Search Results (969)

While the gut microbiota of obese children in Mexico has been studied, its relationship with depressive and anxiety symptoms in obese adults remains unexplored. The aim of this study was to describe the gut microbiota profile of Mexican adults with obesity and its association with depression and anxiety. We sequenced the V3-V4 region of the 16S rRNA gene from stool samples of obese adults categorized into four groups: control (OCG), with depressive symptoms (OD), with anxiety symptoms (OAx), or with both (ODAx). Alpha diversity was assessed using t-tests, beta diversity was assessed with PERMANOVA, and taxonomic differences was assessed with LEfSe. Associations between bacterial genera and clinical variables were analyzed using the Maaslin2 library. Bacteroidota was the most prevalent phylum, and Prevotella was the dominant enterotype across all groups. Although overall diversity did not differ significantly, 30 distinct taxonomic biomarkers were identified among groups as follows: 4 in OCG (Firmicutes), 5 in OD (Firmicutes, Bacteroidota), 13 in OAx (Firmicutes, Bacteroidetes, Fusobacteroidota, Proteobacteria), and 8 in ODAx (Firmicutes). This is the first study to identify distinct gut microbiota profiles in obese Mexican adults with depressive and anxiety symptoms. These findings suggest important microbial biomarkers for improving the diagnosis and treatment of mental health conditions in obesity. Full article

The ecological rice–eel co-culture system is not only beneficial for enhancing productivity and sustainability in agriculture but also plays a crucial role in promoting environmental health. In the present study, based on the long-term positioning trial of the rice–eel co-culture system that began in 2016 and was sampled in 2023, the effects of reduced nitrogen fertilizer application on soil physico-chemical properties and the bacterial community were investigated. Treatments included a conventional regular fertilization treatment (RT), rice–eel co-culture system regular fertilization (IT), and nitrogen-reduction 10%, 30%, and 50% fertilization treatments (IT90, IT70, and IT50). Our research demonstrated the following: (1) Compared to RT, IT significantly increased soil water-stable macroaggregates (R0.25), mean weight diameter (MWD), geometric mean diameter (GMD), and available phosphorus content, with the increases of 15.66%, 25.49%, 36.00%, and 18.42%, respectively. Among the nitrogen-reduction fertilization treatments, IT90 showed the most significant effect. Compared to IT, IT90 significantly increased R0.25, MWD, GMD, and available nitrogen content, with increases of 4.4%, 7.81%, 8.82%, and 28.89%, respectively. (2) Compared to RT, at the phylum level, the diversity of Chloroflexi was significantly increased under IT and IT50, and the diversity of Gemmatimonadota was significantly increased under IT90, IT70, and IT50. The diversity of Acidobacteriota was significantly higher in IT90 and IT70 compared to IT. It was shown that the rice–eel co-culture system and nitrogen fertilizer reduction could effectively improve the degradation capacity of organic matter and promote soil nitrogen cycling. In addition, redundancy analysis (RDA) identified total phosphorus, total nitrogen, and available nitrogen (p = 0.007) as the three most important environmental factors driving changes in the bacterial community. (3) The functional prediction analysis of soil microbiota showed that, compared to RT, the diversity of pathways related to biosynthesis (carbohydrate biosynthesis and cell structure biosynthesis) and metabolism (L-glutamate and L-glutamine biosynthesis) was significantly higher under IT70, IT90, IT, and IT50 (in descending order). However, the diversity of pathways associated with degradation/utilization/assimilation (secondary metabolite degradation and amine and polyamine degradation) was significantly lower under all the rice–eel co-culture treatments. In conclusion, the rice–eel co-culture system improved soil physicochemical properties and the soil microbial environment compared with conventional planting, and the best soil improvement was achieved with 10% less N fertilizer application. Full article

