Differences In Beta Diversity Research Articles

Quantitative microbiome profiling of honey bee (Apis mellifera) guts is predictive of winter colony loss in northern Virginia (USA)

For the past 15 years, the proportion of honey bee hives that fail to survive winter has averaged ~ 30% in the United States. Winter hive loss has significant negative impacts on agriculture, the economy, and ecosystems. Compared to other factors, the role of honey bee gut microbial communities in driving winter hive loss has received little attention. We investigate the relationship between winter survival and honey bee gut microbiome composition of 168 honey bees from 23 hives, nine of which failed to survive through winter 2022. We found that there was a substantial difference in the abundance and community composition of honey bee gut microbiomes based on hive condition, i.e., winter survival or failure. The overall microbial abundance, as assessed using Quantitative Microbiome Profiling (QMP), was significantly greater in hives that survived winter 2022 than in those that failed, and the average overall abundance of each of ten bacterial genera was also greater in surviving hives. There were no significant differences in alpha diversity based on hive condition, but there was a highly significant difference in beta diversity. The bacterial genera Commensalibacter and Snodgrassella were positively associated with winter hive survival. Logistic regression and random forest machine learning models on pooled ASV counts for the genus data were highly predictive of winter outcome, although model performance decreased when samples from the location with no hive failures were excluded from analysis. As a whole, our results show that the abundance and community composition of honey bee gut microbiota is associated with winter hive loss, and can potentially be used as a diagnostic tool in evaluating hive health prior to the onset of winter. Future work on the functional characterization of the honey bee gut microbiome’s role in winter survival is warranted.

The rhizosphere of a drought-tolerant plant species in Morocco: A refuge of high microbial diversity with no taxon preference.

Arid and semi-arid areas are facing increasingly severe water deficits that are being intensified by global climate changes. Microbes associated with plants native to arid regions provide valuable benefits to plants, especially in water-stressed environments. In this study, we used 16S rDNA metabarcoding analysis to examine the bacterial communities in the bulk soil, rhizosphere and root endosphere of the plant Malva sylvestris L. in Morocco, along a gradient of precipitation. We found that the rhizosphere of M. sylvestris did not show significant differences in beta-diversity compared to bulk soil, although, it did display an increased degree of alpha-diversity. The endosphere was largely dominated by the genus Rhizobium and displayed remarkable variation between plants, which could not be attributed to any of the variables observed in this study. Overall, the effects of precipitation level were relatively weak, which may be related to the intense drought in Morocco at the time of sampling. The dominance of Rhizobium in a non-leguminous plant is particularly noteworthy and may permit the utilization of this bacterial taxon to augment drought tolerance; additionally, the absence of any notable selection of the rhizosphere of M. sylvestris suggests that it is not significatively affecting its soil environment.

Influences of Ruminococcus bromii and Peptostreptococcaceae on voluntary exercise behavior in a rodent model

IntroductionThis study investigates the relationship between the gut microbiome and voluntary exercise, focusing on wheel running activity in a rat model. The gut microbiome plays a crucial role in host physiology, homeostasis, and behavior. Alterations in the gut microbiome have been linked to various pathological states and health conditions, including obesity.MethodsGiven the strong association between physical inactivity and obesity development, our study aimed to identify microbiome factors associated with elevated levels of voluntary exercise. Male Sprague Dawley rats were used in the 4-week exercise paradigm in which voluntary wheel running behavior was monitored alongside weekly microbiome sampling from fecal pellets.ResultsWe observed individual differences in running activity among the cohort. Significant positive correlations in running distance were identified across the 4-week time course, suggesting that running activity ranking was largely preserved. Furthermore, earlier running activity emerged as a potential predictor for subsequent running behaviors. Analysis of gut microbiome revealed that alpha diversity was positively correlated with daily running distances, with significant differences in beta diversity observed between high and low running groups. Taxonomic analysis showed distinct abundance differences between running and sedentary conditions, particularly in the Ruminococcaceae and Peptostreptococcaceae families.DiscussionOur results suggest that the microbiome composition changes significantly early in exercise exposure, potentially influencing exercise behavior. Ruminococcaceae, particularly R. bromii, was identified as a significant contributor to exercise adaptation, while Peptostreptococcaceae was inversely related to running performance as well as alpha diversity. This study underscores the potential of the gut microbiome as a modulator of exercise behavior. Future research should focus on the biological mechanisms linking microbiome changes to exercise adaptation, with R. bromii and Peptostreptococcus as promising candidates for influencing exercise behaviors through future interventional studies.

