Higher Alpha Diversity Research Articles

Lower Genital Tract Microbiome in Early Pregnancy in the Eastern European Population.

It is known that the features of the cervicovaginal microbiome can depend on ethnicity, which might be caused by genetic factors, as well as differences in diet and lifestyle. There is no research on the cervicovaginal microbiome of Eastern European women during early pregnancy. We evaluated the cervical and cervicovaginal microbiome of women with first-trimester pregnancy (n = 22), further delivered at term, using the 16S rRNA sequencing method. The predominant bacterial species in both groups was Lactobacillus iners, followed by Prevotella copri, Ileibacterium valens, Gardnerella vaginalis and Muribaculum intestinale in the cervical samples, and Gardnerella vaginalis, Prevotella copri, Bifidobacterium longum, Ileibacterium valens and Muribaculum intestinale in the cervicovaginal samples. The cervical microbiome had higher alpha diversity; a higher abundance of Muribaculum intestinale, Aquabacterium parvum and Methyloversatilis universalis; and a lower abundance of Psychrobacillus psychrodurans. The Lactobacillus iners-dominated microbiome (CST III) was the predominant type of cervical and cervicovaginal microbiome in early pregnancy in the majority of the women. The presence of soil and animal bacteria in the cervicovaginal microbiome can be explained by the rural origin of patients.

New perspectives on soil animal trophic ecology through the lens of C and N stable isotope ratios of oribatid mites

Knowledge of the trophic ecology of soil animals is important for understanding their high alpha diversity as well as their functional role in soil food webs and systems. In the last 20 years, the analysis of natural variations in stable isotope ratios (15N/14N, 13C/12C) has revolutionized our view on soil animal trophic ecology. Here, we review the state of the art of the trophic ecology of a highly abundant and diverse soil animal taxon, oribatid mites (Oribatida), investigated by stable isotope analyses. The review is based on 25 papers reporting stable isotope data of 292 oribatid mite taxa from 30 different sites. Four main findings emerged. (1) Oribatid mites cluster into six trophic groups, i.e. moss feeders, lichen feeders, primary decomposers, fungal feeders/secondary decomposers, predators/scavengers and marine algal feeders, plus one additional group, which incorporates CaCO3 in their cuticle for defence but still belongs to the fungal feeders/secondary decomposers group. (2) Of the 292 species studied 43.7% were classified as fungal feeders/secondary decomposers, 27.0% as primary decomposers and 15.7% as predators/scavengers, only few species include CaCO3 into their skeleton (6.1%), feed on lichens (4.9%), mosses (2.1%) or marine algae (0.7%). (3) In about one-third of the species studied the trophic niche was constant or varied little between sites or habitats, but in two-thirds of the species their trophic niche varied between habitats, with some species even shifting trophic levels, indicating trophic plasticity. (4) When aggregated at higher taxonomic level oribatid mite species clustered in only three instead of six trophic groups. This indicates that species within the same high level taxon often belong to different trophic groups, for example because feeding habits evolved convergently. Therefore, to accurately reflect the trophic ecology of oribatid mites their stable isotope signatures need to be analysed at species level. However, stable isotope analyses also have limitations, e.g. feeding on bacteria and fungi cannot be separated, and the same is true for feeding on ectomycorrhizal and arbuscular mycorrhizal fungi. Other methods such as fatty acid, amino acid and molecular gut content analyses as well as microbiome analyses may complement stable isotope studies and resolve oribatid mite trophic niche differentiation at a higher resolution. This will contribute to a better understanding of the local coexistence of large numbers of species in soil. Finally, we provide perspectives on how to integrate microarthropods into soil food webs using stable isotope and other methods allowing deeper insight into their trophic structure.

Steelhead trout (Oncorhynchus mykiss) fed probiotic during the earliest developmental stages have enhanced growth rates and intestinal microbiome bacterial diversity

