Shifts In Microbial Composition Research Articles

Unveiling the Links Between Microbial Alteration and Host Gene Disarray in Crohn's Disease via TAHMC.

A compelling correlation method linking microbial communities and host gene expression in tissues is currently absent. A novel pipeline is proposed, dubbed Transcriptome Analysis of Host-Microbiome Crosstalk (TAHMC), designed to concurrently restore both host gene expression and microbial quantification from bulk RNA-seq data. Employing this approach, it discerned associations between the tissue microbiome and host immunity in the context of Crohn's disease (CD). Further, machine learning is utilized to separately construct networks of associations among host mRNA, long non-coding RNA, and tissue microbes. Unique host genes and tissue microbes are extracted from these networks for potential utility in CD diagnosis. Experimental validation of the predicted host gene regulation by microbes from the association network is achieved through the co-culturing of Faecalibacterium prausnitzii with Caco-2 cells. Collectively, the TAHMC pipeline accurately recovers both host gene expression and microbial quantification from CD RNA-seq data, thereby illuminating potential causal links between shifts in microbial composition as well as diversity within CD mucosal tissues and aberrant host gene expression.

The evolutionarily ancient FOXA transcription factors shape the murine gut microbiome via control of epithelial glycosylation

Evolutionary adaptation of multicellular organisms to a closed gut created an internal microbiome differing from that of the environment. Although the composition of the gut microbiome is impacted by diet and disease state, we hypothesized that vertebrates promote colonization by commensal bacteria through shaping of the apical surface of the intestinal epithelium. Here, we determine that the evolutionarily ancient FOXA transcription factors control the composition of the gut microbiome by establishing favorable glycosylation on the colonic epithelial surface. FOXA proteins bind to regulatory elements of a network of glycosylation enzymes, which become deregulated when Foxa1 and Foxa2 are deleted from the intestinal epithelium. As a direct consequence, microbial composition shifts dramatically, and spontaneous inflammatory bowel disease ensues. Microbiome dysbiosis was quickly reversed upon fecal transplant into wild-type mice, establishing a dominant role for the host epithelium, in part mediated by FOXA factors, in controlling symbiosis in the vertebrate holobiont.

Comparing Oral Microbiota Changes after Pulpotomy/Pulpectomy in Pediatric Patients

ABSTRACT Background: Pediatric dental procedures like pulpotomy and pulpectomy are commonly performed to treat pulp-related dental issues in primary teeth. The choice of instrumentation, such as traditional rotary instruments or laser technology, can impact the oral microbiota. This study aims to compare the changes in oral microbiota following pulpotomy/pulpectomy in pediatric patients treated with traditional rotary instruments versus laser technology. Materials and Methods: A total of 60 pediatric patients, aged 4–10 years, requiring pulpotomy or pulpectomy were randomly assigned to two groups: group A (traditional) and group B (laser). In group A, traditional rotary instruments were used for pulp removal, while in group B, a dental laser was utilized. Saliva and plaque samples were collected before the procedure (baseline), immediately after the procedure, and at the one-month follow-up. Microbial deoxyribonucleic acid (DNA) was extracted and analyzed using 16S ribosomal ribonucleic acid (rRNA) sequencing to assess changes in the oral microbiota. Results: At baseline, both groups exhibited similar microbial diversity and composition. However, immediate post-procedure results showed a significant decrease in microbial diversity in both groups, with group B (laser) demonstrating a more pronounced reduction. At the one-month follow-up, group A (traditional) showed a partial recovery of microbial diversity, while group B (laser) continued to exhibit lower microbial diversity compared to baseline. Notably, group B (laser) displayed a shift in microbial composition with a decrease in pathogenic species and an increase in beneficial bacteria compared to group A. Conclusion: This study highlights that both traditional rotary instruments and laser technology have a significant impact on the oral microbiota of pediatric patients following pulpotomy/pulpectomy. While both methods initially reduce microbial diversity, laser treatment appears to have a more sustained effect, favoring the growth of beneficial bacteria over time. Further research is needed to assess the long-term clinical implications of these microbiota changes for the oral health of pediatric patients.

Impact of persistently high sea surface temperatures on the rhizobiomes of Zostera marina in a Baltic Sea benthocosms.

