16S rRNA Gene Sequence Analysis Research Articles

Alleviation of allergic asthma by rosmarinic acid via gut-lung axis

BackgroundAsthma affects 3% of the global population, leading to over 0.25 million deaths. Due to its complexity, asthma is difficult to cure or prevent, and current therapies have limitations. This has led to a growing demand for alternative asthma treatments. We found rosmarinic acid (RosA) as a potential new drug candidate from natural medicine. However, RosA has poor bioavailability and remains mainly in the gastrointestinal tract after oral administration, suggesting the involvement of gut microbiota in its bioactivity. PurposeTo investigate the mechanism of RosA in alleviating allergic asthma by gut-lung axis. MethodsWe used 16S rRNA gene sequencing and metabolites analysis to investigate RosA's modulation of gut microbiota. Techniques of molecular biology and metabolomics were employed to study the pharmacological mechanism of RosA. Cohousing was used to confirm the involvement of gut microbiota in RosA-induced improvement of allergic asthma. ResultsRosA decreased cholate levels from spore-forming bacteria, leading to reduced 5-hydroxytryptamine (5-HT) synthesis, bronchoconstriction, vasodilation, and inflammatory cell infiltration. It also increased short-chain fatty acids (SCFAs) levels, facilitating the expression of intestinal tight junction proteins to promote intestinal integrity. SCFAs upregulated intestinal monocarboxylate transporters (MCTs), thereby improving their systemic delivery to reduce Th2/ILC2 mediated inflammatory response and suppress eosinophil influx and mucus production in lung. Additionally, RosA inhibited lipopolysaccharide (LPS) production and translocation, leading to reduced TLR4-NFκB mediated pulmonary inflammation and oxidative stress. ConclusionsThe anti-asthmatic mechanism of oral RosA is primarily driven by modulation of gut microbiota-derived 5-HT, SCFAs, and LPS, achieving a combined synergistic effect. RosA is a safe, effective, and reliable drug candidate that could potentially replace glucocorticoids for asthma treatment.

Nesterenkonia marinintestina sp. nov., isolated from the fish intestine.

A Gram-positive, aerobic, non-motile, irregular short rod, nonspore-forming actinobacterial strain, designated GX14115T, was isolated from fish intestine in Beihai City, Guangxi, China and subjected to a taxonomic polyphasic investigation. Colonies were yellow‒green, circular, smooth, central bulge, convex, opaque and 2.0-3.0mm in diameter after growth on 2216E medium at 30°C for 72h. Growth occurred at 4-45°C (optimum 30°C), at pH 4.5-10.0 (optimum pH 7.5) and in the presence of 0-12% NaCl (w/v) (optimum 3.5%). Chemotaxonomic analysis showed that the main menaquinone of strain GX14115T was MK-7. The major cellular fatty acids were anteiso-C15:0 (44.8%), anteiso-C17:0 (20.5%), and iso-C15:0 (16%). The whole-cell sugars were galactose and xylose. The peptidoglycan type was L-Lys-Gly-D-Asp, and the polar lipids were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), one unknown phospholipid (UP), and one unknown glycolipid (UG). The DNA G + C content of the type of strain was 69.5mol%. The 16S rRNA gene sequence analysis revealed that strain GX14115T is affiliated with the genus Nesterenkonia and is closely related to Nesterenkonia sandarakina YIM 70009T (96.5%) and Nesterenkonia lutea YIM 70081T (96.8%). The calculated results indicated that the average nucleotide identity (ANI) values of GX14115T were 74.49-74.78%, to the two aforementioned type strains, and the digital DNA-DNA hybridization (dDDH) values were 20.1-20.7%. Strain GX14115T was proposed as a novel species of the genus Nesterenkonia by the physiological, chemotaxonomic, and phylogenetic data, for whose the name is Nesterenkonia marinintestina sp. nov. The type of strain is GX14115T (= MCCC 1K06658T = KCTC 49495T).