Sustainable aquaculture practices can help meet the increasing human demand for seafood, while easing pressures on natural fish populations. Studies aimed at increasing fish production in aquaculture have included supplementary dietary probiotics that often promote general health and enhanced growth rates by altering the microbiome of the host. Steelhead trout (Oncorhynchus mykiss) is anadromous, like salmon, and it is a subspecies of rainbow trout capable of rapid growth, making it an attractive fish to the aquaculture industry. In this study, the impact of feeding a Bacillus subtilis probiotic on the bacterial microbiome of steelhead trout was examined temporally across several stages of animal development, from eggs (day -19) through 184 days after hatching, in relation to physiological measures. Diets included: commercial feed only as a control (A), continually-fed probiotic top-coated on commercial feed (B), commercial then switch to probiotic feed (C), or probiotic then switch to commercial feed (D). Validation of probiotic concentrations on feed and in fish tissues was performed using CFU/g and qPCR, respectively. Fish growth was measured and samples for intestinal microbiome analyses were collected at multiple timepoints during fish development. Fish fed diet D yielded higher weights than the other three diets, with little impact on other biometric parameters. However, bacterial microbiome analysis indicated an increasing trend of overall alpha diversity from the egg stage to day 29 for fish fed the various diets with diet D having the highest diversity. Fish fed diets A and D maintained a high alpha diversity beyond day 29 in contrast to a decreased trend for fish still being fed probiotics in diets B and C. The fish fed diets B and C harbored a significantly higher relative abundance of Bacillus sp. in their total microbiomes (feces + mucosa). Interestingly, the mucosal-only microbiome indicated little variation between the four groups of fish. Feeding the probiotic earlier in development, during the hatchery phase, to influence bacterial microbiome composition in the intestine (rather than later after the microbiome has been established) appears to be a more effective aquaculture practice by enhancing microbiome diversity while enabling higher fish yields.

The core microbiome of Carya illinoinensis (pecan) seedlings of different maternal pecan cultivars from the same orchard

Carya illinoinensis (pecan) produce a high valued and desired nut crop; with production expanding worldwide. Important attributes of pecans and their ability to adapt to different environments aside from their native regions are currently being investigated. Microbial communities are known to play an important role in crop productivity and overall plant health. Studies in other plant species have shown that the plant microbiome may be influenced by both the environmental conditions and genetics of the plant. Microbiota research in pecan is in its early stages and here we report insights into the core microbiome of seedlings derived from five pecan cultivars located in an orchard from Las Cruces, New Mexico. Seeds from open-pollinated pecan cultivars (‘Burkett’, ‘Mandan’, ‘Pawnee’, ‘Western’, and ‘Wichita’) were collected and grown in a quarantine greenhouse under highly regulated conditions. DNA from the resulting seedlings were used for next generation sequencing (MiSeq) for 16S and ITS and microbiome analyses revealed significant differences in microbial composition and relative abundance (bacterial and fungal) between seedling organs, with roots having the highest alpha diversity followed by stems and leaves. Bacterial family Chitinophagaceae was identified to be most relatively abundant in the roots of seedlings compared to the bacterial families Rhizobiaceae and Moraxellaceae, which were found to be most relatively abundant in the stems and leaves, respectively. Analyses also indicated that there were several families (bacterial families: Rhizobiaceae, Enterobacteriaceae, Chitinophagaceae, Burkholderiaceae, Sphingomonadaceae, Pseudomonadaceae, Moraxellaceae, Microscillaceae, Rubritaleaceae, Caulobacteraceae; fungal families: Serendipitaceae, Nectriaceae, Ophiostomataceae, Hypocreaceae, Aspergillaceae, and Cephalothecaceae) that were found in all seedlings and these constitute a core microbiome for pecan. There were also differences in microbial composition (bacterial and fungal) between seedlings from different maternal pecan cultivars and these differences are proposed to constitute a signature microbiome for the maternal cultivar. As pecan trees continues to extend to other growing regions it is important to understand the role that these microbes play in pecan. By establishing the core microbiome of pecans, the selection of microbes for breeding and improving pecan production will become a possibility.

Short-Term Tomato Consumption Alters the Pig Gut Microbiome toward a More Favorable Profile.

