16S rRNA Sequencing Research Articles

Axis "microbiota – gut – eye": a review

Every organ in the human body has its own microbiota, and the eye, a complex multi-component organ, is no exception. Due to the limitations of traditional methods, detailed study of the ocular microbiome began only in 2010 as part of the Eye Microbiome Project, when advances in research methods made it possible to obtain detailed data, although there had been debate previously about whether microorganisms were even able to attach to the ocular surface due to the layers of the tear film, which have antibacterial properties. The cornea, conjunctiva, lacrimal glands and tear film, meibomian glands and microbiome form the microenvironment of the ocular surface, interacting together and resisting irritants, allergens and pathogens. Homeostasis of the ocular microbiota is critical for maintaining the health of the visual organ. Most microorganisms are found on the cornea and conjunctiva, and modern research methods, including 16S rRNA sequencing, have allowed us to establish the "core" of the ocular surface microbiota, identifying the most common types: Staphylococcus, Corynebacterium, Propionibacterium, and Streptococcus, although the exact composition of the “core” remains debatable. Many factors can influence the composition of the microbiome, including age, contact lens wear, ophthalmic medications, and antibiotics. Like the microbiome of many other organs, the ocular surface microbiome is influenced by the gut microbiome: this relationship has been called the "microbiota – gut – eye" axis. Within the "gut – eye" axis, healthy gut microbiota produce short-chain fatty acids, indoles, polyamines, and other substances that have a beneficial effect on the immune system and retinal health. The state of dysbiosis leads to disruption of homeostasis, and the increasing inflammatory reaction can contribute to damage to the optic nerve and progression of eye disease. Some ophthalmologic diseases, such as diabetic retinopathy, age-related macular degradation, choroidal neovascularization, uveitis, primary open-angle glaucoma, Sjogren's syndrome, dry eye syndrome are associated with dysbiosis of the intestinal microbial composition. Correction of intestinal dysbiosis using various methods can lead to a decrease in the risk of eye diseases, although additional research is needed to discover new methods for treating ophthalmologic pathologies along the "microbiota – gut – eye" axis.

Effects of simulated low-temperature thermal remediation on the microbial community of a tropical creosote contaminated soil.

In the search for more sustainable remediation strategies for PAH-contaminated soils, an integrated application of thermal remediation and bioremediation (TEB) may allow the use of less impacting temperatures by associating heating to biological degradation. However, the influence of heating on soil microbiota remains poorly understood, especially in soils from tropical regions. This work investigated the effects of low-temperature heating on creosote-contaminated soil bacteria. We used culture-dependent and 16S rRNA sequencing methods to compare the microbial community of soil samples heated to 60 and 100 oC for 1h in microcosms. Heating to 60°C reduced the density of cultivable heterotrophic bacteria compared to control soil (p < 0.05), and exposure to 100°C inactivated the viable heterotrophic community. Burkholderia-Caballeronia-Paraburkholderia (BCP) group and Sphingobium were the predominant genera. Temperature and incubation time affected the Bray-Curtis dissimilarity index (p < 0.05). At 60°C and 30 days incubation, the relative abundance of Sphingobium decreased and BCP increased dominance. The network of heated soil after 30 days of incubation showed fewer nodes and edges but maintained its density and complexity. Both main genera are associated with PAH degradation, suggesting functional redundancy and a likely potential of soil microbiota to maintain biodegradation ability after exposure to higher temperatures. We concluded that TEB can be considered as a potential strategy to bioremediate creosote-contaminated soils, allowing biodegradation in temperature ranges where thermal remediation does not completely remove contaminants. However, we recommend further research to determine degradation rates with this technology.

Exploring the potential role of microbiota and metabolites in acute exacerbation of chronic obstructive pulmonary disease