Combined exposure with microplastics increases the toxic effects of PFOS and its alternative F-53B in adult zebrafish

Microplastics (MPs) can adsorb and desorb organic pollutants, which may alter their biotoxicities. Although the toxicity of perfluorooctane sulfonate (PFOS) and its alternative 6:2 chlorinated polyfluorinated ether sulfonate (F-53B) to organisms has been reported, the comparative study of their combined toxic effects with MPs on aquatic organisms is limited. In this study, adult female zebrafish were exposed to 10 μg/L PFOS/F-53B and 50 μg/L MPs alone or in combination for 14 days to investigate their single and combined toxicities. The results showed that the presence of MPs reduced the concentration of freely dissolved PFOS and F-53B in the exposure solution but did not affect their bioaccumulation in the zebrafish liver and gut. The combined exposure to PFOS and MPs had the greatest impact on liver oxidative stress, immunoinflammatory, and energy metabolism disorders. 16S rRNA gene sequencing analysis revealed that the combined exposure to F-53B and MPs had the greatest impact on gut microbiota. Functional enrichment analysis predicted that the alternations in the gut microbiome could interfere with signaling pathways related to immune and energy metabolic processes. Moreover, significant correlations were observed between changes in gut microbiota and immune and energy metabolism indicators, highlighting the role of gut microbiota in host health. Together, our findings demonstrate that combined exposure to PFOS/F-53B and MPs exacerbates liver immunotoxicity and disturbances in energy metabolism in adult zebrafish compared to single exposure, potentially through dysregulation of gut microbiota.

Molecular characterization of antibiotic-resistant bacteria associated with maggots obtained from chicken droppings

BackgroundThe use of maggots, developed from chicken droppings as alternative fish meal might serve as a reservoir and vehicle for the widespread of single and multiple antibiotic resistant bacteria (MARB). This study aimed at investigating antibiotic resistant bacteria from chicken droppings and maggots developed from them, and the associated resistance genes and mobile genetic elements in their genomes. Freshly collected poultry droppings obtained from three commercial poultry farms, in Akure, Nigeria and maggots developed from their composting were plated on Luria–Bertani (LB) agar plates that had been incorporated with antibiotics. The emerged MARB were presumptively identified by conventional cultural microbiological methods and then authenticated using 16S rRNA gene sequence analysis. The antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) in the genome of MARB were detected by standard molecular tools.ResultsPotential bacterial pathogens isolated include Escherichia coli, Bacillus cereus, Salmonella enterica, Providencia stuartii, P. rettgeri, Pseudomonas aeruginosa, Staphylococcus aureus, Alcaligenes faecalis, Paelnalcaligenes hominis and Micrococcus luteus. Seventeen ARGs were widely distributed among the 19 ARB/MARB. Tetracycline resistance gene was widely distributed among the ARB/MARB with prevalence of 62%, while macrolides and beta lactam resistance gene had 17% and 13%, respectively. At least six MARB isolates showed the presence of two or more class 1 integron, while five isolates was detected to carry two or more class 2 integron among the 19 MARB.ConclusionsThe results highlight a much higher risk of ARGs spreading through maggots derived from chicken droppings to humans and environmental microbiota.

Genomic and phylogenomic analysis of Fusobacteriaceae family and proposal to reclassify Fusobacterium naviforme Jungano 1909 into a novel genus as Zandiella naviformis gen. nov., comb. nov. and reclassification of Fusobacterium necrophorum subsp. funduliforme as later heterotypic synonym of Fusobacterium necrophorum subsp. necrophorum and Fusobacterium equinum as later heterotypic synonym of Fusobacterium gonidiaformans.

The family Fusobacteriaceae is a large family within the phylum Fusobacteriota. The reclassification of F. naviforme as Zandiella naviformis gen. nov., comb. nov. is proposed because of the separate and distinct phylogenetic situation on the basis of the results of 16S rRNA gene sequence analysis, the genetic and genomic differences from all other species and subspecies in the Fusobacteriaceae family. The type strain is ATCC 25832; CCUG 50052; NCTC 13121. In phylogenetic trees drawn using complete genome sequences and 16S rRNA gene sequences, F. necrophorum subsp. funduliforme and F. equinum were clades together with F. necrophorum subsp. necrophorum and F. gonidiaformans, respectively. The average nucleotide identity, average amino acid identity, and digital DNA-DNA hybridization values between themes exceeded the cut-off values for species delineation. Based on these results, F. necrophorum subsp. funduliforme and F. equinum should be reclassified as later heterotypic synonyms of F. necrophorum subsp. necrophorum and F. gonidiaformans, respectively.