Background: Artificial non-nutritive sweeteners (NNSs), such as sucralose, have been associated with gut microbiota (GM) alterations. However, the impact of rebaudioside A (reb A), a natural NNS, on GM has received limited scrutiny. Objective: The objective of this study was to examine the response of GM composition to sucralose and reb A in rats under two dietary conditions. Methods: Male Wistar rats (150–200 g) fed with a normal diet (ND) or a high-fat diet (HFD) were randomly assigned to receive sucralose (SCL), reb A (REB), glucose (GLU, control), or sucrose (SUC). The NNS interventions were administered in water at doses equivalent to the acceptable daily intake (ADI). After eight weeks, the GM composition in fecal samples was analyzed through 16S ribosomal RNA gene sequencing. Results: The NNSs did not modify the diversity, structure, phylum-level composition, or Firmicutes/Bacteroidetes (F/B) ratio of the GM in rats under ND or HFD. However, REB with HFD decreased Bacilli and increased Faecalibacterium abundance at the class level. SCL and REB in rats receiving ND reduced the genera Romboutsia and Lactobacillus. Conclusions: Our study suggests that when sucralose or reb A is consumed at recommended doses, there is no alteration in the diversity or the composition of the GM at the phylum level. The clinical relevance of these findings lies in the potential modifications of the GM at specific taxonomic levels by the consumption of these NNSs. Further research involving humans and including a broader range of microbial analyses is warranted. Full article

There is a growing body of research showing that Alzheimer’s disease (AD) is related to enteric dysbacteriosis. Exercise can be effective in alleviating AD, but the effects that exercise has on the gut microbiota in AD patients needs to be further studied. Through this study, we aimed to investigate the differences in the diversity of gut microorganisms between AD model mice and wild-type mice and the effect that treadmill exercise has on the composition of the gut microbiota in both types of mice. C57BL/6 wild-type mice were randomly divided into a sedentary control group (WTC) and an exercise group (WTE); APP/PS1 double transgenic mice were also randomly divided into a sedentary control group (ADC) and an exercise group (ADE). After the control group remained sedentary for 12 weeks and a 12-week treadmill exercise intervention was adopted for the exercise group, the rectal contents were collected so that they could undergo V3-V4 16S rDNA sequencing, and a comparative analysis of the microbial composition and diversity was also performed. The alpha diversity of the gut microbiota in AD mice was lower than that in wild-type mice, but exercise increased the gut microbial diversity in both types of mice. At the phylum level, the dominant microorganisms in all four groups of mice were Bacteroidetes and Firmicutes. There was an increase in the Bacteroidetes phylum in AD mice. Treadmill exercise reduced the abundance of Bacteroidetes in both groups of mice, whereas the abundance of Firmicutes increased. At the genus level, Muribaculaceae, the Lachnospiraceae_NK4A136_group, Alloprevotella, and Alistipes were in relatively high abundance. Muribaculaceae and Alloprevotella were in greater abundance in AD mice than in wild-type mice, but both decreased after treadmill exercise. Through performing linear discriminant analysis effect size (LEfSe), we found that the dominant strains in AD mice were Campilobacterota, Helicobacteraceae, Escherichia–Shigella, and other malignant bacteria, whereas exercise resulted in an increase in probiotics among the dominant strains in both types of mice. Although gut microbial diversity decreases and malignant bacteria increase in AD mice, treadmill exercise can increase gut microbial diversity and lead to the development of dominant strains of probiotics in both types of mice. These findings provide a basis for applying exercise as a treatment for AD. Full article

