Stability Of Microbiota Research Articles

Benzimidazole Fungicide Carbendazim Induces Gut Inflammation through the TLR5/NF-κB Pathway in Grass Carp.

Fungicides have been increasingly used across various sectors, including agriculture and textiles. The biocidal properties of fungicides may negatively impact the stability of intestinal microbiota, thereby posing a threat to intestinal health. In this study, we investigated the mechanisms of intestinal damage and functional abnormalities in grass carp following a 42-day exposure to the widely used fungicide carbendazim at environmentally relevant concentrations (0.2 to 20 μg/L). Histopathological observations, mRNA and protein expression analyses, biochemical analysis, quantification of short-chain fatty acids (SCFAs), cytokines, lipopolysaccharide (LPS), and 16S ribosomal ribonucleic acid (rRNA), as well as internal transcribed spacer (ITS) sequencing, were performed. At environmentally relevant concentrations, carbendazim strongly induced intestinal inflammation, leading to increased transcriptional and translational levels of genes involved in the toll-like receptor five (TLR5)/nuclear factor kappa B (NF-κB) pathway, including TLR5, NF-κB, interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNFα). Additionally, carbendazim damaged intestinal barriers and reduced the expression of tight junction proteins (e.g., occludin and zonula occludens-1/2), goblet cells, and immunoglobulin M levels, while also disrupting the gut microbiome, leading to intestinal metabolic disorders, particularly decreases in SCFAs and increases in LPS. Treatment with the TLR5 antagonist TH1020 mitigated intestinal inflammation caused by carbendazim, subsequently improving mechanical barrier function. Overall, our findings provide new insights into the toxicological mechanisms underlying intestinal damage caused by carbendazim in grass carp, indicating that carbendazim poses a significant threat to nontarget organisms. Given its widespread detection in the environment, these results underscore the substantial ecological risks to the gut health of fish living in carbendazim-contaminated water bodies.

Synergistic interactions between gut microbiota and short chain fatty acids: Pioneering therapeutic frontiers in chronic disease management.

Microorganisms in the gut play a pivotal role in human health, influencing various pathophysiological processes. Certain microorganisms are particularly essential for maintaining intestinal homeostasis, reducing inflammation, supporting nervous system function, and regulating metabolic processes. Short-chain fatty acids (SCFAs) are a subset of fatty acids produced by the gut microbiota (GM) during the fermentation of indigestible polysaccharides. The interaction between GM and SCFAs is inherently bidirectional: the GM not only shapes SCFAs composition and metabolism but SCFAs also modulate microbiota's diversity, stability, growth, proliferation, and metabolism. Recent research has shown that GM and SCFAs communicate through various pathways, mainly involving mechanisms related to inflammation and immune responses, intestinal barrier function, the gut-brain axis, and metabolic regulation. An imbalance in GM and SCFA homeostasis can lead to the development of several chronic diseases, including inflammatory bowel disease, colorectal cancer, systemic lupus erythematosus, Alzheimer's disease, and type 2 diabetes mellitus. This review explores the synergistic interactions between GM and SCFAs, and how these interactions directly or indirectly influence the onset and progression of various diseases through the regulation of the mechanisms mentioned above.

Effects of Rhodopseudomonas palustris and composite probiotics on growth performance, intestinal health, and non-specific immunity of sea urchin (Strongylocentrotus intermedius).

In recent decades, antibiotics have been widely used in sea urchin aquaculture to prevent diseases and improve water quality. However, their use leads to the emergence of resistant strains and environmental problems. Probiotics can serve as a green and pollution-free alternative. In this study, we mixed probiotics (Rhodopseudomonas palustris) (3×108CFU/mL) and composite probiotics (5×108CFU/mL) in a 1:1 ratio, establishing four supplementation levels: 0% (FC, control group), 0.5% (FL group), 1% (FM group), and 2% (FH group). At the end of the 50-day experiment, compared to the control group (FC), supplementation with R. palustris and composite probiotics (containing 60.13% Lactobacillaceae and 20.79% Acetobacteraceae) in the FL, FM, and FH groups significantly improved the growth performance of sea urchins (Strongylocentrotus intermedius), including final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR), and gonadosomatic index (GSI). Additionally, antioxidant indicators (e.g., total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and catalase (CAT)), immune indicators (e.g., acid phosphatase (ACP), alkaline phosphatase (AKP), and lysozyme (LZM)), and digestive enzyme activity were significantly increased in FM and FH groups. Probiotic supplementation also increased colonization of beneficial bacteria (Rhodobacteraceae) and enhanced microbiota diversity. The FM group, in particular, showed significantly upregulated expression of heat shock protein 70 (HSP70), glutathione peroxidase (GPX), glutathione (GST), toll-like receptor (TLR), and lysozyme (LYZ) genes. Overall, 1% supplementation significantly enhanced growth, antioxidant capacity, digestive ability, microbiota stability, and immune-related gene expression in S. intermedius.

