Small, but smelly: the importance of Solobacterium moorei in halitosis and other human infections

An association between poor oral health, oral microbiota, and pain identified in New Zealand women with central sensitisation disorders: a prospective clinical study

Introduction

The portal to the gastrointestinal tract is the oral cavity, with transient and permanent microbial residents. Oral pathogens are implicated in the aetiology of several chronic conditions. To date, the role of oral health and the oral microbiota in the aetiology of pain in sensitisation disorders have not been explored. Here, we examined associations between self-reported oral health, the oral microbiome, and various pain presentations in women.

Methods

Oral health in women was assessed using the WHO oral health questionnaire. Body pain, migraine, and abdominal pain were determined using validated instruments. Saliva samples were evaluated using metatranscriptomics for relative gene abundance. Demographic and clinical characteristics data were evaluated for relationships between oral health scores, pain measures, and the oral microbiota at three taxa levels.

Results

Participants in the lowest quintiles for oral health were more likely to suffer migraine headaches (χ 2 = 23.24, df 4, p < 0.001) and higher body pain scores. Four oral pathogenic species were significantly associated with SF36 bodily pain (q < 0.05) after controlling for confounders. Relative abundance of Gardnerella (genus) correlated moderately with oral health scores (ρ = -0.346, q = 0.001), while Lancefieldella (genus) and Mycoplasma salivarius were associated with migraine.

Discussion

Low oral health scores correlated with higher pain scores. Both were associated with higher relative abundance of oral pathobionts. This suggests a potential role for the oral microbiota in the aetiology of pain experienced by women with migraine headache and abdominal and body pain. These findings prompt consideration of an oral microbiome-nervous system axis.

Trial registration

The study was registered with the Australia and New Zealand Clinical Trials Registry (ANZCTR), registration number ACTRN12620001337965, on 11/12/2020 https://www.anzctr.org.au/, and with the World Health Organisation, UTN: U1111-1258-5108.

Eight weeks of high-intensity interval training alters the tongue microbiome and impacts nitrate and nitrite levels in previously sedentary men

Nitric oxide (∗NO) is a key signalling molecule, produced enzymatically via ∗NO synthases (NOS) or following the stepwise reduction of nitrate to nitrite via oral bacteria. Exercise training upregulates NOS expression and improves systemic health, but its effect on oral health, and more particularly the oral microbiome, has not been investigated. We used an exercise training study design to investigate changes in the tongue dorsum microbiome, and in nitrate and nitrite levels in the saliva, plasma and muscle, before, during and after an exercise training period. Eleven untrained males (age 25 ± 5 years, mass 64.0 ± 11.2 kg, stature 171 ± 6 cm, V˙ O2peak 2.25 ± 0.42 l min-1) underwent 8-weeks of high-intensity interval training (HIIT), followed by 12-weeks of detraining. The tongue dorsum microbiome was examined using Pac-Bio long-read 16S rRNA sequencing. Nitrate and nitrite levels were quantified with high-performance liquid chromatography. Grouped nitrite-producing species did not change between any timepoints. However, HIIT led to changes in the microbiome composition, increasing the relative abundance of some, but not all, nitrite-producing species. These changes included a decrease in the relative abundance of nitrite-producing Rothia and a decrease in Neisseria, alongside changes in 6 other bacteria at the genus level (all p ≤ 0.05). At the species level, the abundance of 9 bacteria increased post-training (all p ≤ 0.05), 5 of which have nitrite-producing capacity, including Rothia mucilaginosa and Streptococcus salivarius. Post-detraining, 6 nitrite-producing species remained elevated relative to baseline. Nitrate increased in plasma (p = 0.03) following training. Nitrite increased in the saliva after training (p = 0.02) but decreased in plasma (p = 0.03) and muscle (p = 0.002). High-intensity exercise training increased the abundance of several nitrite-producing bacteria and altered nitrate and nitrite levels in saliva, plasma, and muscle. Post-detraining, several nitrite-producing bacteria remained elevated relative to baseline, but no significant differences were detected in nitrate or nitrite levels. Switching from a sedentary to an active lifestyle alters both the microbiome of the tongue and the bioavailability of nitrate and nitrite, with potential implications for oral and systemic health.

Evaluation of extended-spectrum β-lactamase producing bacteria in feces of shelter dogs as a biomarker for altered gut microbial taxa and functional profiles

Background

The USA is home to 83-88 million dogs, with 3-7 million living in shelters. Shelter dogs move through the supply chain from their geographical origin to adoptive homes, with possible exposure to pathogens and shift in their gut microbiota. However, research in this area is limited. This study examined the effects of intestinal colonization by ESBL bacteria on gut taxa abundance, diversity, and functions in 52 shelter dogs of various ages, sexes, and fertility statuses.

Methodology

We isolated fecal DNA, sequenced their 16S, processed the sequences using DADA2, identified taxa profiles in each dog by Phyloseq, and analyzed Chao1, Shannon, and Simpson alpha diversity by ggplot2 and Wilcoxon test. We analyzed beta diversity using Bray-Curtis dissimilarity matrix from the vegan package. Differential abundance of taxa, gut microbiome functions, and differential abundance of microbiome functions were analyzed using DESeq2, PICRUSt2, and ALDEx2, respectively, with Wilcoxon rank and Kruskal-Wallis tests for comparisons between dog groups.

Results

Firmicutes (69.3%), Bacteroidota (13.5%), Actinobacteriota (6.77%), Proteobacteria (5.54%), and Fusobacteriota (4.75%) were the major phyla in the gut of shelter dogs. ESBL bacteria colonized dogs had reduced gut microbiota alpha diversity than non-colonized dogs. The abundance levels of the following phyla (Proteobacteria, Deferribacterota, Bacteroidota, Fusobacteriota, and Spirochaetota), class (Gammaproteobacteria, Bacteroidia, Deferribacteres, Brachyspirae, and Fusobacteria), and families (Enterobacteriaceae, Peptostreptococcaceae, Lactobacillaceae, Lachnospiraceae, Prevotellaceae, and Peptostreptococcaceae) were significantly (p < 0.05) varied between the two dog groups. Further stratified analysis by age, sex, and spaying/neutering status influenced the abundance of taxa in ESBL bacteria colonized dogs, indicating these covariates act as effect modifiers. Most gut metabolic and biosynthetic pathways were downregulated in ESBL bacteria colonized dogs compared to non-colonized dogs. However, alpha-linolenic acid metabolism and shigellosis, fluorobenzoate degradation, allantoin degradation, toluene degradation, glycol degradation, fatty acid and beta-oxidation, and glyoxylate metabolism bypass pathways were increased in dogs colonized by ESBL bacteria.