Persistently high marine temperatures are escalating and threating marine biodiversity. The Baltic Sea, warming faster than other seas, is a good model to study the impact of increasing sea surface temperatures. Zostera marina, a key player in the Baltic ecosystem, faces susceptibility to disturbances, especially under chronic high temperatures. Despite the increasing number of studies on the impact of global warming on seagrasses, little attention has been paid to the role of the holobiont. Using an outdoor benthocosm to replicate near-natural conditions, this study explores the repercussions of persistent warming on the microbiome of Z. marina and its implications for holobiont function. Results show that both seasonal warming and chronic warming, impact Z. marina roots and sediment microbiome. Compared with roots, sediments demonstrate higher diversity and stability throughout the study, but temperature effects manifest earlier in both compartments, possibly linked to premature Z. marina die-offs under chronic warming. Shifts in microbial composition, such as an increase in organic matter-degrading and sulfur-related bacteria, accompany chronic warming. A higher ratio of sulfate-reducing bacteria compared to sulfide oxidizers was found in the warming treatment which may result in the collapse of the seagrasses, due to toxic levels of sulfide. Differentiating predicted pathways for warmest temperatures were related to sulfur and nitrogen cycles, suggest an increase of the microbial metabolism, and possible seagrass protection strategies through the production of isoprene. These structural and compositional variations in the associated microbiome offer early insights into the ecological status of seagrasses. Certain taxa/genes/pathways may serve as markers for specific stresses. Monitoring programs should integrate this aspect to identify early indicators of seagrass health. Understanding microbiome changes under stress is crucial for the use of potential probiotic taxa to mitigate climate change effects. Broader-scale examination of seagrass-microorganism interactions is needed to leverage knowledge on host-microbe interactions in seagrasses.

Influence of Lactobacillus rhamnosus Supplementation on the Glycaemic Index, Lipid Profile, and Microbiome of Healthy Elderly Subjects: A Preliminary Randomized Clinical Trial.

Aging is a time-dependent complex biological process of organisms with gradual deterioration of the anatomical and physiological functions. The role of gut microbiota is inevitable in the aging process. Probiotic interventions improve gut homeostasis and support healthy aging by enhancing beneficial species and microbial biodiversity in older adults. The present preliminary clinical trial delves into the impact of an 8-week Lactobacillus rhamnosus intervention (10 × 109 CFU per day) on the glycaemic index, lipid profile, and microbiome of elderly subjects. Body weight, body fat, fasting blood glucose, total cholesterol, triglyceride, high-density lipoprotein, and low-density lipoprotein (LDL) are assessed at baseline (Week 0) and after treatment (Week 8) in placebo and probiotic groups. Gaussian regression analysis highlights a significant improvement in LDL cholesterol in the probiotic group (p = 0.045). Microbiome analysis reveals numeric changes in taxonomic abundance at various levels. At the phylum level, Proteobacteria increases its relative frequency (RF) from 14.79 ± 5.58 at baseline to 23.46 ± 8.02 at 8 weeks, though statistically insignificant (p = 0.100). Compared to the placebo group, probiotic supplementations significantly increased the proteobacteria abundance. Genus-level analysis indicates changes in the abundance of several microbes, including Escherichia-Shigella, Akkermansia, and Bacteroides, but only Butyricimonas showed a statistically significant level of reduction in its abundance. Probiotic supplementations significantly altered the Escherichia-Shigella and Sutterella abundance compared to the placebo group. At the species level, Bacteroides vulgatus substantially increases after probiotic treatment (p = 0.021). Alpha and beta diversity assessments depict subtle shifts in microbial composition. The study has limitations, including a small sample size, short study duration, single-strain probiotic use, and lack of long-term follow-up. Despite these constraints, the study provides valuable preliminary insights into the multifaceted impact of L. rhamnosus on elderly subjects. Further detailed studies are required to define the beneficial effect of L. rhamnosus on the health status of elderly subjects.

