divided into groups fed a normal chow diet or HFHSD, with or without curcumin supplementation (0.4% w/w) for 8 and 15 weeks. We assessed body weight, food intake, insulin sensitivity, gut microbiota composition, and gene expression in the gut and liver and performed histological analysis of gut tissues. Curcumin supplementation prevented HFHSD-induced weight gain and metabolic disturbances. In the gut, curcumin-treated mice showed a higher abundance of beneficial bacterial genera, such as Lachnospiraceae, Akkermansia, Mucispirillum, and Verrucomicrobiota, alongside a lower abundance of harmful bacterial genera like Desulfobacteria, Alistipes, and Muribaculaceae compared to control. This shift in gut microbiota was associated with improved gut integrity, as demonstrated by increased expression of the tight junction protein occludin and reduced levels of the pro-inflammatory marker interleukin-1β in the ileum. Additionally, curcumin modulated hepatic gene expression involved in bile acid homeostasis, suggesting a positive effect on liver health. Curcumin supplementation can alleviate the negative effects of aging and an HFHSD on the gut microbiome, improve gut barrier integrity, and maintain bile acid homeostasis. These findings highlight curcumin's potential as a dietary intervention for managing obesity- and age-associated gut health issues.

Alterations in Gut Microbiota and Serum Metabolites in Children with Mycoplasma pneumoniae Pneumonia

Background

Over the past years, there has been a significant increase in the incidence of Mycoplasma pneumoniae (MP) infections, particularly among pediatric patients, nationwide. An emerging body of research has established a link between dysbiosis of the host microbiome and the metabolic functioning of the host, which contributes to the development of respiratory diseases.

Methods

A total of 25 children were included in the study, comprising 15 pneumonia patients and 10 healthy children. Stool samples were collected from all participants to analyze the 16S ribosomal RNA (16S rRNA) gene, while serum samples were prepared for untargeted metabolomics to qualitatively and quantitatively assess short-chain fatty acids.

Results

The gut microbial composition of individuals with Mycoplasma pneumoniae pneumonia (MPP) exhibited significant differences compared to healthy children. Notably, diseased children demonstrated higher microbial diversity and an enrichment of opportunistic pathogens, such as Erysipelatoclostridium and Eggerthella. Analysis revealed elevated levels of two specific short-chain fatty acids, namely acetic acid and isobutyric acid, in the MPP group, suggesting their potential as biomarkers for predicting MP infection. Metabolomic signature analysis identified a significant increase in major classes of glycerophospholipids in the MPP group. Moreover, we identified a total of 750 significant correlations between gut microbiota and circulating serum metabolites. MPP enriched genera Erysipelatoclostridium and Eggerthella, exhibited negative associations with indole-3-butyric acid. Additionally, Eggerthella showed a positive correlation with inflammatory metabolites LPC (18:0).

Discussion

Collectively, these findings provide novel insights into the selection of potential biomarkers and the pathogenesis of MPP in children based on the gut microbiota and systemic circulating metabolites.

Intestinal Insights: The Gut Microbiome's Role in Atherosclerotic Disease: A Narrative Review

Recent advances have highlighted the gut microbiota as a significant contributor to the development and progression of atherosclerosis, which is an inflammatory cardiovascular disease (CVD) characterized by plaque buildup within arterial walls. The gut microbiota, consisting of a diverse collection of microorganisms, impacts the host's metabolism, immune responses, and lipid processing, all of which contribute to atherosclerosis. This review explores the complex mechanisms through which gut dysbiosis promotes atherogenesis. We emphasize the potential of integrating microbiota modulation with traditional cardiovascular care, offering a holistic approach to managing atherosclerosis. Important pathways involve the translocation of inflammatory microbial components, modulation of lipid metabolism through metabolites such as trimethylamine-N-oxide (TMAO), and the production of short-chain fatty acids (SCFAs) that influence vascular health. Studies reveal distinct microbial profiles in atherosclerosis patients, with increased pathogenic bacteria (Megamonas, Veillonella, Streptococcus) and reduced anti-inflammatory genera (Bifidobacterium, Roseburia), highlighting the potential of these profiles as biomarkers and therapeutic targets. Probiotics are live microorganisms that have health benefits on the host. Prebiotics are non-digestible dietary fibers that stimulate the growth and activity of beneficial gut bacteria. Interventions targeting microbiota, such as probiotics, prebiotics, dietary modifications, and faecal microbiota transplantation (FMT), present effective approaches for restoring microbial equilibrium and justifying cardiovascular risk. Future research should focus on longitudinal, multi-omics studies to clarify causal links and refine therapeutic applications.