Gut microbiomes are largely unchanged when exposed to their amphibian host's latitudinally variable upper thermal limit.

Climate change will increase the frequency and severity of temperature extremes. Links between host thermal physiology and their gut microbiota suggest that organisms' responses to future climates may be mediated by their microbiomes, raising the question of how the thermal environment influences the microbiome itself. Vertebrate gut microbiomes influence the physiological plasticity of their hosts via effects on immunity, metabolism, and nutrient uptake. The gut microbiota of ectothermic vertebrates in particular are responsive to long-term, sub-lethal gradual increases in environmental temperature. Whether and how the gut microbiota respond to brief exposure to temperatures at the upper limit of host physiological tolerance (CTmax) is poorly understood but could have downstream effects on host fitness. We assayed the CTmax of wood frogs (Lithobates sylvaticus) from 15 populations across a 10° latitudinal gradient. We then characterized the gut microbiota of juveniles at two time points following exposure to CTmax. Frogs from higher latitudes had lower thermal tolerance (lower CTmax) than those from lower latitudes. Unexpectedly, exposure to upper survivable temperature had little to no detectable effect on the frogs' microbiota richness, stability, or composition. Instead, we found a strong effect of time in which frogs kept in recovery conditions for four days had less diverse, but more stable gut microbiota than those that had recovered for only one day, regardless of CTmax exposure. We conclude that while wood frogs from higher latitudes have reduced thermal tolerances than those from lower latitudes, their microbial communities are largely unaffected by brief exposure to high temperatures at the edge of their physiological limits.

Oxygenation and intestinal perfusion and its association with perturbations of the early life gut microbiota composition of children with congenital heart disease.

Early life gut microbiota is known to shape the immune system and has a crucial role in immune homeostasis. Only little is known about composition and dynamics of the intestinal microbiota in infants with congenital heart disease (CHD) and potential influencing factors. We evaluated the intestinal microbial composition of neonates with CHD (n = 13) compared to healthy controls (HC, n = 30). Fecal samples were analyzed by shotgun metagenomics. Different approaches of statistical modeling were applied to assess the impact of influencing factors on variation in species composition. Unsupervised hierarchical clustering of the microbial composition of neonates with CHD was used to detect associations of distinct clusters with intestinal tissue oxygenation and perfusion parameters, obtained by the "oxygen to see" (O2C) method. Overall, neonates with CHD showed an intestinal core microbiota dominated by the genera Enterococcus (27%) and Staphylococcus (20%). Furthermore, a lower abundance of the genera Bacteroides (8% vs. 14%), Parabacteroides (1% vs. 3%), Bifidobacterium (4% vs. 12%), and Escherichia (8% vs. 23%) was observed in CHD compared to HCs. CHD patients that were born by vaginal delivery showed a lower fraction of the genera Bacteroides (15% vs. 21%) and Bifidobacterium (7% vs. 22%) compared to HCs and in those born by cesarean section, these genera were not found at all. In infants with CHD, we found a significant impact of oxygen saturation (SpO2) on relative abundances of the intestinal core microbiota by multivariate analysis of variance (F[8,2] = 24.9, p = 0.04). Statistical modeling suggested a large proportional shift from a microbiota dominated by the genus Streptococcus (50%) in conditions with low SpO2 towards the genus Enterococcus (61%) in conditions with high SpO2. We identified three distinct compositional microbial clusters, corresponding neonates differed significantly in intestinal blood flow and global gut perfusion. Early life differences in gut microbiota of CHD neonates versus HCs are possibly linked to oxygen levels. Delivery method may affect microbiota stability. However, further studies are needed to assess the effect of potential interventions including probiotics or fecal transplants on early life microbiota perturbations in neonates with CHD.

Influence of Cosmetic Skincare Products with pH < 5 on the Skin Microbiome: A Randomized Clinical Evaluation.