Effects of Conventional Non-Biodegradable Film-Derived Microplastics and New Biodegradable Film-Derived Microplastics on Soil Properties and Microorganisms after Entering Sub-Surface Soil

Plastic film mulching, widely used in agriculture, leads to microplastic (MP) pollution in soils. While biodegradable polybutylene adipate terephthalate (PBAT) films may offer a solution, their impacts on subsurface soils and microorganisms remain unclear. To investigate the effects of conventional non-biodegradable polyethylene (PE) and biodegradable PBAT MPs on the properties of sub-surface soils and microbial communities, MPs were added at varying doses in a field experiment and incubated for 160 days. Physicochemical characteristics, nutrient dynamics, and microbial composition, diversity, and networks of soils were analyzed using standard techniques and 16S rRNA/ITS gene sequencing. Correlations between soil properties and microbes were assessed. Both MP types significantly altered soil characteristics, with PBAT-MP elevating pH and the levels of available phosphorus and potassium more than PE-MP. Microbial composition shifts occurred, with low-addition PBAT-MP promoting plastic-degrading genera. The assessment of α/β-diversity indicated that PBAT-MP predominantly influenced fungi while PE-MP impacted bacteria. An examination of microbial co-occurrence networks highlighted that PE-MP primarily disrupted fungal interactions, whereas PBAT-MP streamlined network complexity. Correlation analyses revealed that PBAT-MP promoted fungal diversity/network resilience correlating to nutrients. PE-MP and PBAT-MP significantly altered native soil/microbe relationships. PBAT-MP may exert greater, yet unknown, impacts over time through its biodegradation into newer and smaller fragments. Future research needs to integrate multi-omics and stable isotope science to elucidate the deep mechanistic impacts of degraded film-derived MPs on microbial ecological functions and biogeochemical cycles. Attention should also be paid to the long-term accumulation/transport of MPs in agricultural soils. Overall, this work deepens the impact and understanding of MPs from plastic film on sub-surface soil ecology. Furthermore, it provides a theoretical foundation for managing ‘white pollution’ in the film-covered farmlands of arid and semi-arid regions in China.

Biotreatment of crude oil waste sludge using a novel bacterial formula

To address the challenges faced during the breakdown of crude oil waste sludge (COWS), this study developed an active bacterial formula (ABF) to enhance the breakdown of COWS. The formula used was a bacteria consortium (BC) with the desired characteristics immobilised on corncob powder (CCP). A mixture of soil-COWS (SSM) (w/w) was treated with ABF (w/w) in a laboratory trial for 90 days. The treated SSM was analysed for residual concentrations of hydrocarbon components of the COWS by solvent extraction and GC/MS. To elucidate the bacterial community composition, Illumina/MiSeq was used. Immobilised bacteria cells (IBC) on corncob powder (CCP) were confirmed and effectively shown by scanning electron microscopy (SEM) images. The formula on SSM caused a shift in microbial composition, ascribed to nutrients and carbon sources (CS) used in the treatment and other features such as symbiosis and competition to use the diverse carbon sources. The four phyla Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes identified were dominant and affiliated to 90 genera including Rhodococcus, Bacillus, Gordonia, Dietzia, Ochrobactrum, Clostridium, Pseudomonas, and Microbacterium at a high relative abundance of >1.0 to >10. Parameters such as bacterial diversity (BD) and composition, relative abundance (RA), and PAH-residual concentration were used to assess the effectiveness of ABF. The results obtained suggest that ABF alleviated issues of survival of degrading bacteria and nutrient deficiency, as some PAH were thoroughly degraded (100 %) and others almost wholly degraded (95 %) in 90 days in all the treatments, unlike the 10 months in preceding studies.

Ecological filter walls for efficient pollutant removal from urban surface water

Urban surface water pollution poses significant threats to aquatic ecosystems and human health. Conventional nitrogen removal technologies used in urban surface water exhibit drawbacks such as high consumption of carbon sources, high sludge production, and focus on dissolved oxygen (DO) concentration while neglecting the impact of DO gradients. Here, we show an ecological filter walls (EFW) that removes pollutants from urban surface water. We utilized a polymer-based three-dimensional matrix to enhance water permeability, and emergent plants were integrated into the EFW to facilitate biofilm formation. We observed that varying aeration intensities within the EFW's aerobic zone resulted in distinct DO gradients, with an optimal DO control at 3.19 ± 0.2 mg L−1 achieving superior nitrogen removal efficiencies. Specifically, the removal efficiencies of total organic carbon, total nitrogen, ammonia, and nitrate were 79.4%, 81.3%, 99.6%, and 79.1%, respectively. Microbial community analysis under a 3 mg L−1 DO condition revealed a shift in microbial composition and abundance, with genera such as Dechloromonas, Acinetobacter, unclassified_f__Comamonadaceae, SM1A02 and Pseudomonas playing pivotal roles in carbon and nitrogen elimination. Notably, the EFW facilitated shortcut nitrification-denitrification processes, predominantly contributing to nitrogen removal. Considering low manufacturing cost, flexible application, small artificial trace, and good pollutant removal ability, EFW has promising potential as an innovative approach to urban surface water treatment.

