Search Results (179)

Background/Objectives: Neuroinflammation, a hallmark of Alzheimer’s disease (AD), is characterized by elevated levels of inflammatory signaling molecules, including cytokines and eicosanoids, as well as increased microglial reactivity, and is augmented by gut microbiota dysbiosis via the gut–brain axis. We conducted a pilot experiment to elucidate the anti-inflammatory effects of dietary omega-3 polyunsaturated fatty acid (ω-3 PUFA) eicosapentaenoic acid (EPA) on the gut microbiota and neuroinflammation. Methods: Female APP/PS1 mice (TG) and non-transgenic littermates (WT), 13–14 months old, were fed a diet supplemented with 0.3% EPA or control chow for 3 weeks. The gut microbiota composition, hippocampal and plasma eicosanoids levels, platelet activation, and microglial phagocytosis, as well as the brain and retinal genes and protein expression, were analyzed. Results: EPA supplementation decreased the percentage of Bacteroidetes and increased bacteria of the phylum Firmicutes in APP/PS1 and WT mice. Inflammatory lipid mediators were elevated in the hippocampus of the TG mice, accompanied by a reduction in the endocannabinoid docosahexaenoyl ethanolamide (DHEA). Dietary EPA did not affect hippocampal lipid mediators, but reduced the levels of arachidonic-derived 5-HETE and N-arachidonoylethanolamine (AEA) in WT plasma. Moreover, EPA supplementation decreased major histocompatibility complex class II (MHCII) gene expression in the retina in both genotypes, and MHCII+ cells in the hippocampus of TG mice. Conclusions: This pilot study showed that short-term EPA supplementation shaped the gut microbiota by increasing butyrate-producing bacteria of the Firmicutes phylum and decreasing Gram-negative LPS-producing bacteria of the Bacteroidetes phylum, and downregulated the inflammatory microglial marker MHCII in two distinct regions of the central nervous system (CNS). Further investigation is needed to determine whether EPA-mediated effects on the microbiome and microglial MHCII have beneficial long-term effects on AD pathology and cognition. Full article

Stress has been implicated in the onset of mental disorders such as depression, with the prefrontal cortex (PFC) playing a crucial role. However, the underlying mechanisms remain to be fully elucidated. Metabolites secreted by intestinal flora can enter the bloodstream and exert regulatory effects on the body. Consequently, this study aims to investigate the molecular mechanisms by which gut flora influences ferroptosis in PFC neurons, thereby affecting depression-like behavioral changes in mice subjected to acute stress. Initially, we established a mouse model of acute restraint stress (3-day duration) and verified that stress-induced ferroptosis of PFC neurons contributed to depression-like behavioral alterations in mice, as evidenced by morphological, behavioral, and molecular biology assessments. Subsequently, through fecal microbiota transplantation (FMT) experiments, we established a significant correlation between gut microbiota and ferroptosis of PFC neurons in acute stress-exposed mice. 16S rDNA sequencing identified butyric acid-producing bacteria, specifically g_Butyricimonas and its primary metabolite, butyric acid, as critical regulators of ferroptosis in PFC neurons in acutely stressed mice. Furthermore, the intervention of butyrate demonstrated its potential to ameliorate damage to the intestinal and blood–brain barriers in these mice. This intervention also mitigated depression-like behaviors induced by ferroptosis of PFC neurons by alleviating systemic inflammatory responses. The findings of this study indicate that acute stress-induced ferroptosis of PFC neurons plays a critical role in depression-like behavioral changes in mice. Additionally, the gut microbiota metabolite butyrate can modulate ferroptosis and depression-like behavioral changes through the gut–brain axis. Full article