The human skin acts as a protective barrier against external pathogens and hosts a diverse microbiome consisting of bacteria, fungi, viruses, and archaea. Disruptions to the skin microbiome can impact immune function, leading to inflammatory and autoimmune conditions. The importance of pH for the microbiome is paramount. Cosmetic skincare products interact with the skin microbiome and skin pH, playing a key role in maintaining microbial balance. Research suggests that products with non-physiological pH levels may disrupt the skin microbiota. Our clinical study aimed to evaluate the effects of low-pH cosmetic products (pH < 5) on the skin microbiome, contributing to improved skin health. The clinical study focused on evaluating the skin microbiome diversity following the application for 28 days of four different low-pH cosmetic products (vitamin C, resveratrol, a collagen mask, and a native algae mask) on the forearms of post-menopausal women with skin pH > 5.5. The diversity of the natural skin microbiome increased consistently throughout the study, evident in both the untreated area and after the application of the Vitamin C Concentrate, Resveratrol Concentrate, Collagen Mask, and Native Algae Mask, as indicated by Shannon's diversity index. The native algae mask notably reduced the Corynebacterium genus and significantly lowered the pH. The skin pH changes corresponded with microbiota stability. In conclusion, enhanced diversity of the natural skin microbiome was observed over the study duration. None of the investigational products caused significant disruption to the skin microbiome diversity, as evidenced by the stable Shannon's diversity index and relative abundance of specific genera. Notably, the native algae mask significantly decreased the presence of the opportunistic pathogenic Corynebacterium genus, which is likely attributable to a minor reduction in skin pH following extended product use. The findings suggest that the use of low-pH skincare products, like the native algae mask, do not disrupt skin microbiome diversity and may have the potential to positively impact skin microbiome diversity and health by reducing certain pathogenic microbial populations.

From Structure to Function: How Prebiotic Diversity Shapes Gut Integrity and Immune Balance.

The microbiota stability, diversity, and composition are pillars for an efficient and beneficial symbiotic relationship between its host and itself. Microbial dysbiosis, a condition where a homeostatic bacterial community is disturbed by acute or chronic events, is a predisposition for many diseases, including local and systemic inflammation that leads to metabolic syndrome, diabetes, and some types of cancers. Classical dysbiosis occurs in the large intestine. During this period, pathogenic strains can multiply, taking advantage of the compromised environment. This overgrowth triggers an exaggerated inflammatory response from the human immune system due to the weakened integrity of the intestinal barrier. Such inflammation can also directly influence higher polyp formation and/or tumorigenesis. Prebiotics can be instrumental in preventing or correcting dysbiosis. Prebiotics are molecules capable of serving as substrates for fermentation processes by gut microorganisms. This can promote returning the intestinal environment to homeostasis. Effective prebiotics are generally specific oligo- and polysaccharides, such as FOS or inulin. However, the direct effects of prebiotics on intestinal epithelial and immune cells must also be taken into consideration. This interaction happens with diverse prebiotic nondigestible carbohydrates, and they can inhibit or decrease the inflammatory response. The present work aims to elucidate and describe the different types of prebiotics, their influence, and their functionalities for health, primarily focusing on their ability to reduce and control inflammation in the intestinal epithelial barrier, gut, and systemic environments.

Short term stability of the sputum microbiota in bronchiectasis and cystic fibrosis

Short term stability of the sputum microbiota in bronchiectasis and cystic fibrosis

Bacillus velezensis HBXN2020 alleviates Salmonella Typhimurium infection in mice by improving intestinal barrier integrity and reducing inflammation

Bacillus velezensis is a species of Bacillus that has been widely investigated because of its broad-spectrum antimicrobial activity. However, most studies on B. velezensis have focused on the biocontrol of plant diseases, with few reports on antagonizing Salmonella Typhimurium infections. In this investigation, it was discovered that B. velezensis HBXN2020, which was isolated from healthy black pigs, possessed strong anti-stress and broad-spectrum antibacterial activity. Importantly, B. velezensis HBXN2020 did not cause any adverse side effects in mice when administered at various doses (1×107, 1×108, and 1×109 CFU) for 14 days. Supplementing B. velezensis HBXN2020 spores, either as a curative or preventive measure, dramatically reduced the levels of S. Typhimurium ATCC14028 in the mice’s feces, ileum, cecum, and colon, as well as the disease activity index (DAI), in a model of infection caused by this pathogen in mice. Additionally, supplementing B. velezensis HBXN2020 spores significantly regulated cytokine levels (Tnfa, Il1b, Il6, and Il10) and maintained the expression of tight junction proteins and mucin protein. Most importantly, adding B. velezensis HBXN2020 spores to the colonic microbiota improved its stability and increased the amount of beneficial bacteria (Lactobacillus and Akkermansia). All together, B. velezensis HBXN2020 can improve intestinal microbiota stability and barrier integrity and reduce inflammation to help treat infection by S. Typhimurium.