Salivary microbiome and MRP-8/14 levels in children with gingivitis, healthy children, and their mothers.

Gingivitis is the most common form of periodontal disease among children and adolescents and is associated with disrupted host-microbiome homeostasis. Family is an important factor influencing the prevalence of gingivitis. In the present study, we investigated the salivary microbiome, oral hygiene habits, and the salivary level of myeloid-related protein (MRP)-8/14 in children aged 7-12 years with gingivitis, periodontally healthy children, and their mothers. This study included 24 children with gingivitis (including four sibling pairs) and 22 periodontally healthy children (including two sibling pairs) and their mothers. The whole saliva was collected, DNA was extracted, the variable V3-V4 region of the eubacterial 16S ribosomal RNA gene was amplified, and sample library preparation was performed according to the Illumina protocol. The salivary levels of MRP-8/14 were analyzed by ELISA. Alpha diversity of the salivary microbiome was considerably higher in gingivitis children and mothers of gingivitis children compared to healthy children and their mothers, respectively. Significant differences in beta diversity between healthy and gingivitis children, healthy children and their mothers, and gingivitis children and their mothers were detected. Overall, the number of common core amplicon sequence variants between children and their own mothers was significantly higher than between children and other mothers. The salivary MRP-8/14 levels in children with gingivitis were significantly higher compared to healthy children; a similar tendency was also mentioned for mothers. Our study underlines the importance of family as an essential factor influencing oral health.

Abstract PO4-03-04: Characterization of Gut Microbiome of patients with early-stage breast cancer treated with neoadjuvant chemotherapy

Abstract Objective: The gut microbiome (GM) has been identified as one of the major environmental factors that can regulate the development and maintenance of the immune system. In oncology, while the importance of GM has been evaluated in more immunogenic tumors such as melanoma, lung carcinoma and clear cell carcinoma, its importance in early-stage breast cancer (eBC) is underexplored. The aim of this study was to characterize the GM of patients with eBC who underwent neoadjuvant chemotherapy (NACT) and to evaluate its association with clinicopathologic prognostic factors and outcomes. Methods: This was a prospective study conducted at two Brazilian institutions. Fecal samples were collected at baseline (time 1) and prior to surgery (time 2) from 55 patients who received NACT with anthracycline/taxane. Gut microbiome was analyzed by 16S rRNA amplicon sequencing to characterize the α (InvSimpson index) and β (weighted UniFrac distance metric) diversity, as well as taxonomic composition. Clinicopathologic prognostic factors were retrieved from medical records. Pathological complete response (pCR) was defined as the absence of invasive carcinoma in breast and axillary nodes (ypT0/Tis ypN0). Stromal tumor-infiltrating lymphocytes (sTIL) were reported according to the TIL working group criteria. Information about prior use (< 60 days before stating on NACT) of antibiotic (ATB) was obtained directly from patients. Statistical significance was set at P ≤ 0.05 and analysis of composition of microbiomes (ANCOM-BC2) was used to identify enriched genera with p-values adjusted using FDR correction ≤ 0.25. Results: Median age was 49 years (range 31-73). Eleven patients (20%) reported prior antibiotic use at baseline. About 34.5% of patients had HR+/HER2- tumors, 45.4% had triple negative breast cancer (TNBC), and 20% had HER2-positive breast cancer. Fourteen (25%) patients achieved a pCR. Out of 55, 47 (85.4%) had sTIL information. There was no significant difference in alpha diversity (p = 0.6) or beta-diversity (p = 0.8) between the pCR and residual disease group nor within clinical pathologic factors (age, staging, histological tumor grade, subtype of breast cancer based on IHC, sTIL). The most abundant taxon in both time 1 and time 2 were the same (Blautia at genus level, Lachnospiraceae at family level, and Lachnospirales at order level), and longitudinal samples collected during NACT showed no significant changes in GM composition. At baseline, we found an enrichment for Clostridia sp. among patients who did not use ATB (p < 0.05, pFDR ≤ 0.25). Additionally, we found enrichment for Bifidobacterium (p < 0.05, pFDR ≤ 0.25) among patients with HER2 subtype who presented residual disease. Conclusions: Gut microbiome analysis in early breast cancer is feasible and to our knowledge, this is the first study to evaluate the intestinal microbiota of Brazilian patients with breast cancer. We did not observe any significant association between GM diversity and taxonomic composition with clinical pathologic factors and pCR in this study, nor did we observe changes in the ecological balance of the GM following NACT in breast cancer. Further studies are needed to explore the potential influence of the gut microbial ecosystem on tumor biology and response to neoadjuvant chemo-immunotherapy. Citation Format: Ludmila Thommen, Vitor Heidrich, Rosângela Vieira de Andrade, Luiza Nardin Weis, Maria Sueli Soares Felipe, Melissa Lole Da Cas Vita, Thiago David Alves Pinto, Anamaria Camargo, Romualdo Barroso-Sousa. Characterization of Gut Microbiome of patients with early-stage breast cancer treated with neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-03-04.