Cellulose, the most abundant organic polymer in soil, is degraded by the action of microbial communities. Cellulolytic taxa are widespread in soils, enhancing the biodegradation of cellulose by the synergistic action of different cellulase enzymes. β-glucosidases are the last enzymes responsible for the degradation of cellulose by producing glucose from the conversion of the disaccharide cellobiose. Different soils from the states of Delaware, Maryland, New Jersey, and New York were analyzed by direct DNA extraction, PCR analysis, and next generation sequencing of amplicon sequences coding for β-glucosidase genes. To determine the community structure and diversity of microorganisms carrying β-glucosidase genes, amplicon sequence variant analysis was performed. Results showed that the majority of β-glucosidase genes did not match any known phylum or genera with an average of 84% of sequences identified as unclassified. The forest soil sample from New York showed the highest value with 95.62%. When identification was possible, the bacterial phyla Pseudomonadota, Actinomycetota, and Chloroflexota were found to be dominant microorganisms with β-glucosidase genes in soils. The Delaware soil showed the highest diversity with phyla and genera showing the presence of β-glucosidase gene sequences in bacteria, fungi, and plants. However, the Chloroflexota genus Kallotanue was detected in 3 out of the 4 soil locations. When phylogenetic analysis of unclassified β-glucosidase genes was completed, most sequences aligned with the Chloroflexota genus Kallotenue and the Pseudomonadota species Sphingomonas paucimobilis. Since most sequences did not match known phyla, there is tremendous potential to discover new enzymes for possible biotechnological and pharmaceutical applications. Full article

Mast cell tumours (MCT) are the most common cutaneous neoplasms in dogs, with variable behaviours and patient survival time. Both indolent and aggressive forms have been described, but much remains to be explored regarding prognosis and therapy. Evidence has highlighted the influence of microbiota on multiple health and disease processes, including certain types of cancer in humans. However, knowledge remains scarce regarding microbiota biology and its interactions in both humans and canine cancer patients. This study aimed to characterise the faecal microbiota of dogs with MCT and compare it with that of healthy individuals. Twenty-eight dogs diagnosed with MCT and twenty-eight healthy dogs were enrolled in the study. Faecal samples were collected and analysed by Illumina sequencing of 16S rRNA genes. Alpha diversity was significantly lower in dogs with cancer, and the species diversity InvSimpson Indexwas reduced (p = 0.019). Principal coordinate analysis showed significant differences in the bacterial profile of the two groups: there was a significant lower abundance of the genera Alloprevotella, Holdemanella, Erysipelotrichaceae_UCG-003, and Anaerobiospirillum and, conversely, a significant increase in the genera Escherichia-Shigella and Clostridium sensu stricto 1 in diseased dogs. At the phylum level, Bacteroidota was significantly reduced in diseased dogs (25% in controls vs. 19% in MCT dogs). In conclusion, sequencing analysis provided an overview of the bacterial profile and showed statistical differences in the microbial communities of dogs with MCT compared with healthy dogs, suggesting a link between the gut microbiota and MCT in this species. Full article

L-carnitine and Mildronate are substances that can significantly rearrange the energy metabolism of cells. This can potentially cause changes in the bacterial composition of the gut microbiome and affect testis functionality and male sexual health. Mice of the C57Bl/6 line were used. Sexual behavior was assessed using physiological tests, and gene expression patterns were assessed by qPCR. High-throughput sequencing of mouse fecal microbiota was performed. We showed that long-term administration of Mildronate has no significant effect on the intestinal microbiome, and there was a compensatory increase in the expression of genes involved in fatty acid and leptin metabolism. No impairment of sexual motivation in male mice was observed. Prolonged L-carnitine supplementation caused a decrease in alpha diversity of bacteria and a decrease in some groups of microorganisms that are components of a healthy gut microflora. A correlation was observed between the level of bacteria from Firmicutes phylum, indicators of sexual motivation of mice, and the dynamics of body weight gain. Our results may indicate that metabolic modulators can have a significant impact on the structure of the bacterial community of the gut microbiome, which may influence male sexual health through the gut–semen axis. Full article