Diets rich in fruits and vegetables have been shown to exert positive effects on the gut microbiome. However, little is known about the specific effect of individual fruits or vegetables on gut microbe profiles. This study aims to elucidate the effects of tomato consumption on the gut microbiome, as tomatoes account for 22% of vegetable consumption in Western diets, and their consumption has been associated with positive health outcomes. Using piglets as a physiologically relevant model of human metabolism, 20 animals were assigned to either a control or a tomato powder-supplemented diet (both macronutrient matched and isocaloric) for 14 days. The microbiome was sampled rectally at three time points: day 0 (baseline), day 7 (midpoint), and day 14 (end of study). DNA was sequenced using shotgun metagenomics, and reads were annotated using MG-RAST. There were no differences in body weight or feed intake between our two treatment groups. There was a microbial shift which included a higher ratio of Bacteroidota to Bacillota (formerly known as Bacteroidetes and Firmicutes, respectively) and higher alpha-diversity in tomato-fed animals, indicating a shift to a more desirable phenotype. Analyses at both the phylum and genus levels showed global microbiome profile changes (permutational multivariate analysis of variance [PERMANOVA], P ≤ 0.05) over time but not with tomato consumption. These data suggest that short-term tomato consumption can beneficially influence the gut microbial profile, warranting further investigation in humans. IMPORTANCE The composition of the microorganisms in the gut is a contributor to overall health, prompting the development of strategies to alter the microbiome composition. Studies have investigated the role of the diet on the microbiome, as it is a major modifiable risk factor contributing to health; however, little is known about the causal effects of consumption of specific foods on the gut microbiota. A more complete understanding of how individual foods impact the microbiome will enable more evidence-based dietary recommendations for long-term health. Tomatoes are of interest as the most consumed nonstarchy vegetable and a common source of nutrients and phytochemicals across the world. This study aimed to elucidate the effect of short-term tomato consumption on the microbiome, using piglets as a physiologically relevant model to humans. We found that tomato consumption can positively affect the gut microbial profile, which warrants further investigation in humans.

Upper Respiratory Microbiome in Pregnant Women: Characterization and Influence of Parity.

During pregnancy, the woman's immune system changes to support fetal development. These immunological modifications can increase the risk of respiratory diseases. Because the respiratory microbiome is involved in airway homeostasis, it is important to investigate how it changes during pregnancy. Additionally, since parity is associated with immune system alterations and cohabitants shared a similar microbiome, we investigated whether having a child may influence the respiratory microbiome of pregnant women. We compared the microbiome of 55 pregnant with 26 non-pregnant women using 16S rRNA gene sequencing and analyzed taxonomy, diversity, and metabolic pathways to evaluate the differences among nulliparous, primiparous, and multiparous women. The microbiome was similar in pregnant and non-pregnant women, but pregnant women had higher alpha diversity (Chao1 p-value = 0.001; Fisher p-value = 0.005) and a lower abundance of several metabolic pathways. Multiparous pregnant women had a higher relative abundance of Moraxella (p-value = 0.003) and a lower abundance of Corynebacterium (p-value = 0.002) compared with primiparous women. Both multiparous (pregnant) and primiparous/multiparous (non-pregnant) women reported a higher abundance of Moraxella compared with primiparous (pregnant) or nulliparous ones (p-value = 0.001). In conclusion, we characterized for the first time the upper airway microbiome of pregnant women and observed the influence of parity on its composition.

Impact of Probiotic Geotrichum candidum QAUGC01 on Health, Productivity, and Gut Microbial Diversity of Dairy Cattle.

Gut microbial diversity is a determinant of animal productivity and health. Probiotic supplementation in feed has been known to modulate the gut microbial diversity resulting in better feed utilization and resistance against diseases. The current study was designed to determine the probiotic potential of Geotrichum candidum QAUGC01 (VHDP00000000) in Sahiwal-Friesian crossbred dairy cows and its impact on gut microbial diversity, health, and productivity. To evaluate health and productivity, growth performance, determination of blood parameters, serum biochemistry, feed efficiency, milk yield & composition, and nutrients digestibility was determined and compared between control and experimental groups. Moreover, at the end of the experiment, the gut microbial diversity was evaluated through MiSeq (Illumina) sequencing of bacterial and fungal/yeast DNA in dung samples of both control and experimental cows. Inspite ofa significant reduction in dry matter intake the increase in feed efficiency and milk yield was observed in experimental cows with normal hematological and serum biochemical profile. The increase in anaerobic bacterialcount and decrease in the shredding of pathogenic flora was observed in experimental cows. Metagenomic analysis revealed Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes to be the four dominating phyla among bacteria and, Ascomycota followed by Basidiomycota and Neocallimastigomycota among the fungal population in both groups. The diversity of the core microbiome revealed high bacterial and Fungal Alpha diversity in the experimental group than in control via the Shannon index. This study provided insights into the safe use of G. candidum as a probiotic, to improve growth performance, health, productivity and gut microbial diversity of dairy cattle.