Nestedness of benthic diatom metacommunity in relation to species niche width and environmental variables in a large near-natural catchment

Insight into the non-random distribution patterns of species in different regions is a foundational aim of research in community ecology and biogeography. The nestedness pattern, which investigates changes in species composition and abundance, has been widely used in numerous studies. However, studies on the nestedness of benthic diatoms are extremely rare, and consequently little has been mentioned of their assemblage mechanisms. To fill this gap, based on 168 benthic diatom species from 147 sampling sites in the Thousand Island Lake (TIL) catchment, we calculated their nestedness and niche width with the aim of i) analyzing the nestedness of benthic diatoms communities with different attachment abilities in TIL; ii) calculating niche width differences between nested and idiosyncratic species with different attachment abilities; iii) investigating the differences in alpha and beta diversity between nested and idiosyncratic sites; iv) examining whether environmental variables influencing the nestedness of benthic diatom communities are dependent on attachment ability. The results demonstrated a significant nestedness pattern in the benthic diatom metacommunity, and the sampling sites of low attachment species not only exhibited a nestedness pattern, but also with a lower nestedness value compared to the sampling sites of all species. Nested and idiosyncratic species differed in niche width, whereas differences between nested and idiosyncratic species of low attachment species were smaller. Additionally, significant differences in alpha and beta diversity were observed between nested and idiosyncratic sites. Furthermore, it was revealed that the nestedness of benthic diatom metacommunity in our study area were mostly influenced by local environmental variables. Our study contributes to the understanding of the significant nestedness observed in benthic diatom metacommunity in TIL, highlighting its relevance to biodiversity conservation efforts.

Characterization of the Equine Placental Microbial Population during Nocardioform Placentitis

Nocardioform placentitis is a poorly understood disease of equine late gestation. The presence of nocardioform, filamentous branching gram-positive bacteria, has been linked to the disease, with Crossiella equi, Amycolatopsis spp., and Streptomyces spp. being the most frequently identified bacteria. However, these bacteria are not found in all clinical cases in addition to being isolated from healthy, normal postpartum placentas. To better understand this form of placentitis, we analyzed the microbial composition in the equine placenta (chorioallantois) of both healthy postpartum (control; n = 11) and nocardioform-affected samples (n = 22) using 16S rDNA sequencing. We found a lower Shannon index in nocardioform samples, a higher Chao1 index in nocardioform samples, and a difference in beta diversity between control and nocardioform samples (p<0.05), suggesting the presence of dysbiosis during the disease. In the majority of the NP samples (77%), one of the following genera—Amycolatopsis, Crossiella, Lentzea, an unidentified member of the Pseudonocardiaceae family, Mycobacterium, or Enterococcus —represented over 70% of the relative abundance. Overall, the data suggest that a broader spectrum of potential opportunistic pathogens could be involved in nocardioform placentitis, extending beyond the traditionally recognized bacteria, resulting in a similar histomorphological profile.

Gut Microbiota Profiles in Myopes and Nonmyopes.

To identify compositional differences in the gut microbiome of nonmyopes (NM) and myopes using 16S ribosomal RNA sequencing and to investigate whether the microbiome may contribute to the onset or progression of the condition. Faecal samples were collected from 52 adult participants, of whom 23 were NM, 8 were progressive myopes (PM), and 21 were stable myopes (SM). The composition of the gut microbiota in each group was analysed using 16S ribosomal RNA gene sequencing. There were no significant differences in alpha and beta diversity between the three groups (NM, PM, and SM). However, the distributions of Bifidobacterium, Bacteroides, Megamonas, Faecalibacterium, Coprococcus, Dorea, Roseburia, and Blautia were significantly higher in the myopes (SM and PM combined) when compared with emmetropes. The myopes exhibited significantly greater abundance of bacteria that are linked to the regulation of dopaminergic signalling, such as Clostridium, Ruminococcus, Bifidobacterium, and Bacteroides. Individuals with stable myopia were found to have a significantly higher proportion of Prevotella copri than those with progressive myopia. Bifidobacterium adolescentis, a gamma-aminobutyric acid (GABA)-producing bacterium, was significantly higher in all myopes than in NM and, in the comparison between SM and PM, it is significantly higher in SM. B. uniformis and B. fragilis, both GABA-producing Bacteroides, were present in relatively high abundance in all myopes and in SM compared with PM, respectively. The presence of bacteria related to dopamine effect and GABA-producing bacteria in the gut microbiome of myopes may suggest a role of these microorganisms in the onset and progression of myopia.

