Relative Abundance Of Bacteroides Research Articles

Probiotic potential of a Lactobacillus rhamnosus cheese isolate and its effect on the fecal microbiota of healthy volunteers

The present study describes an in vitro characterization of strains of lactic acid bacteria, focusing on physiological characters of probiotic interest, and a subsequent placebo-controlled, crossover administration trial, with a cohort of healthy volunteers. The strains of lactic acid bacteria were previously isolated from a fermented food (ripened cheese) and several ones resulted to have promising probiotic characteristics. Based on comprehensive evaluation of the data obtained, one strain was chosen and supplemented in a fermented milk. The fermented milk was then used in the administration trial with the goal of assessing its effect on the composition of the intestinal microbiota, as reflected in the feces. The fermented milk, with or without probiotic, had an effect on the intestinal microbiota and significant inter-individual differences were observed in response to the intervention. A common trend was observed related to two important populations of the human gut microbiota; a reduction in the relative abundance of Bacteroides and increase in the abundance of Prevotella in subjects during treatment compared to baseline were registered.

Melatonin reprogramming of gut microbiota improves lipid dysmetabolism in high-fat diet-fed mice.

Melatonin has been shown to improve lipid metabolism and gut microbiota communities in animals and humans; however, it remains to know whether melatonin prevents obesity through gut microbiota. Here, we found that high-fat diet promoted the lipid accumulation and intestinal microbiota dysbiosis in mice, while oral melatonin supplementation alleviated the lipid accumulation and reversed gut microbiota dysbiosis, including the diversity of intestinal microbiota, relative abundances of Bacteroides and Alistipes, and functional profiling of microbial communities, such as energy metabolism, lipid metabolism, and carbohydrate metabolism. Interestingly, melatonin failed to alleviate the high-fat-induced lipid accumulation in antibiotic-treated mice; however, microbiota transplantation from melatonin-treated mice alleviated high-fat diet-induced lipid metabolic disorders. Notably, short-chain fatty acids were decreased in high-fat diet-fed mice, while melatonin treatment improved the production of acetic acid. Correlation analysis found a marked correlation between production of acetic acid and relative abundances of Bacteroides and Alistipes. Importantly, sodium acetate treatment also alleviated high-fat diet-induced lipid metabolic disorders. Taken together, our results suggest that melatonin improves lipid metabolism in high-fat diet-fed mice, and the potential mechanisms may be associated with reprogramming gut microbiota, especially, Bacteroides and Alistipes-mediated acetic acid production. Future studies are needed for patients with metabolic syndrome to fully understand melatonin's effects on body weight and lipid profiles and the potential mechanism of gut microbiota.

Shift of uterine microbiota associated with antibiotic treatment and cure of metritis in dairy cows

Broad-spectrum antibiotics such as ceftiofur and ampicillin are recommended for the treatment of metritis in dairy cows. Nonetheless, little is known about the impacts of antibiotics on the uterine microbiota. Here, we evaluated the shift in uterine microbiota after treating metritic cows with ceftiofur or ampicillin, and also gained insight into the uterine microbiota associated with cure of metritis. Uterine swabs from ceftiofur-treated, ampicillin-treated, and untreated metritic Holstein cows were collected on the day of metritis diagnosis (D1) and on D6 and then used for genomic DNA extraction and sequencing of the V4 hypervariable region of the 16S rRNA gene on the Illumina MiSeq platform. The uterine microbiota consolidated over time by decreasing species richness and increasing evenness; therefore, becoming more homogeneous. The uterine microbial community showed distinct clustering patterns on D6 according to antibiotic treatment, which could be attributed to more dynamic changes in the microbial structure from D1 to D6 in ceftiofur-treated cows. Ceftiofur led to significant changes at the community level, phylum level, and genus level, whereas the changes in ampicillin and untreated cows, although following the same pattern, were mostly non-significant. Bacteroidetes was significantly increased in ceftiofur-treated cows but was not changed after ampicillin and no treatment. Different responses to antibiotics were observed in Porphyromonas, which increased in relative abundance with ceftiofur and decreased with ampicillin. Regardless of treatment group, failure to cure metritis was associated with a decrease in diversity of uterine microbiota and an increase in the relative abundance of Bacteroides, Porphyromonas, and Fusobacterium.