Conclusion

Colonization by ESBL bacteria marks altered gut microbiota. Dog's demography and fertility status modify the alterations, indicating host factors and ESBL bacteria interplay to shape gut microbiota. ESBL bacteria or other factors reprogram gut microbiome functions through down and upregulating multiple metabolic and biosynthesis pathways to promote ESBL bacteria colonization.

Solobacterium moorei promotes tumor progression via the Integrin α2/β1-PI3K-AKT-mTOR-C-myc signaling pathway in colorectal cancer

More and more evidences show that the imbalance of intestinal flora homeostasis can contribute to the progression of colorectal cancer (CRC). Solobacterium moorei (S. moorei), an anaerobic Gram-positive bacillus, was found to be enriched in fecal samples from CRC patients. However, the signaling regulatory mechanism of S. moorei promoting CRC progression remain unknown. Three CRC mouse models (ApcMin/+ mice, AOM/DSS-treated mice and subcutaneous colorectal xenograft mice) and two cell lines (DLD-1 and HT-29) were used to investigate the biological functions and molecular mechanisms of S. moorei on tumor progression of CRC in vivo and in vitro. S. moorei abundance increased in fecal samples and tumor tissues, and was significantly positively correlated with tumor staging of CRC. S. moorei promoted tumor progression in various CRC mouse models and it selectively adhered to cancer cells in comparison to colonic mucosal epithelial cells, enhancing CRC cell proliferation and inhibiting cell apoptosis. Mechanistically, S. moorei cellwall protein Cna B-type domain-containing protein binds to integrin α2/β1 on CRC cells, leading to the activation of PI3K-AKT-mTOR-C-myc pathway via phospho-FAK, thereby promoted tumor cell growth and progression. Blockade of integrin α2/β1 abolished S. moorei-mediated oncogenic response in vitro and in vivo. In summary, this study demonstrated that S. moorei promoted tumor progression via the integrin α2/β1-PI3K-AKT-mTOR-C-myc signaling pathway, which is a novel specific pathogen-mediated mechanism that might be a new potential target for CRC prevention, diagnosis, and treatment.

Gastric Microbiota Associated with Gastric Precancerous Lesions in Helicobacter pylori-Negative Patients

Studies on the gastric microbiota associated with gastric precancerous lesions remain limited. This study aimed to profile the gastric mucosal microbiota in patients with Helicobacter pylori-negative precancerous lesions. Gastric mucosal samples were obtained from 67 H. pylori-negative patients, including those with chronic gastritis (CG), intestinal metaplasia (IM), and dysplasia. The V3-V4 region of the 16S rRNA gene was sequenced and analyzed. No significant difference was observed in the alpha or beta diversity of the gastric microbiota among the groups. However, a taxonomic analysis revealed a significant enrichment of Lautropia mirabilis and the depletion of Limosilactobacillus reuteri, Solobacxterium moorei, Haemophilus haemolyticus, and Duncaniella dubosii in the IM and dysplasia groups compared to those in the CG group. Prevotella jejuni and the genus Parvimonas were enriched in the IM group. A predictive functional analysis revealed enrichment of the ornithine degradation pathway in the IM and dysplasia groups, suggesting its role in persistent gastric mucosal inflammation associated with gastric precancerous lesions. The gastric microbiota associated with H. pylori-negative gastric precancerous lesions showed an increased abundance of oral microbes linked to gastric cancer and a reduction in anti-inflammatory bacteria. These alterations might contribute to chronic gastric mucosal inflammation, promoting carcinogenesis in the absence of H. pylori infection.

Microbial functional pathways based on metatranscriptomic profiling enable effective saliva-based health assessments for precision wellness

It is increasingly recognized that an important step towards improving overall health is to accurately measure biomarkers of health from the molecular activities prevalent in the oral cavity. We present a general methodology for computationally quantifying the activity of microbial functional pathways using metatranscriptomic data. We describe their implementation as a collection of eight oral pathway scores using a large salivary sample dataset (n = 9350), and we evaluate score associations with oropharyngeal disease phenotypes within an unseen independent cohort (n = 14,129). Through this validation, we show that the relevant oral pathway scores are significantly worse in individuals with periodontal disease, acid reflux, and nicotine addiction, compared with controls. Given these associations, we make the case to use these oral pathway scores to provide molecular health insights from simple, non-invasive saliva samples, and as molecular endpoints for actionable interventions to address the associated conditions.

The Multiple Challenges of Nutritional Microbiome Research During COVID-19-A Perspective and Results of a Single-Case Study

The global coronavirus disease 2019 (COVID-19) pandemic has affected multiple aspects of people's lives, which may also influence the results of studies conducted during this period across diverse research domains. This particularly includes the field of nutritional science, investigating the gut microbiota as a potential mediator in the association between dietary intake and health-related outcomes. This article identifies the challenges currently facing this area of research, points out potential solutions, and highlights the necessity to consider a range of issues when interpreting trials conducted during this period. Some of these issues have arisen specifically because of the measures implemented to interrupt the spread of small acute respiratory syndrome coronavirus 2 (SARS-CoV-2), while others remain relevant beyond the pandemic.

Tongue microbiota in relation to the breathing preference in children undergoing orthodontic treatment

BACKGROUND

Mouth breathing (MB), a risk factor of oral dysbiosis and halitosis, is linked with craniofacial anomalies and pediatric obstructive sleep apnea. Here, we aimed to analyze tongue microbiota in children from the perspective of their breathing pattern before/during orthodontic treatment.

METHODS

This prospective case-control study included 30 children with orthodontic anomalies, 15 with MB and 15 with nasal breathing (NB), matched by age, sex, and body mass index. All underwent orthodontic examination and sleep apnea monitoring. Tongue swabs were collected before starting (timepoint M0) and approx. six months into the orthodontic therapy (timepoint M6). Oral candidas and bacteriome were analyzed using mass spectrometry technique and 16S rRNA sequencing, respectively.