Bacillus velezensis HBXN2020 alleviates Salmonella Typhimurium infection in mice by improving intestinal barrier integrity and reducing inflammation.

Bacillus velezensis is a species of Bacillus that has been widely investigated because of its broad-spectrum antimicrobial activity. However, most studies on B. velezensis have focused on the biocontrol of plant diseases, with few reports on antagonizing Salmonella Typhimurium infections. In this investigation, it was discovered that B. velezensis HBXN2020, which was isolated from healthy black pigs, possessed strong anti-stress and broad-spectrum antibacterial activity. Importantly, B. velezensis HBXN2020 did not cause any adverse side effects in mice when administered at various doses (1×107, 1×108, and 1×109 CFU) for 14 days. Supplementing B. velezensis HBXN2020 spores, either as a curative or preventive measure, dramatically reduced the levels of S. Typhimurium ATCC14028 in the mice's feces, ileum, cecum, and colon, as well as the disease activity index (DAI), in a model of infection caused by this pathogen in mice. Additionally, supplementing B. velezensis HBXN2020 spores significantly regulated cytokine levels (Tnfa, Il1b, Il6, and Il10) and maintained the expression of tight junction proteins and mucin protein. Most importantly, adding B. velezensis HBXN2020 spores to the colonic microbiota improved its stability and increased the amount of beneficial bacteria (Lactobacillus and Akkermansia). All together, B. velezensis HBXN2020 can improve intestinal microbiota stability and barrier integrity and reduce inflammation to help treat infection by S. Typhimurium.

Long-term garlic‒maize rotation maintains the stable garlic rhizosphere microecology

BackgroundCrop rotation is a sophisticated agricultural practice that can modify the demographic structure and abundance of microorganisms in the soil, stimulate the growth and proliferation of beneficial microorganisms, and inhibit the development of harmful microorganisms. The stability of the rhizosphere microbiome is crucial for maintaining both soil ecosystem vitality and crop prosperity. However, the effects of extended garlic‒maize rotation on the physicochemical characteristics of garlic rhizosphere soil and the stability of its microbiome remain unclear. To investigate this phenomenon, soil samples from the garlic rhizosphere were collected across four different lengths of rotation in a garlic–maize rotation.ResultsThere were notable positive associations between the total nitrogen and total phosphorus contents in the soil and the duration of rotation. Prolonged rotation could increase the maintenance of microbiome α diversity. The number of years of rotation and the soil organic carbon (SOC) content emerged as principal determinants impacting the evolution of the bacterial community structure, with the SOC content playing a pivotal role in sculpting the species diversity within the garlic rhizosphere bacterial community. Additionally, SOC remains predominant in shaping the root-associated bacterial community’s β-nearest taxon index. However, these factors do not have a notable effect on the fungal community inhabiting the garlic rhizosphere. In comparison with monoculture, rotation can amplify the interconnectivity and intricacy of microbial ecological networks. Long-term rotation can further maintain the stability of both microbial ecological networks and interactions between bacterial and fungal communities. It can enlist a plethora of beneficial Bacillus species microorganisms within the garlic rhizosphere to form a biological barricade that aids in safeguarding garlic against encroachment by the pathogenic fungus Fusarium oxysporum, consequently diminishing disease incidence. This study provides a theoretical foundation for the sustainable development of garlic through long-term crop rotation with maize.ConclusionsOur research results indicate that long-term garlic‒maize rotation maintains stable garlic rhizosphere microecology. Our study provides compelling evidence for the role of long-term crop rotation in maintaining microbiota and community stability, emphasizing the importance of cultivating specific beneficial microorganisms to enhance rotation strategies for garlic farming, thereby promoting sustainability in agriculture.