Gut microbiota was highly related to the immune status in chronic obstructive pulmonary disease patients.

This study aimed to explore the profile of gut microbiota and immunological state in COPD patients. 80 fecal and blood samples were collected from 40 COPD patients and 40 healthy controls (HC) and analyzed with 16s-rRNA gene sequencing and immunofactor omics analysis to investigate the profile of gut microbiota and immunologic factors (IFs). The linear discriminant analysis (LDA) effect size (LefSe) was used to determine the biomarker's taxa. The random forest and LASSO regression analysis were executed to screen IFs and develop an IFscore model. The correlation between gut microbiota and IFs, along with the IFscore and the diversity of gut microbiota, was evaluated with the Spearman analysis. The α and β diversity showed that the composition and distribution of gut microbiota in the COPD group differed from that of the HC group. 7 differential taxa at the phylum level and 17 differential taxa at the genus level were found. LefSe analysis screened out 5 biomarker's taxa. 32 differential IFs (up-regulated 27 IFs and down-regulated 5 IFs) were identified between two groups, and 5 IFs (CCL3, CXCL9, CCL7, IL2, IL4) were used to construct an IFscore model. The Spearman analysis revealed that 29 IFs were highly related to 5 biomarker's taxa and enriched in 16 pathways. Furthermore, the relationship between the IFscore and gut microbiota diversity was very close. The gut microbiota and IFs profile in COPD patients differed from that in healthy individuals. Gut microbiota was highly related to the immune status in COPD patients.

Biodiversity of hydrolytic enzymes-producing soil bacteria from a Durian Park, Jombang, Indonesia: Beneficial prospect for sustainable agriculture

Abstract. Ni’matuzahroh, Affandi M, Supriyanto A, Rustantina B, Jaiyah LA, Rahmawati A, Nurhayati H, Sari SK, Khiftiyah AM, Huri D. 2024. Biodiversity of hydrolytic enzymes-producing soil bacteria from a Durian Park, Jombang, Indonesia: Beneficial prospect for sustainable agriculture. Biodiversitas 25: 392-403. Biofertilizer is an alternative to chemical fertilizer that can enhance plant growth but is specific to certain plants and soils. Various biofertilizers have been produced, but the specific biofertilizers to enhance durian growth have not been widely available. This study aims to determine the potential of hydrolytic enzyme-producing bacteria, one of the microbial components of biofertilizers, in the De Durian Park (DDP) area, Wonosalam, Jombang District, Indonesia. The bacteria were isolated using the selective medium plating technique. The obtained isolates were screened for their ability to produce cellulase, amylase, protease, and lipase. The clear zone around the colony indicated the ability of the isolates to produce hydrolytic enzymes, and then the clear zone index was obtained. The best three isolates for each enzyme production were characterized macroscopically, microscopically, and biochemically, then identified using 16S rRNA gene sequence analysis. Fifty-two isolates were successfully obtained from the soil of DDP. The best three cellulolytic bacteria had indices ranging from 1.83 to 2.14, categorized as moderate-strong, identified as Bacillus anthracis, B. pacificus, and B. cereus. The amylolytic bacteria ranged from 1.25 to 1.35, categorized as moderate, and identified as Bacillus anthracis, B. paranthracis, and B. paramycoides. The proteolytic bacteria ranged from 1.33 to 1.50, categorized as moderate, identified as B. pumilus, B. paramycoides, and B. cereus. The lipolytic bacteria ranged from 1.94 to 3.87, categorized as moderate-strong, and were identified as Enterobacter sichuanensis, B. pacificus, and E. asburiae. These cellulolytic, amylolytic, proteolytic, and lipolytic bacteria have the potency as candidates for a biofertilizer formula.