RESULTS

MB was associated with higher apnea-hypopnea index. At M0, oral candidas were equally present in both groups. At M6, Candida sp. were found in six children with MB but in none with NB. No significant differences in bacterial diversity were observed between groups and timepoints. However, presence/relative abundance of genus Solobacterium was higher in children with MB than NB at M0.

CONCLUSIONS

Significant links between MB and the presence of genus Solobacterium (M0) as well as Candida sp. (M6) were found in children with orthodontic anomalies, highlighting the risk of halitosis in them.

Gut microbiome and function are altered for individuals living in high fluoride concentration areas in Pakistan

BACKGROUND

Endemic fluorosis refers to the condition when individuals are exposed to excessive amounts of fluoride ion due to living in a region characterized by elevated levels of fluorine in the drinking water, food, and/or air. In Pakistan, a substantial proportion of the population is thereby affected, posing a public health concern.

OBJECTIVES

Assessing how the gut microbiota and its metabolic profiles are impacted by chronic exposure to fluoride in drinking water (that caused Dental Fluorosis) as well as to perceive how this microbiota is connected to adverse health outcomes prevailing with fluoride exposure.

METHODS

Drinking water (n=27) and biological samples (n=100) of blood, urine and feces were collected from 70 high fluoride exposed (with Dental Fluorosis) and 30 healthy control (without Dental Fluorosis) subjects. Water and urinary fluoride concentrations were determined. Serum/plasma biochemical testing was performed. Fecal DNA extraction, 16S rRNA analysis of microbial taxa, their predicted metabolic function and fecal short chain fatty acids (SCFAs) quantification were carried out.

RESULTS

The study revealed that microbiota taxonomic shifts and their metabolic characterization had been linked to certain host clinical parameters under the chronic fluoride exposure. Some sets of genera showed strong specificity to water and urine fluoride concentrations, Relative Fat Mass index and SCFAs. The SCFAs response in fluoride-exposed samples was observed to be correlated with bacterial taxa that could contribute to adverse health effects.

CONCLUSIONS

Microbial dysbiosis as a result of endemic fluorosis exhibits a structure that is associated with risk of metabolic deregulation and is implicated in various diseases. Our results may form the development of novel interventions and may have utility in diagnosis and monitoring.

Bifidobacterium longum subsp. longum BG-L47 boosts growth and activity of Limosilactobacillus reuteri DSM 17938 and its extracellular membrane vesicles

The aim of this study was to identify a Bifidobacterium strain that improves the performance of Limosilactobacillus reuteri DSM 17938. Initial tests showed that Bifidobacterium longum subsp. longum strains boosted the growth of DSM 17938 during in vivo-like conditions. Further characterization revealed that one of the strains, BG-L47, had better bile and acid tolerance compared to BG-L48, as well as mucus adhesion compared to both BG-L48 and the control strain BB536. BG-L47 also had the capacity to metabolize a broad range of carbohydrates and sugar alcohols. Mapping of glycoside hydrolase (GH) genes of BG-L47 and BB536 revealed many GHs associated with plant-fiber utilization. However, BG-L47 had a broader phenotypic fiber utilization capacity. In addition, B. longum subsp. longum cells boosted the bioactivity of extracellular membrane vesicles (MV) produced by L. reuteri DSM 17938 during co-cultivation. Secreted 5'-nucleotidase (5'NT), an enzyme that converts AMP into the signal molecule adenosine, was increased in MV boosted by BG-L47. The MV exerted an improved antagonistic effect on the pain receptor transient receptor potential vanilloid 1 (TRPV1) and increased the expression of the immune development markers IL-6 and IL-1ß in a peripheral blood mononuclear cell (PBMC) model. Finally, the safety of BG-L47 was evaluated both by genome safety assessment and in a human safety study. Microbiota analysis showed that the treatment did not induce significant changes in the composition. In conclusion, B. longum subsp. longum BG-L47 has favorable physiological properties, can boost the in vitro activity of L. reuteri DSM 17938, and is safe for consumption, making it a candidate for further evaluation in probiotic studies.

IMPORTANCE

By using probiotics that contain a combination of strains with synergistic properties, the likelihood of achieving beneficial interactions with the host can increase. In this study, we first performed a broad screening of Bifidobacterium longum subsp. longum strains in terms of synergistic potential and physiological properties. We identified a superior strain, BG-L47, with favorable characteristics and potential to boost the activity of the known probiotic strain Limosilactobacillus reuteri DSM 17938. Furthermore, we demonstrated that BG-L47 is safe for consumption in a human randomized clinical study and by performing a genome safety assessment. This work illustrates that bacteria-bacteria interactions differ at the strain level and further provides a strategy for finding and selecting companion strains of probiotics.

Influence of Varied Environment Conditions on the Gut Microbiota of Yaks

Despite the crucial role of the gut microbiota in different physiological processes occurring in the animal body, reports regarding the gut microbiota of animals residing in different environmental conditions like high altitude and different climate settings are limited. The Qinghai-Tibetan Plateau is renowned for its extreme climatic conditions that provide an ideal environment for exploring the effects of high altitude and temperature on the microbiota of animals. Yaks have unique oxygen delivery systems and genes related to hypoxic response. Damxung, Nyêmo, and Linzhou counties in Tibet have variable altitudes and temperatures that offer distinct settings for studying yak adaptation to elevated terrains. The results of our study suggest that amplicon sequencing of V3-V4 and internal transcribed spacer 2 (ITS2) regions yielded 13,683 bacterial and 1912 fungal amplicon sequence variants (ASVs). Alpha and beta diversity indicated distinct microbial structures. Dominant bacterial phyla were Firmicutes, Bacteroidota, and Actinobacteriota. Genera UCG-005, Christensenellaceae_R-7_group, and Rikenellaceae_RC9_gut_group were dominant in confined yaks living in Damxung county (DXS) and yaks living in Linzhou county (LZS), whereas UCG-005 prevailed in confined yaks living in Nyêmo county (NMS). The linear discriminant analysis effect size (LEfSe) analysis highlighted genus-level differences. Meta-stat analysis revealed significant shifts in bacterial and fungal community composition in yaks at different high altitudes and temperatures. Bacterial taxonomic analysis revealed that two phyla and 32 genera differed significantly (p < 0.05). Fungal taxonomic analysis revealed that three phyla and four genera differed significantly (p < 0.05). Functional predictions indicated altered metabolic functions, especially in the digestive system of yaks living in NMS. This study reveals significant shifts in yak gut microbiota in response to varying environmental factors, such as altitude and temperature, shedding light on previously unexplored aspects of yak physiology in extreme environments.