The acute exacerbation of chronic obstructive pulmonary disease seriously affects the respiratory system function and quality of life of patients. This study employed 16S rRNA sequencing and metabolomics techniques to analyze the respiratory microbiota and serum metabolites of COPD and AECOPD patients. The results showed that the microbial diversity in the respiratory tract of AECOPD patients was significantly lower than that of COPD patients, and the relative abundance of Bacteroidetes, Prevotella and Neisseria in the respiratory tract of AECOPD patients was significantly lower than that of COPD patients. However, the relative abundance of Haemophilus_D, Veillonella_A and Pseudomonas_E, in AECOPD patients was significantly higher than that of COPD patients, and the ability of respiratory microbiota in AECOPD patients to participate in alanine metabolism was significantly lower than that of COPD patients. Metabolome results further revealed that the serum alanine levels in AECOPD patients were significantly lower than those in COPD patients, and these differential metabolites were mainly involved in linoleic acid metabolism, protein digestion and absorption and regulation of lipolysis in adipocytes. In summary, the structural characteristics of respiratory microbiota in COPD and AECOPD patients are different from those in healthy populations, and their microbiota diversity decreases and microbial community structure and function will also undergo changes when acute exacerbations occur. In addition, the predicted microbial community function and metabolomics results indicate that the onset of AECOPD is mainly related to energy and amino acid metabolism disorders, especially alanine metabolism.

Temporal Changes in Jejunal and Ileal Microbiota of Broiler Chickens with Clinical Coccidiosis (Eimeria maxima).

Coccidiosis in broiler chickens continues to be a major disease of the gastrointestinal tract, causing economic losses to the poultry industry worldwide. The goal of this study was to generate a symptomatic Eimeria maxima (1000 oocysts) infection to determine its effect on the luminal and mucosal microbiota populations (L and M) in the jejunum and ileum (J and IL). Samples were taken from day 0 to 14 post-infection, and sequencing of 16S rRNA was performed using Illumina technology. Infected birds had significantly (p < 0.0001) lower body weight gain (BWG), higher feed conversion ratio (FCR) (p = 0.0015), increased crypt depth, and decreased villus height (p < 0.05). The significant differences in alpha and beta diversity were observed primarily at height of infection (D7). Analysis of taxonomy indicated that J-L and M were dominated by Lactobacillus, and in IL-M, changeover from Candidatus Arthromitus to Lactobacillus as the major taxon was observed, which occurred quicky in infected animals. LEfSe analysis found that in the J-M of infected chickens, Lactobacillus was significantly more abundant in infected (IF) chickens. These findings show that E. maxima infection affects the microbiota of the small intestine in a time-dependent manner, with different effects on the luminal and mucosal populations.

Isolation and characterization of Streptococcus agalactiae inducing mass mortalities in cultured Nile tilapia (Oreochromis niloticus) with trials for disease control using zinc oxide nanoparticles and ethanolic leaf extracts of some medicinal plants

BackgroundStreptococcus agalactiae (Group B streptococcus, GBS) induces a serious infection that can harm not only aquatic life but also humans and other animals. In a fish farm in southern Egypt, Nile tilapia (Oreochromis niloticus) has developed an epidemic with clinical symptoms resembling piscine streptococcosis.ResultsInitial microscopic inspection of the affected fish brain and kidney indicated the presence of Gram-positive cocci. S. agalactiae was effectively isolated and identified using nucleotide homology of the 16S rRNA and species-specific PCR. The partial 16S rRNA sequence was deposited in the GenBank database at the NCBI and given the accession number MW599202. Genotyping using RAPD analysis indicated that the isolates in the present study belonged to the same genotypes and had the same origin. The challenge test, via immersion (9.2 × 107, 9.2 × 106, and 9.2 × 105 CFU/ml for 1 h) or intraperitoneal injection (4.6 × 107, 4.6 × 106, and 4.6 × 105 CFU/fish), elicited clinical symptoms resembling those of naturally infected fish with a mortality rate as high as 80%. The ability to create a biofilm as one of the pathogen virulence factors was verified. Zinc oxide nanoparticles and the ethanolic leaf extracts of nine medicinal plants demonstrated considerable antibacterial activities against the tested S. agalactiae strain with low minimum bactericidal concentrations (MBC) and minimum inhibitory concentrations (MIC). The ethanolic leaf extracts from Lantana camara and Aberia caffra showed potent antibacterial activity with MBC values of 0.24 and 0.485 mg/ml, and MIC values of 0.12 & 0.24 mg/ml, respectively.ConclusionThis study isolated S. agalactiae from O. niloticus mortalities in a fish farm in Assiut, Egypt. The pathogen persists in fish environments and can escape through biofilm formation, suggesting it cannot be easily eliminated. However, promising findings were obtained with in vitro control employing zinc oxide nanoparticles and medicinal plant extracts. Nevertheless further in vivo research is needed.