Emerging trends and hotspots in intestinal microbiota research in sepsis: bibliometric analysis

Background

The association between the gut microbiota and sepsis has garnered attention in the field of intestinal research in sepsis. This study utilizes bibliometric methods to visualize and analyze the literature on gut microbiota research in sepsis from 2011 to 2024, providing a scientific foundation for research directions and key issues in this domain.

Methods

Original articles and reviews of gut microbiota research in sepsis, which published in English between 2011 and 2024, were obtained from the Web of Science Core Collection on June 21, 2024. Python, VOSviewer, and CiteSpace software were used for the visual analysis of the retrieved data.

Results

A total of 1,031 articles were analyzed, originating from 72 countries or regions, 1,614 research institutions, and 6,541 authors. The articles were published in 434 different journals, covering 89 different research fields. The number of publications and citations in this research area showed a significant growth trend from 2011 to 2024, with China, the United States, and the United Kingdom being the main research forces. Asada Leelahavanichkul from Thailand was identified as the most prolific author, making him the most authoritative expert in this field. "Nutrients" had the highest number of publications, while "Frontiers in Cellular and Infection Microbiology," "Frontiers in Immunology" and "the International Journal of Molecular Sciences" have shown increasing attention to this field in the past 2 years. Author keywords appearing more than 100 times included "gut microbiota (GM)," "sepsis" and "microbiota." Finally, this study identified "lipopolysaccharides (LPS)," "short-chain fatty acids (SCFAs)," "probiotics," "fecal microbiota transplantation (FMT)" and "gut-liver axis" as the research hotspots and potential frontier directions in this field.

Conclusion

This bibliometric study summarizes current important perspectives and offers comprehensive guidance between sepsis and intestinal microbiota, which may help researchers choose the most appropriate research directions.

Uncovering new Firmicutes species in vertebrate hosts through metagenome-assembled genomes with potential for sporulation

Metagenome-assembled genomes (MAGs) have contributed to identifying non-culturable microorganisms and understanding their ecological functions. MAGs offer an advantage in investigating sporulation-associated genes, especially given the difficulty of isolating many species residing in the gut microbiota of multiple hosts. Bacterial sporulation is a key survival mechanism with implications for pathogenicity and biotechnology. Here, we investigate MAGs from vertebrate hosts, emphasizing taxonomic identification and identifying sporulation-associated genes in potential novel species within the Firmicutes phylum. We identified potential new species in the classes Clostridia (Borkfalkiaceae, Lachnospiraceae, Monoglobaceae, and Oscillospiraceae families) and Bacilli (Bacillaceae and Erysipelotrichaceae families) through phylogenetic and functional pathway analyses, highlighting their sporulation potential. Our study covers 146 MAGs, 124 of them without refined taxonomic assignments at the family level. We found that Clostridia and Bacilli have unique sporulation gene profiles in the refined family MAGs for cattle, swine, poultry, and human hosts. The presence of genes related to Spo0A regulon, engulfment, and spore cortex in MAGs underscores fundamental mechanisms in sporulation processes in currently uncharacterized species with sporulation potential from metagenomic dark matter. Furthermore, genomic analyses predict sporulation potential based on gene presence, genome size, and metabolic pathways involved in spore formation. We emphasize MAGs covering families not yet characterized through the phylogenetic analysis, and with extensive potential for spore-forming bacteria within Clostridia, Bacilli, UBA4882, and UBA994 classes. These findings contribute to exploring spore-forming bacteria, which provides evidence for novel species diversity in multiple hosts, their adaptive strategies, and potential applications in biotechnology and host health.IMPORTANCESpores are essential for bacterial survival in harsh environments, facilitating their persistence and adaptation. Exploring sporulation-associated genes in metagenome-assembled genomes (MAGs) from different hosts contributes to clinical and biotechnological domains. Our study investigated the extent of genes associated with bacterial sporulation in MAGs from poultry, swine, cattle, and humans, revealing these genes in uncultivated bacteria. We identified potential novel Firmicutes species with sporulation capabilities through phylogenetic and functional analyses. Notably, MAGs belonging to Clostridia, Bacilli, and unknown classes, namely UBA4882 and UBA994, remained uncharacterized at the family level, which raises the hypothesis that sporulation would also be present in these genomes. These findings contribute to our understanding of microbial adaptation and have implications for microbial ecology, underlining the importance of sporulation in Firmicutes across different hosts. Further studies into novel species and their sporulation capability can contribute to bacterial maintenance mechanisms in various organisms and their applications in biotechnology studies.