Intestinal inflammation involves barrier impairment, immune hyperactivation, and oxidative stress imbalance. Bioactive polysaccharides universally alleviate inflammation via anti-inflammatory, antioxidant, and microbiota-modulating effects, yet exhibit distinct core mechanisms. Elucidating these differences is vital for targeted polysaccharide applications. This research examines distinct regulatory pathways through which diverse bioactive polysaccharides mitigate lipopolysaccharide-triggered intestinal inflammation in male Kunming (KM) mice. This experiment employed Lentinula edodes polysaccharide (LNT), Auricularia auricula polysaccharide (AAP), Cordyceps militaris polysaccharide (CMP), Lycium barbarum polysaccharide (LBP), and Brassica rapa polysaccharide (BRP). The expression levels of biomarkers associated with the TLR4 signaling pathway, oxidative stress, and intestinal barrier function were quantified, along with comprehensive gut microbiota profiling. The results showed that all five polysaccharides alleviated inflammatory responses in mice by inhibiting inflammatory cytokine release, reducing oxidative damage, and modulating gut microbiota, but their modes of action differed: LBP significantly suppressed the TLR-4/MyD88 signaling pathway and its downstream pro-inflammatory cytokine expression, thereby blocking inflammatory signal transduction and reducing oxidative damage; LNT and CMP enhanced the body’s antioxidant capacity by increasing antioxidant enzyme activities and decreasing malondialdehyde (MDA) levels; AAP and BRP enriched Akkermansia (Akk.) within the Verrucomicrobia (Ver.) phylum, upregulating tight junction protein expression to strengthen the intestinal mucosal barrier and indirectly reduce oxidative damage. This research demonstrates that different polysaccharides alleviate inflammation through multi-target synergistic mechanisms: LBP primarily inhibits inflammatory pathways; AAP and BRP focus on intestinal barrier protection and microbiota modulation; and LNT and CMP exert effects via antioxidant enzyme activation. These data support designing polysaccharide blends that leverage complementary inflammatory modulation mechanisms. Full article

The combined effect of temperature-adapted inocula and anaerobic fermentation (AF) settings (pH 5.1 and 50 °C) were assessed to produce short-chain carboxylates (SCCs). In this study, the AF of carrot pulp was investigated using inocula adapted at different temperatures (25, 35, and 55 °C) with the aim of shifting the microbiome activity from biogas to SCC production. The highest SCC content (17.2 g COD L⁻¹), and bioconversion (26.1%) and acidification efficiency (56.3%) were achieved with 35 °C-adapted inoculum. Lactic acid production prevailed in all reactors, demonstrating a high selectivity in SCC production. Both the microbial richness and diversity sharply diminished in the 35 °C and 55 °C operated reactors, with Firmicutes phylum identified as key players of the lactic acid production in AF. The results demonstrated that the operating temperature played a key role in shaping the microbial structure of inocula, leading to different process performances and highlighting thermophilic AF as a feasible process to produce lactic acid. Full article

Streptococcus agalactiae (SA) is a severe prevalent pathogen, resulting in high morbidity and mortality in the global tilapia industry. With increasing bacterial resistance to antibiotics, alternative strategies are urgently needed. This study aims to investigate the antibacterial activity and the underlying mechanisms of the natural product xanthohumol (XN) against SA infection in tilapia (Oreochromis niloticus). The results showed that XN could significantly reduce the bacterial loads of SA in different tissues (liver, spleen and brain) after treatment with different tested concentrations of XN (12.5, 25.0 and 50.0 mg/kg). Moreover, XN could improve the survival rate of SA-infected tilapia. 16S rRNA gene sequencing demonstrated that the alpha-diversity index (Chao1 and Shannon_e) was significantly increased in the XN-treated group (MX group) compared to the SA-infected group (CG group) (p < 0.05), and the Simpson diversity index significantly decreased. The Bray–Curtis similarity analysis of non-metric multidimensional scaling (NMDS) and principal coordinate analysis (PCA) showed that there were significant differences in microbial composition among groups. At the phylum level, the relative abundance of the phyla Actinobacteria, Proteobacteria and Bacteroidetes decreased in the MX group compared to the CG group, while the relative abundance of the phyla Fusobacteria, Firmicutes and Verrucomicrobia increased. Differences were also observed at the genus level; the relative abundance of Mycobacterium decreased in the MX group, but the abundance of Cetobacterium and Clostridium_sensu_stricto_1 increased. Metabolomics analysis revealed that XN changed the metabolic profile of the liver and significantly enriched aspartate metabolism, glycine and serine metabolism, phosphatidylcholine biosynthesis, arginine and proline metabolism, glutamate metabolism, urea cycle, purine metabolism, methionine metabolism, betaine metabolism, and carnitine synthesis. Correlation analysis indicated an association between the intestinal microbiota and metabolites. In conclusion, XN may be a potential drug for the prevention and treatment of SA infection in tilapia, and its mechanism of action may be related to the regulation of the intestinal microbiota and liver metabolism. Full article