Isolation and identification of Bifidobacterium species from human breast milk and infant feces in Indonesia

Abstract. Dosan R, Mudana SO, Julyanto CMP, Purnama ET, Sugata M, Jo J, Tan TJ. 2024. Isolation and identification of Bifidobacterium species from human breast milk and infant feces in Indonesia. Biodiversitas 25: 337-343. There has been a growing interest in identifying emerging probiotic strains because of their benefits for human health. Many bifidobacteria originated from humans have been reported to possess probiotics properties. They are commonly found in the intestine of breast-fed infants. Hence, this study aimed to isolate and identify bifidobacteria from human breast milk and infant fecal samples in Indonesia and evaluate their probiotic properties. Twenty colonies were isolated from two independent fecal samples and two independent breast milk samples. Ten isolates (BR1-M1, BR1-B1, BR2-5, BR2-6, BR2-12, BS2-PB3, BS2-PB5, BS2-PS1, BS2-PS2, BS2-MB1) showed a compatible phenotypic character with Bifidobacteria based on the Bergey’s Manual, including Gram-positive, irregular rods, no catalase activity, non-spore-forming, and non-motile. Subsequently, four isolates with similar carbohydrate fermentation patterns as Bifidobacterium spp. were selected for further molecular identification based on 16S rRNA gene sequencing analysis. The results showed that BR2-5 and BR2-6 were found to be closely related to Bifidobacterium animalis subspecies lactis with 100 and 98.39% similarity, respectively. Meanwhile, BS2-PS1 and BS2-PB3 were found to be closely related to Bifidobacterium breve with 100 and 98.26% similarity, respectively. Further investigation revealed that BR2-5 and BS2-PB3 were resistant to low pH (?4) and could tolerate the exposure of bile salts (1%). Both isolates survived under different oxidative stress conditions (aerobic and microaerophilic). In conclusion, BR2-5 and BS2-PB3 exhibited promising characteristics as probiotic candidates, though further investigations are required to substantiate these current findings.

Glycomyces niveus sp. nov., a novel actinomycete isolated from sandy soil.

A novel mycelium-forming actinomycete, designated strain NEAU-S30T, was isolated from the sandy soil of a sea beach in Shouguang city, Shandong province, PR China. The strain developed long chains of non-motile cylindrical spores with smooth surfaces on aerial mycelia. The results of a polyphasic taxonomic study indicated that NEAU-S30T represented a member of the genus Glycomyces. The results of 16S rRNA gene sequence analysis indicated that NEAU-S30T was closely related to 'Glycomycesluteolus' (98.97 % sequence similarity), Glycomycesalgeriensis (98.90 %), 'Glycomyces tritici' (98.83 %) and Glycomyces lechevalierae (98.76 %). The average nucleotide identity (ANI) values between NEAU-S30T and 'G. luteolus' NEAU-A15, G. algeriensis DSM 44727T, 'G. tritici' NEAU-C2 and G. lechevalierae DSM 44724T were 87.77, 87.53, 87.41 and 87.80 %, respectively. The digital DNA G+C content of the genomic DNA was 70.5 %. The whole-cell sugars contained ribose and xylose. The predominant menaquinones were MK-10(H2), MK-10(H4) and MK-10(H6). The predominant fatty acids were anteiso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and iso-C15 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified glycolipid. On the basis of the results of comparative analysis of genotypic, phenotypic and chemotaxonomic data, the novel actinomycete strain NEAU-S30T (=JCM 33975T=CGMCC 4.7890T) represents the type strain of a novel species within the genus Glycomyces, for which the name Glycomyces niveus sp. nov. is proposed.