Fermented black chokeberry (Aronia melanocarpa (Michx.) Elliott) products - A systematic review on the composition and current scientific evidence of possible health benefits

Black chokeberry (Aronia melanocarpa (Michx.) Elliott) is recognized for its potential health benefits, largely attributed to its high phenolic content. However, many phenolic compounds possess a low bioavailability, potentially limiting their beneficial effects. Fermentation of chokeberry has been proposed as a method to improve bioavailability, bioactive composition, sensory qualities, and nutritional value. This systematic review provides an overview of fermented chokeberry products, including compound composition, sensory attributes, and health benefits observed in in vivo and in vitro studies. While sensory evaluations highlighted diverse flavour profiles and acceptability, human intervention studies suggested potential benefits for glucose-dependent insulinotropic peptide increase. Animal models indicated anti-obesity and immunomodulatory properties, while in vitro studies demonstrate antioxidant, anti-melanogenesis, and anti-diabetic effects. Despite some promising findings in human and animal trials, challenges such as participant adherence and dosing inconsistencies force further protocol improvements. Through continuous scientific research, fermented chokeberry products may emerge as functional foods contributing to human health.

Effects of acetylated polysaccharide on the prebiotic properties of grape seed proanthocyanidins - Based on in vitro fermentation with Artemisia sphaerocephala Krasch glucomannan

This study evaluated the impact of Artemisia sphaerocephala Krasch glucomannan with different degrees of acetyl group substitution (DS) on the prebiotic properties of grape seed proanthocyanidins (GSP). UV spectra, CIELab, and dynamic light scattering analyses indicated DS-influenced variable interactions between GSP and glucomannan. In vitro fermentation demonstrated that glucomannan enhanced the solubility of some phenolic compounds, and decreased the pH value of fermentation liquids. The production of acetate acid and total short chain fatty acids in the GSP fermentation liquid increased with the degree of DS of glucomannan. Notably, acetylated glucomannan exerted dramatic effects on GSP-induced gut microbiota modulation. The relative abundances of Bacteroides ovatus and Bacteroides decreased as DS increased. Meanwhile, Bacteroides acidifaciens and Akkermansia muciniphila have a positive correlation, even though the GSP-promoted enrichment of A. muciniphila was inhibited by the added glucomannan. Moreover, glucomannan enhanced the metabolism of nucleotides, secondary bile acid, and glycan inhibited by GSP. These findings suggest that acetylated glucomannan affect the prebiotic properties of GSP with its DS serving as a key factor.

Modulation of the Immune Environment in Glioblastoma by the Gut Microbiota

Studies increasingly support the role of the gut microbiota in glioma development and treatment, although the exact mechanisms remain unclear. Research indicates that the gut microbiota can influence glioma progression, response to therapies, and the effectiveness of treatments like immunotherapy, with certain microbial compositions being linked to better outcomes. Additionally, the gut microbiota impacts the tumor microenvironment, affecting both tumor growth and the response to treatment. This review will explore glioma, the gut microbiota, and how their interaction shapes glioma development and therapy responses. Additionally, this review examines the influence of gut microbiota metabolites, such as short-chain fatty acids (SCFAs) and tryptophan, on glioma development and treatment. It also explores gut microbiome signaling via pattern recognition receptors, and the role of molecular mimicry between microbial and tumor antigens in glioblastoma, and if these interactions affect glioma development and treatment.