This study aims to investigate the response of surface bacterial communities in Trachinotus ovatus to Cryptocaryon irritans infection at different stages of a single infection cycle (0~168 h). These samples were analyzed using high-throughput 16S rRNA sequencing. Alpha diversity analysis showed a reduction in the richness and diversity of skin microbiota during infection, with partial recovery post-detachment. Beta diversity analysis revealed distinct structural shifts in skin microbiota at early (24 h) and post-detachment (168 h) stages compared to other phases, while gill microbiota remained stable except during detachment. At the phylum level, Proteobacteria, Actinobacteriota, Bacteroidetes, and Firmicutes were dominant on the skin at different stages, whereas the gill microbiota was predominantly Proteobacteria (>90%). At the genus level, opportunistic pathogens, such as Vibrio and Nautella, increased in relative abundance on the skin with the infection progression, while gill microbiota composition barely changed. The hepatic bacterial load continued to increase with infection duration. These findings indicate that C. irritans alters microbiota composition on skin, facilitating pathogen invasion, thereby elevating the risk of secondary bacterial infections in T. ovatus. Full article

Horizontal gene transfer (HGT), the non-Mendelian transfer of genetic material between organisms, is relatively frequent in prokaryotes, whereas its extent among eukaryotes remains unclear. Here, we raise the hypothesis of a possible cross-phylum HGT event involving 5S ribosomal DNA (rDNA). A specific type of 5S rDNA sequence from the anuran Xenopus laevis was highly similar to a 5S rDNA sequence of the genome of its flatworm parasite Protopolystoma xenopodis. A maximum likelihood analysis revealed phylogenetic incongruence between the gene tree and the species trees, as the 5S rDNA sequence from Pr. xenopodis was grouped along with the sequences from the anurans. Sequence divergence analyses of the gene region and non-transcribed spacer also agree with an HGT event from Xenopus to Pr. xenopodis. Additionally, we examined whether contamination of the Pr. xenopodis genome assembly with frog DNA could explain our findings but found no evidence to support this hypothesis. These findings highlight the possible contribution of HGT to the high diversity observed in the 5S rDNA family. Full article