A gut-focused perinatal dietary intervention is associated with lower alpha diversity of the infant gut microbiota: results from a randomised controlled trial

ABSTRACT Objectives: In experimental models, the prenatal diet influences gut microbiota composition in mothers and offspring; however, it is unclear whether this occurs in humans. We investigated the effects of a gut-focused perinatal dietary intervention on maternal and infant gut microbiota composition four weeks after birth. Methods: This randomised controlled trial randomised pregnant women to receive dietary advice as part of standard care, or additionally receive a dietary intervention focused on the Australian Dietary Guidelines and increasing prebiotic and probiotic/fermented food intakes (ACTRN12616000936426). Study assessments occurred from gestation week 26 (baseline) to four weeks postpartum (follow-up). Faecal samples, collected at baseline for mothers, and follow-up for mothers and infants, underwent 16SrRNA sequencing. The primary outcome was a between-group mean difference in infant faecal Shannon index. Secondary outcomes included between-group differences in other microbiota measures, including maternal change from baseline CLR-transformed Prevotella abundance. Results: Forty-four women and 45 infants completed the study. The mean Shannon index of infants in the intervention group was −0.35 (95% CI: −0.64, −0.06, SD: 0.52) units lower than control group infants, corresponding to a medium effect size (Cohen’s D: −0.74, 95% CI: −1.34, −0.13). The findings were similar using other metrics of α-diversity. There were no between-group differences in β-diversity, nor any differentially abundant taxa in infants. The intervention increased abundances of the genus Prevotella in mothers compared to controls. Discussion: This gut-focused perinatal dietary intervention was associated with differences in the maternal and infant gut microbiota composition. Larger studies are required to replicate and extend these findings.

Helicobacter cappadocius sp. nov., from lizards: The first psychrotrophic Helicobacter species

It was aimed to determine the prevalence of Helicobacter in some reptilian and amphibian species in Türkiye and to describe the bacteria. For this purpose, 73 cloacal swab samples were used as material. The description of the isolates was performed by detailed phenotypic tests, whole genome analyses, and MALDI-TOF MS. As a result of the phenotypic analysis, two helical, curved Gram-negative, motile isolates were recovered. It was determined through the analysis of 16S rRNA gene sequences that two isolates belonged to the genus Helicobacter. These isolates were found to be in a distinct group from other Helicobacter species. However, the 16S rRNA sequence did not match any identified species, with the closest match being Helicobacter mustelae strain R85-13-6T, which had an identity level of 96.2 %. Additionally, it was found that strains faydin-H75T and faydin-H76 had a 99.3 % identity level for their 16S rRNA genes. After conducting dDDH and ANI analyses, it was found that strains faydin-H75T and their close neighbors H.anseris ATCC BAA-1299T shared 13.5 % and 68.8 % similarity, respectively. The genome size of the strains was 1.7 Mb while G + C contents were 33.5 %. Metagenomic analyses using IMNGS and Protologger tools revealed the presence of faydin-H75T in various lizard species with high similarity, confirming its broad distribution and host specificity. The results indicated that these two strains represent a novel species, for which we propose the name Helicobacter cappadocius with faydin-H75T (=NCTC014972 = LMG 33382 = DSM117062) as the respective type strain. The current novel species is the first Helicobacter species to exhibit a psychrotrophic feature.

Phenylethanol Glycosides from Cistanche tubulosa Modulate the Gut Microbiota and Cecal Metabolites to Ameliorate Diabetic Nephropathy Induced by Streptozotocin Combined with High-Fat Diet in Rats.