Artemisinin supplementation improves growth, lipid metabolism, and intestinal microbiota of golden pompano (Trachinotus ovatus) fed high cottonseed meal diets

This study aimed to investigate the effect of artemisinin supplementation to high cottonseed meal (CSM) diet on the growth, lipid metabolism and intestinal microbiota of golden pompano (Trachinotus ovatus). Five diets were formulated, including the control (CM, with CSM replacing 16 % of fishmeal) and experimental groups (CA0, CA2, CA4, and CA8, with CSM replacing 36 % of fishmeal and supplemented with 0 %, 0.20 %, 0.40 %, and 0.80 % of artemisinin, respectively). 375 fishes (initial weight 22.45 ± 0.07 g) were randomized into five groups of triplicates each and fed in tanks for 8 weeks. Results indicated that 0.8 % artemisinin improved final weight, weight gain rate and specific growth rate, reduced the serum lipid levels under the condition of 36 % fishmeal replaced with CSM. In the liver, artemisinin supplementation alleviated hepatocyte vacuolization and lipid deposition induced by the high level CSM replacement fishmeal diet, reduced the activity of lipogenesis-related enzymes and increased lipolysis-related enzyme activity. In the intestine, supplementation with 0.8 % artemisinin significantly increased the activities of intestinal digestive enzymes. Supplementation with 0.8 % artemisinin significantly increased the diversity and stability of the intestinal microbiota of the golden pompano, while also reducing the abundance of potentially harmful Vibrio associated with high CSM levels. In conclusion, 0.8 % artemisinin supplementation mitigated the negative effects of high CSM diets on growth, lipid metabolism, and liver health in golden pompano by enhancing lipid metabolism, intestinal digestive enzyme activity, and modulating intestinal microbiota.

Characterizing the urobiome in geriatric males with chronic indwelling urinary catheters: an exploratory longitudinal study.

The impact of chronic indwelling urinary catheters (IUCs) on the composition and stability of the urinary microbiota remains unknown. The primary aim of this study was to describe the urinary microbiomes of geriatric males with chronic IUCs. A secondary aim was to explore clinical catheter-associated urinary tract infection (CAUTI) courses of the participants. Geriatric male patients with chronic IUCs were followed longitudinally. Catheterized urine, catheter tips, and both urethral and periurethral swabs were collected from participants at monthly intervals. Microbes were isolated and identified from each specimen using an enhanced culture method called expanded quantitative urine culture (EQUC) and targeted 16S rRNA gene DNA sequencing. Microbial outcomes were examined both in the absence of urinary symptoms and in the context of clinical diagnosis of CAUTI. Ten male participants (mean age 86 years) were enrolled. Urinary microbiomes differed for each participant. However, within each individual, microbiomes were similar over time and across niches (bladder, catheter, urethra, and periurethra). Within-niche microbiomes differed across individuals, and this was observed over time. The most abundant bacteria isolated from all niches were known uropathogens. Six of 10 individuals met diagnostic criteria for CAUTI at least once during the 12-month observation period, but no evidence of this or antibiotic treatment/response was discernable in our monthly samples. The microbiomes of each participant were unique and remained similar over time and across niches. Longitudinal EQUC or 16S rRNA gene sequencing data could be useful to clinicians when diagnosing or treating possible CAUTI.IMPORTANCECatheter-associated urinary tract infections (CAUTIs) are serious but preventable nosocomial infections. The most common risk factor for developing CAUTI is prolonged use of indwelling urinary catheters (IUCs). This study provides the first longitudinal description of the urinary microbiomes of geriatric males with chronic IUCs, in the absence of urinary signs and symptoms, as a first step toward enhancing our knowledge of the impact of chronic IUCs on the composition and stability of the urinary microbiota. This is an understudied area, particularly for males.

Divergence and convergence in epiphytic and endophytic phyllosphere bacterial communities of rice landraces.