Microbiome changes through the ontogeny of the marine sponge Crambe crambe

BackgroundPoriferans (sponges) are highly adaptable organisms that can thrive in diverse marine and freshwater environments due, in part, to their close associations with internal microbial communities. This sponge microbiome can be acquired from the surrounding environment (horizontal acquisition) or obtained from the parents during the reproductive process through a variety of mechanisms (vertical transfer), typically resulting in the presence of symbiotic microbes throughout all stages of sponge development. How and to what extent the different components of the microbiome are transferred to the developmental stages remain poorly understood. Here, we investigated the microbiome composition of a common, low-microbial-abundance, Atlantic-Mediterranean sponge, Crambe crambe, throughout its ontogeny, including adult individuals, brooded larvae, lecithotrophic free-swimming larvae, newly settled juveniles still lacking osculum, and juveniles with a functional osculum for filter feeding.ResultsUsing 16S rRNA gene analysis, we detected distinct microbiome compositions in each ontogenetic stage, with variations in composition, relative abundance, and diversity of microbial species. However, a particular dominant symbiont, Candidatus Beroebacter blanensis, previously described as the main symbiont of C. crambe, consistently occurred throughout all stages, an omnipresence that suggests vertical transmission from parents to offspring. This symbiont fluctuated in relative abundance across developmental stages, with pronounced prevalence in lecithotrophic stages. A major shift in microbial composition occurred as new settlers completed osculum formation and acquired filter-feeding capacity. Candidatus Beroebacter blanensis decreased significatively at this point. Microbial diversity peaked in filter-feeding stages, contrasting with the lower diversity of lecithotrophic stages. Furthermore, individual specific transmission patterns were detected, with greater microbial similarity between larvae and their respective parents compared to non-parental conspecifics.ConclusionsThese findings suggest a putative vertical transmission of the dominant symbiont, which could provide some metabolic advantage to non-filtering developmental stages of C. crambe. The increase in microbiome diversity with the onset of filter-feeding stages likely reflects enhanced interaction with environmental microbes, facilitating horizontal transmission. Conversely, lower microbiome diversity in lecithotrophic stages, prior to filter feeding, suggests incomplete symbiont transfer or potential symbiont digestion. This research provides novel information on the dynamics of the microbiome through sponge ontogeny, on the strategies for symbiont acquisition at each ontogenetic stage, and on the potential importance of symbionts during larval development.

Interindividual differences in aronia juice tolerability linked to gut microbiome and metabolome changes—secondary analysis of a randomized placebo-controlled parallel intervention trial