Chronic stress poses threats to the physical and psychological well-being of dogs. Resveratrol (Res) is a polyphenol with antidepressant properties and has rarely been studied in dogs. This study aimed to investigate the stress-relieving effects and underlying mechanism of Res in dogs. Dogs were fed a basal diet supplemented with Res for 35 days. The fecal microbiota of the dogs was cultured with Res in vitro. The results show that Res improved the stress-related behaviors and increased the serum levels of 5-hydroxytryptamine (5-HT), brain-derived neurotrophic factor (BDNF), immunoglobulin A, and antioxidant capacity in dogs. Res downregulated the hormones of the hypothalamic–pituitary–adrenal axis. The abundance of butyric-producing bacteria, like Blautia, increased, while the growth of Fusobacterium related to gut inflammation was inhibited in the Res group. A higher content of fecal butyric acid was observed in the Res group. The metabolome indicated that Res increased the fecal and serum levels of tryptophan (Trp) and decreased the consumption of Trp by microorganisms. A chronic unpredictable mild stress mouse model was established, and Res was administered for 35 days. The results show that Res ameliorated the stress-related behavior and increased the levels of Trp and 5-HT in the whole brains of mice. The relative mRNA expression of genes associated with the tight junction protein, aryl hydrocarbon receptor, and Trp transporters in the colon were upregulated. In conclusion, Res could ameliorate canine stress by increasing 5-HT, BDNF, and the antioxidant capacity and improving the immune function and stress response, which was attributed to the role of Res in the restructuring of gut microbiota and the modulation of tryptophan metabolism. Full article

Metabolic disorders, including type 2 diabetes mellitus (T2DM), obesity, and metabolic syndrome, are systemic conditions that profoundly impact the skin microbiota, a dynamic community of bacteria, fungi, viruses, and mites essential for cutaneous health. Dysbiosis caused by metabolic dysfunction contributes to skin barrier disruption, immune dysregulation, and increased susceptibility to inflammatory skin diseases, including psoriasis, atopic dermatitis, and acne. For instance, hyperglycemia in T2DM leads to the formation of advanced glycation end products (AGEs), which bind to the receptor for AGEs (RAGE) on keratinocytes and immune cells, promoting oxidative stress and inflammation while facilitating Staphylococcus aureus colonization in atopic dermatitis. Similarly, obesity-induced dysregulation of sebaceous lipid composition increases saturated fatty acids, favoring pathogenic strains of Cutibacterium acnes, which produce inflammatory metabolites that exacerbate acne. Advances in metabolomics and microbiome sequencing have unveiled critical biomarkers, such as short-chain fatty acids and microbial signatures, predictive of therapeutic outcomes. For example, elevated butyrate levels in psoriasis have been associated with reduced Th17-mediated inflammation, while the presence of specific Lactobacillus strains has shown potential to modulate immune tolerance in atopic dermatitis. Furthermore, machine learning models are increasingly used to integrate multi-omics data, enabling personalized interventions. Emerging therapies, such as probiotics and postbiotics, aim to restore microbial diversity, while phage therapy selectively targets pathogenic bacteria like Staphylococcus aureus without disrupting beneficial flora. Clinical trials have demonstrated significant reductions in inflammatory lesions and improved quality-of-life metrics in patients receiving these microbiota-targeted treatments. This review synthesizes current evidence on the bidirectional interplay between metabolic disorders and skin microbiota, highlighting therapeutic implications and future directions. By addressing systemic metabolic dysfunction and microbiota-mediated pathways, precision strategies are paving the way for improved patient outcomes in dermatologic care. Full article