Phyllosphere-associated microbes can significantly alter host plant fitness, with distinct functions provided by bacteria inhabiting the epiphytic (external surface) vs endophytic niches (internal leaf tissue). Hence, it is important to understand the assembly and stability of these phyllosphere communities, especially in field conditions. Broadly, epiphytic communities should encounter more environmental fluctuations and frequent immigration, whereas endophytic microbiota should face stronger host selection. As a result, we expect greater variability in epiphytic than endophytic communities. We analyzed the structure and stability of leaf phyllosphere microbiota of four traditionally cultivated rice landraces and one commercial variety from northeast India grown in the field for 3 consecutive years, supplemented with opportunistic sampling of eight other landraces. Epiphytic and endophytic bacterial communities shared dominant core genera such as Methylobacterium and Sphingomonas. Consistent with an overall strong environmental effect, both communities varied more across sampling years than across host landraces. Seeds sampled from a focal landrace did not support vertical transmission of phyllosphere bacteria, suggesting that both types of communities are assembled anew each generation. Despite these points of convergence, epiphytic communities had distinct composition and significantly higher microbial load and were more rich, diverse, modular, and unstable than endophytic communities. Finally, focused sampling of one landrace across developmental stages showed that the divergence between the two types of communities arose primarily at the flowering stage. Thus, our results show both convergent and divergent patterns of community assembly and composition in distinct phyllosphere niches in rice, identifying key bacterial genera and host developmental stages that may aid agricultural interventions to increase rice yield.IMPORTANCEPhyllosphere (leaf-associated) microbes significantly impact plant fitness, making it crucial to understand how these communities are assembled and maintained. While many studies have analyzed epiphytic (surface) phyllosphere communities, we have a relatively poor understanding of endophytic communities which colonize the very distinct niche formed inside leaf tissues. We found that across several rice landraces, both communities are largely colonized by the same core genera, indicating divergence at the species level across the two leaf niches and highlighting the need to understand the mechanisms underlying this divergence. Surprisingly, both epiphytic and endophytic communities were only weakly shaped by the host landrace, with a much greater role for environmental factors that likely vary over time. Thus, microbiome-based agricultural interventions for increasing productivity could perhaps be generalized across rice varieties but would need to account for the temporal instability of the microbiota. Our results thus highlight the importance of data sets such as ours-with extensive sampling across landraces and years-for understanding phyllosphere microbiota and their applications in the field.

Gender and age-related variations in rumen fermentation and microbiota of Qinchuan cattle.

Our study aimed to investigate the gender and age-related variations in rumen fermentation, serum metabolites, and microbiota in Qinchuan cattle. A total of 38 Qinchuan beef cattle were selected and maintained on a uniform diet for three months. Rumen fluid and blood samples were collected to determine rumen fermentation, serum metabolites, and microbial 16S rRNA sequencing. The results revealed that the concentration of rumen butyrate in female Qinchuan cattle was significantly higher than in males (P<0.05). Isobutyrate, butyrate, and isovalerate exhibited significant age-related differences. Females exhibited lower serum GLU and higher TG, NEFA levels compared to males (P<0.05). Serum ALB and UREA levels increased with age (P<0.05). Furthermore, the alpha diversity of rumen bacteria improved with age (P<0.05), with no gender differences observed. Males had higher relative abundances of Bacteroidota, Verrucomicrobiota, and Cyanobacteria, while females had higher Firmicutes and Desulfobacterota (P<0.05). The cellulose-degrading genus Ruminococcus and propionate-producing genus Succiniclasticum were more abundant in females, whereas the anti-inflammatory genus Lachnospiraceae_NK4A136_group and the hemicellulose-degrading genus Prevotella were more abundant in males (P<0.05). Age-related differences in bacteria were found in Pseudobutyrivibrio and several members of the Lachnospiraceae. Functional prediction indicated that "Amino acid metabolism" and "Lipid metabolism" were mainly enriched in females, whereas "Carbohydrate metabolism" and "Glycan biosynthesis and metabolism" were enriched in males (P<0.05). RDA analysis highlighted butyrate as a key factor influencing the rumen bacterial community. NK4A214_group and Ruminococcus were positively correlated with butyrate, while Prevotella and Pseudobutyrivibrio were negatively correlated with butyrate (P<0.05). We observed a significant improvement in the diversity and stability of rumen microbiota as age increased. Ruminococcus, NK4A214_group, and Prevotella were likely contributors to variations in energy utilization and fat deposition between male and female Qinchuan cattle.

Stability of Gastric Fluid and Fecal Microbial Populations in Healthy Horses under Pasture and Stable Conditions.