487 - Adult atopic dermatitis is associated with impaired oral health and oral dysbiosis - a case-control study

Abstract Background Previous studies linked chronic oral diseases to skin disorders such as psoriasis. However, data about oral health and oral microbiota in atopic dermatitis (AD) is sparse. Objectives To compare the oral health status and oral microbiota of AD patients and healthy controls. Methods This was a prospective sex and age- matched case-control study comparing adult participants with and without dermatologist-verified AD. Exclusion criteria included recent use of oral, topical, or systemic medication that could affect oral health or microbiome assessment. Oral health indices including Gingival Index, Plaque Index, Oral Hygiene Index, Caries Severity Index and prosthodontics status, were assessed by a dentist. Samples of oral flora were collected and subjected to high-throughput 16S rRNA gene sequencing analysis for microbiome analysis. Results Forty-five AD participants and 41 non-AD controls were recruited. The two groups had no significant differences in terms of their demographic and clinical characteristics, except for the higher rate of atopic co-morbidities in the AD group (p<.001). Compared to the control group, participants with AD had significantly poorer plaque (p=0.04) and oral hygiene indices (p=0.04) and a trend towards higher gingival index (p=0.05). The results of the Faith phylogenetic diversity (FDR) test indicated that the oral microbial diversity in the AD group was significantly higher (α-diversity, FDR-adjusted p=0.0007) when compared with the control group. Characterization of the similarities and differences in the composition of the microbial communities between the samples (β-diversity) from the AD patients and controls indicated that they clustered separately. The groups showed significant dissimilarity and distinct clustering of microbial abundance (FDR-adjusted p=0.001). Importantly, higher community diversity was previously linked to periodontitis and gingival disease. Furthermore, AD patients had a significantly increased abundance of taxa correlated with oral diseases and decreased abundance of oral health-associated bacteria. Conclusion AD appears to be associated with poorer oral health and oral dysbiosis, and thus, there is a need to increase the awareness of both patients and physicians about oral health.

Myceligenerans pegani sp. nov., an endophytic actinomycete isolated from Peganum harmala L. in Xinjiang, PR China.

An endophytic actinomycete designated TRM65318T, was isolated from the root of Peganum harmala L. Its taxonomic status was determined using a polyphasic approach. Comparative 16S rRNA gene sequence analysis indicated that strain TRM65318T is phylogenetically most closely related to Myceligenerans salitolerans XHU 5031T (98.15 %) and Myceligenerans xiligouense DSM 15700T (97.78 %). The peptidoglycan belonged to type A4α. The polar lipids were phosphatidylinositol, phosphatidylglycerol, diphosphatidylglycerol, two unknown lipids and three glycolipids. The predominant menaquinones were MK-9(H4) and MK-9(H6) and the whole-cell sugars contained glucose, mannose and galactose. Major fatty acids were anteiso-C15 : 0, iso-C15 : 0 and C16 : 0. Strain TRM65318T had a genome size of 5881012 bp with a genome G+C content of 71.79 mol%. The average nucleotide identity and DNA-DNA hybridization values between strain TRM65318T and the most closely related species were much lower than the thresholds commonly used to define species. At the same time, differences in phenotypic and genotypic data showed that strain TRM65318T could be clearly distinguished from M. salitolerans XHU 5031T. Therefore, it is concluded that strain TRM65318T represents a novel species of the genus of Myceligenerans. The proposed name for this organism is Myceligenerans pegani sp. nov., with type strain TRM65318T (=CCTCC AA 2019057T=LMG 31679T).

Promotion of anaerobic biodegradation of azo dye RR2 by different biowaste-derived biochars: Characteristics and mechanism study by machine learning

The addition of biochar resulted in a 31.5 % to 44.6 % increase in decolorization efficiency and favorable decolorization stability. Biochar promoted extracellular polymeric substances (EPS) secretion, especially humic-like and fulvic-like substances. Additionally, biochar enhanced the electron transfer capacity of anaerobic sludge and facilitated surface attachment of microbial cells. 16S rRNA gene sequencing analysis indicated that biochar reduced microbial species diversity, enriching fermentative bacteria such as Trichococcus. Finally, a machine learning model was employed to establish a predictive model for biochar characteristics and decolorization efficiency. Biochar electrical conductivity, H/C ratio, and O/C ratio had the most significant impact on RR2 anaerobic decolorization efficiency. According to the results, the possible mechanism of RR2 anaerobic decolorization enhanced by different types of biochar was proposed.

Description of Chryseobacterium fluminis sp. nov., a keratinolytic bacterium isolated from a freshwater river.

