Project description:<h4>Background</h4>Chemotherapy is the primary treatment modality used for patients with acute lymphoblastic leukemia (ALL), but inevitably causes microbiota-related oral complications. This study is aimed at investigating the effects of chemotherapy on oral health status, caries risk, and oral microbiome in pediatric patients with ALL.<h4>Methods</h4>Thirty-nine children with ALL receiving chemotherapy were enrolled, and a gender-, age-, dentition stage, and socioeconomic class matched healthy counterpart were recruited. Demographic information and overall health condition were obtained through the questionnaire and medical records. Oral examination was performed to assess caries and salivary status, plaque index, and other oral manifestations. Cariogram was used to assess the overall caries risk. Supragingival samples of thirteen ALL subjects and their counterparts were randomly selected to perform a 16S ribosomal RNA gene 454 pyrosequencing. Raw sequence data were screened, trimmed, and filtered using Seqcln and MOTHUR.<h4>Results</h4>The prevalence of dental caries, gingivitis, oral mucositis, xerostomia, and candidiasis in ALL groups was higher than that of the control group (<i>p</i> < 0.05). Children with ALL demonstrated higher caries risk compared to healthy controls (HC) based upon Cariogram (<i>p</i> < 0.05). The oral microbial structure of ALL patients receiving chemotherapy is different from that of healthy controls. Oral microbiota of ALL groups showed less alpha diversity and significant differences in the composition of the oral microbiome compared to healthy controls.<h4>Conclusions</h4>ALL patients receiving chemotherapy demonstrated compromised oral health, high caries risk, alteration of caries-related factors, and dysbiosis of oral microbiota. These findings may be of clinical importance in developing better strategies for personalized preventive management of oral diseases for pediatric children with ALL.
Project description:We report the initial characterization of the gastrointestinal tract (gut) and oral microbiota (bacteria) in 32 urban Pakistani adults. Study participants were between ages 18 and 40, had body mass index between 18 and 25 Kg/m2, and were students or early-career professionals. These individuals donated a total of 61 samples (32 gut and 29 oral) that were subjected to 16S ribosomal RNA (rRNA) gene sequencing. Microbiome composition of Pakistani individuals was compared against the uBiome database of selected individuals who self-reported to be in excellent health. We observed strong gender-based differences in the gut microbiome of Pakistani individuals, a skewness toward Firmicutes, and unusually high levels of Proteobacteria in the Pakistani men. These observations may indicate microbiota dysbiosis, though 16S data alone can neither establish cause nor effect to human health. Albeit conducted on a smaller scale, our report provides a first snapshot about the composition and diversity of gut and oral microbiota communities in Pakistani individuals.
Project description:We used 16S rRNA gene sequencing to examine the posteffects of antibiotic treatment on the structure and metabolism of rumen microbiota. Twelve goats were randomly assigned into two groups, with one group receiving intramuscular streptomycin injection at 40 mg/kg bodyweight daily for 10 days. At 4 weeks after treatment with antibiotic, three goats were randomly selected from each group and switched to a 35% concentrate diet. The remaining six goats continued with the 10% concentrate diet. At 4 weeks after dietary shift, ruminal fluid and epithelium were collected to analyze the microbiota composition and short-chain fatty acid (SCFA) concentrations of the rumen. We found that antibiotic administration led to increases in the diversity and richness of recovered mucosal microbiota and to decreases in those of recovered fluid microbiota. When dietary modulation was performed after antibiotic intake, both communities showed little difference in structure from premodulated states. Additionally, antibiotic pretreatment reduced the basal lines of individual SCFAs but did not affect the increased percentages of SCFAs. Overall, our results indicate that antibiotic administration affects the structure of both rumen fluid and mucosal microbiota and reduces the functional redundancy of rumen microbiota.
Project description:To prevent or combat infection, increasing the effectiveness of the immune response is highly desirable, especially in case of compromised immune system function. However, immunostimulatory therapies are scarce, expensive, and often have unwanted side-effects. ?-glucans have been shown to exert immunostimulatory effects in vitro and in vivo in experimental animal models. Oral ?-glucan is inexpensive and well-tolerated, and therefore may represent a promising immunostimulatory compound for human use.We performed a randomized open-label intervention pilot-study in 15 healthy male volunteers. Subjects were randomized to either the ? -glucan (n?=?10) or the control group (n?=?5). Subjects in the ?-glucan group ingested ?-glucan 1000 mg once daily for 7 days. Blood was sampled at various time-points to determine ?-glucan serum levels, perform ex vivo stimulation of leukocytes, and analyze microbicidal activity.?-glucan was barely detectable in serum of volunteers at all time-points. Furthermore, neither cytokine production nor microbicidal activity of leukocytes were affected by orally administered ?-glucan.The present study does not support the use of oral ?-glucan to enhance innate immune responses in humans.ClinicalTrials.gov NCT01727895.