Diabetic nephropathy (DN) is a prevalent complication and serious microvascular of diabetes mellitus. After previous studies, we found that phenylethanol glycosides (CPhGs) derived from Cistanche tubulosa (Schenk) Wight exerts antidiabetic and renoprotective effects. However, the effects of CPhGs on DN remain incompletely understood. The study aimed to examine the effects of CPhGs on DN in rats and explore the underlying mechanism involved. A DN rat model was established by streptozotocin (STZ) combined with a high-fat diet. Reagent kits were used to assess the extent to which CPhGs ameliorate hyperglycemia, insulin resistance (IR), renal dysfunction, kidney oxidative stress, and peripheral inflammation. Histology and immunohistochemical staining were used to detect the changes in renal tissue structure and the expression levels of α-smooth muscle actin (α-SMA) and collagen I. Furthermore, we analyzed the cecal contents of DN rats to investigate the effect of CPhGs on gut microbiota by using 16S rRNA sequencing and broad-spectrum metabolite profiling. The results showed that CPhGs demonstrated a range of advantageous outcomes in DN, encompassing the enhancement of kidney function and alleviation of hyperglycemia, IR, renal injury, oxidative stress, and peripheral inflammatory reactions. In addition, CPhGs regulated the abundance of the [Eubacterium]_coprostanoligenes_group, Oscillospiraceae_UCG-005, etc. to modulate the gut microbiota. CPhGs significantly upregulated the content of vitamin B6 and tyrosyl-tryptophan and downregulated histamine, L-methionine, etc. In summary, the therapeutic efficacy of CPhGs on DN rats may be achieved by modulating the gut microbiota and cecal metabolites to restore the metabolic disorders of vitamin B6, histidine, etc.

Comprehensive characterization and resistome analysis of Antarctic Pseudomonas migulae strain CAS19.

Although traditionally considered pristine, Antarctica faces an increasing threat of antibiotic resistance due to human intervention. Here, we obtained a bacterial isolate, the CAS19 strain, from a lake water sample from Ardley Island, Antarctica and characterized it comprehensively. The CAS19 was a psychrotrophic and neutrophilic/alkalitolerant bacterium thriving at temperatures from 15 to 33°C and pH levels from 6.0 to 9.0. Besides the production of siderophore and indole acetic acid, it also exhibited proteolytic and lipolytic activities. It was identified as Pseudomonas migulae by multilocus (16S rRNA, gyrB, rpoB and rpoD) sequence analysis, and its genome was 6.5 Mbps in length, had 59% GC content, and contained 5,821 coding sequences. The CAS19 was resistant to several antibiotics, including trimethoprim, penicillin, vancomycin, and erythromycin, confirmed by RT-qPCR analysis, with a notable increase in dfr (63-fold), bla (461-fold), vanW (31.7-fold) and macA (24.7-fold) expressions upon antibiotic exposure. Additionally, CAS19 exhibited resistance to heavy metals with an order of Cr(III) = Cu(II) > Ni(II) > Zn(II) > Cd(II), and showed diesel fuel (5%) degradation capacity. Cold-related genes cspA_2 and cspD were overexpressed at 4 and 15°C, consistent with the cold adaptation mechanism. In conclusion, for the first time an Antarctic P. migulae isolate has been characterized in detail, uncovering a rich resistome repertoir that might be associated with anthropogenic disturbances.

Integrative taxonomy of Tethya: description of four new species based on morphology, phylogeny and microbiome diversity

The genus Tethya, one of the most iconic groups in the phylum Porifera. includes nearly 100 valid species. Tethya shows a nearly cosmopolitan distribution, and thus this clade could help elucidate global mechanisms of speciation in sponges. Contrasting with many other marine organisms, Tethya peaks in diversity in the temperate region, with only ∼30% of diversity occurring in the tropics. This pattern may however be related to a lack of studies in the tropics, masked by dubious taxonomic identifications. To address this question, we studied new collections from the Western Atlantic (Caribbean and Brazil) and the Northeastern Atlantic, as well as museum material from the Indian Ocean. Combining morphological investigation with molecular phylogenetics and the study of the sponge’s microbial communities, we conclude that four constitute new species that we describe here: Tethya martini Riesgo, Giribet, & Santodomingo, sp. nov.; Tethya simoni Santodomingo, Zea, & Riesgo, sp. nov.; Tethya erici Díez-Vives, Santodomingo, Moles, & Riesgo, sp. nov.; Tethya orioni Kenny, Santodomingo & Riesgo, sp. nov. Some species thought to be widespread (e.g., T. aurantium and T. seychellensis), each represent multiple species with unique geographic distributions. A phylogenetic analysis of Tethya (based on COI and 28S rRNA sequence data) recovered five main clades, which were also characterized by distinct prokaryotic communities. This suggests that microbiomes could be used as a guide for taxonomic identification in Tethya. We finally explored the existence of a phylosymbiotic pattern in sponges at different levels of prokaryotic taxonomic resolution (i.e., at phylum, class, and genus-level analysis of prokaryotes). Remarkably, our analysis revealed high levels of coevolution of Tethya and their associated microbial communities, even when microbiomes were analysed at the genus level. Our findings support the use of an integrative approach to better understand the evolutionary history of sponges. http://zoobank.org/urn:lsid:zoobank.org:pub:54F80E5E-99A4-43CE-BA3A-BCD01E715595

