Abundance Of Specific Microbes Research Articles

Baseline gut microbiome alpha diversity predicts chemotherapy-induced gastrointestinal symptoms in patients with breast cancer.

Chemotherapy frequently causes debilitating gastrointestinal symptoms, which are inadequately managed by current treatments. Recent research indicates the gut microbiome plays a role in the pathogenesis of these symptoms. The current study aimed to identify pre-chemotherapy microbiome markers that predict gastrointestinal symptom severity after breast cancer chemotherapy. Fecal samples, blood, and gastrointestinal symptom scores were collected from 59 breast cancer patients before, during, and after chemotherapy. Lower pre-chemotherapy microbiome alpha diversity and abundance of specific microbes (e.g., Faecalibacterium) predicted greater chemotherapy-induced gastrointestinal symptoms. Notably, tumor and diet characteristics were associated with lower pre-chemotherapy alpha diversity. Lower baseline alpha diversity also predicted higher chemotherapy-induced microbiome disruption, which was positively associated with diarrhea symptoms. The results indicate certain cancer patients have lower microbiome diversity before chemotherapy, which is predictive of greater chemotherapy-induced gastrointestinal symptoms and a less resilient microbiome. These patients may be strong candidates for pre-chemotherapy microbiome-directed preventative interventions (e.g., diet change).

Mechanisms of microbe-mediated immune development in the context of antibiotics and asthma.

The gut houses 70%-80% of the body's immune cells and represents the main point of contact between the immune system and the outside world. Immune maturation occurs largely after birth and is guided by the gut microbiota. In addition to the many human clinical studies that have identified relationships between gut microbiota composition and disease outcomes, experimental research has demonstrated a plethora of mechanisms by which specific microbes and microbial metabolites train the developing immune system. The healthy maturation of the gut microbiota has been well-characterized and discreet stages marked by changes in abundance of specific microbes have been identified. Building on Chapter 8, which discusses experimental models used to study the relationship between the gut microbiota and asthma, the present review aims to dive deeper into the specific microbes and metabolites that drive key processes in immune development. The implications of microbiota maturation patterns in the context of asthma and allergies, as well as the effects of antibiotics on microbe-immune crosstalk, will also be discussed.

Associations of Intermittent Hypoxia Burden with Gut Microbiota Dysbiosis in Adult Patients with Obstructive Sleep Apnea.

Clinical studies focusing on the association between the gut microbiota and obstructive sleep apnea (OSA) are limited. This study aimed to explore the relationship between intermittent hypoxia and the composition of gut microbiota in adults by analyzing the differences in the characteristics and functional distribution of gut microbiota between patients with different severities of OSA and healthy individuals. A cohort of 113 individuals from the First Affiliated Hospital of Sun Yat-sen University underwent overnight polysomnography from July 2019 to August 2021. The individuals included 16 healthy controls and 97 patients with OSA, categorized by the apnea-hypopnea index into mild, moderate, and severe groups. Fecal samples were analyzed using high-throughput sequencing of the 16S rRNA V3-V4 region to assess gut microbiota composition and function. Correlation analysis was used to evaluate the association between clinical indicators and microbiota markers. In patients with OSA, the gut microbiota diversity and the abundance of specific microbes that produce short-chain fatty acids decreased (P<0.05). The phyla Verrucomicrobia and Candidatus Saccharibacteria, genera Gemmiger and Faecalibacterium, and the species Gemmiger formicilis exhibited decreasing abundance with increasing OSA severity. Correlation analysis revealed a robust association between the proportion of total sleep time, characterized by nighttime blood oxygen saturation below 90%, and the alterations in the gut microbiota, demonstrating that elevated levels of desaturation are correlated with pronounced microbiota dysbiosis (P<0.05). Compared to the control group, the intermittent hypoxia exhibited by patients with OSA may be related to alterations in the composition and structure of the gut microbiota. Our results demonstrate the importance of monitoring hypoxia indicators in future clinical practice.

The social microbiome: gut microbiome diversity and abundance are negatively associated with sociality in a wild mammal.

The gut microbiome has a well-documented relationship with host fitness. Greater microbial diversity and abundance of specific microbes have been associated with improved fitness outcomes. Intestinal microbes also may be associated with patterns of social behaviour. However, these associations have been largely studied in captive animal models; we know less about microbiome composition as a potential driver of individual social behaviour and position in the wild. We used linear mixed models to quantify the relationship between fecal microbial composition, diversity and social network traits in a wild population of yellow-bellied marmots (Marmota flaviventer). We focused our analyses on microbes previously linked to sociability and neurobehavioural alterations in captive rodents, primates and humans. Using 5 years of data, we found microbial diversity (Shannon-Wiener and Faith's phylogenetic diversity) has a modest yet statistically significant negative relationship with the number of social interactions an individual engaged in. We also found a negative relationship between Streptococcus spp. relative abundance and two social network measures (clustering coefficient and embeddedness) that quantify an individual's position relative to others in their social group. These findings highlight a potentially consequential relationship between microbial composition and social behaviour in a wild social mammal.