Methanogen Levels Are Significantly Associated with Fecal Microbiota Composition and Alpha Diversity in Healthy Adults and Irritable Bowel Syndrome Patients.

Hydrogenotrophic microbes, primarily including the three functional groups methanogens, sulfate-reducing bacteria, and reductive acetogens, use hydrogen as an energy source and play an important role in maintaining the hydrogen balance in gut ecosystems. A distorted hydrogen balance has been associated with irritable bowel syndrome (IBS). However, the role of hydrogenotrophic microbes in overall microbiota composition and function remains largely unknown. This study aims to assess the distribution and stability of hydrogenotrophic functional groups in healthy adults (HAs) and IBS patients and their association with overall microbiota composition and IBS symptoms. A two-time-point study with 4 weeks in between was performed with 27 HAs and 55 IBS patients included. Our observations revealed that methanogens showed a bimodal distribution across samples. A high-level methanogen microbiota was consistently associated with higher alpha diversity, and its composition was significantly different from that of individuals with a low-level methanogen microbiota. In general, these associations were more pronounced in IBS patients than in HAs. The differences in the copy numbers of genes indicative of total bacteria and acetogens between HAs and IBS patients and their correlations with IBS symptom severity, anxiety, depression, and quality of life (QoL) were sampling time dependent. Hydrogenotrophic functional groups did not show negative abundance correlations with each other in HAs and IBS patients. These findings suggest that methanogen levels in the gut have a pronounced association with microbiota alpha diversity and composition, and the interactions between hydrogenotrophic functional groups are complex in gut ecosystems. IMPORTANCE Hydrogenotrophic microbes play an essential role in the disposal of hydrogen and the maintenance of the hydrogen balance in gut ecosystems. Their abundances vary between individuals and have been reported to be associated with human gut disorders such as irritable bowel disease. This study confirms that methanogen levels show a bimodal distribution. Moreover, a high-level methanogen microbiota was associated with higher alpha diversity, and its composition was different from that of individuals with a low-level methanogen microbiota. These associations are more pronounced in IBS patients than in healthy subjects. In addition, associations between hydrogenotrophic microbes and IBS symptom scores vary over time, which argues for the use of longitudinal study designs. Last but not least, this study suggests that the different hydrogenotrophic microbes coexist with each other and do not necessarily compete for hydrogen in the gut. The findings in this study highlight the impact of methanogens on overall microbiota composition and function.

Microbiome of Citrullus colocynthis (L.) Schrad. Reveals a Potential Association with Non-Photosynthetic Cyanobacteria.

Citrullus colocynthis grows in the sandy desert soil of the Arabian Peninsula with limited access to water, aside from occasional precipitation or dew. Understanding its ability to produce water-filled fruit and nutrient-rich seeds despite the harsh environment, can be useful for agricultural applications. However, information regarding the microbiome of C. colocynthis is lacking. We hypothesized that C. colocynthis associates with bacteria that aid its survival, like what has been observed in other desert plants. Here, we used 16S rRNA gene data to gain insight into the microbiome of C. colocynthis to identify its associated bacteria. In total, 9818 and 6983 OTUs were generated from root, soil, and leaf samples combined. Overall, bulk soils had the highest alpha diversity, followed by rhizosphere and root zone soils. Furthermore, C. colocynthis is associated with known plant-growth-promoting bacteria (including Acidobacteria, Bacterioidetes, and Actinobacteria), and interestingly a class of non-photosynthetic Cyanobacteria (Melainabacteria) that is more abundant on the inside and outside of the root surface than control samples, suggesting its involvement in the rhizophagy process. This study will provide a foundation for functional studies to further understand how C. colocynthis-microbes interactions help them grow in the desert, paving the path for possible agricultural applications.

Sex-specific associations between gut microbiota and skeletal muscle mass in a population-based study.