Unraveling the phylogenetics of genetically closely related species, Haemaphysalis japonica and Haemaphysalis megaspinosa, using entire tick mitogenomes and microbiomes.

Ticks have a profound impact on public health. Haemaphysalis is one of the most widespread genera in Asia, including Japan. The taxonomy and genetic differentiation of Haemaphysalis spp. is challenging. For instance, previous studies struggled to distinguish Haemaphysalis japonica and Haemaphysalis megaspinosa due to the dearth of nucleotide sequence polymorphisms in widely used barcoding genes. The classification of H. japonica japonica and its related sub-species Haemaphysalis japonica douglasi or Haemaphysalis jezoensis is also confused due to their high morphological similarity and a lack of molecular data that support the current classification. We used mitogenomes and microbiomes of H. japonica and H. megaspinosa to gain deeper insights into the phylogenetic relationships and genetic divergence between two species. Phylogenetic analyses of concatenated nucleotide sequences of protein-coding genes and ribosomal DNA genes distinguished H. japonica and H. megaspinosa as monophyletic clades, with further subdivision within the H. japonica clade. The 16S rRNA and NAD5 genes were valuable markers for distinguishing H. japonica and H. megaspinosa. Population genetic structure analyses indicated that genetic variation within populations accounted for a large proportion of the total variation compared to variation between populations. Microbiome analyses revealed differences in alpha and beta diversity between H. japonica and H. megaspinosa: H. japonica had the higher diversity. Coxiella sp., a likely endosymbiont, was found in both Haemaphysalis species. The abundance profiles of likely endosymbionts, pathogens, and commensals differed between H. japonica and H. megaspinosa: H. megaspinosa was more diverse.

Health-associated changes of the fecal microbiota in dairy heifer calves during the pre-weaning period.

Neonatal calf diarrhea is a multifactorial condition that occurs in early life when calves are particularly susceptible to enteric infection and dysbiosis of the gut microbiome. Good calf health is dependent on successful passive transfer of immunity from the dam through colostrum. There are limited studies on the developing gut microbiota from birth to weaning in calves. Therefore, the objective of this study was to examine the effect of immune status and diarrheal incidence on the development of the fecal microbiota in Jersey (n = 22) and Holstein (n = 29) heifer calves throughout the pre-weaning period. Calves were hand-fed a colostrum volume equivalent to 8.5% of their birthweight, from either the calf's dam (n = 28) or re-heated mixed colostrum (≤2 cows, ≤1d; n = 23) within 2 h of birth. All calves were clinically assessed using a modified Wisconsin-Madison calf health scoring system and rectal temperature at day (d) 0, d7, d21, or disease manifestation (DM) and weaning (d83). Weights were recorded at d0, d21, and d83. Calf blood samples were collected at d7 for the determination of calf serum IgG (sIgG). Fecal samples were obtained at d7, d21/DM [mean d22 (SE 0.70)], and at weaning for 16S rRNA amplicon sequencing of the fecal microbiota. Data were processed in R using DADA2; taxonomy was assigned using the SILVA database and further analyzed using Phyloseq and MaAsLin 2. Significant amplicon sequence variants (ASVs) and calf performance data underwent a Spearman rank-order correlation test. There was no effect (p > 0.05) of colostrum source or calf breed on serum total protein. An effect of calf breed (p < 0.05) was observed on sIgG concentrations such that Holstein calves had 6.49 (SE 2.99) mg/ml higher sIgG than Jersey calves. Colostrum source and calf breed had no effect (p > 0.05) on health status or the alpha diversity of the fecal microbiota. There was a relationship between health status and time interaction (p < 0.001), whereby alpha diversity increased with time; however, diarrheic calves had reduced microbial diversity at DM. No difference (p > 0.05) in beta diversity of the microbiota was detected at d7 or d83. At the genus level, 33 ASVs were associated (adj.p < 0.05) with health status over the pre-weaning period.