Bacterial and clinical metabolic signatures and their interactions in obese patients post-bariatric surgery

BackgroundObesity is a growing health concern in China, closely linked to metabolic disorders such as type 2 diabetes. Laparoscopic Sleeve Gastrectomy (LSG) is effective in promoting weight loss and improving metabolic outcomes. Emerging evidence highlights the role of gut microbiota in metabolic regulation, yet the specific alterations in gut microbiota and their association with metabolic changes post-surgery in Chinese patients remain unclear. Understanding these shifts could provide key insights into optimizing treatment strategies for metabolic improvement following bariatric surgery.MethodsStool samples and clinical data were collected from 30 obese patients before and 6 months after surgery. The composition of the gut microbiota was analyzed through 16S rRNA sequencing, and Spearman correlation analysis was used to determine the association between gut microbiota and clinical indicators.ResultsThe analysis of 30 patients showed a significant decrease in Body Mass Index (BMI) (36.75 ± 4.09 kg/m2 vs 26.37 ± 3.47 kg/m2, p < 0.0001). Glucose metabolism, including Hemoglobin A1C levels, improved significantly (6.05 ± 0.96 vs 5.05 ± 0.25, p < 0.0001), and liver function as well as serum lipid levels were also notably improved. LSG increased the richness and composition of gut microbiota in obese patients post-surgery. These changes in gut microbiota were closely associated with improved clinical metabolic parameters.ConclusionLSG not only significantly reduces body weight while also alleviating metabolic syndrome and comorbidities by altering gut microbiota.

Molecular Characterization of Anaplasma spp. in Cattle from Kazakhstan.

Bovine anaplasmosis is an infectious vector-borne disease caused by bacteria of the genus Anaplasma, which have a wide global distribution and represent a high economic burden for agriculture. The use of molecular genetic techniques has increased our knowledge of the species diversity of Anaplasma spp. and naturally susceptible animals. Monitoring studies allow us to assess the level of infection in herds, as well as the involvement of natural vectors in the processes of maintaining and spreading infection. Despite the high prevalence of Theileria and Babesia in cattle in Kazakhstan, there is no information on the distribution and species diversity of Anaplasma spp in this country. As part of this work, 7027 DNA samples isolated from the whole blood of cattle from 175 settlements in all 17 Kazakhstan regions were PCR-tested for the presence of Anaplasma spp. Anaplasma carriers were found in 1.3% (90 out of 7027) of the tested animals in 9 of the 17 regions of Kazakhstan. The highest percentage of infected animals was recorded in Turkistan (South Kazakhstan) and North Kazakhstan with 4.46% and 2.48% positive samples, respectively. The partial sequencing of 16S rRNA and the groEL gene allowed us to identify five species of Anaplasma: A. centrale, A. marginale, Candidatus Anaplasma Mongolica, A. ovis, and Unknown Anaplasma with infection rates of 0.63%, 0.44%, 0.13%, 0.01%, and 0.01%, respectively.

Association of Gut Microbiota Composition with Stunting Incidence in Children under Five in Jakarta Slums.

Stunting can be linked to various factors, one of which is dysbiosis. This study aims to analyze the microbiota composition and related contributing factors of stunted and non-stunted children in the slum areas of Jakarta. The subjects in this study included 21 stunted (HAZ ≤ -2SD) and 21 non-stunted children (-2SD ≤ HAZ ≤ 3SD) aged 2-5 years. Microbiota analysis was performed by extracting DNA from the subjects' feces and then via 16S rRNA sequencing using next-generation sequencing (NGS). The results of this study showed that in stunted children, the abundance of Mitsuokella (24,469 OTUs), Alloprevotella (23,952 OTUs), and Providencia alcalifaciens (861 OTUs) was higher, while in non-stunted children, that of Blautia (29,755 OTUs), Lachnospiraceae (6134 OTUs), Bilophila (12,417 OTUs), Monoglobus (484 OTUs), Akkermansia muciniphila (1116 OTUs), Odoribacter splanchnicus (42,993 OTUs), and Bacteroides clarus (8900 OTUs) was higher. Differences in microbiota composition in the two groups were influenced by nutrient intake, birth history, breastfeeding history, handwashing habits before eating, drinking water sources, and water sources for other activities. This study highlights that stunted children have a significantly different gut microbiota composition compared to non-stunted children, with higher levels of pathogenic bacteria and lower levels of beneficial bacteria. Future research should focus on interventions that can improve the gut microbiota composition to prevent stunting in children.