Oral microbiota transplantation for intra-oral halitosis: a feasibility analysis based on an oral microbiota colonization trial in Wistar rats

BACKGROUND

Intra-oral halitosis (IOH) is bad breath produced locally by the mouth in addition to systemic diseases and is one of the main causes of interpersonal communication and psychological disorders in modern society. However, current treatment modalities still only alleviate IOH and do not eradicate it. Therefore, based on the differential performance of oral microecology in IOH patients, we propose a microbiota transplantation treatment aimed at restoring oral microecological balance and analyze its feasibility by oral flora colonization test in Wistar rats.

OBJECTIVE

Saliva flora samples were collected from IOH patients and healthy subjects to analyze the feasibility of oral microbiota transplantation (OMT) for the treatment of IOH by the Wistar rat oral flora colonization test.

METHODS

Seven patients with IOH who visited the First Affiliated Hospital of Xinjiang Medical University from June 2017 to June 2022 with the main complaint of halitosis and three healthy subjects were randomly selected. A Halimeter portable breath detector was used to record breath values and collect saliva flora samples. Sixteen SPF-grade male Wistar rats were housed in the Animal Experiment Center of Xinjiang Medical University and randomly divided into an experimental group (Group E) and a control group (Group C) for the oral flora colonization test. Species composition and associated metabolic analysis of oral flora during the Wistar rat test using 16SrRNA sequencing technology and PICRUSt metabolic analysis. Also, the changes in the breath values of the rats were recorded during the test.

RESULTS

The proportion of Porphyromonas, Fusobacterium, Leptotrichia, and Peptostreptococcus was significantly higher in group E compared to group C after colonization of salivary flora of IOH patients (all P < 0.05), and the abundance with Gemella was zero before colonization, while no colonization was seen in group C after colonization compared to baseline. PICRUSt metabolic analysis also showed significantly enhanced IOH-related metabolic pathways after colonization in group E (all P < 0.05), as well as significantly higher breath values compared to baseline and group C (all P < 0.0001). After colonization by salivary flora from healthy subjects, group E rats showed a decrease in the abundance of associated odor-causing bacteria colonization, a reduction in associated metabolism, and a significant decrease in breath values. In contrast, group C also showed differential changes in flora structure and breath values compared to baseline after salivary flora colonization of IOH patients.

CONCLUSIONS

OMT for IOH is a promising green treatment option, but the influence of environmental factors and individual differences still cannot be ignored.

Inflammatory Dietary Potential Is Associated with Vitamin Depletion and Gut Microbial Dysbiosis in Early Pregnancy

Pregnancy alters many physiological systems, including the maternal gut microbiota. Diet is a key regulator of this system and can alter the host immune system to promote inflammation. Multiple perinatal disorders have been associated with inflammation, maternal metabolic alterations, and gut microbial dysbiosis, including gestational diabetes mellitus, pre-eclampsia, preterm birth, and mood disorders. However, the effects of high-inflammatory diets on the gut microbiota during pregnancy have yet to be fully explored. We aimed to address this gap using a system-based approach to characterize associations among dietary inflammatory potential, a measure of diet quality, and the gut microbiome during pregnancy. Forty-seven pregnant persons were recruited prior to 16 weeks of gestation. Participants completed a food frequency questionnaire (FFQ) and provided fecal samples. Dietary inflammatory potential was assessed using the Dietary Inflammatory Index (DII) from the FFQ data. Fecal samples were analyzed using 16S rRNA amplicon sequencing. Differential taxon abundances with respect to the DII score were identified, and the microbial metabolic potential was predicted using PICRUSt2. Inflammatory diets were associated with decreased vitamin and mineral intake and a dysbiotic gut microbiota structure and predicted metabolism. Gut microbial compositional differences revealed a decrease in short-chain fatty acid producers such as Faecalibacterium, and an increase in predicted vitamin B12 synthesis, methylglyoxal detoxification, galactose metabolism, and multidrug efflux systems in pregnant individuals with increased DII scores. Dietary inflammatory potential was associated with a reduction in the consumption of vitamins and minerals and predicted gut microbiota metabolic dysregulation.

Solobacterium moorei promotes the progression of adenomatous polyps by causing inflammation and disrupting the intestinal barrier

BACKGROUND

Adenomatous polyps (APs) with inflammation are risk factors for colorectal cancer. However, the role of inflammation-related gut microbiota in promoting the progression of APs is unknown.

METHODS

Sequencing of the 16S rRNA gene was conducted to identify characteristic bacteria in AP tissues and normal mucosa. Then, the roles of inflammation-related bacteria were clarified by Spearman correlation analysis. Furthermore, colorectal HT-29 cells, normal colon NCM460 cells, and azoxymethane-treated mice were used to investigate the effects of the characteristic bacteria on progression of APs.

RESULTS

The expression levels of inflammation-related markers (diamine oxidase, D-lactate, C-reactive protein, tumor necrosis factor-α, interleukin-6 and interleukin-1β) were increased, whereas the expression levels of anti-inflammatory factors (interleukin-4 and interleukin-10) were significantly decreased in AP patients as compared to healthy controls. Solobacterium moorei (S. moorei) was enriched in AP tissues and fecal samples, and significantly positively correlated with serum inflammation-related markers. In vitro, S. moorei preferentially attached to HT-29 cells and stimulated cell proliferation and production of pro-inflammatory factors. In vivo, the incidence of intestinal dysplasia was significantly increased in the S. moorei group. Gavage of mice with S. moorei upregulated production of pro-inflammatory factors, suppressed proliferation of CD4+ and CD8+cells, and disrupted the integrity of the intestinal barrier, thereby accelerating progression of APs.

CONCLUSIONS

S. moorei accelerated the progression of AP in mice via activation of the NF-κB signaling pathway, chronic low-grade inflammation, and intestinal barrier disruption. Targeted reduction of S. moorei presents a potential strategy to prevent the progression of APs.

Solobacterium moorei promotes the progression of adenomatous polyps by causing inflammation and disrupting the intestinal barrier

BACKGROUND

Adenomatous polyps (APs) with inflammation are risk factors for colorectal cancer. However, the role of inflammation-related gut microbiota in promoting the progression of APs is unknown.