BackgroundAronia melanocarpa is a berry rich in polyphenols known for health benefits. However, the bioavailability of polyphenols has been questioned, and the individual taste acceptance of the fruit with its specific flavor varies. We recently observed substantial differences in the tolerability of aronia juice among healthy females, with half of the individuals tolerating aronia juice without complaints. Given the importance of the gut microbiome in food digestion, we investigated in this secondary analysis of the randomized placebo-controlled parallel intervention study (ClinicalTrials.gov registration: NCT05432362) if aronia juice tolerability was associated with changes in intestinal microbiota and bacterial metabolites, seeking for potential mechanistic insights into the impact on aronia polyphenol tolerance and metabolic outcomes.ResultsForty females were enrolled for this 6-week trial, receiving either 100 ml natural aronia juice (verum, V) twice daily or a polyphenol-free placebo (P) with a similar nutritional profile, followed by a 6-week washout. Within V, individuals were categorized into those who tolerated the juice well (Vt) or reported complaints (Vc). The gut microbiome diversity, as analyzed by 16S rRNA gene-based next-generation sequencing, remained unaltered in Vc but changed significantly in Vt. A MICOM-based flux balance analysis revealed pronounced differences in the 40 most predictive metabolites post-intervention. In Vc carbon-dioxide, ammonium and nine O-glycans were predicted due to a shift in microbial composition, while in Vt six bile acids were the most likely microbiota-derived metabolites. NMR metabolomics of plasma confirmed increased lipoprotein subclasses (LDL, VLDL) post-intervention, reverting after wash out. Stool samples maintained a stable metabolic profile.ConclusionIn linking aronia polyphenol tolerance to gut microbiota-derived metabolites, our study explores adaptive processes affecting lipoprotein profiles during high polyphenol ingestion in Vt and examines effects on mucosal gut health in response to intolerance to high polyphenol intake in Vc. Our results underpin the importance of individualized hormetic dosing for beneficial polyphenol effects, demonstrate dynamic gut microbiome responses to aronia juice, and emphasize personalized responses in polyphenol interventions.Graphical DsmAL-oYwbuhyB_vVwEdDjVideo

Microbial community analysis of membrane bioreactor incorporated with biofilm carriers and activated carbon for nitrification of urine

The integration of powdered activated carbon and biofilm carriers in a membrane bioreactor (MBR) presents a promising approach to address the challenge of long hydraulic retention time (HRT) for nitrification of hydrolysed urine. This study investigated the effect of the incorporation in the MBR on microbial dynamics, focusing on dominant nitrifying bacteria. The results showed that significant shifts in microbial compositions were observed with the feed transition to full-strength urine and across different sludge growth forms. Remarkably, the nitrite-oxidizing bacteria Nitrospira were highly enriched in the suspended sludge. Simultaneously, ammonia-oxidizing bacteria, Nitrosococcaceae thrived in the attached biomass, showing a significant seven-fold increase in relative abundance compared to its suspended counterpart. Consequently, the incorporated MBR displayed 36% higher nitrification rate and 40% HRT reduction compared to the conventional MBR. This study provides valuable insights on the potential development of household or building scale on-site nutrient recovery from urine to fertiliser.

Metagenomics analysis of mice gut microbiome to unravel the role of metal exposure and piperine.

The gut and intestinal microbiota consists of trillions of microorganisms inhabiting the human gastrointestinal tract. It plays a crucial role in human health leading to understanding the dynamic crosstalk of host-microbe interaction in the gut and has become necessary for the detection, prevention, or therapy of diseases. Gut microbiota deviations are linked with many diseases, suggesting that various pathways involved in immunity, energy, lipid, and glucose metabolism are affected. Further, it is also altered by external insults such as metal toxicity, antibiotics and pesticides. Heavy metals like arsenic, mercury, cadmium and chromium are some of the well-studied classes of environmental pollutants. Mouse models have become the model of choice for most studies in this emerging field, as they allow perturbations in the gut microbiota to be studied in a controlled experimental setup. Here, we investigate the composition and diversity of intestinal microbes utilizing cecal samples from different intervention groups: arsenic exposure (As(III)), arsenic and piperine co-administration (As +Pp), piperine per se and control group. We obtained DNA samples from these groups and performed PCR amplification and sequencing of the 16S V3-V4 region. The findings showed shift in microbial composition and abundance among different intervention groups, revealing taxa that may contribute to the microbial diversity.

Inflammatory Bowel Disease and Gut Microbiota Dysbiosis: Current understanding and Future Direction