A Gram-stain-negative, aerobic, rod-shaped bacterial strain, designated MMS21-Ot14T, was isolated from a freshwater river, and shown to represent a novel species of the genus Chryseobacterium on the basis of the results from a polyphasic approach. The 16S rRNA gene sequence analysis revealed that MMS21-Ot14T represented a member of the genus Chryseobacterium of the family Weeksellaceae and was closely related to Chryseobacterium hagamense RHA2-9T (97.52 % sequence similarity), Chryseobacterium gwangjuense THG A18T (97.46 %) and Chryseobacterium gregarium P 461/12T (97.27 %). The optimal growth of MMS21-Ot14T occurred at 25-30 °C, pH 6.0-7.0 and in the absence of NaCl. MMS21-Ot14T was capable of hydrolysing casein, starch, DNA, Tween 20 and tyrosine. The strain also showed keratinolytic activity with keratin azure and decolourising activity with remazol brilliant blue R (RBBR), which indicated potential ability to degrade keratin and lignin. The main polar lipids of MMS21-Ot14T were phosphatidylethanolamine, unidentified aminophospholipids, unidentified aminolipids, an unidentified phospholipid and several unidentified lipids. The predominant fatty acids of MMS21-Ot14T were iso-C15 : 0 and iso-C17 : 0 3-OH, and the major isoprenoid quinone was menaquinone 6 (MK-6). The whole genome of MMS21-Ot14T was 5 062 016 bp in length with a DNA G+C content of 37.7 %. The average nucleotide identity and digital DNA-DNA hybridisation values between MMS21-Ot14T and phylogenetically related members of the genus Chryseobacterium were well below the threshold values for species delineation. It is evident from the results of this study that MMS21-Ot14T should be classified as representing a novel species of the genus Chryseobacterium, for which the name Chryseobacterium fluminis sp. nov. (type strain, MMS21-Ot14T = KCTC 92255T = LMG 32529T) is proposed.

Microbiome function and neurodevelopment in Black infants: vitamin B12 emerges as a key factor

ABSTRACT The early life gut microbiome affects the developing brain, and therefore may serve as a target to support neurodevelopment of children living in stressful and under-resourced environments, such as Black youth living on the South Side of Chicago, for whom we observe racial disparities in health. Microbiome compositions/functions key to multiple neurodevelopmental facets have not been studied in Black children, a vulnerable population due to racial disparities in health; thus, a subsample of Black infants living in urban, low-income neighborhoods whose mothers participated in a prenatal nutrition study were recruited for testing associations between composition and function of the gut microbiome (16S rRNA gene sequencing, shotgun metagenomics, and targeted metabolomics of fecal samples) and neurodevelopment (developmental testing, maternal report of temperament, and observed stress regulation). Two microbiome community types, defined by high Lachnospiraceae or Enterobacteriaceae abundance, were discovered in this cohort from 16S rRNA gene sequencing analysis; the Enterobacteriaceae-dominant community type was significantly negatively associated with cognition and language scores, specifically in male children. Vitamin B12 biosynthesis emerged as a key microbiome function from shotgun metagenomics sequencing analysis, showing positive associations with all measured developmental skills (i.e., cognition, language, motor, surgency, effortful control, and observed stress regulation). Blautia spp. also were identified as substantial contributors of important microbiome functions, including vitamin B12 biosynthesis and related vitamin B12-dependent microbiome functions, anti-inflammatory microbial surface antigens, competitive mechanisms against pathobionts, and production of antioxidants. The results are promising with respect to the potential for exploring therapeutic candidates, such as vitamin B12 nutritional or Blautia spp. probiotic supplementation, to support the neurodevelopment of infants at risk for experiencing racial disparities in health.

Identification of environmental Actinobacteria in buildings by means of chemotaxonomy, 16S rRNA sequencing, and MALDI-TOF MS.