METHODS

Sequencing of the 16S rRNA gene was conducted to identify characteristic bacteria in AP tissues and normal mucosa. Then, the roles of inflammation-related bacteria were clarified by Spearman correlation analysis. Furthermore, colorectal HT-29 cells, normal colon NCM460 cells, and azoxymethane-treated mice were used to investigate the effects of the characteristic bacteria on progression of APs.

RESULTS

The expression levels of inflammation-related markers (diamine oxidase, D-lactate, C-reactive protein, tumor necrosis factor-α, interleukin-6 and interleukin-1β) were increased, whereas the expression levels of anti-inflammatory factors (interleukin-4 and interleukin-10) were significantly decreased in AP patients as compared to healthy controls. Solobacterium moorei (S. moorei) was enriched in AP tissues and fecal samples, and significantly positively correlated with serum inflammation-related markers. In vitro, S. moorei preferentially attached to HT-29 cells and stimulated cell proliferation and production of pro-inflammatory factors. In vivo, the incidence of intestinal dysplasia was significantly increased in the S. moorei group. Gavage of mice with S. moorei upregulated production of pro-inflammatory factors, suppressed proliferation of CD4+ and CD8+cells, and disrupted the integrity of the intestinal barrier, thereby accelerating progression of APs.

CONCLUSIONS

S. moorei accelerated the progression of AP in mice via activation of the NF-κB signaling pathway, chronic low-grade inflammation, and intestinal barrier disruption. Targeted reduction of S. moorei presents a potential strategy to prevent the progression of APs.

Gut microbial ecology and exposome of a healthy Pakistani cohort

BACKGROUND

Pakistan is a multi-ethnic society where there is a disparity between dietary habits, genetic composition, and environmental exposures. The microbial ecology of healthy Pakistani gut in the context of anthropometric, sociodemographic, and dietary patterns holds interest by virtue of it being one of the most populous countries, and also being a Lower Middle Income Country (LMIC).

METHODS

16S rRNA profiling of healthy gut microbiome of normo-weight healthy Pakistani individuals from different regions of residence is performed with additional meta-data collected through filled questionnaires. The current health status is then linked to dietary patterns through [Formula: see text] test of independence and Generalized Linear Latent Variable Model (GLLVM) where distribution of individual microbes is regressed against all recorded sources of variability. To identify the core microbiome signature, a dynamic approach is used that considers into account species occupancy as well as consistency across assumed grouping of samples including organization by gender and province of residence. Fitting neutral modeling then revealed core microbiome that is selected by the environment.

RESULTS

A strong determinant of disparity is by province of residence. It is also established that the male microbiome is better adapted to the local niche than the female microbiome, and that there is microbial taxonomic and functional diversity in different ethnicities, dietary patterns and lifestyle habits. Some microbial genera, such as, Megamonas, Porphyromonas, Haemophilus, Klebsiella and Finegoldia showed significant associations with consumption of pickle, fresh fruits, rice, and cheese. Our analyses suggest current health status being associated with the diet, sleeping patterns, employment status, and the medical history.

CONCLUSIONS

This study provides a snapshot of the healthy core Pakistani gut microbiome by focusing on the most populous provinces and ethnic groups residing in predominantly urban areas. The study serves a reference dataset for exploring variations in disease status and designing personalized dietary and lifestyle interventions to promote gut health, particularly in LMICs settings.

Inflammatory dietary potential is associated with vitamin depletion and gut microbial dysbiosis in early pregnancy

Background

Pregnancy alters many physiological systems, including the maternal gut microbiota. Diet is a key regulator of this system and can alter the host immune system to promote inflammation. Multiple perinatal disorders have been associated with inflammation, maternal metabolic alterations, and gut microbial dysbiosis, including gestational diabetes mellitus, preeclampsia, preterm birth, and mood disorders. However, the effects of high inflammatory diets on the gut microbiota during pregnancy have yet to be fully explored.

Objective

To use a systems-based approach to characterize associations among dietary inflammatory potential, a measure of diet quality, and the gut microbiome during pregnancy.

Methods

Forty-nine pregnant persons were recruited prior to 16 weeks of gestation. Participants completed a food frequency questionnaire (FFQ) and provided fecal samples. Dietary inflammatory potential was assessed using the Dietary Inflammatory Index (DII) from FFQ data. Fecal samples were analyzed using 16S rRNA amplicon sequencing. Differential taxon abundance with respect to DII score were identified, and microbial metabolic potential was predicted using PICRUSt2.

Results

Inflammatory diets were associated with decreased vitamin and mineral intake and dysbiotic gut microbiota structure and predicted metabolism. Gut microbial compositional differences revealed a decrease in short chain fatty acid producers such as Faecalibacterium, and an increase in predicted vitamin B12 synthesis, methylglyoxal detoxification, galactose metabolism and multi drug efflux systems in pregnant individuals with increased DII scores.

Conclusions

Dietary inflammatory potential was associated with a reduction in the consumption of vitamins & minerals and predicted gut microbiota metabolic dysregulation.

Urinary microbiota signatures associated with different types of urinary diversion: a comparative study

Background

Radical cystectomy and urinary diversion (UD) are gold standards for non-metastatic muscle-invasive bladder cancer. Orthotopic neobladder (or Studer), ileal conduit (or Bricker) and cutaneous ureterostomy (CU) are mainstream UD types. Little is known about urinary microbiological changes after UD.

Methods

In this study, urine samples were collected from healthy volunteers and patients with bladder cancer who had received aforementioned UD procedures. Microbiomes of samples were analyzed using 16S ribosomal RNA gene sequencing, and microbial diversities, distributions and functions were investigated and compared across groups.

Results

Highest urine microbial richness and diversity were observed in healthy controls, followed by Studer patients, especially those without hydronephrosis or residual urine, α-diversity indices of whom were remarkably higher than those of Bricker and CU groups. Studer UD type was the only independent factor favoring urine microbial diversity. The urine microflora structure of the Studer group was most similar to that of the healthy individuals while that of the CU group was least similar. Studer patients and healthy volunteers shared many similar urine microbial functions, while Bricker and CU groups exhibited opposite characteristics.

Conclusion

Our study first presented urinary microbial landscapes of UD patients and demonstrated the microbiological advantage of orthotopic neobladder. Microbiota might be a potential tool for optimization of UD management.