Effects of Lactobacillus paracasei N1115 on intestinal microbiota and serum lipid of dyslipidemias

Effects of Lactobacillus paracasei N1115 on intestinal microbiota and serum lipid of dyslipidemias

Abstract A26: Diet quality vs quantity in relation to the fecal microbiome among colonoscopy patients

Abstract Diet remains a promising target with the potential to impact colorectal cancer risk via the balance of energy and body weight, as well via specific food components with known anti-carcinogenic properties. Growing evidence implicates the importance of the gut microbiome in the interaction of diet, energy balance, and inflammation—key mechanisms associated with colorectal cancer development. The tight coupling of diet and the gut microbiota may hold new answers for colorectal cancer prevention. Methods: We conducted a pilot epidemiologic study among 50 cancer-free MD Anderson colonoscopy patients with no underlying familial/genetic or chronic inflammatory bowel conditions. With the overall goal to identify dietary intervention targets in obese and lean individuals at varied risk of colorectal neoplasia, patients provided fasting blood at colonoscopy, stool samples via mail ~ 1 month post-polypectomy, and comprehensive dietary assessments. Total energy intake was derived from responses to both the Diet History (DH) and 24-hour dietary recalls (24HR) and diet quality was defined by the Healthy Eating Index (HEI). We conducted 16S rRNA gene sequencing of the fecal microbiota and measured circulating blood adipocytokines via Luminex multiplex assays (Millipore). Results: Majority of colonoscopy patients recruited into the study were female (67%) and diagnosed with precancerous colorectal polyps (57%), primarily tubular and sessile serrated adenomas. Patients with precancerous polyps removed at colonoscopy were more likely to be obese than patients without precancerous polyps, but otherwise similar by age, macronutrient composition, and HEI. Differences in the overall composition of the fecal microbiome via weighted and unweighted unifrac were observed by reason for colonoscopy (symptomatic vs asymptomatic screening), chronic medication use (yes vs. no), total energy and alcohol intake (tertiles); and effects of each these factors were considered in subsequent analyses. No differences were observed by other clinicopathologic features, demographics, or lifestyle factors. High total energy intake was significantly correlated with higher alpha diversity of the fecal microbiome. This linear relationship remained following adjustment for diet quality and was consistent across colonoscopy status, BMI, medication use and alcohol intake (FDR-adj P<0.05). Total energy intake was inversely correlated with the relative abundance of Bacteroides (r2=0.27; FDR-adj P<0.001), while diet quality was positively associated with multiple bacteria involved in short chain fatty acid metabolism, including Faecalibacterium, Subdoligranulum, and Pseudobutyrivibrio (all P<0.05). Many of these same bacteria were significantly correlated with blood levels of circulating adipocytokines, including C-peptide, TNF-alpha, lipocalin-2, and PAI-1. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis further revealed that gut bacteria may mediate the relationship between diet quality and adipocytokine signaling pathways. Conclusion: Modifiable aspects of diet quality and quantity were more closely linked to the composition of the gut microbiome than obesity or a recent diagnosis of precancerous colorectal polyps. In general, low microbial diversity has been associated with states of disease/poor health, but in our case, eating more may mean exposure to a more varied diet, promoting proliferation of a number of distinct bacteria, both “good” and “bad”. We plan to further explore functional relationships and pathways between diet, the microbiome, and adipocytokines with ongoing metagenomic analysis of the fecal microbiome. Citation Format: Carrie R. Daniel, Kristi L. Hoffman, Akhil Sood, G.S. Raju, Samir M. Hanash, Xifeng Wu, Joseph F. Petrosino. Diet quality vs quantity in relation to the fecal microbiome among colonoscopy patients. [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer: From Initiation to Outcomes; 2016 Sep 17-20; Tampa, FL. Philadelphia (PA): AACR; Cancer Res 2017;77(3 Suppl):Abstract nr A26.

Agaro-Oligosaccharides Regulate Gut Microbiota and Adipose Tissue Accumulation in Mice.

Gut microbiota are deeply associated with the prevalence of obesity. Agarose is hydrolyzed easily to yield oligosaccharides, designated as agaro-oligosaccharides (AGO). This study evaluated the effects of AGO on obese phenotype and gut microbial composition in mice. Mice were administered AGO in drinking water (AGO-receiving mice). 16S rRNA gene sequencing analyses revealed their fecal microbiota profiles. Serum bile acids were ascertained using a LC-MS/MS system. Compared to the control group, AGO administration significantly reduced epididymal adipose tissue weights and serum non-esterified fatty acid concentrations, but the cecal content weights were increased. Data from the serum bile acid profile show that concentrations of primary bile acids (cholic acid and chenodeoxycholic acid), but not those of secondary bile acids (deoxycholic acid, lithocholic acid, and ursodeoxycholic acid), tended to increase in AGO-receiving mice. 16S rRNA gene sequencing analyses showed that the relative abundances of 15 taxa differed significantly in AGO-receiving mice. Of these, the relative abundances of Rikenellaceae and Lachnospiraceae were found to be positively correlated with epididymal adipose tissue weight. The relative abundances of Bacteroides and Ruminococcus were correlated negatively with epididymal adipose tissue weight. Although the definitive role of gut microbes of AGO-received mice is still unknown, our data demonstrate the possibility that AGO administration affects the gut microbial composition and inhibits obesity in mice.