Project description:SCOPE:GTPs (green tea polyphenols) exert anti-CRC (colorectal cancer) activity. The intestinal microbiota and intestinal colonization by bacteria of oral origin has been implicated in colorectal carcinogenesis. GT modulates the composition of mouse gut microbiota harmonious with anticancer activity. Therefore, the effect of green tea liquid (GTL) consumption on the gut and oral microbiome is investigated in healthy volunteers (n = 12). METHODS AND RESULTS:16S sequencing and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis of both fecal and saliva samples (collected before intervention, after 2 weeks of GTL (400 mL per day) and after a washout period of one week) in healthy volunteers show changes in microbial diversity and core microbiota and difference in clear classification (partial least squares-discriminant analysis [PLS-DA]). An irreversible, increased FIR:BAC (Firmicutes to Bacteroidetes ratio), elevated SCFA producing genera, and reduction of bacterial LPS synthesis in feces are discovered in response to GTL. GTL alters the salivary microbiota and reduces the functional pathways abundance relevance to carcinogenesis. Similar bacterial networks in fecal and salivary microbiota datasets comprising putative oral bacteria are found and GTL reduces the fecal levels of Fusobacterium. Interestingly, both Lachnospiraceae and B/E (Bifidobacterium to Enterobacteriacea ratio-markers of colonization resistance [CR]) are negatively associated with the presence of oral-like bacterial networks in the feces. CONCLUSION:These results suggest that GTL consumption causes both oral and gut microbiome alterations.
Project description:Background: The oral cavity harbors a complex microbial ecosystem, intimately related to oral health and disease. The use of polyol-sweetened gum is believed to benefit oral health through stimulation of salivary flow and impacting oral pathogenic bacteria. Maltitol is often used as sweetener in food products. This study aimed to establish the in vivo effects of frequent consumption of maltitol-sweetened chewing gum on the dental plaque microbiota in healthy volunteers and to establish the cellular and molecular effects by in vitro cultivation and transcriptional analysis. Results: An intervention study was performed in 153 volunteers, randomly assigned to three groups (www.trialregister.nl; NTR4165). One group was requested to use maltitol gum five times daily, one group used gum-base, and the third group did not use chewing gum. At day 0 and day 28, 24 h-accumulated supragingival plaque was collected at the lingual sites of the lower jaw and the buccal sites of the upper jaw and analyzed by 16S ribosomal rRNA gene sequencing. At day 42, 2 weeks after completion of the study, lower-jaw samples were collected and analyzed. The upper buccal plaque microbiota composition had lower bacterial levels and higher relative abundances of (facultative) aerobic species compared to the lower lingual sites. There was no difference in bacterial community structure between any of the three study groups (PERMANOVA). Significant lower abundance of several bacterial phylotypes was found in maltitol gum group compared to the gum-base group, including Actinomyces massiliensis HOT 852 and Lautropia mirabilis HOT 022. Cultivation studies confirmed growth inhibition of A. massiliensis and A. johnsonii by maltitol at levels of 1% and higher. Transcriptome analysis of A. massiliensis revealed that exposure to maltitol resulted in changes in the expression of genes linked to osmoregulation, biofilm formation, and central carbon metabolism. Conclusion: The results showed that chewing itself only marginally impacted the plaque microbiota composition. Use of maltitol-sweetened gum lowered abundance of several bacterial species. Importantly, the species impacted play a key role in the early formation of dental biofilms. Further studies are required to establish if frequent use of maltitol gum impacts early dental-plaque biofilm development.
Project description:The microbiota of the human lower intestinal tract helps maintain healthy host physiology, for example through nutrient acquisition and bile acid recycling, but specific positive contributions of the oral microbiota to host health are not well established. Nitric oxide (NO) homeostasis is crucial to mammalian physiology. The recently described entero-salivary nitrate-nitrite-nitric oxide pathway has been shown to provide bioactive NO from dietary nitrate sources. Interestingly, this pathway is dependent upon oral nitrate-reducing bacteria, since humans lack this enzyme activity. This pathway appears to represent a newly recognized symbiosis between oral nitrate-reducing bacteria and their human hosts in which the bacteria provide nitrite and nitric oxide from nitrate reduction. Here we measure the nitrate-reducing capacity of tongue-scraping samples from six healthy human volunteers, and analyze metagenomes of the bacterial communities to identify bacteria contributing to nitrate reduction. We identified 14 candidate species, seven of which were not previously believed to contribute to nitrate reduction. We cultivated isolates of four candidate species in single- and mixed-species biofilms, revealing that they have substantial nitrate- and nitrite-reduction capabilities. Colonization by specific oral bacteria may thus contribute to host NO homeostasis by providing nitrite and nitric oxide. Conversely, the lack of specific nitrate-reducing communities may disrupt the nitrate-nitrite-nitric oxide pathway and lead to a state of NO insufficiency. These findings may also provide mechanistic evidence for the oral systemic link. Our results provide a possible new therapeutic target and paradigm for NO restoration in humans by specific oral bacteria.
