Compound dietary fiber and high-grade protein diet improves glycemic control and ameliorates diabetes and its comorbidities through remodeling the gut microbiota in mice.

Dietary intervention with a low glycemic index and full nutritional support is emerging as an effective strategy for diabetes management. Here, we found that the treatment of a novel compound dietary fiber and high-grade protein diet (CFP) improved glycemic control and insulin resistance in streptozotocin-induced diabetic mice, with a similar effect to liraglutide. In addition, CFP treatment ameliorated diabetes-related metabolic syndromes, such as hyperlipidemia, hepatic lipid accumulation and adipogenesis, systemic inflammation, and diabetes-related kidney damage. These results were greatly associated with enhanced gut barrier function and altered gut microbiota composition and function, especially those bacteria, microbial functions, and metabolites related to amino acid metabolism. Importantly, no adverse effect of CFP was found in our study, and CFP exerted a wider arrange of protection against diabetes than liraglutide. Thereby, fortification with balanced dietary fiber and high-grade protein, like CFP, might be an effective strategy for the management and treatment of diabetes.

A human stool-derived Bilophila wadsworthia strain caused systemic inflammation in specific-pathogen-free mice.

BACKGROUND: Bilophila wadsworthia is a major member of sulfidogenic bacteria in human gut, it was originally recovered from different clinical specimens of intra-abdominal infections and recently was reported potentially linked to different chronic metabolic disorders. However, there is still insufficient understanding on its detailed function and mechanism to date. METHODS: A B. wadsworthia strain was isolated from fresh feces of a latent autoimmune diabetes in adults patient and we investigated its pathogenicity by oral administration to specific-pathogen-free mice. Tissue samples and serum were collected after sacrifice. Stool samples were collected at different time points to profile the gut microbiota. RESULTS: Bilophila wadsworthia infection resulted in the reduction of body weight and fat mass, apparent hepatosplenomegaly and elevated serum inflammatory factors, including serum amyloid A and interleukin-6, while without significant change of the overall gut microbiota structure. CONCLUSIONS: These results demonstrated that higher amount of B. wadsworthia caused systemic inflammatory response in SPF mice, which adds new evidence to the pathogenicity of this bacterium and implied its potential role to the chronic inflammation related metabolic diseases like diabetes.

Time-resolved analysis of a denitrifying bacterial community revealed a core microbiome responsible for the anaerobic degradation of quinoline.

Quinoline is biodegradable under anaerobic conditions, but information about the degradation kinetics and the involved microorganisms is scarce. Here, the dynamics of a quinoline-degrading bacterial consortium were studied in anoxic batch cultures containing nitrate. The cultures removed 83.5% of the quinoline during the first 80 hours, which were dominated by denitrification, and then switched to methanogenesis when the nitrogen oxyanions were depleted. Time-resolved community analysis using pyrosequencing revealed that denitrifiying bacteria belonging to the genus Thauera were enriched during the denitrification stage from 12.2% to 38.8% and 50.1% relative abundance in DNA and cDNA libraries, respectively. This suggests that they are key organisms responsible for the initial attack on quinoline. Altogether, 13 different co-abundance groups (CAGs) containing 76 different phylotypes were involved, directly or indirectly, in quinoline degradation. The dynamics of these CAGs show that specific phylotypes were associated with different phases of the degradation. Members of Rhodococcus and Desulfobacterium, as well as Rhodocyclaceae- and Syntrophobacteraceae-related phylotypes, utilized initial metabolites of the quinoline, while the resulting smaller molecules were used by secondary fermenters belonging to Anaerolineae. The concerted action by the different members of this consortium resulted in an almost complete anaerobic mineralization of the quinoline.

Fiber-utilizing capacity varies in Prevotella- versus Bacteroides-dominated gut microbiota.

The gut microbiota of individuals are dominated by different fiber-utilizing bacteria, which ferment dietary fiber into short chain fatty acids (SCFAs) known to be important for human health. Here, we show that the dominance of Prevotella versus Bacteroides in fecal innocula, identified into two different enterotypes, differentially impacts in vitro fermentation profiles of SCFAs from fibers with different chemical structures. In a microbiome of the Prevotella enterotype, fructooligosaccharides, and sorghum and corn arabinoxylans significantly promoted one single Prevotella OTU with equally high production of total SCFAs with propionate as the major product. Conversely, in the Bacteroides-dominated microbiota, the three fibers enriched different OTUs leading to different levels and ratios of SCFAs. This is the first report showing how individual differences in two enterotypes cause distinctly different responses to dietary fiber. Microbiota dominated by different fiber-utilizing bacteria may impact host health by way of producing different amounts and profiles of SCFAs from the same carbohydrate substrates.

Accelerated dysbiosis of gut microbiota during aggravation of DSS-induced colitis by a butyrate-producing bacterium.