Comparative analysis of crop rotation systems: the impact of ginger (Zingiber officinale) and sponge gourd (Luffa aegyptiaca) residues on growth of Chinese cabbage (Brassica rapa var. chinensis).

Continuous cropping in greenhouse cultivation often leads to increased pest and disease problems, reducing crop quality and yield. Crop rotation is a common strategy to address these issues. This study compared the growth of Chinese cabbage (Brassica rapa var. chinensis) following rotations with ginger (Zingiber officinale) and sponge gourd (Luffa aegyptiaca). The Chinese cabbage exhibited normal growth following ginger rotation but showed abnormal growth after sponge gourd rotation. The study investigated the underlying causes by analyzing soil physicochemical properties and rhizosphere microbial communities of Chinese cabbage using 16S rRNA and ITS sequencing. The results revealed that soil from ginger-Chinese cabbage rotation had higher levels of soil organic carbon (SOC) and available phosphorus (AP), but lower total nitrogen (TN) and available potassium (AK). Despite similar alpha-diversity for both bacterial and fungal communities, distinct bacterial and fungal community structures between two rotation cropping systems were observed. This suggests that even if the alpha-diversity does not change, the composition of the microbial community can shift in ways that might influence soil health and plant growth. Furthermore, redundancy analysis revealed a significant correlation between microbial community structures and soil physicochemical properties of two rotation cropping systems. The SOC and TN were revealed to be the most significant of the investigated soil physicochemical parameters with respect to the variation of both bacterial and fungal assemblages, respectively. The identified biomarkers in bacterial community composition further emphasize the potential for specific microbes to influence crop health positively or negatively. We found that the indicator genera of the bacterial community composition of the ginger-Chinese cabbage rotation system were Amycolatopsis (genus), Pseudonocardiales (order), Pseudonocardiaceae (family), and Amycolatopsis mediterranei, which are known as producers of secondary metabolites, such as antibiotics. These findings highlight the importance of crop selection in rotation strategies for optimizing agricultural outcomes.

Mechanisms of Electroacupuncture in Alleviating Visceral Hypersensitivity in Post-Infectious Irritable Bowel Syndrome Mice: The Role of GDNF Signaling Pathway and Gut Microbiota.

Post-infectious irritable bowel syndrome (PI-IBS) is a functional bowel disease that develops following an acute gastrointestinal infection. Electroacupuncture (EA) can regulate the gut microbiota and alleviate visceral hypersensitivity. Glial cell-derived neurotrophic factor (GDNF) is a potential factor in visceral hypersensitivity reactions. The aim of this study was to explore whether EA could alleviate visceral hypersensitivity in PI-IBS by regulating gut microbiota through GDNF signaling. 2,4,6-trinitrobenzene sulfonic acid (TNBS) was used to induce visceral hypersensitivity in PI-IBS mice. Assessment of intestinal visceral sensitivity using the abdominal withdrawal reflex (CRD). 16S ribosomal RNA (16S rRNA) sequencing to profile the gut microbiome community. GDNF can exacerbate the imbalances of the gut microbiota and increase visceral hypersensitivity compared with the model group. Whereas EA treatment increases the richness and diversity of the gut microbiota, decreases differences among species and alleviates visceral sensitivity. EA can alleviate visceral hypersensitivity in PI-IBS by regulating the gut microbiota via GDNF signaling, providing new insights for mechanistic research on EA in PI-IBS treatment.