Canastra cheese, an artisanal cheese produced in Serra da Canastra—Brazil, has great cultural importance. Furthermore, this cheese has nutritional and sensory attributes that make it of great economic importance. Its microbiota is composed of different bacteria and yeasts. Some yeasts already isolated by our research group have been characterized as potential probiotics. Probiotic microorganisms have garnered scientific interest, as improvements in the physical, chemical and sensory characteristics of food products have been reported when these microorganisms are used. In this context, the objective of this work was to evaluate Kluyveromyces lactis and Torulaspora delbrueckii, which were previously isolated from Canastra cheese, as autochthonous starter cultures. Canastra cheese was produced under three different conditions: (1) cheese with “Pingo” (natural starter), (2) cheese with “Pingo” + yeast mixed culture, and (3) cheese with only mixed yeast culture. The results showed that the mixed yeast inoculum significantly influenced the lactic acid bacteria population. Yeast populations remained at around 106 CFU/g after 45 days of maturation. Furthermore, cheeses containing the yeast mixed with inoculum had an initial lactose content reduced by 92.80% compared to cheese produced with “Pingo” (87.70%). The antioxidant activity, evaluated using the ABTS method, showed that cheeses containing the mixed yeast culture had higher percentages of antioxidant activity at 45 days of maturation. The texture profile of the cheeses changed over time. In general, the cheese containing the yeast mixed culture and “Pingo” and the cheese containing “Pingo” had the lowest hardness at 30 days of maturation (5245 and 5404 N, respectively). Among the volatile compounds, 3-methylbutyl octanoate, phenethyl butyrate, phenethyl propionate, isobutyl butanoate and pentyl propionate were found only in cheeses produced with yeast mixed culture. The obtained results demonstrated that the use of autochthones probiotic cultures could improve the cheese characteristics without negatively impacting the traditional physicochemical attributes of Canasta cheese. Full article

Kombucha, a fermented tea beverage, is produced through the symbiotic interaction of several microbial strains, including acetic acid bacteria, lactic acid bacteria, and yeast, collectively known as symbiotic culture of bacteria and yeast (SCOBY). As its health benefits and distinctive flavor gain wider recognition, consumer demand and research on kombucha fermentation have increased. This study focused on developing starter cultures to produce functional kombucha through precision fermentation technology using selected microbial strains newly isolated from food sources. The isolated bacterial and yeast strains were evaluated and selected based on their fermentation characteristics. Notably, a lactic acid bacterial strain was chosen for its ability to overproduce the γ-amino butyric acid (GABA), a functional food component known to enhance cognitive function and reduce mental stress. To produce the GABA-fortified kombucha, selected single strains of Acetobacter pasteurianus, Lactiplantibacillus plantarum, and Saccharomyces cerevisiae were mixed and used as starter cultures. By optimizing the inoculation ratios and initial sugar concentration, a functional kombucha enriched with acetic acid, lactic acid, and GABA was successfully produced. The resulting kombucha demonstrated 2.2 mg/L of GABA production and 1.15 times higher antioxidant activity after the fermentation, highlighting its enhanced health-promoting properties. Full article

In a previous experiment, we showed that the odor of Bos taurus manure slurries could be improved by anaerobic incubation with the sugars glucose, lactose, and sucrose. This improvement was due to reductions in the concentrations of malodorants, including dimethyl disulfide, p-cresol, p-ethylphenol, indole, and skatole, and a shift to the production of fruity esters, including ethyl butyrate and propyl propanoate. Due to large concentrations of lactic acid produced by the sugar-amended manure slurries, we inferred that lactic acid bacteria were involved in improving the manure slurry odor. Here, through 16S rRNA amplicon sequencing for microbiome analysis, we show that lactic acid bacterial growth was promoted by the addition of all three sugars. Lactobacillus buchneri and an unknown Lactobacillus sp. were the most prominent lactic acid bacteria stimulated by sugar addition. Lactobacillales were found only in trace abundances in unamended manure slurries. The relative abundance of orders such as Clostridiales, Bifidobacteriales, and Erysipelotrichales were not noticeably affected by sugar amendment. However, the disaccharides lactose and sucrose seemed to increase the relative abundance of Bifidobacterium, whereas the monosaccharide glucose did not. We conclude that lactic acid bacteria are the primary bacteria involved in improving odor in dairy cow manure slurries and present strategies to enhance their abundance in animal wastes. Full article