Alterations in the fecal microbiota of methamphetamine users with bad sleep quality during abstinence

BackgroundMethamphetamine (MA) abuse has resulted in a plethora of social issues. Sleep disturbance is a prominent issue about MA addiction, which serve as a risk factor for relapse, and the gut microbiota could play an important role in the pathophysiological mechanisms of sleep disturbances. Therefore, improving sleep quality can be beneficial for treating methamphetamine addiction, and interventions addressing the gut microbiota may represent a promising approach.MethodWe recruited 70 MA users to investigate the associations between sleep quality and fecal microbiota by the Pittsburgh Sleep Quality Index (PSQI), which was divided into MA-GS (PSQI score < 7, MA users with good sleep quality, n = 49) and MA-BS group (PSQI score ≥ 7, MA users with bad sleep quality, n = 21). In addition, we compared the gut microbiota between the MA-GS and healthy control (HC, n = 38) groups. 16S rRNA sequencing was applied to identify the gut bacteria.ResultThe study revealed that the relative abundances of the Thermoanaerobacterales at the order level differed between the MA-GS and MA-BS groups. Additionally, a positive correlation was found between the relative abundance of the genus Sutterella and daytime dysfunction. Furthermore, comparisons between MA users and HCs revealed differences in beta diversity and relative abundances of various bacterial taxa.ConclusionIn conclusion, the study investigated alterations in the gut microbiota among MA users. Furthermore, we demonstrated that the genus Sutterella changes may be associated with daytime dysfunction, suggesting that the genus Sutterella may be a biomarker for bad sleep quality in MA users.

Microbiome signatures associated with clinical stages of gastric Cancer: whole metagenome shotgun sequencing study

BackgroundGastric cancer is one of the global health concerns. A series of studies on the stomach have confirmed the role of the microbiome in shaping gastrointestinal diseases. Delineation of microbiome signatures to distinguish chronic gastritis from gastric cancer will provide a non-invasive preventative and treatment strategy. In this study, we performed whole metagenome shotgun sequencing of fecal samples to enhance the detection of rare bacterial species and increase genome sequence coverage. Additionally, we employed multiple bioinformatics approaches to investigate the potential targets of the microbiome as an indicator of differentiating gastric cancer from chronic gastritis.ResultsA total of 65 patients were enrolled, comprising 33 individuals with chronic gastritis and 32 with gastric cancer. Within each group, the chronic gastritis group was sub-grouped into intestinal metaplasia (n = 15) and non-intestinal metaplasia (n = 18); the gastric cancer group, early stage (stages 1 and 2, n = 13) and late stage (stages 3 and 4, n = 19) cancer. No significant differences in alpha and beta diversities were detected among the patient groups. However, in a two-group univariate comparison, higher Fusobacteria abundance was identified in phylum; Fusobacteria presented higher abundance in gastric cancer (LDA scored 4.27, q = 0.041 in LEfSe). Age and sex-adjusted MaAsLin and Random Forest variable of importance (VIMP) analysis in species provided meaningful features; Bacteria_caccae was the most contributing species toward gastric cancer and late-stage cancer (beta:2.43, se:0.891, p:0.008, VIMP score:2.543). In contrast, Bifidobacterium_longum significantly contributed to chronic gastritis (beta:-1.8, se:0.699, p:0.009, VIMP score:1.988). Age, sex, and BMI-adjusted MasAsLin on metabolic pathway analysis showed that GLCMANNANAUT-PWY degradation was higher in gastric cancer and one of the contributing species was Fusobacterium_varium.ConclusionMicrobiomes belonging to the pathogenic phylum Fusobacteria and species Bacteroides_caccae and Streptococcus_anginosus can be significant targets for monitoring the progression of gastric cancer. Whereas Bifidobacterium_longum and Lachnospiraceae_bacterium_5_1_63FAA might be protection biomarkers against gastric cancer.

Alterations in Gut Microbiota and Their Correlation with Brain Beta-Amyloid Burden Measured by 18F-Florbetaben PET in Mild Cognitive Impairment Due to Alzheimer's Disease.

(1) Background: This study investigated changes in the gut microbial composition of individuals with mild cognitive impairment (MCI) due to Alzheimer's disease (AD) and their relationship with positron emission tomography (PET) amyloid accumulation. (2) Methods: In total, 17 cognitively normal individuals without amyloid-beta (Aβ) accumulation (Aβ-NC) and 24 with Aβ-positive mild cognitive impairment (Aβ+MCI) who underwent 18F-florbetaben PET and fecal bacterial 16S ribosomal RNA gene sequencing were enrolled. The taxonomic compositions of the Aβ-NC and Aβ+MCI groups were compared. The abundance of taxa was correlated with the standardized uptake value ratio (SUVR), using generalized linear models. (3) Results: There were significant differences in microbiome richness (ACE, p = 0.034 and Chao1, p = 0.024), alpha diversity (Shannon, p = 0.039), and beta diversity (Bray-Curtis, p = 0.018 and Generalized UniFrac, p = 0.034) between the Aβ-NC and Aβ+MCI groups. The global SUVR was positively correlated with the genus Intestinibacter (q = 0.006) and negatively correlated with the genera Roseburia (q = 0.008) and Agathobaculum (q = 0.029). (4) Conclusions: In this study, we identified significant changes in the gut microbiota composition that occur in individuals with MCI due to AD. In particular, the correlation analysis results between PET amyloid burden and gut microbial abundance showed that amyloid deposition is associated with a reduction in specific taxa involved in butyrate production.

