Perturbations in lipid metabolism and gut microbiota composition precede cardiac dysfunction in a mouse model of thalassemia.

Cardiomyopathy is a major complication of thalassemia, yet the precise underlying molecular mechanisms remain unclear. We examined whether altered lipid metabolism is an early driving factor in the development of cardiomyopathy using the Th3/+ mouse model of thalassemia. At age 20 weeks, male and female Th3/+ mice manifested anemia and iron overload; however, only males displayed metabolic defects and altered cardiac function. Untargeted lipidomics indicated that the circulating levels of 35 lipid species were significantly altered in Th3/+ mice compared to wild-type controls: triglycerides (TGs) with saturated fatty acids (FAs; TG42:0 and TG44:0) were elevated, while TGs with unsaturated FAs (TG(18:2_20:5_18:2 and TG54:8)) were reduced. Similarly, phosphatidylcholines (PCs) with long chain FAs (palmitic (16:0) or oleic (18:1)) were increased, while PCs with polyunsaturated FAs decreased. Circulating PC(16:0_14:0), GlcCer(d18:1/24:0) correlated significantly with iron overload and cardiac hypertrophy. 16S rRNA gene profiling revealed alterations in the intestinal microbiota of Th3/+ mice. Differentially abundant bacterial genera correlated with PC(39:6), PC(18:1_22:6), GlcCer(d18:1/24:1) and CE(14:0). These results provide new knowledge on perturbations in lipid metabolism and the gut microbiota of Th3/+ mice and identify specific factors which may represent early biomarkers or therapeutic targets to prevent development of cardiomyopathy in ß-thalassemia.

Gnotobiotic mice housing conditions critically influence the phenotype associated with transfer of faecal microbiota in a context of obesity.

OBJECTIVE: Faecal microbiota transplantation (FMT) in germ-free (GF) mice is a common approach to study the causal role of the gut microbiota in metabolic diseases. Lack of consideration of housing conditions post-FMT may contribute to study heterogeneity. We compared the impact of two housing strategies on the metabolic outcomes of GF mice colonised by gut microbiota from mice treated with a known gut modulator (cranberry proanthocyanidins (PAC)) or vehicle. DESIGN: High-fat high-sucrose diet-fed GF mice underwent FMT-PAC colonisation in sterile individual positive flow ventilated cages under rigorous housing conditions and then maintained for 8 weeks either in the gnotobiotic-axenic sector or in the specific pathogen free (SPF) sector of the same animal facility. RESULTS: Unexpectedly, 8 weeks after colonisation, we observed opposing liver phenotypes dependent on the housing environment of mice. Mice housed in the GF sector receiving the PAC gut microbiota showed a significant decrease in liver weight and hepatic triglyceride accumulation compared with control group. Conversely, exacerbated liver steatosis was observed in the FMT-PAC mice housed in the SPF sector. These phenotypic differences were associated with housing-specific profiles of colonising bacterial in the gut and of faecal metabolites. CONCLUSION: These results suggest that the housing environment in which gnotobiotic mice are maintained post-FMT strongly influences gut microbiota composition and function and can lead to distinctive phenotypes in recipient mice. Better standardisation of FMT experiments is needed to ensure reproducible and translatable results.

The metabolic benefits of substituting sucrose for maple syrup are associated with a shift in carbohydrate digestion and gut microbiota composition in high-fat high-sucrose diet-fed mice.

Overconsumption of added sugars is now largely recognized as a major culprit in the global situation of obesity and metabolic disorders. Previous animal studies reported that maple syrup (MS) is less deleterious than refined sugars on glucose metabolism and hepatic health, but the mechanisms remain poorly studied. Beyond its content in sucrose, MS is a natural sweetener containing several bioactive compounds, such as polyphenols and inulin, which are potential gut microbiota modifiers. We aimed to investigate the impact of MS on metabolic health and gut microbiota in male C57Bl/6J mice fed a high-fat high-sucrose (HFHS + S) diet or an isocaloric HFHS diet in which a fraction (10% of the total caloric intake) of the sucrose was substituted by MS (HFHS + MS). Insulin and glucose tolerance tests were performed at 5 and 7 wk into the diet, respectively. The fecal microbiota was analyzed by whole-genome shotgun sequencing. Liver lipids and inflammation were determined, and hepatic gene expression was assessed by transcriptomic analysis. Maple syrup was less deleterious on insulin resistance and decreased liver steatosis compared with mice consuming sucrose. This could be explained by the decreased intestinal α-glucosidase activity, which is involved in carbohydrate digestion and absorption. Metagenomic shotgun sequencing analysis revealed that MS intake increased the abundance of Faecalibaculum rodentium, Romboutsia ilealis, and Lactobacillus johnsonii, which all possess gene clusters involved in carbohydrate metabolism, such as sucrose utilization and butyric acid production. Liver transcriptomic analyses revealed that the cytochrome P450 (Cyp450) epoxygenase pathway was differently modulated between HFHS + S- and HFHS + MS-fed mice. These results show that substituting sucrose for MS alleviated dysmetabolism in diet-induced obese mice, which were associated with decreased carbohydrate digestion and shifting gut microbiota.NEW & NOTEWORTHY The natural sweetener maple syrup has sparked much interest as an alternative to refined sugars. This study aimed to investigate whether the metabolic benefits of substituting sucrose with an equivalent dose of maple syrup could be linked to changes in gut microbiota composition and digestion of carbohydrates in obese mice. We demonstrated that maple syrup is less detrimental than sucrose on metabolic health and possesses a prebiotic-like activity through novel gut microbiota and liver mechanisms.