Weaning in piglets presents significant physiological and immunological challenges, including gut dysbiosis and increased susceptibility to post-weaning diarrhoea (PWD). Abrupt dietary, environmental, and social changes during this period disrupt the intestinal barrier and microbiota, often necessitating antimicrobial use. Sustainable dietary strategies are critical to addressing these issues while reducing reliance on antimicrobials. Reducing dietary crude protein mitigates the availability of undigested proteins for pathogenic bacteria, lowering harmful by-products like ammonia and branched-chain fatty acids, which exacerbate dysbiosis. Organic acid supplementation improves gastric acidification, nutrient absorption, and microbial balance, while also serving as an energy-efficient alternative to traditional grain preservation methods. Increasing intestinal butyrate, a key short-chain fatty acid with anti-inflammatory and gut-protective properties, is particularly promising. Butyrate strengthens intestinal barrier integrity by upregulating tight junction proteins, reduces inflammation by modulating cytokine responses, and promotes anaerobic microbial stability. Exogenous butyrate supplementation via salts provides immediate benefits, while endogenous stimulation through prebiotics (e.g., resistant starch) and probiotics promotes sustained butyrate production. These interventions selectively enhance butyrate-producing bacteria such as Roseburia and Faecalibacterium prausnitzii, further stabilising the gut microbiota. Integrating these strategies can enhance gut integrity, microbial resilience, and immune responses in weaned piglets. Their combination offers a sustainable, antimicrobial-free approach to improving health and productivity in modern pig production systems. Full article

Yeast fermentation products (YFPs) are known to contain bioactive compounds, such as nutritional metabolites and cell wall polysaccharides (specifically glucan and mannan), which have been demonstrated to exert positive effects on the growth performance and immunity of livestock and poultry. However, the impact of YFPs on intestinal inflammation and microflora composition in pigs infected with Salmonella typhimurium remains unclear. To investigate this, a total of 18 weaned pigs were divided into three treatment groups: a non-challenged control group (Con), a group challenged with Salmonella typhimurium (ST), and a group challenged with Salmonella typhimurium and supplemented with 0.4% YFP (YFP). The experiment spanned five weeks, encompassing a period of 21 days prior to and 14 days subsequent to the initial Salmonella typhimurium challenge. The findings indicated that the YFP group exhibited an increase in average daily gain (ADG) and a decrease in the feed-gain ratio (F/G) in comparison to the ST group following the Salmonella challenge. Additionally, the YFP group demonstrated a reduction in the levels of inflammatory cytokines in plasma and a decrease in the expression of inflammatory genes in the colon. Treatment with YFP also resulted in improved colon histomorphology, heightened alpha diversity of the gut microbiota, augmented the abundance of butyrate-producing bacteria, and elevated concentrations of short-chain fatty acids (SCFAs). In addition, YFP reprogrammed energy metabolism in colon epithelial cells by blunting glycolysis. Together, dietary YFP supplementation alleviated colon inflammation in weaned pigs challenged with Salmonella typhimurium, and shaped the beneficial microbiota, thereby maintaining gut homeostasis. The results provided evidence supporting the application of yeast fermentation products in livestock production. Full article

Background: Cactus contains dietary fiber and minerals and is expected to have preventive effects against diabetes, arteriosclerosis, and other diseases. Additionally, cactus intake induces the production of short-chain fatty acids derived from the gut microbiota, which might influence immune functions. In this study, we examined the effects of a cactus (Nopalea cochenillifera: NC)-supplemented diet on lipopolysaccharide (LPS)-induced immune responses and intestinal barrier function. Methods: Male C3H/HeN mice were randomly divided into three groups—no fiber (NF), cellulose-containing fiber (Cellu), and cactus-added (NC) diets—for 6 weeks. The TNF-α and IL-10 responses to LPS, antibody titers, and intestinal barrier function, as well as the fecal microbiota, were analyzed. Results: The plasma TNF-α but not the IL-10 concentrations were significantly higher in the NC group than in the NF and Cellu groups. Furthermore, the plasma IgG antibody titers were significantly higher in the NC group than in the other groups. The NC group showed higher mucin content and IgA antibody titers in their feces compared with the Cellu group. The succinate and lactate contents, which induce a reduction in TNF-α secretion by macrophages, in the cecum of the NC group were significantly lower than those in the Cellu and NF groups. In contrast, the butyrate content was significantly higher in the cecum of the NC group compared to that of the Cellu group, with a significantly higher relative abundance of butyrate-producing bacteria. Conclusions: Taken together, we found that cactus intake regulates innate and adaptive immune function via the gut microbiota in mice. Therefore, cactus supplementation might serve as a strategy to develop novel functional foods with dietary fiber. Full article