Butyrate-producing bacteria (BPB) are potential probiotic candidates for inflammatory bowel diseases as they are often depleted in the diseased gut microbiota. However, here we found that augmentation of a human-derived butyrate-producing strain, Anaerostipes hadrus BPB5, significantly aggravated colitis in dextran sulphate sodium (DSS)-treated mice while exerted no detrimental effect in healthy mice. We explored how the interaction between BPB5 and gut microbiota may contribute to this differential impact on the hosts. Butyrate production and severity of colitis were assessed in both healthy and DSS-treated mice, and gut microbiota structural changes were analysed using high-throughput sequencing. BPB5-inoculated healthy mice showed no signs of colitis, but increased butyrate content in the gut. In DSS-treated mice, BPB5 augmentation did not increase butyrate content, but induced significantly more severe disease activity index and much higher mortality. BPB5 didn't induce significant changes of gut microbiota in healthy hosts, but expedited the structural shifts 3 days earlier toward the disease phase in BPB5-augmented than DSS-treated animals. The differential response of gut microbiota in healthy and DSS-treated mice to the same potentially beneficial bacterium with drastically different health consequences suggest that animals with dysbiotic gut microbiota should also be employed for the safety assessment of probiotic candidates.

Differential responses of gut microbiota to the same prebiotic formula in oligotrophic and eutrophic batch fermentation systems.

The same prebiotics have produced inconsistent effects on microbiota when evaluated in different batch fermentation studies. To understand the reasons behind these discrepancies, we compared impact of one prebiotic formula on the same inoculated fecal microbiota in two frequently used batch systems: phosphate-buffered saline (PBS, oligotrophic) and basal culture medium (BCM, eutrophic). The microbiota was monitored using 454 pyrosequencing. Negative controls (no prebiotic) of both systems showed significant shifts in the microbiota during fermentation, although their pH remained relatively stable, especially in BCM, with increases in Bilophila and Escherichia/Shigella but a decrease in Faecalibacterium. We identified prebiotic responders via redundancy analysis by including both baseline and negative controls. The key positive and negative responders in the two systems were very different, with only 8 consistently modulated OTUs (7 of the 28 positive responders and 1 of the 35 negative responders). Moreover, some OTUs within the same genus responded to the prebiotic in opposite ways. Therefore, to obtain a complete in vitro evaluation of the modulatory effects of a prebiotic on microbiota, it is necessary to use both oligotrophic and eutrophic systems, compare treatment groups with both baseline and negative controls, and analyze the microbiota changes down to the OTU level.

A gut microbiota-targeted dietary intervention for amelioration of chronic inflammation underlying metabolic syndrome.

Chronic inflammation induced by endotoxin from a dysbiotic gut microbiota contributes to the development of obesity-related metabolic disorders. Modification of gut microbiota by a diet to balance its composition becomes a promising strategy to help manage obesity. A dietary scheme based on whole grains, traditional Chinese medicinal foods, and prebiotics (WTP diet) was designed to meet human nutritional needs as well as balance the gut microbiota. Ninety-three of 123 central obese volunteers (BMI ≥ 28 kg m(-2) ) completed a self-controlled clinical trial consisting of 9-week intervention on WTP diet followed by a 14-week maintenance period. The average weight loss reached 5.79 ± 4.64 kg (6.62 ± 4.94%), in addition to improvement in insulin sensitivity, lipid profiles, and blood pressure. Pyrosequencing of fecal samples showed that phylotypes related to endotoxin-producing opportunistic pathogens of Enterobacteriaceae and Desulfovibrionaceae were reduced significantly, while those related to gut barrier-protecting bacteria of Bifidobacteriaceae increased. Gut permeability, measured as lactulose/mannitol ratio, was decreased compared with the baseline. Plasma endotoxin load as lipopolysaccharide-binding protein was also significantly reduced, with concomitant decrease in tumor necrosis factor-α, interleukin-6, and an increase in adiponectin. These results suggest that modulation of the gut microbiota via dietary intervention may enhance the intestinal barrier integrity, reduce circulating antigen load, and ultimately ameliorate the inflammation and metabolic phenotypes.

Characterisation of the bacterial community in expressed prostatic secretions from patients with chronic prostatitis/chronic pelvic pain syndrome and infertile men: a preliminary investigation.

The expressed prostatic secretions (EPSs) of men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), infertile men and normal men were subjected to microbiological study. EPSs were collected from the subjects, which included 26 normal men, 11 infertile patients and 51 CP/CPPS patients. DNA was extracted from each specimen, and the V3 regions of the 16S rRNA genes were amplified using universal bacterial primers. The results showed that the EPS 16S rRNA gene-positive rate in the CP/CPPS and infertile patients was much higher than in the normal men, but without any difference among the three patient groups. The denaturing gradient gel electrophoresis (DGGE) method was used to characterize the EPS bacterial community structure of the prostate fluid from patients with CP/CPPS or infertility issues. Principal component analysis (PCA) and partial least squares (PLS) analyses of PCR-DGGE profiles revealed that the EPS bacterial community structure differed among the three groups. Three bands were identified as the key factors responsible for the discrepancy between CP/CPPS patients and infertile patients (P<0.05). Two bands were identified as priority factors in the discrepancy of category IIIA and category IIIB prostatitis patients (P<0.05). According to this research, the ecological balance of the prostate and low urethra tract, when considered as a microenvironment, might play an important role in the maintenance of a healthy male reproductive tract.