Early-life exposure to polystyrene micro- and nanoplastics disrupts metabolic homeostasis and gut microbiota in juvenile mice with a size-dependent manner

Early-life exposure to different sizes of micro- and nanoplastics (MNPs) affects biotoxicity, which is related not only to the dose but also directly to particle size. In this study, pregnant ICR mice received drinking water containing 5 μm polystyrene microplastics (5 μm PS-MPs) or 0.05 μm polystyrene nanoplastics (0.05 μm PS-NPs) from pregnancy to the end of lactation. Histopathological and molecular biological detection, 16s rRNA sequencing for intestinal flora analysis, and targeted metabolomics analysis were used to look into how early-life exposure to MNPs of various sizes affects young mice's growth and development, gut flora, and metabolism. The outcomes showed that 0.05 μm and 5 μm PS-MNPs can pass through the placental and mammary barriers, and MNPs accumulating in various organs were size-dependent: the greater the accumulation in organs, the smaller the particle size. Further studies found that the larger 5 μm PS-MPs caused only small accumulation in organs, with the main health hazard being the disruption of intestinal barrier and liver function, indirectly causing gut dysbiosis and metabolic disorders. In contrast, the smaller 0.05 μm PS-NPs caused excessive accumulation in organs, not only impaired the function of the intestine and liver, but also caused direct mechanical damage to physical tissues, and ultimately resulted in more severe intestinal and metabolic disorders. Our findings underline the size-dependent risks associated with micro- and nanoplastics exposure early in life and highlight the necessity for tailored approaches to address health damages from early MNPs exposure.

Unique Gut Microbiome and Metabolic Profiles in Chinese Workers Exposed to Dust: Insights from a Case-Control Study.

This study aimed to identify distinct gut microbiome and serum metabolic features in workers exposed to dust compared to healthy controls. A case-control study was conducted with dust-exposed workers without silicosis and age-matched healthy controls. Gut microbiome composition was analyzed using 16S rRNA sequencing, and serum and fecal metabolomic profiles were assessed by LC-MS. Dust-exposed workers showed higher levels of Blautia and Trichoderma and lower levels of Anaplasma, Aspergillus, Plasmodiophoromycetes, and Escherichia coli-Shigella. Metabolites such as indole-3-acetate and gentamicin C1a were downregulated, while adenine, 2-phenylacetamide, and 4-pyridoxic acid were upregulated. Blautia spp. were linked to altered metabolites in dust-exposed workers, suggesting microbiome-metabolite interactions that may affect silicosis progression. However, the small sample size and cross-sectional design limit generalizability, and further longitudinal studies are needed.

The potential mediating role of the gut microbiome and metabolites in the association between PFAS and kidney function in young adults: A proof-of-concept study.

Chronic kidney disease (CKD) affects over 10% of the global population and can lead to kidney failure and death. Exposure to per- and polyfluoroalkyl substances (PFAS) is associated with increased risk of CKD, yet studies examining the mechanisms linking PFAS and kidney function are lacking. In this exploratory study, we examined longitudinal associations of PFAS exposure with kidney function, and tested if associations were mediated by altered gut bacterial taxa or plasma metabolites using a multi-omics mediation analysis. Seventy-eight young adults from the Children's Health Study were included in this longitudinal cohort study. At baseline, seven plasma PFAS and untargeted plasma metabolomics were measured using liquid chromatography/mass-spectrometry. Baseline gut bacterial abundance was characterized using 16S rRNA sequencing and examined at the genus level. At follow-up, serum creatinine and cystatin-C concentrations were quantified to estimate glomerular filtration rate (eGFR). High-dimensional multi-omics analyses were conducted to assess the association between baseline PFAS exposure with follow-up eGFR, mediated by gut microbiome and circulating metabolite levels. PFAS burden score, a variable developed to estimate exposure to chemical mixtures, was associated with kidney function. Each standard deviation increase in baseline PFAS burden score was associated with a 2.4% lower eGFR at follow-up (95% CI:[0.1%,4.8%]). Following high-dimensional mediation analyses with the microbiome and circulating metabolites, a joint component (characterized by reduced Lachnospiraceae and 17b-estradiol and increased succinate, retinoate and dodecanoic acid) and a metabolite component (characterized by increased hypotaurine and decreased D-pinitol and ureidopropionate) mediated 38% and 50% of the effect between PFAS burden score and eGFR, respectively. Our proof-of-concept analysis provides the first evidence that reduced short-chain fatty acid-producing bacteria and anti-inflammatory metabolites may link PFAS exposure with impaired kidney function. This study raises the possibility of future targeted interventions that can alter gut microbiome or circulating metabolite profiles to prevent PFAS induced kidney damage.