Intestinal mucosal barrier damage is regarded as the critical factor through which chronic unpredictable mild stress (CUMS) leads to a variety of physical and mental health problems. However, the exact mechanism by which CUMS induces intestinal mucosal barrier damage is unclear. In this study, 14, 28, and 42 d CUMS model mice were established. The indicators related to ileal mucosal barrier damage (IMBD), the composition of the ileal microbiota and its amino acid (AA) and short-chain fatty acid (SCFA) metabolic functions, and free amino acid (FAA) and SCFA levels in the ileal lumen were measured before and after each stress period. The correlations between them are analyzed to investigate how CUMS induces intestinal mucosal barrier damage in male C57BL/6 mice. With the progression of CUMS, butyric acid (BA) levels decreased (14 and 28 d) and then increased (42 d), and IMBD progressively increased. In the late CUMS stage (42 d), the degree of IMBD is most severe and positively correlated with significantly increased BA levels (p < 0.05) in the ileal lumen and negatively correlated with significantly decreased FAAs, such as aspartic, glutamic, alanine, and glycine levels (p < 0.05). In the ileal lumen, the abundance of BA-producing bacteria (Muribaculaceae, Ruminococcus, and Butyricicoccus) and the gene abundance of specific AA degradation and BA production pathways and their related enzymes are significantly increased (p < 0.05). In addition, there is a significant decrease (p < 0.05) in the abundance of core bacteria (Prevotella, Lactobacillus, Turicibacter, Blautia, and Barnesiella) that rely on these specific AAs for growth and/or are sensitive to BA. These changes, in turn, promote further colonization of BA-producing bacteria, exacerbating the over-accumulation of BA in the ileal lumen. These results were validated by ileal microbiota in vitro culture experiments. In summary, in the late CUMS stages, IMBD is related to an excessive accumulation of BA caused by dysbiosis of the ileal microbiota and its overactive AA degradation. Full article

Short-chain fatty acids (SCFAs) are produced by the fermentation of undigested polysaccharides; they are a group of metabolites resulting from the activity of intestinal bacteria. The main SCFAs are acetic, butyric, propionic, valeric, and caproic acid, and their levels and proportions depend on various factors. The aim of this study was to investigate the relationship between the concentration of SCFAs and the occurrence of specific gastrointestinal symptoms in infants. This study was conducted using faecal samples obtained at 1, 3, 6, and 12 months of age. The SCFA content was measured using gas chromatography. At 1 month, an association was found between butyric acid and flatulence. At 3 months, an association was found between butyric acid and flatulence/gas and between 3,4-methylovaleric acid and mucus in the stool. At 6 months, an association was found between butyric and valeric acids and flatulence. By 12 months, the gastrointestinal symptoms had decreased significantly. This study confirms that there is an association between SCFA levels and the presence of bloating, gas, mucus in the stool, and constipation in the gastrointestinal tract. Higher levels of butyric and valeric acids may lead to an increase in troublesome symptoms, such as flatulence and gas, in the first few months of life but are not associated with the occurrence of intestinal colic. The level of 3,4-methylovaleric acid is associated with the presence of allergies, whereas a decrease in acetic acid and an increase in isovaleric acid may exacerbate defecation problems in infants. Full article