Effect of seabuckthorn (Hippophae rhamnoides ssp. sinensis) leaf extract on the swimming endurance and exhaustive exercise-induced oxidative stress of rats.

BACKGROUND: Seabuckthorn (SBT) leaves have significant antioxidant, immunomodulatory and anti-inflammatory properties. The objective of this study was to assess the anti-fatigue, antioxidant and tissue-protective properties of aqueous lyophilised extracts of SBT dried leaves in the hearts of Wistar male rats undergoing exhaustive physical exercise. Doses of 50, 200 and 800 mg kg⁻¹ body weight (BW) day⁻¹ were given orally for 1 week. A week later the rats were forced to swim in barrels until they were exhausted. The times were noted to establish the effective dose of the extracts in rats. After establishing the effective dose, the rats were then sacrificed and assessed for various biochemical parameters. RESULTS: SBT leaf aqueous extracts (200 and 800 mg kg⁻¹ BW) markedly prolonged the swim time of rats. Supplementation with SBT leaf aqueous extracts helped reduce the exhaustive exercise-induced increase in malondialdehyde level and selenium-dependent glutathione peroxidase activity. Alanine aminotransferase and creatine kinase levels were lowered in the exhaustive exercise with SBT treatment group (E + SBT) compared with the exhaustive exercise group (E). CONCLUSION: The findings suggest that SBT leaf aqueous extract supplements can enhance exercise capacity and protect against oxidative damage caused by exhaustive exercise in rats.

Effects of cadmium exposure on lipid peroxidation and the antioxidant system in fourth-instar larvae of Propsilocerus akamusi (Diptera: Chironomidae) under laboratory conditions.

Enzymatic antioxidants such as selenium-dependent glutathione peroxidase (GPx), glutathione transferase (GST), glutathione reductase (GR), and superoxide dismutases (SOD), as well as the concentration of hydrogen peroxide (H2O2) and malondialdehyde (MDA, an indicator of lipid peroxidation) were determined to identify which antioxidant enzymes participate in the efficient scavenging of ROS generated upon exposure to high doses of Cd2+ in fourth-instar Propsilocerus akamusi (Tokuna) (Diptera: Chironomidae) larvae after 72-h exposure. A significant increase in MDA levels and a change in GR and GPx activities in the Cd(2+)-treated P. akamusi were observed. The MDA in 25.0 and 50.0 mmol/liter treatments was significantly higher than that of the control dose after 72 h exposure. GPx activity was significantly induced by Cd2+ exposure only in the 50.0-mmol/liter treatment with a 0.59-fold increase in the control. All doses of Cd2+ significantly suppressed GR activity compared with the findings for the control dose, with an inhibited rate up to 0.55-fold in the 25.0 mmol/liter Cd2+ treatment. SOD and GST activities were not altered. The results indicate that Cd2+ can induce oxidative stress as indicated by the changes in lipid peroxidation and antioxidant status. For P. akamusi, an increase in the dose that the threshold needed for defense (namely, MDA level and GPx activity) activation was achieved. From this, organisms can be hypothesized to enable cells to avoid oxidant stress up to a certain extent where damage is again measurable (higher Cd2+ concentration).

[Genetic diversity of different geographical populations of Oxya chinensis based on AFLP analysis].

In order to study the genetic diversity and genetic structure of populations, 7 populations of Oxya chinensis from 7 provinces (or cities) of China were analyzed using AFLP technique. A total of 336 reproducible bands were amplified with 7 primer combinations from 128 individuals. Two hundred and ninety-two bands (86.90%) were polymorphic. High genetic diversity was found among O. chinensis populations and Wanning population had higher genetic diversity than other populations. Mantel test (r=0.27, P=0.89) suggested that there was no significant association between genetic distance and geographic distance. Remarkable genetic differentiation was found among populations. Unweighted pair group method average (UPGMA) tree showed that the 7 O. chinensis populations were divided into 3 groups: Changping of Beijing, Tai-yuan of Shanxi and Jining of Shandong populations in the north; Hanzhong of Shaanxi, Changsha of Hunan and Laibin of Guangxi populations in the south; and Wanning of Hainan population. Principal component analysis indicated significant genetic differentiation of the north and the south populations and island and continent populations existed in the 7 O. chinensis populations because of geographic isolation.