A gut-muscle axis through which the microbiome influences skeletal muscle has been hypothesized. However, sex-specific association between the characteristics of gut microbiota and skeletal muscle mass has not yet been reported. Herein, we performed sex-specific analyses of faecal microbiota composition for the skeletal muscle mass in a population-based cohort. We collected faecal samples of 1052 middle-aged participants (621 men and 431 women) who attended health screenings, and we analysed the intestinal microbiota using 16S rRNA gene sequencing. Relative muscle mass was calculated using a bioelectrical impedance analysis and presented as the skeletal muscle mass index [SMI (%)=total appendicular muscle mass (kg)/weight (kg)×100]. We categorized the subjects into four groups by the quartile of the SMI. Association tests between gut microbiota and SMI were conducted according to the microbial diversity, taxonomic profiling and functional inference in a sex-stratified manner. The mean age and SMI of the total participants were 44.8years (standard deviation [SD], 8.2) and 41.4% (SD, 3.9), respectively. After adjustments for possible covariates such as age, body mass index and regular physical activity, the highest quartile (Q4) group of SMI had higher alpha diversity than the lowest quartile (Q1) group in male participants (coefficient=10.79, P<0.05, linear regression model), whereas there was no difference in diversity among SMI groups in females. At the species level, Haemophilus parainfluenzae (coefficient=1.910) and Roseburia faecis (coefficient=1.536) were more abundant in the highest SMI (Q4) group than in the lowest SMI (Q1) group in males. However, no significant taxon was observed along the SMI groups in females. The gut microbiota of the lowest SMI group (Q1) was enriched with genes involved in biosynthesis of amino acids and energy generation compared with that of the highest SMI group (Q4) in both sexes, although the significance of the inferred pathways was weak (P<0.05 but the false discovery rate q>0.05). In this large sample of middle-aged individuals, this study highlights fundamental sex-specific differences in the microbial diversity, composition and metabolic pathways inferred from gut microbiota according to SMI. The gut microbiota may provide novel insights into the potential mechanisms underlying the sex dependence of skeletal muscle mass.

The First Evidence of Bacterial Foci in the Hair Part and Dermal Papilla of Scalp Hair Follicles: A Pilot Comparative Study in Alopecia Areata.

The role of the microbiome in hair follicle (HF) growth represents a growing field of research. Here, we studied the bacterial population in the scalp hair follicles of subjects with alopecia areata (AA). Two Healthy and two AA subjects, respectively (20–60 years old), were enrolled and studied regarding the microbial community in the subepidermal scalp compartments by means of a 4-mm biopsy punch. Samples were examined by 16S sequencing, histochemical staining (Gram’s method), and transmission electron microscopy (TEM). Bacterial foci were observed in the AA subjects’ follicles with both the two adopted complementary approaches (electron microscopy and Gram staining). Significant (p < 0.05) differences were also found in the three-layer biopsy samples (p < 0.05) regarding the bacterial population. In particular, in the deep epidermis and dermis levels, a significant (p < 0.05) lower abundance of Firmicutes and a higher abundance of Proteobacteria were found in AA samples compared to the healthy control. Firmicutes also showed a significant (p < 0.05) lower abundance in hypodermis in AA subjects. In addition, Enterobacteriaceae and the genera Streptococcus, Gemella, Porphyromonas, and Granulicatella were relatively more abundant in AA groups at the deep epidermis level. The Staphylococcus and Flavobacterium genera were significantly less abundant in AA samples than in controls in all three-layer biopsy samples (p < 0.05). In contrast, Veillonella and Neisseriaceae were relatively more abundant in the healthy control group compared to the AA sample. Therefore, higher alpha diversity was observed in all three-layer biopsy samples of AA patients compared to the control. In conclusion, our data suggest that tAA could be defined as a “hair disease associated with dysregulated microbiome-immunity axis of hair follicles”.

Seasonal responses and host uniqueness of gut microbiome of Japanese macaques in lowland Yakushima.

BackgroundChanges in the gut microbial composition is an important response to cope with the seasonal fluctuations in the environment such as food availability. We examined the bacterial gut microbiome of the wild nonhuman primate, Japanese macaque (Macaca fuscata) in Yakushima over 13 months by noninvasive continuous sampling from three identified adult females.ResultsDietary composition varied considerably over the study period and displayed marked shifts with the seasons. Feeding of leaves, fruits, and invertebrates were their main foods for at least one month. Diet had a significant influence on the gut microbiome. We also confirmed significant effect of host uniqueness in the gut microbiome among the three macaques. Leaf-dominated diet shaped unique gut microbiome structures where the macaques had the highest alpha diversity and their gut microbiome was enriched with Spirochaetes and Tenericutes. Diet-related differences in the putative function were detected, such as a differentially abundant urea cycle during the leaf-feeding season.ConclusionBoth diet and host individuality exerted similar amounts of effect on gut microbe community composition. Major bacterial taxa showed a similar response to monthly fluctuations of fruit and invertebrate feeding, which was largely opposite to that of leaf feeding. The main constituents of fruits and invertebrates are both digestible with the enzyme of the host animals, but that of leaves is not available as an energy source without the aid of the fermentation of the gut microbiome.Supplementary InformationThe online version contains supplementary material available at 10.1186/s42523-022-00205-9.