Gut Microbiota and Symptom Expression and Severity in Neonatal Abstinence Syndrome.

Problem: Neonatal abstinence syndrome (NAS) affecting neonates with fetal exposure to opioids, is defined by expression and severity of symptoms. The pathophysiology behind symptoms variability is lacking. The study aims were to examine (a) differences in gut microbiota of neonates with and without NAS, (b) the relationships between gut microbiota and symptom expression and NAS severity, and (c) the changes in the neonate gut microbiota diversity during the course of NAS treatment. Methods: A cross-sectional observational design was used to examine differences in microbiota and a longitudinal, repeated measures approach was used to determine relationships between gut microbiota and NAS symptoms. Symptom data were collected using the Finnegan Neonatal Abstinence Scoring Tool and the Neonatal Pain Agitation and Sedation Scale. Stool samples were collected for microbiome analyses with 16S rRNA microbiome sequencing. Results: Differences in alpha and beta diversity between neonates with and without NAS were seen. Relative abundance results revealed 18 taxa were different in neonates with NAS compared to neonates without NAS. No differences were found in alpha or beta diversity in neonates with NAS between enrollment and hospital discharge. There was increased abundance of Escherichia-Shigella and Bacteriodes genera related to higher symptom scores. Discussion: Differences in alpha and beta diversity between neonates with and without NAS may be due to differences in birth mode and type of feeding. The findings of specific increased bacteria related to increased symptoms in the neonates with NAS may also be influenced by birth mode and type of feeding.

Menopausal status induces vaginal dysbiosis in women with human papillomavirus infection

In this study, we examined the difference in the vaginal microbiota of women infected with human papillomavirus (HPV), according to menopausal status. A total of 75 cervicovaginal swab samples from 38 pre- and 37 postmenopausal women with HPV infection were obtained from the Korean HPV cohort. Vaginal microbiota analysis, including microbial diversity and specific bacterial abundances, was performed using 16S rRNA gene sequencing. The mean age of the pre- and postmenopausal women were 29.5 and 55.8 years, respectively (p < 0.0001). Lactobacillus spp. were predominant in both groups; however, a marked decrease was observed in postmenopausal women compared to premenopausal women (44.3% vs. 74.2%). Various anaerobic bacteria also showed a relatively high abundance in the postmenopausal group; Atopobium vagina and Gardnerella vaginalis significantly increased in postmenopausal women. Interestingly, no significant differences in bacterial richness were observed between the two groups. However, significant differences in beta-diversity were observed using the Bray–Curtis (p = 0.001), Generalized UniFrac (p = 0.002), Jensen-Shannon (p = 0.001), and UniFrac algorithms (p = 0.002). Theres results indicate that postmenopausal women with HPV infection exhibited a higher degree of vaginal dysbiosis than premenopausal women. Further, HPV-infected postmenopausal women had increased vaginal microbial diversity, characterized by an increase in anaerobic bacteria and concomitant depletion of Lactobacillus spp.

Abstract 756: Differences in composition, diversity, and function of the fecal microbiota of post-menopausal breast cancer patients compared to healthy, age-matched controls