Association between primary Sjögren's syndrome and gut microbiota disruption: a systematic review and meta-analysis.

Evidence of gut microbiota disruption for numerous autoimmune diseases has accumulated. Recently, the relationship between the microbiota and primary Sjögren's disease has been increasingly investigated but has yet to be systematically elucidated. Therefore, a meta-analysis of publications dealing on topic was conducted. Case-control studies comparing primary Sjögren's syndrome patients and healthy controls (HCs) were systematically searched in nine databases from inception to March 1, 2023. The primary result quantitatively evaluated in this meta-analysis was the α-diversity. The secondary results qualitatively extracted and analyzed were the β-diversity and relative abundance. In total, 22 case-control studies covering 915 pSS patients and 2103 HCs were examined. The quantitative analysis revealed a slight reduction in α-diversity in pSS patients compared to HCs, with a lower Shannon-Wiener index (SMD = - 0.46, (- 0.68, - 0.25), p < 0.0001, I2 = 71%), Chao1 richness estimator (SMD = - 0.59, (- 0.86, - 0.32), p < 0.0001, I2 = 81%), and ACE index (SMD = - 0.92, (- 1.64, - 0.19), p = 0.01, I2 = 86%). However, the Simpson index (SMD = 0.01, (- 0.43, 0.46) p = 0.95, I2 = 86%) was similar in the two groups. The β-diversity significantly differed between pSS patients and HCs. Variations in the abundance of specific microbes and their metabolites and potential functions contribute to the pSS pathogenesis. Notably, the abundance of the phylum Firmicutes decreased, while that of Proteobacteria increased. SCFA-producing microbes including Ruminococcaceae, Lachnospiraceae, Faecalibacterium, Butyricicoccus, and Eubacterium hallii were depleted. In addition to diversity, the abundances of some specific microbes were related to clinical parameters. According to this systematic review and meta-analysis, gut microbiota dysbiosis, including reduced diversity, was associated with proinflammatory bacterium enrichment and anti-inflammatory bacterium depletion in pSS patients. Further research on the relationship between the gut microbiota and pSS is warranted.

Potential Association between Vaginal Microbiota and Cervical Carcinogenesis in Korean Women: A Cohort Study.

Convincing studies demonstrated that vaginal flora is one of the most impactful key components for the well-being of the genital tract in women. Nevertheless, the potential capability of vaginal-derived bacterial communities as biomarkers to monitor cervical carcinogenesis (CC) has yet to be studied actively compared to those of bacterial vaginosis (BV). We hypothesized that vaginal microbiota might be associated with the progression of CC. In this study, we enrolled 23 participants, including healthy controls (HC group; n = 7), patients with cervical intraepithelial neoplasia (CIN) 2 and 3 (CIN group, n = 8), and patients with invasive cervical cancer (CAN group; n = 8). Amplicon sequencing was performed using the Ion Torrent PGM to characterize the vaginal microbiota. Patients with CIN and CAN presented vaginal microbiota dysbiosis compared with HC. The alpha diversity analysis revealed that CC has a trend to be increased in terms of diversity indexes. Moreover, CC was associated with the abundance of specific microbes, of which Lactobacillus and Gardnerella were the most significantly different between HC and CIN, whereas Streptococcus was differentially abundant in CAN compared with CIN. We then evaluated their diagnostic abilities. Testing in terms of diagnostic ability using the three genera revealed considerably high performance with an area under the receiver-operating characteristic curve of 0.982, 0.953, and 0.922. The current study suggests that the presence of Gardnerella and Streptococcus may be involved in the advancment of CC.

Changes in the Microbiome of the Inner Surface of Clear Aligners After Different Usage Periods

Clear aligners are removable orthodontic appliances that cover the tooth surface. The microbial composition and pH of the inner surface of aligners directly affect the enamel health. In this study, eight subjects who used the same type of clear aligners were instructed to brush their teeth normally and to not clean their aligners until sampling. Saliva and the contents of the inner surface of the aligners (liquid and plaque) were collected at 0h (T0), 4h (T4), 8h (T8), 12h (T12), and 24h (T24) after usage, and pH values and microbial compositions were measured. The microbial composition was analyzed with 16S rRNA gene sequencing, and changes were assessed based on operational taxonomic unit abundance. The pH, alpha diversity values, and abundance of specific microbes on the inner surface of the aligners gradually decreased from T0 to T24 (P < 0.05). An insignificant increase in microbial community beta diversity was observed from T0 to T24. Principal component analysis revealed that the microbial composition at T0 was different from at T12 and T24. The relative abundances of phylum Firmicutes (P < 0.01), orders Lactobacillales and Bacteroidales (P < 0.05), and genus Streptococcus and species Streptococcus infantis increased significantly, while those of genera Actinomyces and Rothia and species Rothia aeria decreased significantly at T24 (P < 0.05). These findings reveal that uncleaned aligners might lead to enamel damage, especially after continuous usage for 12h. Thus, clear aligners should be cleaned after 12h of usage or at least within 24h of usage.