Comparison of Methods to Identify and Monitor Mold Damages in Buildings

Molds thrive in indoor environments, challenging the stability of building materials and occupants’ health. Diverse sampling and analytical techniques can be applied in the microbiology of buildings, with specific benefits and drawbacks. We evaluated the use of two methods, the microscopy of visible mold growth (hereinafter “mold” samples) (tape lifts) and the DNA metabarcoding of mold and dust samples (swabs), for mapping mold-damage indicator fungi in residential buildings in Oslo. Overall, both methods provided consistent results for the mold samples, where nearly 80% of the microscopy-identified taxa were confirmed by DNA analyses. Aspergillus was the most abundant genus colonizing all materials, while some taxa were associated with certain substrates: Acremonium with gypsum board, Chaetomium with chipboard, Stachybotrys with gypsum board and wood, and Trichoderma with wood. Based on the DNA data, the community composition was clearly different between the mold and the dust, with a much higher alpha diversity in the dust. Most genera identified in the mold were also detected with a low abundance in the dust from the same apartments. Their spatial distribution indicated some local spread from the mold growth to other areas, but there was no clear correlation between the relative abundances and the distance to the damages. To study mold damages, different microbiological analyses (microscopy, cultivation, DNA, and chemistry) should be combined with a thorough inspection of buildings. The interpretation of such datasets requires the collaboration of skilled mycologists and building consultants.

Unexpected diversity found within benthic microbial mats at hydrothermal springs in Crater Lake, Oregon.

Crater Lake, Oregon is an oligotrophic freshwater caldera lake fed by thermally and chemically enriched hydrothermal springs. These vents distinguish Crater Lake from other freshwater systems and provide a unique ecosystem for study. This study examines the community structure of benthic microbial mats occurring with Crater Lake hydrothermal springs. Small subunit rRNA gene amplicon sequencing from eight bacterial mats was used to assess community structure. These revealed a relatively homogeneous, yet diverse bacterial community. High alpha diversity and low beta diversity indicate that these communities are likely fueled by homogeneous hydrothermal fluids. An examination of autotrophic taxa abundance indicates the potential importance of iron and sulfur inputs to the primary productivity of these mats. Chemoautotrophic potential within the mats was dominated by iron oxidation from Gallionella and Mariprofundus and by sulfur oxidation from Sulfuricurvum and Thiobacillus with an additional contribution of nitrite oxidation from Nitrospira. Metagenomic analysis showed that cbbM genes were identified as Gallionella and that aclB genes were identified as Nitrospira, further supporting these taxa as autotrophic drivers of the community. The detection of several taxa containing arsC and nirK genes suggests that arsenic detoxification and denitrification processes are likely co-occurring in addition to at least two modes of carbon fixation. These data link the importance of the detected autotrophic metabolisms driven by fluids derived from benthic hydrothermal springs to Crater Lake’s entire lentic ecosystem.

Foliar application of lambda-cyhalothrin modulates root exudate profile and the rhizosphere bacteria community of dioecious Populus cathayana

Dioecious plants show sexual differences in resistance traits to abiotic stresses. However, the effects of exogenous pesticide application on female and male plant growth and their associated adaptation mechanisms are unclear. Our study investigated the effects of the broad-spectrum pesticide lambda-cyhalothrin (λ-CY) on dioecious Populus cathayana growth and explored the factors through which λ-CY changed the rhizosphere bacterial community and physicochemical soil properties via sex-specific metabolomics. The sequential application of λ-CY significantly suppressed male shoot- and root biomass, with little effect on the growth of females. Females possessed a higher intrinsic chemo-diversity within their root exudates, and their levels of various metabolites (sugars, fatty acids, and small organic acids) increased after exposure to λ-CY with consequences on bacterial community composition. Maintaining high bacterial alpha diversity and recruiting specific bacterial groups slowed down the loss of rhizosphere nutrients in females. In contrast, the reduction in bacterial alpha diversity and network structure stability in males was associated with lower rhizosphere nutrient availability. Spearman's correlation analysis revealed that several bacterial groups were positively correlated with the root secretion of lipids and organic acids, suggesting that these metabolites can affect the soil bacterial groups actively involved in the nutrient pool. This study provided novel insights that root exudates and soil microbial interactions may mediate sex-specific differences in response to pesticide application.