Longitudinal analysis at three oral sites links oral microbiota to clinical outcomes in allogeneic hematopoietic stem-cell transplant

IMPORTANCE

The oral cavity is the ultimate doorway for microbes entering the human body. We analyzed oral microbiota dynamics in allogeneic hematopoietic stem-cell transplant recipients and showed that microbiota injury and recovery patterns were highly informative on transplant complications and outcomes. Our results highlight the importance of tracking the recipient's microbiota changes during allogeneic hematopoietic stem-cell transplant to improve our understanding of its biology, safety, and efficacy.

IgYs: on her majesty's secret service

There has been an increasing interest in using Immunoglobulin Y (IgY) antibodies as an alternative to "classical" antimicrobials. Unlike traditional antibiotics, they can be utilized on a continual basis without leading to the development of resistance. The veterinary IgY antibody market is growing because of the demand for minimal antibiotic use in animal production. IgY antibodies are not as strong as antibiotics for treating infections, but they work well as preventative agents and are natural, nontoxic, and easy to produce. They can be administered orally and are well tolerated, even by young animals. Unlike antibiotics, oral IgY supplements support the microbiome that plays a vital role in maintaining overall health, including immune system function. IgY formulations can be delivered as egg yolk powder and do not require extensive purification. Lipids in IgY supplements improve antibody stability in the digestive tract. Given this, using IgY antibodies as an alternative to antimicrobials has garnered interest. In this review, we will examine their antibacterial potential.

Bacterial pathogens in pediatric appendicitis: a comprehensive retrospective study

Background

Appendicitis is a frequent condition, with peak incidences in the second decade of life. Its pathogenesis is under debate, but bacterial infections are crucial, and antibiotic treatment remains essential. Rare bacteria are accused of causing complications, and various calculated antibiotics are propagated, yet there is no comprehensive microbiological analysis of pediatric appendicitis. Here we review different pre-analytic pathways, identify rare and common bacterial pathogens and their antibiotic resistances, correlate clinical courses, and evaluate standard calculated antibiotics in a large pediatric cohort.

Method

We reviewed 579 patient records and microbiological results of intraoperative swabs in standard Amies agar media or fluid samples after appendectomies for appendicitis between May 2011 and April 2019. Bacteria were cultured and identified via VITEK 2 or MALDI-TOF MS. Minimal inhibitory concentrations were reevaluated according to EUCAST 2022. Results were correlated to clinical courses.

Results

Of 579 analyzed patients, in 372 patients we got 1330 bacterial growths with resistograms. 1259 times, bacteria could be identified to species level. 102 different bacteria could be cultivated. 49% of catarrhal and 52% of phlegmonous appendices resulted in bacterial growth. In gangrenous appendicitis, only 38% remained sterile, while this number reduced to 4% after perforation. Many fluid samples remained sterile even when unsterile swabs had been taken simultaneously. 40 common enteral genera were responsible for 76.5% of bacterial identifications in 96.8% of patients. However, 69 rare bacteria were found in 187 patients without specifically elevated risk for complications.

Conclusion

Amies agar gel swabs performed superior to fluid samples and should be a standard in appendectomies. Even catarrhal appendices were only sterile in 51%, which is interesting in view of a possible viral cause. According to our resistograms, the best in vitro antibiotic was imipenem with 88.4% susceptible strains, followed by piperacillin-tazobactam, cefuroxime with metronidazole, and ampicillin-sulbactam to which only 21.6% of bacteria were susceptible. Bacterial growths and higher resistances correlate to an elevated risk of complications. Rare bacteria are found in many patients, but there is no specific consequence regarding antibiotic susceptibility, clinical course, or complications. Prospective, comprehensive studies are needed to further elicit pediatric appendicitis microbiology and antibiotic treatment.

Limited Impact of SARS-CoV-2 on the Human Naso-Oropharyngeal Microbiota in Hospitalized Patients

Numerous studies have reported dysbiosis in the naso- and/or oro-pharyngeal microbiota of COVID-19 patients compared with healthy individuals; however, only a few small-scale studies have also included a disease control group. In this study, we characterized and compared the bacterial communities of pooled nasopharyngeal and throat swabs from hospitalized COVID-19 patients (n = 76), hospitalized non-COVID-19 patients with respiratory symptoms or related illnesses (n = 69), and local community controls (n = 76) using 16S rRNA gene V3-V4 amplicon sequencing. None of the subjects received antimicrobial therapy within 2 weeks prior to sample collection. Both COVID-19 and non-COVID-19 hospitalized patients differed in the composition, alpha and beta diversity, and metabolic potential of the naso-oropharyngeal microbiota compared with local controls. However, the microbial communities in the two hospitalized patient groups did not differ significantly from each other. Differential abundance analysis revealed the enrichment of nine bacterial genera in the COVID-19 patients compared with local controls; however, six of them were also enriched in the non-COVID-19 patients. Bacterial genera uniquely enriched in the COVID-19 patients included Alloprevotella and Solobacterium. In contrast, Mogibacterium and Lactococcus were dramatically decreased in COVID-19 patients only. Association analysis revealed that Alloprevotella in COVID-19 patients was positively correlated with the level of the inflammation biomarker C-reactive protein. Our findings reveal a limited impact of SARS-CoV-2 on the naso-oropharyngeal microbiota in hospitalized patients and suggest that Alloprevotella and Solobacterium are more specific biomarkers for COVID-19 detection. IMPORTANCE Our results showed that while both COVID-19 and non-COVID-19 hospitalized patients differed in the composition, alpha and beta diversity, and metabolic potential of the naso-oropharyngeal microbiota compared with local controls, the microbial communities in the two hospitalized patient groups did not differ significantly from each other, indicating a limited impact of SARS-CoV-2 on the naso-oropharyngeal microbiota in hospitalized patients. Besides, we identified Alloprevotella and Solobacterium as bacterial genera uniquely enriched in COVID-19 patients, which may serve as more specific biomarkers for COVID-19 detection.

Bloodstream infection caused by Solobacteriummoorei: A case report and literature review

Solobacterium moorei is an asporogenous, strictly anaerobic, short-to-long bacillus belonging to the family Erysipelotrichidae and phylum Firmicutes. This bacterium rarely causes bloodstream infections. Here, we report a case of the postoperative recurrence and metastasis of gastric antral adenocarcinoma combined with S. moorei bloodstream infection.