The manuscript addresses the challenges in identifying environmental bacteria using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) Biotyper-based protein profiling. The matter of the studies-actinobacterial strains-has been isolated mostly from building materials that originated from a confirmed moisture-damaged situation. Polyphasic taxonomy, 16S RNA gene sequencing, and MALDI-TOF mass spectrometry were applied for identification purposes. In this experimental paper, a few important facts are highlighted. First, Actinobacteria are abundant in the natural as well as built environment, and their identification on the species and genus levels is difficult and time-consuming. Second, MALDI-TOF MS is an effective tool for identifying bacterial environmental strains, and in parallel, continuous enrichment of the proteomics mass spectral databases is necessary for proper identification. Third, the chemical approach aids in the taxonomical inquiry of Actinobacteria environmental strains.

Differences in Bacterial Communities and Pathogen Indicators of Raw and Lagoon-Stabilized Farm Dairy Effluents.

One practice for handling farm dairy effluent (DE) comprises recycling them to the soil with the challenge of balancing the tradeoff associated with environmental pollution through nutrient and microorganism loading. This study investigated seasonal bacterial community composition, diversity, abundance, and pathogenic indicators in untreated (Raw) and lagoon-stabilized (Lagoon) DE. The correlation between bacterial profiles and DE physicochemical characteristics was also analyzed. Pathogen-indicator bacteria were studied by enumerating viable counts and the bacterial community structure by 16S rRNA gene sequence analysis. Lagoon storage effectively reduced total solids (64%), suspended solids (77%), organic carbon (40%), and total nitrogen (82%), along with total coliforms, Escherichia coli, and enterococci. However, this efficiency was compromised in winter. Lagoon and Raw sample bacterial communities presented different compositions, with several environmental variables correlating to microbial community differences. Lagoon-treated DE exhibited the most diverse bacterial community, dominated by Firmicutes (40%), Proteobacteria (30%), and Bacteroidota (7.6%), whereas raw DE was mainly composed of Firmicutes (76%). Regardless of the season, dominant genera included Trichococcus, Romboutsia, Corynebacterium, and Paeniclostridium. Overall, the study emphasizes the importance of lagoon treatment for DE stabilization, showcasing its role in altering bacterial community composition and mitigating environmental risks associated with pathogens and nutrients, particularly in summer.

Bifidobacterium animalis subsp. lactis F1-7 Alleviates Lipid Accumulation in Atherosclerotic Mice via Modulating Bile Acid Metabolites to Downregulate Intestinal FXR.

The dysfunction of intestinal microbiota and bile acid metabolism is related to the pathogenesis of atherosclerosis. This study we explored the mechanism of Bifidobacterium animalis subsp. lactis F1-7 (Bif. animalis F1-7), improving atherosclerosis by regulating the bile acid metabolism and intestinal microbiota in the ApoE-/- mice. The Bif. animalis F1-7 effectively reduced aortic plaque accumulation and improved the serum and liver lipid levels in atherosclerotic mice. The untargeted metabolomics revealed that Bif. animalis F1-7 reduced the glycine-conjugated bile acids and the levels of differential metabolite lithocholic acid (LCA) significantly. Downregulation of LCA decreased the intestinal levels of the farnesoid X-activated receptor (FXR) and regulated the bile acid metabolism through the FXR/FGF15/CYP7A1 pathway. Furthermore, the 16srRNA gene sequencing analysis revealed that structural changes in intestinal microbiota with an increase in the abundance of Bifidobacterium, Lactobacillus, Faecalibaculum, Desulfovibrio, and a decrease in Dubosiella, Clostridium_sensu_stricto_1, and Turicibacter following the Bif. animalis F1-7 intervention. Correlation analysis showed that the changes in intestinal microbiota mentioned above were significantly correlated with bile acid metabolism in atherosclerotic mice. In conclusion, this study sheds light on the mechanisms by which Bif. animalis F1-7 regulates atherosclerosis.

Sialyllactose Enhances the Short-Chain Fatty Acid Production and Barrier Function of Gut Epithelial Cells via Nonbifidogenic Modification of the Fecal Microbiome in Human Adults.