Higher pathogen load in children from Mozambique vs. USA revealed by comparative fecal microbiome profiling

The infant gut microbiome has lifelong implications on health and immunity but there is still limited understanding of the microbiome differences and similarities between children in low- and middle-income countries (LMICs) vs. high-income countries (HICs). Here, we describe and compare the microbiome profile of children aged under 48 months in two urban areas: Maputo, Mozambique and Atlanta, USA using shotgun metagenomics. The gut microbiome of American children showed distinct development, characterized by higher alpha diversity after infancy, compared to the same age group of African children, and the microbiomes clustered separately based on geographic location or age. The abundances of antibiotic resistance genes (ARGs) and virulence factors (VFs) were significantly higher in Maputo children, driven primarily by several primary and opportunistic pathogens. Most notably, about 50% of Maputo children under the age of two were positive for enterotoxigenic (ETEC) and typical enteropathogenic (EPEC) Escherichia coli diagnostic genes while none of the Atlanta age-matched children showed such a positive signal. In contrast, commensal species such as Phocaeicola vulgatus and Bacteroides caccae were more abundant in Atlanta, potentially reflecting diets rich in animal protein and susceptibility to inflammatory diseases. Overall, our results suggest that the different environments characterizing the two cities have significant, distinctive signatures on the microbiota of children and its development over time. Lack of safe water, sanitation, and hygiene (WASH) conditions and/or unsafe food sources may explain the higher enteric pathogen load among children in Maputo.

Cross‐sectional and longitudinal associations between gut microbiota composition and cognition in the second year of life: Findings from the Child Health and Resident Microbes study

The relationship between the gut microbiota and brain function are receiving increasing research attention. Studies investigating gut microbiota and early childhood neurocognition are limited, particularly in longitudinal measurements. We examined cross‐sectional relationships between gut microbiota of a cohort of otherwise healthy children using 16S rRNA sequencing and their cognitive development measured with Bayley's Scales of Infant Development III at 24 months of age (n = 43), and longitudinal relationships between gut microbiota composition at 12 months (n = 41) of age and neurodevelopment at 24 months of age. Associations between gut microbiota characteristics and cognitive development were observed both cross‐sectionally and longitudinally, notably with butyrate producing bacteria among some children. Bacterial diversity varied between cross‐sectional and longitudinal observations, where the gut microbiota community of children with lower cognitive scores had a trend toward higher alpha diversity, whereas, in the longitudinal observation, a trend toward reduced alpha diversity was observed. This study is limited by a small sample size and its exploratory nature. Yet, the study contributes to knowledge in the gut microbiota characteristics and early life neurodevelopment, a field of study which is underexplored, presenting opportunities for future larger specific studies.

The Oral Microbiome and Lung Cancer Risk: An Analysis of 3 Prospective Cohort Studies.

Previous studies suggested associations between the oral microbiome and lung cancer, but studies were predominantly cross-sectional and underpowered. Using a case-cohort design, 1306 incident lung cancer cases were identified in the Agricultural Health Study; National Institutes of Health-AARP Diet and Health Study; and Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Referent subcohorts were randomly selected by strata of age, sex, and smoking history. DNA was extracted from oral wash specimens using the DSP DNA Virus Pathogen kit, the 16S rRNA gene V4 region was amplified and sequenced, and bioinformatics were conducted using QIIME 2. Hazard ratios and 95% confidence intervals were calculated using weighted Cox proportional hazards models. Higher alpha diversity was associated with lower lung cancer risk (Shannon index hazard ratio = 0.90, 95% confidence interval = 0.84 to 0.96). Specific principal component vectors of the microbial communities were also statistically significantly associated with lung cancer risk. After multiple testing adjustment, greater relative abundance of 3 genera and presence of 1 genus were associated with greater lung cancer risk, whereas presence of 3 genera were associated with lower risk. For example, every SD increase in Streptococcus abundance was associated with 1.14 times the risk of lung cancer (95% confidence interval = 1.06 to 1.22). Associations were strongest among squamous cell carcinoma cases and former smokers. Multiple oral microbial measures were prospectively associated with lung cancer risk in 3 US cohort studies, with associations varying by smoking history and histologic subtype. The oral microbiome may offer new opportunities for lung cancer prevention.