Inflammatory Bowel Disease (IBD) represents a group of chronic, relapsing inflammatory disorders primarily affecting the gastrointestinal tract. The pathogenesis of IBD is multifaceted, involving genetic predisposition, environmental triggers, and dysregulation of the immune response. Recent research has illuminated the pivotal role of gut microbiota dysbiosis in the development and perpetuation of IBD. The human gut harbors a complex and dynamic ecosystem of microorganisms that profoundly influences host health and disease. Alterations in the composition, diversity, and function of the gut microbiota, termed dysbiosis, have been consistently linked to IBD. Shifts in microbial composition, reduction in microbial diversity, and imbalances in beneficial versus pathogenic microorganisms characterize the dysbiotic state associated with IBD.The intricate interplay between the host immune system and the gut microbiota is a key determinant in IBD pathogenesis. Dysbiosis triggers aberrant immune responses, leading to chronic mucosal inflammation and tissue damage. Furthermore, dysbiotic alterations disrupt essential microbial-derived metabolites and signaling molecules crucial for gut homeostasis, further exacerbating the disease. Advancements in high-throughput sequencing technologies and metagenomic analysis have enabled comprehensive characterization of microbial communities in IBD, uncovering microbial signatures and functional pathways associated with disease phenotypes and treatment responses. Therapeutic interventions targeting the gut microbiota, such as probiotics, prebiotics, fecal microbiota transplantation, and microbial-based therapies, have shown promise in preclinical and clinical studies for modulating dysbiosis and ameliorating IBD symptoms.
 Keywords: Inflammatory Bowel Disease, Dysbiosis, Fecal microbiota, Probiotics

Anodic biodegradation of phenol in a microbial desalination cell through microbial composition shift for energy recovery and water desalination

This study assessed the performance of a three-chamber microbial desalination cell (MDC) for simultaneous electricity generation, phenol biodegradation, and salt removal from water. The MDC operated with anaerobic sludge in the anode chamber at varying phenol concentrations in the range of 100–1000 mg L−1 and bio-cathode with sodium acetate as the catholyte. The highest power density (7.5 W m−3), desalination efficiency (66.9 %), and current efficiency (75.5 %) were obtained at optimal phenol concentration of 700 mg L−1. Non-electroactive bacteria dominated the anode microbial community through high-throughput sequencing analysis. The population of electroactive bacteria decreased, including Geobacter and Rhodopseudomonas from 9.8 % and 7.8 % to 0.9 % and 0.6 %, respectively, due to phenol toxicity, Cl− migration, and pH fluctuations. Meanwhile, other genera, such as Chryseobacterium (from 0.8 % to 4.5 %) and Clostridium (from 1.4 % to 2.2 %), were observed to thrive in the saline and acidic phenolic environment of the anode chamber.

Alterations in intestinal microbiota and enzyme activities under cold-humid stress: implications for diarrhea in cold-dampness trapped spleen syndrome.

Cold and humid environments alter the intestinal microbiota, and the role of the intestinal microbiota in the development of diarrhea associated with cold-dampness trapped spleen syndrome in Chinese medicine is unclear. The 30 mice were randomly divided into normal and model groups, with the model group being exposed to cold and humid environmental stresses for 7 days. Then, mouse intestinal contents were collected and analyzed their intestinal microbiota and digestive enzymes. Our findings revealed significant increases in sucrase and lactase activities, as well as microbial activity, in the model group (p < 0.05). β-diversity analysis highlighted distinct intestinal microbiota compositions between the two groups. Specifically, the experimental group showed a unique dominance of the genera and strains Clostridium sensu stricto 1 and Clostridium sp. ND2. LEfSe analysis identified Helicobacter, Roseburia, and Eubacterium plexicaudatum ASF492 as differentially abundant species in them model group. Network analysis demonstrated that rare bacterial species mostly governed the microbial interactions, exhibiting increased mutual promotion. On the other hand, abundant species like Lactobacillus johnsonii and Lactobacillus reuteri showed mutual inhibitory relationships. In summary, exposure to cold and humid conditions led to increased intestinal enzyme activities and a shift in microbial composition, favoring the growth of rare bacterial species. These changes suggest that rare bacteria in the intestinal microbiota play a critical role in the pathology of diarrhea associated with cold-dampness trapped spleen syndrome, revealing unique survival strategies among bacterial populations under stressful conditions.

Chronic supplementation of a multi-ingredient herbal supplement increases speed of cognitive task performance alongside changes in the urinary metabolism of dopamine and the gut microbiome in cognitively intact older adults experiencing subjective memory decline: a randomized, placebo controlled, parallel groups investigation.