Equine gastrointestinal microbial communities vary across the gastrointestinal tract and in response to diet or disease. Understanding the composition and stability of gastric fluid microbiota in healthy horses is a prerequisite to understanding changes associated with the development of disease. The objective of this study was to describe microbial communities in the gastric fluid and feces of healthy horses longitudinally. Horses were maintained on pasture (6 weeks), stabled (5 weeks), then returned to pasture. A consistent forage diet was provided throughout. Native gastric fluid and feces were collected weekly for full-length 16S ribosomal DNA sequencing and microbial profiling analysis. Fewer taxa were identified in the gastric fluid (770) than in the feces (5284). Species richness and diversity were significantly different between sample types (p < 0.001), but not between housing locations (p = 0.3). There was a significant effect of housing and horse on the Bray-Curtis compositional diversity of gastric (p = 0.005; p = 0.009) and fecal (p = 0.001; p = 0.001) microbiota. When horses moved from pasture to stable, the relative proportions of gastric fluid Lactobacillaceae increased and Streptococcaceae decreased, while fecal Firmicutes increased and Bacteriodota decreased. Within each housing condition, there was no significant week-to-week variation in gastric (p = 0.9) or fecal (p = 0.09) microbiota. Overall, these findings support the maintenance of stable gastric and fecal microbial populations under each management condition, providing a basis for further investigation of gastric fluid microbiota in diseases of the foregut.

Understanding the probiotic potential of Lactobacillus plantarum: Antioxidant capacity, non-specific immunity and intestinal microbiota improvement effects on Manila clam Ruditapes philippinarum

Lactic acid bacteria (LAB) have beneficial effects on aquatic animals, improving their immune system and intestinal microbiota. Nevertheless, the probiotic effects of LAB on the Manila clam Ruditapes philippinarum remain poorly understood. Herein, the effects of administering Lactobacillus plantarum at final doses of 1 × 105 CFU/L (T5 group), 1 × 107 CFU/L (T7 group), and 1 × 109 CFU/L (T9 group) in the rearing water for eight weeks were evaluated for the antioxidant capacity, non-specific immunity, resistance to Vibrio parahaemolyticus infection, and intestinal microbiota of R. philippinarum. The rearing water without the addition of L. plantarum served as a control. The results showed that the T7 and T9 groups demonstrated a significant elevation in the disease resistance of clams against V. parahaemolyticus, in the activities of alkaline phosphatase and lysozyme in the hepatopancreas, and in the expression of antioxidant- and immune-related genes, including SOD, GPx, and GST. Meanwhile, the T7 group showed a significant enhancement in superoxide dismutase and catalase activities and CAT expression, while the T9 group experienced a remarkable elevation in reduced glutathione content. Only catalase activity was markedly elevated in the T5 group. The expression of SOD, CAT, GPx, and GST was significantly elevated in three treatment groups following the V. parahaemolyticus challenge. The T7 group exhibited a significant increase in intestinal microbiota richness. Significant increases were noted in Firmicutes abundance across all three treatment groups and in Actinobacteriota in the T5 and T7 groups. Additionally, the opportunistic pathogen Escherichia-Shigella abundance significantly decreased in three treatment groups. Furthermore, administration of 1 × 107 CFU/L L. plantarum enhanced the stability of the intestinal microecosystem, whereas a dose of 1 × 109 CFU/L might have a negative effect. The application of three doses of L. plantarum significantly enhanced intestinal microbiota functions related to the immune response and oxidative stress regulation, while a higher dose (1 × 109 CFU/L) might inhibit several functions. In conclusion, the application of L. plantarum in the rearing water exerted beneficial effects on the antioxidant capacity, non-specific immunity, resistance to V. parahaemolyticus, and the intestinal microbiota stability and functions of R. philippinarum. The beneficial effects of L. plantarum on R. philippinarum were dose-dependent, and the final dose of 1 × 107 CFU/L exhibited the optimal effects.

The gut microbiota of healthy individuals remains resilient in response to the consumption of various dietary fibers

This study focuses on the resilience of gut microbiota during a five-month multi-interventional nutrition trial. The modulatory effects of beta-glucan, rye bran and two dietary fiber mixtures on the fecal pH and compositional changes of the microbiome of healthy subjects were studied. To analyze the stability of intestinal microbiota, we collected an extensive dataset of sequential fecal samples (23–29 from each participant) during a week of the base, beta-glucan consumption and wash-out periods accompanied by the collection of daily food diary data. Microbiota analyses were also conducted after the end of each fiber intake and wash-out period, along with measurements of fecal organic acids and pH. Based on the dominant bacterial taxa, two prevalent microbiota types were identified. The Prevotella-type microbiota responded more to the tested dietary fibers, while the Bacteroides-type microbiota was the least affected. Three microbiota types could not be clustered and behaved differently. Although we noted individual effects of definite fibers on participants’ gut microbiota and metabolic profile, relative abundances of bacteria remained stable in the base period (z-scores − 2.2 to 2.3). In most cases, the bacterial abundances of the final samples remained within the normal fluctuation range stressing out the resilience of healthy microbiota. The pH of all fecal samples varied between 6.1 and 8.3 and was associated with the concentration of organic acids and microbial composition. The effect of dietary fibers on the metabolism of fecal microbiota clearly depended on the individual microbiota type. Combining the analysis of gut microbiota with knowledge of the properties of dietary fibers would provide a powerful strategy for nutrition guidance and disease prevention.