Abstract Gut microbiota are a community of organisms that colonize the intestinal tract with essential roles in immune function, gut epithelial integrity, and metabolite production. Dysbiosis occurs when the gut microbiota environment is negatively altered causing detrimental changes to these functions, which may predispose an individual to breast cancer development. To understand the relationship between dysbiosis and breast cancer development, fecal microbiota samples were collected from 27 post-menopausal breast cancer patients of varying hormone receptor statuses (ER+HER2-, ER+Her2+, ER-HER2+, or ER-Her2-) prior to starting chemotherapeutic treatment. Samples were compared to 25 healthy controls, and all samples underwent 16srRNA sequencing. Samples from breast cancer patients and control groups were compared for significant differences (P&amp;lt;.05) in alpha (within sample) and beta (between sample) diversity. Using the Shannon Index and Generalized Least Squares Model, significant differences in alpha diversity were identified between all breast cancer types vs. controls (P=.0104), and between ER+HER2- breast cancer vs. controls (P=.00153). Healthy controls exhibited a higher mean Shannon Index than breast cancer patients, thus higher within sample diversity. Using principal coordinate analyses, significant differences in beta diversity were identified between all breast cancer types vs. controls (P = .01199), and ER+HER2- breast cancer vs. control (P = .008991). Further analyses identified significant taxa of microbiota with functions related to breast cancer development and progression. Of note, Lachnoclostridium, a genus of bacteria that can produce β-glucuronidase, which can deconjugate estrogen, was increased in all breast cancer types and ER+HER2- breast cancer when compared to controls. Deconjugation of estrogen can cause elevated blood estrogen levels, potentially increasing Estrogen Receptor binding in hormone-receptor-positive breast cancer. Additionally, Akkermansia, a genus implicated in gut barrier dysfunction, was decreased in ER+HER2- patients, while Parvimonas, a tumorigenic cell-cycle regulator, was increased. Elucidating if these effects are causative or reactionary may have important implications for understanding breast cancer etiology. Samples are currently undergoing additional metagenomic analyses using long-read sequencing to identify specific bacteria, viruses, fungi, parasites, and phages that may be contributing to dysbiosis. Overall, this study is the first, to our knowledge, to employ short and long-read sequencing to the fecal samples of untreated postmenopausal breast cancer patients. We provide mechanistic insight into the relationship between microbiota and breast cancer development, with the intent of informing future patient screening and prevention. Citation Format: Nadia Kabbej, Frederick Ashby, Erika Atencio, Erinn Rosenkrantz, Dominique Day, Khloe Dang, Josee Gauthier, Rachel Newsome, John Sommerville, Taqwa Naas, Raad Gharaibeh, Christian Jobin, Amira Quevedo, Coy D. Heldermon. Differences in composition, diversity, and function of the fecal microbiota of post-menopausal breast cancer patients compared to healthy, age-matched controls [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 756.

Abstract 3805: Intestinal microbiome with chemotherapy response and RAS mutation in patients with advanced or metastatic colorectal cancer: a pilot, exploratory study

Abstract Intestinal microbiomes interact with the tumor microenvironment, participating in inflammation and immune regulation, and are associated with the response to anticancer therapy. However, there has been limited research exploring the relationship between changes in the microbiome and treatment response in patients with metastatic colorectal cancer (mCRC) during chemotherapy and radiation therapy.This study included all 15 patients with mCRC treated with first-line systemic therapy between October 2021 and February 2023. We conducted 16S rRNA sequencing on baseline stool samples and investigated the association of intestinal microbiome with chemotherapy response and RAS mutation. The QIIME2 and R packages were used for analysis. As a results, Median age was 61 years (range, 35-73), and there were 8 patients with RAS-mutated mCRC. All patients were treated with first-line systemic therapy; FOLFOX (5-fluorouracil and oxaliplatin)-based (n=13) and FOLFIRI (5-fluorouracil and irinotecan)-based chemotherapy (n=2). Of them, 2 patients received short-course radiotherapy (ScRTx) to primary tumor before systemic chemotherapy, where pre- and post-ScRTx stool samples were collected. Among 15 patients, 9 patients (60%) achieved responses. Non-responders tend to exhibit higher alpha diversity (Chao1, Observed ASV) compared to responders. Firmicutes, Lactobacillus, Faecalibacterium, and the [Luminococcus]_gauvreauii_group were more prevalent in responders, whereas Bacteroidota, Prevotella, DTU089, Alistipes, Christensenellaceae_R-7_group, and Porphyromonas in non-responders. Despite no statistical significance, alpha diversity decreased in post-ScRTx compared to pre-ScRTx samples. Akkermansia, Prevotella, and Peptostreptococcus were more prevalent in the post-ScRTx compared to pre-ScRTx samples. Regarding the association of intestinal microbiome with RAS mutation, Bray curtis and weighted unifrac analyses revealed significant differences in beta diversity; higher incidence of Faecalibacterium, Lactobacillus, Prevotella, Anaerofilum, and UCG-005 in the RAS-wild type mCRC, while Bacteroides, Collinsella, Holdemanella, and Anaerostipes in RAS-mutated mCRC.This pilot study suggests the prognostic value of gut microbiomes and its association with RAS mutation in patients with mCRC treated with first line systemic therapy. A microbial functional study with immune cytokine change is planned to confirm these findings in future. Citation Format: Jwa Hoon Kim, Boyeon Kim, Soohyeon Lee. Intestinal microbiome with chemotherapy response and RAS mutation in patients with advanced or metastatic colorectal cancer: a pilot, exploratory study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3805.