Gut Microbiota-Derived Metabolites and Their Role in the Pathogenesis of Necrotizing Enterocolitis in Preterm Infants: A Narrative Review

Background: Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease that occurs predominantly in premature infants and is characterized by the inflammation and necrosis of the intestine, showing high morbidity and mortality rates. Despite decades of research efforts, a specific treatment is currently lacking, and preventive strategies are the mainstays of care. This review aims to help understand the complex interplay between gut microbiota and their metabolites in NEC pathogenesis. In particular, we focused on how these factors can influence gut health, immune responses, and intestinal barrier integrity. Discussion: Current research has increasingly focused on the role of the gut microbiota and their metabolites in NEC pathogenesis, thanks to their involvement in modulating gut health, immune responses, and intestinal barrier integrity. Conclusions: A deeper understanding of the interplay between gut microbiota and their metabolites is essential for developing personalized strategies to prevent NEC. By targeting these microbial interactions, new therapeutic approaches may emerge that offer improved outcomes for preterm infants at a high risk of NEC.

The role of dietary fibre in intestinal heat shock protein regulation

The gastrointestinal tract serves as a pivotal physical barrier that prevents the translocation of exogenous substances from the intestinal lumen into the systemic circulation. Dysfunction of intestinal barrier function has been implicated in the pathogenesis of several diseases, such as metabolic disorders. Heat shock proteins (HSPs) play a critical role in maintaining the resilience and viability of epithelial cells when exposed to stressors. Evidence suggests that dietary fibre (DF), a known inducer of HSP production, may be a promising candidate for strengthening the intestinal barrier. Understanding the regulation of intestinal HSPs and the protective effect of DF is critical to defending against environmental threats and preserving human health. To date, six DFs—pectin, chicory, psyllium, guar gum, partially hydrolysed guar gum, and xylooligosaccharide—have been reported to have promotive effects on intestinal HSP induction. DF promotes intestinal HSP induction through gut microbiota-dependent and independent mechanisms. DF is fermented by gut microbiota to produce short-chain fatty acids, specifically butyrate and propionate, to promote HSP production. Meanwhile, DF also promotes intestinal HSP induction through direct interaction with intestinal epithelial cells, independent of gut microbiota activity, although the precise mechanism is still unclear. Regulation of intestinal HSP occurs by transcriptional modulation through activation of heat shock transcription factors, primarily heat shock factor 1, or at the post-transcriptional level by modulation of the translation process. This review highlights recent advances in understanding the role of DF in improving intestinal barrier function, with particular emphasis on the regulatory mechanisms of intestinal HSPs.

Reutilization of Fruit Waste as Potential Prebiotic for Probiotic or Food-grade Microorganisms in Food Applications: A Review

Food waste has been a global issue with 2.5 billion tons generated globally in 2021. Approximately 46% of the food waste is contributed by fruit and vegetable waste. Due to improper waste handling, these fruit by-products have a negative impact on the environment through soil and water pollution, the greenhouse effect, global warming, and eutrophication. However, research has shown the potential to reuse fruit waste in various applications for sustainability owing to their high source of valuable components and potential health benefits. In recent years, researchers have also explored the potential of reutilizing fruit waste as a prebiotic. Hence, literatures from the past 10 years has been critically analyzed and presented in this review. This review focused on the potential of fruit waste as a prebiotic for probiotic and gastrointestinal microorganisms and its food applications. The nutritional composition and bioactive compounds of the fruit wastes had been introduced to reflect their potential as prebiotics. Moreover, the increase in bioactive compounds and bioactivities in probiotics with the presence of fruit wastes has been reviewed. The impact of fruit by-products on the growth of the probiotic and its survivability in food matrices as compared to established prebiotic and the absence of prebiotics have also been extensively discussed in this review. This review also highlighted some of the factors that might contribute to the negative effect of fruit waste on probiotics. The safety concerns and future prospects of reutilizing fruit wastes for food applications have been emphasized. The review article is beneficial for researchers exploring fruit wastes as prebiotics and industrialists who are interested in incorporating fruit wastes as an added-value ingredient for food applications.