The impact of mechanized processes on the properties of Xifeng Baijiu, as well as the differences between Baijiu produced through mechanized versus traditional methods, remains insufficiently understood. In this study, the differences in physicochemical properties, microorganisms, volatile flavor compounds, and their correlations in the traditional and mechanized processes of producing Xifeng Baijiu were compared. High-throughput sequencing revealed that the abundance and diversity of bacteria and fungi were higher in the traditional process compared to the mechanized one. The bacterial population exhibited a more pronounced succession pattern than the fungal population throughout the fermentation. In the early stages, Firmicutes and Actinobacteria were the dominant bacterial phyla in both processes, with Lactobacillus, Saccharopolyspora, Bacillus, Acetobacter, Weissella, and Thermoactinomyces being the predominant bacterial genera, and Saccharomycopsis, Issatchenkia, Kazachstania, Thermoascus, Pichia, and Rhizopus are the dominant fungi. Chemical analysis identified 71 volatile flavor components in the fermented grains, predominantly esters and alcohols. Ethyl caproate, 1-nonyl alcohol, ethyl acetate, acetic acid, butyric acid, furfuryl alcohol, caproic acid, and 2,4-di-tert-butylphenol were the key differential compounds between the two production methods. Pearson correlation analysis indicated a stronger relationship between bacteria and flavor compounds than between fungi and these substances, with Lactobacillus showing a negative correlation with other dominant bacterial genera. These findings offer a foundation for future research into the factors contributing to differences in Baijiu produced by traditional and mechanized methods and serve as a reference for improving mechanized processes. Full article

Background: Preterm infants discharged from the neonatal intensive care unit (NICU) have a risk of severe viral respiratory tract infections (RTIs). Researchers have recently reported the potential use of postbiotics to decrease RTIs in young children. However, the safety and efficacy of postbiotics for preventing RTIs in preterm infants is not yet established. Methods: We conducted a pilot double-blind, randomized, placebo-controlled study of the heat-killed lactic acid bacterium Pediococcus acidilactici K15 in 41 preterm infants born at <36 weeks of gestation and discharged from the NICU at Chiba University Hospital. Results: Following once-daily K15 or placebo treatment for one year, no significant differences were found in the mean number of febrile days (4.5 [1.5–7.4] days vs. 6.6 [2.6–10.5] days). The subgroup analysis showed that the effect of treatment on the number of febrile days was more prominent in the K15 group than in the placebo group, among children with older siblings. The 16S rRNA gene sequencing of fecal samples illustrated that the genus Faecalimonas was enriched in the K15 group, potentially promoting butyrate production by butyrate-producing bacteria. No adverse events were found to be associated with K15 intake. Conclusion: There were no clear data to show the effectiveness of K15 in preventing fever and RTIs in preterm babies during infancy. A larger clinical trial is warranted. Full article

The co-ensiling technique is widely used to improve silage quality; however, it remains unclear as to what high-quality silages can be made by co-ensiling Napier grass (NG) with Sugarcane top (ST). The aim of this study was to evaluate the fermentation characteristics, chemical composition, and microbiological profile of silage produced from mixtures of NG and ST in varying ratios. Silage was prepared using a small-scale fermentation system, and treatments were designed as control silage (NG ensiled alone) or with 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%ST on a fresh matter basis with six replicates, respectively. Increasing ST in the silage reduced the contents of crude protein, ash, acetic acid, butyric acid, ammonia-N, as well as pH, but increased the contents of dry matter, ether extract, neutral detergent fiber, acid detergent fiber, water-soluble carbohydrate, lactic acid, and lactic acid bacteria. Lactobacillales and Enterobacterales were the dominant orders, with Lactiplantibacillus and Weissella as the dominant genera. Co-ensiling NG with ST enhanced microbial diversity and richness. ST, as a local by-product, is a viable additive to improve NG silage quality and nutrition. This study suggests that good-quality silages can be produced with NG: ST ratios of 40:60 to 20:80 and that these silages offer an opportunity to optimize the nutrient supply for ruminants. Full article