Vitamin B6 Metabolic Pathway is Involved in the Pathogenesis of Liver Diseases via Multi-Omics Analysis.

PurposeTo clarify the underlying regulatory mechanisms of progression from liver cirrhosis to hepatocellular carcinoma (HCC), we analyzed the microbiomics, metabolomics, and proteomics in plasma and tissues from patients with HCC or decompensated liver cirrhosis (DC).Patients and MethodsTissues and plasma from 44 HCC patients and 28 patients with DC were collected for metabolomic analysis. 16S rRNA sequencing was performed in nine HCC tissues (HCCT), four distal noncancerous tissues (HCCN), and 11 DC tissues (DCT). Five HCC tissues had liver cirrhosis (HCCT-LC). Five hepatocellular carcinoma tissues without liver cirrhosis (HCCT-NLC) and five DCT were selected for proteomic sequencing. After combining proteomic and metabolomic analysis, we constructed a mouse model of chronic liver injury using carbon tetrachloride (CCl4) and treated them with vitamin B6 (VB6).Results16s rRNA sequence results showed that HCC tissues had higher alpha diversity. The highest LDA scores were detected for Elizabethkingia in HCCT, Subsaxibacter in DCT, and Stenotrophomon in HCCN. Metabolomics results demonstrated some metabolites, including capric acid, L-threonate, choline, alpha-D-Glucose, D-ribose, betaine, 2E-eicosenoic acid, linoleic acid, L-palmitoylcarnitine, taurodeoxycholic acid, L-pyroglutamic acid, androsterone sulfate, and phthalic acid mono-2-ethylhexyl ester (MEHP), had better diagnostic efficacy than AFP (AUC: 0.852; 95% CI: 0.749, 0.954). In a combined analysis of metabolomics and proteomics, we found that HCCT-LC had more obvious disorders of VB6 metabolism and pentose and glucuronate interconversions than DCT, and kynurenine metabolism disorder was more significant in HCCT-LC than in HCCT-NLC. In the CCl4-induced chronic liver injury model, after VB6 supplementation, inflammatory cell infiltration, hepatocyte edema, and degeneration were significantly improved.ConclusionWe found significant differences in the flora distribution between HCCT and DC; MEHP was a new diagnostic biomarker of HCC, and VB6 ameliorated the inflammatory cell infiltration, hepatocyte edema, and degeneration in chronic liver injury.

Effect of breast milk with or without bacteria on infant gut microbiota

BackgroundThe breast milk microbiome could be a source of infant intestinal microbiota. Several studies have found that some breast milk is extremely low in bacteria or is even sterile. There are limited studies on the effect of milk without bacteria on the infant gut microbiota. The purpose of this study was to investigate the gut microbiota of infants fed with bacterial milk or sterile milk. Meanwhile, we attempted to find the cause of undetectable bacteria in milk.MethodsA total of 17 healthy pregnant women and 17 infants were enrolled in this study. Fecal samples were collected from full-term pregnant women. Milk samples and infant fecal samples were collected on the 14th postnatal day. Breast milk and fecal samples were examined using 16S rRNA sequencing technology. Pregnant women and infants were grouped according to milk with or without bacteria. To compare the differences in gut microbiota and clinical characteristics between groups.ResultsBacteria were detected in 11 breast milk samples, and the bacterial detection rate was 64.7%. Infants fed with bacterial milk showed higher Shannon index and Simpson index (P = 0.020, P = 0.048), and their relative abundance of Lachnospirales, Lachnospiraceae and Eggerthellaceae was markedly higher. In addition, there were more bacterial associations in the co-occurrence network of infants fed with bacterial milk. Pregnant women with sterile and bacterial breast milk showed no significant differences in their clinical characteristics, and microbial composition and diversity.ConclusionsSome breast milk from healthy postpartum women failed to be sequenced due to low microbial DNA quantities or is sterile. Research is needed to explore the reasons for this phenomenon. Infants fed with bacterial milk had higher Alpha diversity and more complex microbiota networks. These findings provide novel insight into milk microbiota and infant gut microbiota.