Lacticaseibacillus paracasei 207-27 alters the microbiota-gut-brain axis to improve wearable device-measured sleep duration in healthy adults: a randomized, double-blind, placebo-controlled trial.

Objective: Probiotics have been reported to exert beneficial effects on sleep through the gut-brain axis. Therefore, this randomized, double-blind, placebo-controlled trial assessed the effects of Lacticaseibacillus paracasei 207-27 supplementation on sleep quality and its safety and potential mechanisms. Method and study design: Healthy adults under mild stress aged 18-35 years consumed low or high doses of L. paracasei 207-27 or a placebo for 28 days. Fecal samples, blood samples, and questionnaires were collected at the baseline and the end of the intervention. Sleep quality was measured using wearable devices and Pittsburgh sleep quality index (PSQI) questionnaire. Serum inflammatory markers, corticotropin-releasing hormone, adrenocorticotropic hormone (ACTH), cortisol (COR), γ-aminobutyric acid, and 5-hydroxytryptamine levels were detected using enzyme-linked immunosorbent assay. The gut microbiota was analyzed using 16S rRNA sequencing and bioinformatics. Short-chain fatty acids levels were detected using gas chromatography-mass spectrometry. Results: Both the low-dose and high-dose groups exhibited significant improvements in wearable device- measured sleep duration compared to the placebo group. The global scores of PSQI in three groups significantly decreased after intervention without statistical difference between groups. At the phylum level, the low-dose group exhibited a higher relative abundance of Bacteroidota and a lower Firmicutes-to-Bacteroidetes (F/B) ratio. At the genus level, two treatment groups had higher relative abundance of Bacteroides and Megamonas, alongside lower levels of Escherichia-Shigella. Furthermore, the low-dose group exhibited significant increases in acetic acid, propionic acid, butyric acid, and valeric acid levels, while two treatment groups exhibited a significant decrease in COR levels. Correlation analysis revealed that the increased levels of acetic acid and butyric acid in the low-dose group may be associated with decreased ACTH. Conclusion: L. paracasei 207-27 administration in healthy adults resulted in improvements in gut microbiota community and sleep duration. The mechanisms might involve modulation of the gut microbiota structure to regulate the function of the gut-brain axis, including increases in SCFA levels and decreases in hypothalamic-pituitary-adrenal axis activity. The Chinese clinical trial registry number is ChiCTR2300069453 (https://www.chictr.org.cn/showproj.html?proj=191193, registered 16 May 2023 - retrospectively registered).

A New Multiplex PCR Assay Reveals the Occurrence of E. bangladeshi alongside E. histolytica and E. moshkovskii in Eastern India.

Epidemiological studies on amoebic infections are complicated due to morphologically identical and clinically important Entamoeba species. Therefore, newer, simpler, and more economical diagnostic techniques are required for differentiating clinically important Entamoeba species. We developed a single-round multiplex PCR assay to identify E. histolytica, E. moshkovskii, E. dispar, E. bangladeshi, and E. coli. Primers were designed based on variations in 18S rRNA sequences. Sensitivity and specificity were assessed using known positive and negative samples. Furthermore, we screened 472 diarrheal samples using this technique alongside the reference PCR method to evaluate its suitability for epidemiological studies and clinical diagnosis. DNA sequencing and phylogenetic analysis of the isolates were conducted. All statistical analyses of the data were performed using GraphPad Prism. The designed primers successfully yielded species-specific PCR products of different sizes as expected. We did not observe any non-specific amplifications of the primer set. The diagnostic performance was also convincing. After screening clinical samples using the method, we observed that 2.33% (n = 11) tested positive for E. moshkovskii, 1.06% (n = 5) tested positive for E. histolytica, and 0.85% (n = 4) tested positive for E. bangladeshi in the studied area. DNA sequencing further confirmed the identified species. The constructed phylogenetic tree also demonstrated clear separation of the detected species lineages. The study suggests the multiplex PCR assay could be a reliable diagnostic tool for amoebic infections. This study is particularly significant as it marks the first reported occurrence of E. bangladeshi since its documentation in South Africa and its native Bangladesh.