The effects of herbs on brain function are often investigated in isolation, yet herbal preparations are often complex combinations of phytochemicals, designed to target widespread mechanisms. To assess the effects of chronic, 12 weeks, supplementation of a multi-ingredient herbal supplement (containing Bacopa monnieri, Gotu kola leaf, Turmeric whole powder, Reishi full spectrum, Rosemary, Cardamom, Holy Basil, Turmeric Wholistic™ extract, Green Tea & Seagreens) on cognitive function in older adults with subjective memory decline. Secondly, to investigate whether effects are underpinned by shifts in microbial composition and/or metabolism of the herbs. Male and female participants (N = 128) aged between 55-75 years completed lab-based cognitive assessments, and provided stool and urine samples, at baseline and then following 90 days of multi-ingredient herb, or placebo, supplementation. Deficits in memory were observed in response to 90 days of multi-ingredient herbal supplement supplementation but the positive effects were all focused on speed of cognitive task performance, with an additional improvement in the false alarm rate on the rapid visual information processing task. These improvements coincided with an increased presence of tyrosine in the urinary metabolome and this may implicate the role of dopamine in these processing and/or motor speed increases. Finally, multi-ingredient herbal supplementation significantly reduced levels of 3 bacterial species in the gut microbiome and one of these, Sutterella, coincides with lower levels of constipation reported in the multi-ingredient herbal supplement condition. A multi-ingredient herbal supplement increases speed of cognitive task performance and increased metabolism of tyrosine suggests that this is modulated by increased dopaminergic activity. Reduced levels of Sutterella in the gut is associated with improved bowel movements of participants. Interpretation of the negative effects on memory are, however, stymied by an unequal randomization of participants into treatment groups pre- and post-COVID 19.Clinical trial registration: identifier NCT05504668.

Isoxanthohumol improves obesity and glucose metabolism via inhibiting intestinal lipid absorption with a bloom of Akkermansia muciniphila in mice

ObjectivePolyphenols have health-promoting effects, such as improving insulin resistance. Isoxanthohumol (IX), a prenylated flavonoid found in beer hops, has been suggested to reduce obesity and insulin resistance; however, the mechanism remains unknown. MethodsHigh-fat diet-fed mice were administered IX. We analyzed glucose metabolism, gene expression profiles and histology of liver, epididymal adipose tissue and colon. Lipase activity, fecal lipid profiles and plasma metabolomic analysis were assessed. Fecal 16s rRNA sequencing was obtained and selected bacterial species were used for in vitro studies. Fecal microbiota transplantation and monocolonization were conducted to antibiotic-treated or germ-free (GF) mice. ResultsThe administration of IX lowered weight gain, decreased steatohepatitis and improved glucose metabolism. Mechanistically, IX inhibited pancreatic lipase activity and lipid absorption by decreasing the expression of the fatty acid transporter CD36 in the small intestine, which was confirmed by increased lipid excretion in feces. IX administration increased markers of intestinal barrier function, including thickening the mucin layer and increasing caludin-1, a tight-junction related protein in the colon. In contrast, the effects of IX were nullified by antibiotics. As revealed using 16S rRNA sequencing, the microbial community structure changed with a significant increase in the abundance of Akkermansia muciniphila in the IX-treated group. An anaerobic chamber study showed that IX selectively promoted the growth of A. muciniphila while exhibiting antimicrobial activity against some Bacteroides and Clostridium species. To further explore the direct effect of A. muciniphila on lipid and glucose metabolism, we monocolonized either A. muciniphila or Bacteroides thetaiotaomicron to GF mice. A. muciniphila monocolonization decreased CD36 expression in the jejunum and improved glucose metabolism, with decreased levels of multiple classes of fatty acids determined using plasma metabolomic analysis. ConclusionsOur study demonstrated that IX prevents obesity and enhances glucose metabolism by inhibiting dietary fat absorption. This mechanism is linked to suppressing pancreatic lipase activity and shifts in microbial composition, notably an increase in A. muciniphila. These highlight new treatment strategies for preventing metabolic syndrome by boosting the gut microbiota with food components.

Single-strain behavior predicts responses to environmental pH and osmolality in the gut microbiota.