Structural Characteristics of Microbial Communities in the Sediments of the Niyang River in Tibet

The Niyang River is an important tributary of the Yarlong Zangbo River, which is also an important water source in the Gongbujiangda and Linzhi areas of Tibet. In this study, water and sediment samples from 18 sites in the Niyang River were collected. The physical and chemical properties, concentrations of 12 heavy metals, and the microbial community in the sediments were determined. The microbial community structures in the sediments collected in 2017 and 2018 were highly similar at the phylum and genus levels. The most dominant type of bacteria in the sediment of the Niyang River was Proteobacteria. Other dominant bacteria included Bacteroidetes, Acidbacteria, and Actinobacteria. At the genus level, the abundance of Flavobacterium was high. Other conditional pathogenic bacteria, such as Aeromonas and Acinetobacter, were detected. Cluster analysis found that there were certain spatial differences among the upstream, midstream, and downstream microbial communities. The microbial community of sediments in the power station reservoir area was unique. Correlation analysis showed that the temperature, dissolved oxygen, electrical conductance, Cr, Zn, Sr, and Ba in the sediments had high correlation with abundance of specific microbes at the phylum level. Redundancy analysis suggested that total nitrogen, total phosphorus, dissolved oxygen, Cr, Sr, Ba, and Mn were the main influencing factors of microbial community structure in the sediments of the Niyang River. The results of this study provide data support for understanding the spatial and temporal distribution of the microbial community in sediments of the Niyang River and identifying their environmental impact factors.

Soil prokaryotes are associated with decreasing Fusarium oxysporum density during anaerobic soil disinfestation in the tomato field

Anaerobic soil disinfestation (ASD) is a chemical-independent method that can reduce pathogens, such as Fusarium oxysporum. Although soil microbes play essential roles in ASD, the relationship between the microbial community structure and disinfestation efficiency remains unclear. Thus for improving our understanding of this relationship, we investigated the changes in the microbial community and pathogen density during an ASD period for 14 days in a greenhouse using three different substrates, as wheat bran, sugar-contained diatoms, and dried molasses. Soil samples were collected at 0, 3, 7, and 14 days after ASD treatment. The pathogen densities were analyzed by real-time polymerase chain reactions. Furthermore, prokaryotic community analysis was conducted by using an Illumina Miseq sequencer, and the factors related to pathogen density were statistically analyzed. The pathogen density rapidly decreased by >90% at 3 days after treatment and then slowly decreased until day 14; however the rate of decrease differed among the substrates. On the other hand, the microbial communities were altered after 3 days but recovered to their original state on day 14. The iron reduction level, microbial diversity, richness, and community structure did not correlate with pathogen density. The operational taxonomic units that drastically negatively correlated with pathogen density were Clostridia and Bacilli, both belonging to Firmicutes. This study showed that the changes in the prokaryotic community as a whole did not correlate to ASD efficiency, whereas changes in the abundance of specific microbes in the community were likely related to disinfestation efficiency.

Dose- and time - dependent abundance of some soil-microbes at chlorsulfuron herbicide application

Introduction Intensification of crop production practices, has enhanced the pesticide use in the agriculture. Among the xenobiotics the herbicides are the most frequently applied agrochemicals (KECSKES, 1976), for improve the yield-production and quality. Apart from the desired toxic effects of some herbicides on weeds, however, the treatments may also have adverse effects on non-target organisms in the soil, in plants (SZENTPETERY et al. 2005, JOLANKAI et al. 2006) and the rhizosphere, like to other results on the GMO-s (VILLANYI et al. 2006). Either the structure or the function of microbial communities may be influenced by pesticide applications. In case of some herbicides the fast degradation, metabolisation is also known by several soil microbes (KATAI et al. 2002). Mechanisms of such toxic or metabolic effects are highly depending on the types and rates of pesticides, the chemical formulations and also the microbial species, exposed. Herbicides are generally most toxic to phototrophic microorganisms through the disruption of photosynthesis (DELORENZO et al. 2000). Beside the reduced applyed rates, the “new generation” herbicides are offering less harmful effects to the beneficial soil-living organisms, by keeping its weed-control capacity throughout the whole vegetation periods (NAGY, 1989). In the agriculture in comparison with conventional herbicides, the Glean (with a 75 % of chlorsulfuron content) can be still 100 times more efficient against the weeds. Regarding the soil biological consequences, an active role in the detoxification of chlorsulfuron by moulds and Actinomycetes was reported in an earlier study (JOSHI et al., 1985). The biodegradation pathway of chlorsulfuron, operated by Aspergillus niger, a common soil fungus was studied under laboratory conditions by BOSCHIN et al. (2003). The fate of chlorsulfuron herbicid could be potentially managed by some soil-microbes in the soils. Several microbial groups from the soil was studied, therefore in their sensitivity to the various doses of the chlorsulfuron (Glean 75) herbicide. There was a timedependent effect considered, when the 3-weeks and 3-months abundance was also assessed in a soil-incubation model-experiment. A simplified, rapid and economic plating method was developed to estimate the abundance of specific microbes from the herbicide treated soil at different application rates.