Altered Mucosal Microbiome Diversity and Disease Severity in Sjögren Syndrome.

There is mounting evidence that the microbiome has potent immunoregulatory functions. We assessed the effects of intestinal dysbiosis in a model of Sjögren syndrome (SS) by subjecting mice to desiccating stress (DS) and antibiotics (ABX). We characterized the conjunctival, tongue and fecal microbiome profiles of patients with SS. Severity of ocular surface and systemic disease was graded. 16S ribosomal RNA gene sequencing characterized the microbiota. ABX + DS mice had a significantly worse dry eye phenotype compared to controls, a decrease in Clostridium and an increase in Enterobacter, Escherichia/Shigella, and Pseudomonas in stool after ABX + DS for 10 days. Goblet cell density was significantly lower in ABX treated groups compared to controls. Stool from SS subjects had greater relative abundances of Pseudobutyrivibrio, Escherichia/Shigella, Blautia, and Streptococcus, while relative abundance of Bacteroides, Parabacteroides, Faecalibacterium, and Prevotella was reduced compared to controls. The severity of SS ocular and systemic disease was inversely correlated with microbial diversity. These findings suggest that SS is marked by a dysbiotic intestinal microbiome driven by low relative abundance of commensal bacteria and high relative abundance of potentially pathogenic genera that is associated with worse ocular mucosal disease in a mouse model of SS and in SS patients.

Kiwifruit fermentation drives positive gut microbial and metabolic changes irrespective of initial microbiota composition

It is well established that individuals vary greatly in the composition of their core microbiota. Despite differing ecology, we show here that metabolic capacity converges under the pressure of kiwifruit substrates in a model gut system. The impact of pre-digested green and gold kiwifruit on the human colonic microbiota and their metabolic products was assessed using in vitro, pH-controlled, anaerobic batch culture fermenters. Phylogenetic analyses revealed that bacterial composition changed over time, irrespective of whether a substrate was added or not, indicating a natural adjustment period to the gut model environment. Adding kiwifruit substrate caused additional changes in terms of growth of specific bacterial groups, bacterial diversity and metabolite profiles. Relative abundance of Bacteroides spp. increased with both green and gold kiwifruit substrate while Bifidobacterium spp. increased only with green kiwifruit. NMR spectroscopy and GC demonstrated an increase in organic acids (primarily acetate, butyrate, and propionate) and a concomitant decrease in several amino acids and oligosaccharides following addition of green and gold kiwifruit substrate. The experiments demonstrated that despite markedly different baseline profiles in individual donor inoculum, kiwifruit components can induce substantive change in microbial ecology and metabolism which could have consequences for human health.

Multiplex quantification of 16S rDNA of predominant bacteria group within human fecal samples by polymerase chain reaction – ligase detection reaction (PCR-LDR)

A new method, based on ligase detection reaction (LDR), was developed for quantitative detection of multiplex PCR amplicons of 16S rRNA genes present in complex mixtures (specifically feces). LDR has been widely used in single nucleotide polymorphism (SNP) assay but never applied for quantification of multiplex PCR products. This method employs one pair of DNA probes, one of which is labeled with fluorescence for signal capture, complementary to the target sequence. For multiple target sequence analysis, probes were modified with different lengths of polyT at the 5' end and 3' end. Using a DNA sequencer, these ligated probes were separated and identified by size and dye color. Then, relative abundance of target DNA were normalized and quantified based on the fluorescence intensities and exterior size standards. 16S rRNA gene of three preponderant bacteria groups in human feces: Clostridium coccoides, Bacteroides and related genera, and Clostridium leptum group, were amplified and cloned into plasmid DNA so as to make standard curves. After PCR-LDR analysis, a strong linear relationship was found between the florescence intensity and the diluted plasmid DNA concentrations. Furthermore, based on this method, 100 human fecal samples were quantified for the relative abundance of the three bacterial groups. Relative abundance of C. coccoides was significantly higher in elderly people in comparison with young adults, without gender differences. Relative abundance of Bacteroides and related genera and C. leptum group were significantly higher in young and middle aged than in the elderly. Regarding the whole set of sample, C. coccoides showed the highest relative abundance, followed by decreasing groups Bacteroides and related genera, and C. leptum. These results imply that PCR-LDR can be feasible and flexible applied to large scale epidemiological studies.