Changes to gut environmental factors such as pH and osmolality due to disease or drugs correlate with major shifts in microbiome composition; however, we currently cannot predict which species can tolerate such changes or how the community will be affected. Here, we assessed the growth of 92 representative human gut bacterial strains spanning 28 families across multiple pH values and osmolalities in vitro. The ability to grow in extreme pH or osmolality conditions correlated with the availability of known stress response genes in many cases, but not all, indicating that novel pathways may participate in protecting against acid or osmotic stresses. Machine learning analysis uncovered genes or subsystems that are predictive of differential tolerance in either acid or osmotic stress. For osmotic stress, we corroborated the increased abundance of these genes in vivo during osmotic perturbation. The growth of specific taxa in limiting conditions in isolation in vitro correlated with survival in complex communities in vitro and in an in vivo mouse model of diet-induced intestinal acidification. Our data show that in vitro stress tolerance results are generalizable and that physical parameters may supersede interspecies interactions in determining the relative abundance of community members. This study provides insight into the ability of the microbiota to respond to common perturbations that may be encountered in the gut and provides a list of genes that correlate with increased ability to survive in these conditions.IMPORTANCETo achieve greater predictability in microbiota studies, it is crucial to consider physical environmental factors such as pH and particle concentration, as they play a pivotal role in influencing bacterial function and survival. For example, pH is significantly altered in various diseases, including cancers, inflammatory bowel disease, as well in the case of over-the-counter drug use. Additionally, conditions like malabsorption can affect particle concentration. In our study, we investigate how changes in environmental pH and osmolality can serve as predictive indicators of bacterial growth and abundance. Our research provides a comprehensive resource for anticipating shifts in microbial composition and gene abundance during complex perturbations. Moreover, our findings underscore the significance of the physical environment as a major driver of bacterial composition. Finally, this work emphasizes the necessity of incorporating physical measurements into animal and clinical studies to better understand the factors influencing shifts in microbiota abundance.

Limnospira indica PCC8005 and Lacticaseibacillus rhamnosus GG Mixed Dietary Combination Reduces Pelvic Irradiation-Induced Symptoms in Mice

Throughout their cancer treatments, around half of all patients will undergo irradiation that is accompanied by several side effects reducing their quality of life and leading to the interruption or extension of their treatment course. Pelvic irradiation leads to the triggering of mucositis and dysbiosis, further impairing the daily life of the patients. In this work, we address the ability of Limnospira indica strain PCC 8005 and Lacticaseibacillus rhamnosus GG ATCC 53103 in alleviating the above-mentioned side effects triggered by the local pelvic irradiation of 12 Gy in a mouse model. We found that the combinatorial administration of these food supplements was able to confer partial tight junction protection while the bacterial translocation towards the mesenteric lymph nodes was found to be identical between the saline sham-irradiated and supplemented irradiated group. Furthermore, the supplemented group did not present a significant shift in microbial composition following pelvic irradiation, indicating that the bacterial formulation was able to mitigate the dysbiosis induced by the latter treatment, as observed in the saline irradiated group. These very promising results will be further completed by investigating the mode of action and/or active molecules mediating the beneficial effects of both L. indica PCC 8005 and L. rhamnosus GG.

The Age of Absorptive Roots Impacts Root-Adjacent Microbial Composition in Grapevines

In grapevine, metabolic activity of absorptive roots changes rapidly as roots age but it is unclear whether nearby microbial assemblages shift as well. Here, we investigated whether first-order root age affects bacterial and fungal variation adjacent to the root surface, and whether root age should be integrated into future studies on root functional traits and associated microbes. We hypothesized that microbial diversity and composition would differ between young (≤11 days old) and old (11.5 to 40 days old) first-order roots due to expected differences in metabolism over the root lifespan (i.e., higher metabolism in young roots). Overall, we found that microbial composition was distinct between young and old absorptive roots, with stronger evidence at the phylum and amplicon sequence variant (ASV) taxonomic levels for fungi ( P = 0.003 and P = 0.038, respectively) than bacteria ( P = 0.082 and P = 0.129, respectively). Furthermore, we identified differentially abundant fungal and bacterial ASVs in young and old roots that related to expected differences in root function, including instances of microbes previously described as copiotrophs more abundant adjacent to young roots and microbes described as oligotrophs and saprotrophs more abundant adjacent to old roots. In contrast to the distinct shifts in microbial composition, there was little evidence of shifts in α diversity (i.e., observed ASVs and Shannon diversity) between young and old roots. Our study suggests that future work on the impacts of root functional traits on localized microbial composition may improve results interpretation and reduce some variation by accounting for root age at sampling.