Impact of Microplastic Exposure on Blood Glucose Levels and Gut Microbiota: Differential Effects under Normal or High-Fat Diet Conditions.

Microplastics are emerging pollutants that have garnered significant attention, with evidence suggesting their association with the pathogenesis of type 2 diabetes mellitus. In order to assess the impact of polystyrene microplastic exposure on alterations in the gut microbiota and the subsequent implications for glucose dysregulation under different dietary conditions in mice, we investigated the effects and disparities in the blood glucose levels induced by polystyrene microplastic exposure in mice fed a high-fat diet versus those fed a normal diet. Using 16S rRNA sequencing and bioinformatics analyses, we explored the dynamic changes and discrepancies in the gut microbiota stability induced by polystyrene microplastic exposure under varied dietary conditions, and we screened for gut genera associated with the potential of polystyrene microplastics to disrupt glucose homeostasis. Our findings indicate that a high-fat diet resulted in abnormal mouse body weight, energy intake, blood glucose levels and related metabolic parameters. Additionally, polystyrene microplastic exposure exacerbated the glucose metabolism disorders induced by a high-fat diet. Furthermore, the composition and diversity of the mouse gut microbiota were significantly altered following microplastic exposure, with 11 gut genera exhibiting a differential presence between mice fed a high-fat diet combined with microplastic exposure compared to those fed a normal diet with microplastic exposure. Moreover, Ucg-009 played an intermediary role in the association between a high-fat diet and the fasting blood glucose. Hence, our study demonstrates that polystyrene microplastic exposure exacerbates high-fat diet-induced glucose metabolism disorders, whereas its impact on the blood glucose under normal dietary conditions is not significant, highlighting the differential influence attributable to distinct alterations in characteristic gut genera.

Mapping the relationship between atopic dermatitis and gut microbiota: a bibliometric analysis, 2014-2023.

Atopic dermatitis (AD) is a chronic inflammatory skin condition affecting a significant portion of the population, with prevalence rates of 25% in children and 7-10% in adults. AD not only poses physical challenges but also profoundly impacts patients' mental well-being and quality of life. The stability of gut microbiota is crucial for overall health and can influence AD progression by modulating immune function, skin barrier integrity, and neuroendocrine signaling, which may be an effective target for the prevention and treatment of AD. Thus, exploring the interactions between AD and gut microbiota, particularly in infants, can provide insights into potential preventive and therapeutic strategies. This study aimed to explore the correlation between AD and gut microbiota while providing an overview of current research trends and emerging areas of interest in this field. A comprehensive search was conducted on the Web of Science Core Collection (WOSCC) for relevant publications from January 1, 2014, to December 31, 2023. English-language articles and reviews were included. Two investigators independently screened the publications, and visual analysis was performed using CiteSpace, VOSviewer, Scimago Graphica, and Microsoft Excel software. A total of 804 articles were included, showing a significant increase in publications over the past decade. The United States, Wageningen University, and University Ulsan (represented by Hong SJ) had the highest number of published papers. Nutrients was the journal with the most publications, while the Journal of Allergy and Clinical Immunology had the highest number of citations and centrality among co-cited journals. Keyword visualization analysis identified "atopic dermatitis" and "gut microbiota" as central themes. Notably, there has been a notable shift in research focus over the years, with early studies concentrating on "Fecal microbiota," "caesarean section," and "first 6 months," while recent studies have highlighted the roles of "cells," "dysbiosis," and "prebiotics." This shift indicates growing interest in the underlying mechanisms and potential therapeutic interventions related to the intestinal microecology in AD treatment. The field of AD and gut microbiota research has evolved significantly, with an increasing focus on understanding the intricate interactions between gut microbiota and AD pathogenesis. Recent years have witnessed increased interest in understanding the relationship between AD and gut microbiota, with researchers conducting extensive studies exploring various aspects of this connection. This review analyzes research trends over the past decade, highlighting trends and hotspots in the study of AD, particularly in infants, and the role of microbiota. This review serves as a valuable reference for future investigations, aiming to provide deeper insights into this burgeoning field and suggests directions for future research.