Alterations of Microorganisms in Tongue Coating of Gastric Precancerous Lesion Patients with a Damp Phlegm Pattern

Objective. In the research, the microbial changes in the tongue coating of patients with a damp phlegm pattern of gastric precancerous lesion (GPL) were investigated. Methods. This was a case-control study, in which 80 tongue coating samples were collected including 40 patients with a damp phlegm pattern of GPL, 20 patients with a nondamp phlegm pattern of GPL, and 20 healthy control people. The 16S rRNA microbiome technology was used to analyze the alterations of microorganisms in tongue coating of GPL patients with a damp phlegm pattern. Results. Microorganisms in the genus level were analyzed. Compared with the healthy control group, the relative abundance of 4 microorganisms (Solobacterium, Rothia, Oribacterium, and Alloprevotella) in the GPL group was significantly higher ( $P<0.05$ ). The relative abundance of 10 microorganisms (Terrisporobacter, Solobacterium, Porphyromonas, Parvimonas, Lactobacillus, Johnsonella, Gemella, Fusibacter, Azoarcus, and Acidothermus) in the GPL damp phlegm pattern group was significantly lower than that in the GPL nondamp phlegm pattern group ( $P<0.05$ ). In the comparison of phenotype “forms biofilms,” the relative abundance of microorganisms in the GPL group was significantly higher than that in the healthy control group ( $P<0.05$ ). In the comparison of phenotype “contains mobile elements,” the relative abundance of microorganisms in the GPL damp phlegm pattern group was significantly lower than that in the GPL nondamp phlegm pattern group ( $P<0.05$ ). In the comparison of microbial metabolic functions, the abundance ratio of “infectious diseases: bacterial” in the GPL group was significantly lower than that in the healthy control group ( $P<0.05$ ). The abundance ratio of the “excretory system” and “folding, sorting, and degradation” in the GPL group was significantly higher than that in the healthy control group ( $P<0.05$ ). Conclusions. Solobacterium may be a marker microorganism of the GPL damp phlegm pattern. The differential phenotype of microorganisms in tongue coating of the GPL damp tongue pattern is mainly reflected in “forms biofilms” and “contains mobile elements.”

The Effect of Short-Term Consumption of Lactic Acid Bacteria on the Gut Microbiota in Obese People

Obesity is a problem of modern health care that causes the occurrence of many concomitant diseases: arterial hypertension, diabetes mellitus, non-alcoholic fatty liver disease, and cardiovascular diseases. New strategies for the treatment and prevention of obesity are being developed that are based on using probiotics for modulation of the gut microbiota. Our study aimed to evaluate the bacterial composition of the gut of obese patients before and after two weeks of lactic acid bacteria (Lactobacillus acidophilus, Lactiplantibacillus plantarum, Limosilactobacillus fermentum, and Lactobacillus delbrueckii) intake. The results obtained showed an increase in the number of members of the phylum Actinobacteriota in the group taking nutritional supplements, while the number of phylum Bacteroidota decreased in comparison with the control group. There has also been an increase in potentially beneficial groups: Bifidobacterium, Blautia, Eubacterium, Anaerostipes, Lactococcus, Lachnospiraceae ND3007, Streptococcus, Escherichia-Shigella, and Lachnoclostridium. Along with this, a decrease in the genera was demonstrated: Faecalibacterium, Pseudobutyrivibrio, Subdoligranulum, Faecalibacterium, Clostridium sensu stricto 1 and 2, Catenibacterium, Megasphaera, Phascolarctobacterium, and the Oscillospiraceae NK4A214 group, which contribute to the development of various metabolic disorders. Modulation of the gut microbiota by lactic acid bacteria may be one of the ways to treat obesity.

Changes in halitosis value before and after Helicobacter pylori eradication: A single-institutional prospective study

BACKGROUND AND AIM

Although patients report either improved or worsened halitosis after Helicobacter pylori eradication therapy, such complaints are subjective. Only a few studies have objectively evaluated reports of changes in halitosis after H. pylori eradication; thus, this study aimed to investigate these changes after a successful H. pylori eradication.

METHODS

Between February 2015 and October 2018, 56 347 patients visited the clinic. Informed consent for participation in this study was obtained from 164 patients scheduled to undergo upper gastrointestinal endoscopy due to halitosis. Of the 91 patients with H. pylori infection, the halitosis values were evaluated as Refres breath (RB) values using a Total Gas Detector™ System and compared before and after successful H. pylori eradication, as confirmed with urea breath testing.

RESULTS

Among the 91 patients treated, 77 patients were successfully eradicated of H. pylori and had their Refres values measured (21 men and 56 women; mean age, 64.2 ± 11.5 years, including 10 smokers); among these 77 patients, 27 showed RB values of > 60. Their RB values significantly improved from 73.5 Â (95% confidence interval [CI], 64.1-82.9) to 59.4 Â (95% CI, 50.0-68.8) (P = 0.038). Of the 30 patients who could be followed up for > 2 years after successful H. pylori eradication, 8 with an RB value ≥ 60 showed significant RB value improvements from 77.9 Â (95% CI, 59.4-96.4) to 30.1 Â (95% CI, 11.6-48.6) (P = 0.0016).

CONCLUSIONS

Helicobacter pylori eradication therapy could improve halitosis, and such improvement could be maintained even 2 years after successful eradication.

The Oral, Gut Microbiota and Cardiometabolic Health of Indigenous Orang Asli Communities

The Orang Asli (OA) of Malaysia have been relatively understudied where little is known about their oral and gut microbiomes. As human health is closely intertwined with the human microbiome, this study first assessed the cardiometabolic health in four OA communities ranging from urban, rural to semi-nomadic hunter-gatherers. The urban Temuan suffered from poorer cardiometabolic health while rural OA communities were undergoing epidemiological transition. The oral microbiota of the OA were characterised by sequencing the V4 region of the 16S rRNA gene. The OA oral microbiota were unexpectedly homogenous, with comparably low alpha diversity across all four communities. The rural Jehai and Temiar PP oral microbiota were enriched for uncharacterised bacteria, exhibiting potential for discoveries. This finding also highlights the importance of including under-represented populations in large cohort studies. The Temuan oral microbiota were also elevated in opportunistic pathogens such as Corynebacterium, Prevotella, and Mogibacterium, suggesting possible oral dysbiosis in these urban settlers. The semi-nomadic Jehai gut microbiota had the highest alpha diversity, while urban Temuan exhibited the lowest. Rural OA gut microbiota were distinct from urban-like microbiota and were elevated in bacteria genera such as Prevotella 2, Prevotella 9, Lachnospiraceae ND3007, and Solobacterium. Urban Temuan microbiota were enriched in Odoribacter, Blautia, Parabacetroides, Bacteroides and Ruminococcacecae UCG-013. This study brings to light the current health trend of these indigenous people who have minimal access to healthcare and lays the groundwork for future, in-depth studies in these populations.