Oral and gut microbial profiling in periodontitis and Parkinson’s disease

ABSTRACT Objectives We tested the hypothesis that Parkinson’s disease (PA) alters the periodontitis-associated oral microbiome. Method Patients with periodontitis with Parkinson’s disease (PA+P) and without PA (P) and systemically and periodontally healthy individuals (HC) were enrolled. Clinical, periodontal and neurological parameters were recorded. The severity of PA motor functions was measured. Unstimulated saliva samples and stool samples were collected. Next-generation sequencing of 16S ribosomal RNA (V1-V3 regions) was performed. Results PA patients had mild-to-moderate motor dysfunction and comparable plaque scores as those without, indicating that oral hygiene was efficient in the PA+P group. In saliva, there were statistically significant differences in beta diversity between HC and PA+P (p = 0.001), HC and P (p = 0.001), and P and PA+P (p = 0.028). The microbial profiles of saliva and fecal samples were distinct. Mycoplasma faucium, Tannerella forsythia, Parvimonas micra, and Saccharibacteria (TM7) were increased in P; Prevotella pallens, Prevotella melaninogenica, Neisseria multispecies were more abundant in PA+P group, Ruthenibacterium lactatiformans, Dialister succinatiphilus, Butyrivibrio crossotus and Alloprevotella tannerae were detected in fecal samples in P groups compared to healthy controls. Conclusions No significant differences were detected between Parkinson’s and non-Parkinson’s gut microbiomes, suggesting that Parkinson’s disease modifies the oral microbiome in periodontitis subjects independent of the gut microbiome.

Gastrointestinal Microbiota & Symptoms of Depression and Anxiety in Anorexia Nervosa-A Re-Analysis of the MICROBIAN Longitudinal Study.

The microbiota-gut-brain axis may play a role in the pathophysiology of anorexia nervosa (AN). Here, the relationship between the gastrointestinal microbiota and symptoms of depression, anxiety, and eating disorder pathology in patients with AN before (n = 55) and after weight restoration (n = 44) was investigated by reanalyzing the data of the MICROBIAN study. The gastrointestinal microbiota was analyzed using 16S rRNA amplicon sequencing. Symptoms of anxiety disorder, depression, and the severity of the eating disorder were measured by validated questionnaires. All analyses were adjusted for the body mass index (BMI). Several significant findings between psychological parameters and the gastrointestinal microbiota were not evident after controlling for the BMI. No differences in alpha and beta diversity between groups of higher and lower symptom severity levels for depression and anxiety were found. Positive associations between species of Blautia and Ruminococcus and depression symptoms, and between the phylum Firmicutes and anxiety symptoms were observed after rehabilitation, respectively. A positive correlation was found between propionate and acetate levels and the reduction of depression severity during inpatient treatment. Accounting for the weight status when analyzing the relationship between psychological parameters and the gastrointestinal microbiota in patients with underweight is important since the BMI may be the driver for many observed changes.

Differences in diversity and community composition of the shell microbiome of apparently healthy lobsters Homarus americanus across Atlantic Canada.

Host-microbe dynamics are of increasing interest in marine research due to their role in host health and productivity. Changes in the shell microbiome of American lobsters have been associated with epizootic shell disease, a syndrome that is spreading northwards across the eastern U.S. and Canadian Atlantic coast. This study analyzed differences in alpha and beta diversity, as well as differentially abundant taxa, in the shell-associated bacterial community of apparently healthy lobsters from four lobster fishing areas (LFAs) in Atlantic Canada. Over 180 lobsters from New Brunswick, Nova Scotia and Prince Edward Island (PEI) were sampled during seven sampling events over four sampling months. The bacterial community was identified using novel PacBio long-read sequencing, while alpha and beta diversity parameters were analyzed using linear regression models and weighted UniFrac distances. The bacterial richness, diversity and evenness differed by sampling location, sampling month, and molt stage, but not by lobster sex or size, nor sampling depth. Similarly, based on LFA, sampling month, year and lobster molt stage, the shell microbiome differed in microbial community composition with up to 34 out of 162 taxa differing significantly in abundance between sampling groups. This large-scale microbial survey suggests that the shell microbial diversity of apparently healthy lobsters is influenced by spatial and temporal factors such as geographic location, as well as the length of time the carapace is exposed to the surrounding seawater.