Although various benefits of human milk oligosaccharides (HMOs) have been reported, such as promoting Bifidobacterium growth in the infant gut, their effects on adults have not been fully studied. This study investigated the effects of two types of sialyllactose, 3'-sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL), on the adult intestinal microbiome using the simulator of human intestinal microbial ecosystem (SHIME®), which can simulate human gastrointestinal conditions. HPLC metabolite analysis showed that sialyllactose (SL) supplementation increased the short-chain fatty acid content of SHIME culture broth. Moreover, 16S rRNA gene sequencing analysis revealed that SL promoted the growth of Phascolarctobacterium and Lachnospiraceae, short-chain fatty acid-producing bacteria, but not the growth of Bifidobacterium. Altogether, both types of SL stimulated an increase in short-chain fatty acids, including propionate and butyrate. Additionally, SHIME culture supernatant supplemented with SL improved the intestinal barrier function in Caco-2 cell monolayers. These results suggest that SL could act as a unique prebiotic among other HMOs with a nonbifidogenic effect, resulting in intestinal barrier protection.

Effects of host-associated low-temperature probiotics in olive flounder (Paralichthys olivaceus) aquaculture

This study investigated the effects of supplementation of low-temperature probiotics isolated from the intestines of olive flounder on the growth performance, digestibility, and regulation of intestinal microbiota and the expression of genes related to growth, immunity, and apoptosis in olive flounder. Bacteria showing high growth at approximately 15–20 °C, which is the temperature of olive flounder culture, were isolated and confirmed to be Pseudomonas species through 16S rRNA gene sequence analysis. Whole-genome sequencing revealed that the strain has a 6,195,122 bp single circular chromosome and a guanine–cytosine content of 59.9%. In the feeding trial, supplementation with 1 × 108 CFU/g of the isolate strain positively modulated growth performances, digestive enzyme activity, and gut microbiota composition of olive flounder. RT-qPCR for the comparison of growth, immunity, and apoptosis-related gene expression levels showed no significant differences between the groups. Therefore, the isolated host-associated low-temperature probiotics improved the growth performance of olive flounder by causing positive changes in digestive activity and intestinal microbial composition without affecting host gene expression.

P1225 The interplay of donor-derived gut microbiota correlates with the efficacy of combination therapy of fecal microbiota transplantation with antibiotics for ulcerative colitis

Abstract Background Our previous reports suggest fecal microbiota transplantation (FMT) following bowel cleansing with amoxicillin, fosfomycin, and metronidazole (Antibiotic FMT: A-FMT) improved its efficacy and the recovery of the Bacteroidota species composition, which is associated with ulcerative colitis (UC) severity. Building upon these previous findings, we considered that manipulating the intestinal microbiome to improve the intestinal immune system seems to be a feasible therapeutic regimen for patients with UC. In this study, we explored the gut microbiota signatures through elucidating donor-derived microbe that colonized the recipients and examined the contributions of these microbe to the efficacy of A-FMT. Methods In this study, 97 patients with active UC were enrolled between March 2014 and October 2019, of whom 49 patients were individually assigned a different donor on a one patient-to-one donor basis. FMT was performed via colonoscopy after a two-weeks oral administration of three antibacterial agents. The Lichtiger’s clinical activity index (CAI) at 4 weeks after A-FMT treatment was defined as "response" if the CAI was ≤9 points and improved by ≥3 points. Each case contributed three fecal samples (pre A-FMT, post A-FMT, and Donor). 16S rRNA gene sequence analysis was performed on 147 collected fecal samples, and 6,501 Amplicon Sequence Variants (ASV) were identified and characterized. Results In responders, the relative abundance of 6 taxonomies including Alistipes were significantly abundant in both post A-FMT treatment samples and their donors’ samples, while 6 other taxonomies were significantly low. In non-responder, significantly low proportion of donor-derived and significantly high proportions of patients-origin and/or new ASV were observed compared with responders. The similarity of gut microbiota composition between donor and post A-FMT treatment was predominantly higher in responders compared to non-responders (Figure 1). Conclusion This study revealed that the engraftment of specific donor-derived microbes is a major factor in A-FMT outcomes, which may be the foundation for precision FMT. Rational identification of patient and donor characteristics can further advance the development of A-FMT therapy for UC.