Efficacy of Melaleuca alternifolia and chlorhexidine mouth rinses in reducing oral malodor and Solobacterium moorei levels. A 1 week, randomized, double-blind, parallel study

OBJECTIVES

The objective is to evaluate the association of Solobacterium moorei (S. moorei) to halitosis and to also check for the effects of two different mouth rinses on levels of S. moorei in saliva and tongue coating and its impact on oral halitosis.

MATERIALS AND METHODS

This was a placebo-controlled parallel study of 160 individuals who were randomized and the study was performed using double-blinded protocol. Enrolled individuals filled a structured questionnaire regarding demographic data, oral hygiene habits, and dietary habits. Full mouth organoleptic odor scores (OLR), volatile sulfur compounds levels, Miyazaki's tongue coating index, and Plaque scores were recorded before intervention (baseline) and after 1-week post treatment. Microbiological samples obtained from the tongue and saliva was investigated for S. moorei levels using real time polymerase chain reaction. Participants were randomly assigned for two test mouth rinses (Melaleuca alternifolia and Chlorhexidine) and placebo groups.

RESULTS

All salivary and tongue coating samples were tested positive for S. moorei in the halitosis group. One week post-treatment S. moorei counts in saliva and tongue coating samples of test group showed a significant reduction at P < 0.001. Paired t-test results showed that Melaleuca alternifolia was comparable with chlorhexidine in reduction of OLR, and VSC scores (P < 0.001). Salivary levels of S. moorei in Melaleuca alternifolia group showed a higher reduction (5.67 log¹⁰ copies/mL) than chlorhexidine group (5.1log¹⁰ copies/mL).

CONCLUSION

S. moorei showed a positive correlation with oral halitosis scores. Both Melaleuca alternifolia and chlorhexidine were equally effective in reducing S. moorei levels and halitosis score.

Variations in the oral microbiome are associated with depression in young adults

A growing body of evidence supports an important role for alterations in the brain-gut-microbiome axis in the aetiology of depression and other psychiatric disorders. The potential role of the oral microbiome in mental health has received little attention, even though it is one of the most diverse microbiomes in the body and oral dysbiosis has been linked to systemic diseases with an underlying inflammatory aetiology. This study examines the structure and composition of the salivary microbiome for the first time in young adults who met the DSM-IV criteria for depression (n = 40) and matched controls (n = 43) using 16S rRNA gene-based next generation sequencing. Subtle but significant differences in alpha and beta diversity of the salivary microbiome were observed, with clear separation of depressed and healthy control cohorts into distinct clusters. A total of 21 bacterial taxa were found to be differentially abundant in the depressed cohort, including increased Neisseria spp. and Prevotella nigrescens, while 19 taxa had a decreased abundance. In this preliminary study we have shown that the composition of the oral microbiome is associated with depression in young adults. Further studies are now warranted, particuarly investigations into whether such shifts play any role in the underling aetiology of depression.

A New Look at the Genus Solobacterium: A Retrospective Analysis of Twenty-Seven Cases of Infection Involving S. moorei and a Review of Sequence Databases and the Literature

Solobacterium moorei is an anaerobic Gram-positive bacillus present within the oral and the intestinal microbiota that has rarely been described in human infections. Besides its role in halitosis and oral infections, S. moorei is considered to be an opportunistic pathogen causing mainly bloodstream and surgical wound infections. We performed a retrospective study of 27 cases of infections involving S. moorei in two French university hospitals between 2006 and 2021 with the aim of increasing our knowledge of this unrecognized opportunistic pathogen. We also reviewed all the data available in the literature and in genetic and metagenomic sequence databases. In addition to previously reported infections, S. moorei had been isolated from various sites and involved in intra-abdominal, osteoarticular, and cerebral infections more rarely or not previously reported. Although mostly involved in polymicrobial infections, in seven cases, it was the only pathogen recovered. Not included in all mass spectrometry databases, its identification can require 16S rRNA gene sequencing. High susceptibility to antibiotics (apart from rifampicin, moxifloxacin, and clindamycin; 91.3%, 11.8%, and 4.3% of resistant strains, respectively) has been noted. Our global search strategy revealed S. moorei to be human-associated, widely distributed in the human microbiota, including the vaginal and skin microbiota, which may be other sources for infection in addition to the oral and gut microbiota.

Effects of altitude on human oral microbes

Human oral microbes play a vital role maintaining host metabolic homeostasis. The Qinghai-Tibet Plateau is mainly characterized by a high altitude, dry, cold, and hypoxic environment. The oral microbiota is subject to selective pressure from the plateau environment, which affects oral health. Only a few studies have focused on the characteristics of oral microbiota in high-altitude humans. We collected saliva samples from 167 Tibetans at four altitudes (2800 to 4500 m) in Tibet to explore the relationship between the high altitude environment and oral microbiota. We conducted a two (high- and ultra-high-altitude) group analysis based on altitude, and adopted the 16S rRNA strategy for high-throughput sequencing. The results show that the alpha diversity of the oral microbiota decreased with altitude, whereas beta diversity increased with altitude. A LEfSe analysis revealed that the oral microbial biomarker of the high-altitude group (< 3650 m) was Streptococcus, and the biomarker of the ultra-high-altitude group (> 4000 m) was Prevotella. The relative abundance of Prevotella increased with altitude, whereas the relative abundance of Streptococcus decreased with altitude. A network analysis showed that the microbial network structure was more compact and complex, and the interaction between the bacterial genera was more intense in the high altitude group. Gene function prediction results showed that the amino acid and vitamin metabolic pathways were upregulated in the ultra-high-altitude group. These result show that altitude is an important factor affecting the diversity and community structure of the human oral microbiota.