Background: Early time-restricted eating combined with energy restriction (eTRE + ER) has been shown to reduce fat mass, diastolic blood pressure (DBP) and fasting glucose more effectively than late TRE with energy restriction (lTRE + ER) or energy restriction (ER) alone. Given the gut microbiome’s sensitivity to circadian rhythms, we examined whether adding TRE, particularly eTRE, to ER alters gut microbiota composition beyond ER alone, and whether such effects persist during follow-up. Methods: We analysed anthropometric, biochemical and gut microbiome data from 76 participants at baseline and after a 3-month intervention (eTRE + ER: n = 33; lTRE + ER: n = 23; ER: n = 20). Follow-up microbiome data 6-months after the end of intervention were available for 43 participants. Gut microbiota composition was assessed via 16S rRNA gene sequencing of stool samples. Results: No significant between-group differences in beta diversity were observed over time. However, changes in alpha diversity differed significantly across groups at the end of the intervention (Shannon: F = 5.72, p < 0.001; Simpson: F = 6.72, p < 0.001; Richness: F = 3.99, p = 0.01) and at follow-up (Richness: F = 3.77, p = 0.02). lTRE + ER led to the greatest reductions in diversity post intervention, while ER was least favourable during follow-up. Although no significant between-group differences were observed at the phylum level either at the end of the intervention or during follow-up, only the eTRE + ER group exhibited a significant decrease in Bacillota and an increase in Bacteroidota during follow-up. At the genus level, differential abundance analysis revealed significant shifts in taxa such as Faecalibacterium, Subdoligranulum, and other genera within the Ruminococcaceae and Oscillospiraceae families. In the eTRE + ER, Faecalibacterium and Subdoligranulum increased, while in other groups decreased. Notably, the changes in Faecalibacterium were negatively correlated with fasting glucose, while the increase in Subdoligranulum was inversely associated with DBP; however, both associations were weak in strength. Conclusions: eTRE + ER may promote beneficial, lasting shifts in the gut microbiome associated with improved metabolic outcomes. These results support further research into personalized TRE strategies for treatment of obesity. Full article

Insects are often associated with diverse microorganisms that enhance their metabolism and nutrient assimilation. These microorganisms, residing in the insect’s gut, play a crucial role in breaking down complex molecules into simpler compounds essential for the host’s growth. This study investigates the diversity and functional potential of symbiotic bacteria in the gut of Arsenura armida (Lepidoptera: Saturniidae) larvae, an edible insect from southeastern Mexico, using culture-dependent and metagenomic approaches. Bacterial strains were isolated from different gut sections (foregut, midgut, and hindgut) and cultured on general-purpose media. Isolates were identified through 16S rRNA gene sequencing and genomic fingerprinting. Metagenomics revealed the bacterial community structure and diversity, along with their functional potential. A total of 96 bacterial strains were isolated, predominantly Gram-negative bacilli. Rapidly growing colonies exhibited enzymatic activity, cellulose degradation, and sugar production. Phylogenetic analysis identified eight genera, including Acinetobacter, Bacillus, Enterobacter, Pseudomonas, and others, with significant cellulose-degrading capabilities. Metagenomics confirmed Bacillota as the most abundant phylum. These complementary methods revealed abundant symbiotic bacteria with key metabolic roles in A. armida, offering promising biotechnological applications in enzymatic bioconversion and cellulose degradation. Full article

Deciphering the spatiotemporal distribution of bacteria during breast cancer progression may provide critical insights for developing bacterial-based therapeutic strategies. Using a murine breast cancer model, we longitudinally profiled the microbiota in breast tumor tissue, mammary gland, spleen, and cecal contents at 3-, 5-, and 7- weeks post-tumor implantation through 16S rRNA gene sequencing. Breast tumor progression was associated with lung metastasis and splenomegaly, accompanied by distinct tissue-specific microbial dynamics. While alpha diversity remained stable in tumors, mammary tissue, and cecal contents, it significantly increased in the spleen (p < 0.05). Longitudinal analysis revealed a progressive rise in Firmicutes and a decline in Proteobacteria abundance within tumors, mammary tissue, and cecum, whereas the spleen microbiota displayed unique phylum-level compositional shifts. Tissue- and time-dependent microbial signatures were identified at phylum, genus, and species levels during breast tumor progression. Strikingly, the spleen microbiota integrated nearly all genera enriched in other sites, suggesting its potential role as a microbial reservoir. Gut-associated genera (Lactobacillus, Desulfovibrio, Helicobacter) colonized both cecal contents and the spleen, with Lactobacillus consistently detected across all tissues, suggesting microbial translocation. The spleen exhibited uniquely elevated diversity and compositional shifts, potentially driving splenomegaly. These results delineated the trajectory of microbiota translocation and colonization, and demonstrated tissue-specific microbial redistribution during breast tumorigenesis, offering valuable implications for advancing microbiome-targeted cancer therapies. Full article