Project description:The aim was to evaluate the effects of orally administered Lactobacillus rhamnosus GG (LGG) and Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on the number of salivary mutans streptococci (MS), amount of plaque, gingival inflammation and the oral microbiota in healthy young adults.The study was a randomised, controlled, double-blind trial. Healthy volunteers used lozenges containing a combination of LGG and BB-12 (test group, n?=?29) or lozenges without added probiotics (control group, n?=?31) for 4 weeks. At baseline and at the end of the test period, the plaque index (PI) and gingival index (GI) were determined, and stimulated saliva was collected. The microbial composition of saliva was assessed using human oral microbe identification microarray (n?=?30). MS and lactobacilli (LB) were plate cultured.The probiotic lozenge decreased both PI and GI (p?<?0.05) while no changes were observed in the control group. However, no probiotic-induced changes were found in the microbial compositions of saliva in either group.The probiotic lozenge improved the periodontal status without affecting the oral microbiota.Short-term consumption of LGG and BB-12 decreased the amount of plaque which was associated with a clinical impact: a decrease in gingival inflammation.
Project description:Population specific associations between cardiovascular disease with various risk factors including pre-hypertension and hypertension were reported. We aimed to investigate the association of higher than optimal blood pressure with measures of dysglycemia, dyslipidemia, and markers of inflammation in non-diabetic Saudi adults hoping to improve current Saudi guidelines to prevent cardiovascular disease. Volunteers were recruited randomly from public healthcare centers in Jeddah. Demographic information, blood pressure (BP), and anthropometric measurements were taken. Fasting blood samples were drawn, then again following 1-hour oral glucose tolerance test. Glycated hemoglobin, fasting plasma glucose (FPG), lipid profile, highly sensitive C- reactive protein, gamma glutamyl transferase, and 1-hour plasma glucose were measured. Complete data was found for 742 men and 592 women. Pre-hypertension was found in 47.2% of men, and 24.7% of women, while 15.1% of men, and 14.6% of women were hypertensive. Means of measured variables differed significantly between normotensive, pre-hypertensive, and hypertensive groups of men and women in gender specific manner. Association between measured variables and elevated BP, and hypertension were assessed using logistic regression models. After adjustment for age, body mass index and waist circumference, elevated blood pressure was associated with elevated triglycerides in men, while hypertension was significantly associated with elevated fasting plasma glucose, total cholesterol, triglycerides, low density lipoprotein- cholesterol, and low high density lipoprotein- cholesterol in men, and elevated triglycerides, and total cholesterol in women. Therefore, it is strongly recommended to measure lipid profile, specifically TG, for all diagnosed pre-hypertensive and hypertensive patients in addition to FPG for men.
Project description:<h4>Background</h4>In Thailand, almost one-quarter of strokes are related to atrial fibrillation (AF), and many could be prevented if AF were diagnosed and treated prior to the stroke. Therefore, we tested a novel strategy to screen large numbers of community residents using village health volunteers and primary care nurses.<h4>Methods</h4>Local primary care nurses and village health volunteers in Phetchaburi and Lopburi provinces, Thailand were trained to perform AF screening using a blood pressure device with AF algorithm (Microlife A200 AFib). 10% of residents aged ? 65 years were randomly selected for screening during home-visits. Participants with possible AF were given follow-up appointments for further testing, including 12-lead ECG and echocardiogram.<h4>Results</h4>Over two-months, 9.7% (13,864/143,478) of the target population were screened: mean age 73.2 ± 6.4 years, 32.4% male. The estimated AF prevalence (detected by Microlife A200 AFib) was 2.8% (95% CI, 2.6-3.1%) for age ? 65 years (i.e. 393/13,864 participants). Prevalence increased with age from 1.9% (65-69 years) to 5.0% (?85 years) (p < 0.001). Only 58% (226/393) of participants with suspected AF attended the follow-up appointment (1-3 months after initial screen): mean CHA2DS2-VASc score 3.2 ± 1.2; 86.3% (195/226) had Class-1 oral anticoagulation recommendation, and 33% (75/226) had AF on 12-lead ECG.<h4>Conclusions</h4>In Thailand, large-scale AF screening in the community is feasible using trained volunteer health workers, allowing screening of large numbers in a short time-period. Further investigation of this strategy is warranted, ensuring mechanisms to obtain a timely rhythm strip or 12-lead ECG locally, and a designated pathway to treatment.