Hypoabsorptive surgeries cause limb-dependent changes in the gut endocannabinoidome and microbiome in association with beneficial metabolic effects.

OBJECTIVE: To determine whether the metabolic benefits of hypoabsorptive surgeries are associated with changes in the gut endocannabinoidome (eCBome) and microbiome. METHODS: Biliopancreatic diversion with duodenal switch (BPD-DS) and single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) were performed in diet-induced obese (DIO) male Wistar rats. Control groups fed a high-fat diet (HF) included sham-operated (SHAM HF) and SHAM HF-pair-weighed to BPD-DS (SHAM HF-PW). Body weight, fat mass gain, fecal energy loss, HOMA-IR, and gut-secreted hormone levels were measured. The levels of eCBome lipid mediators and prostaglandins were quantified in different intestinal segments by LC-MS/MS, while expression levels of genes encoding eCBome metabolic enzymes and receptors were determined by RT-qPCR. Metataxonomic (16S rRNA) analysis was performed on residual distal jejunum, proximal jejunum, and ileum contents. RESULTS: BPD-DS and SADI-S reduced fat gain and HOMA-IR, while increasing glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) levels in HF-fed rats. Both surgeries induced potent limb-dependent alterations in eCBome mediators and in gut microbial ecology. In response to BPD-DS and SADI-S, changes in gut microbiota were significantly correlated with those of eCBome mediators. Principal component analyses revealed connections between PYY, N-oleoylethanolamine (OEA), N-linoleoylethanolamine (LEA), Clostridium, and Enterobacteriaceae_g_2 in the proximal and distal jejunum and in the ileum. CONCLUSIONS: BPD-DS and SADI-S caused limb-dependent changes in the gut eCBome and microbiome. The present results indicate that these variables could significantly influence the beneficial metabolic outcome of hypoabsorptive bariatric surgeries.

Probiotic Supplementation, Hepatic Fibrosis, and the Microbiota Profile in Patients with Nonalcoholic Steatohepatitis: A Randomized Controlled Trial.

BACKGROUND: Promising results in improvement of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis (NASH) have been identified following probiotic (PRO) treatment. OBJECTIVES: To evaluate PRO supplementation on hepatic fibrosis, inflammatory and metabolic markers, and gut microbiota in NASH patients. METHODS: In a double-blind, placebo-controlled clinical trial, 48 patients with NASH with a median age of 58 y and median BMI of 32.7 kg/m2 were randomly assigned to receive PROs (Lactobacillus acidophilus 1 × 109 colony forming units and Bifidobacterium lactis 1 × 109 colony forming units) or a placebo daily for 6 mo. Serum aminotransferases, total cholesterol and fractions, C-reactive protein, ferritin, interleukin-6, tumor necrosis factor-α, monocyte chemoattractant protein-1, and leptin were assessed. To evaluate liver fibrosis, Fibromax was used. In addition, 16S rRNA gene-based analysis was performed to evaluate gut microbiota composition. All assessments were performed at baseline and after 6 mo. For the assessment of outcomes after treatment, mixed generalized linear models were used to evaluate the main effects of the group-moment interaction. For multiple comparisons, Bonferroni correction was applied (α = 0.05/4 = 0.0125). Results for the outcomes are presented as mean and SE. RESULTS: The AST to Platelet Ratio Index (APRI) score was the primary outcome that decreased over time in the PRO group. Aspartate aminotransferase presented a statistically significant result in the group-moment interaction analyses, but no statistical significance was found after the Bonferroni correction. Liver fibrosis, steatosis, and inflammatory activity presented no statistically significant differences between the groups. No major shifts in gut microbiota composition were identified between groups after PRO treatment. CONCLUSIONS: Patients with NASH who received PRO supplementation for 6 mo presented improvement in the APRI score after treatment. These results draw attention to clinical practice and suggest that supplementation with PROs alone is not sufficient to improve enzymatic liver markers, inflammatory parameters, and gut microbiota in patients with NASH. This trial was registered at clinicaltrials.gov as NCT02764047.

Consistent gut bacterial and short-chain fatty acid signatures in hypoabsorptive bariatric surgeries correlate with metabolic benefits in rats.

OBJECTIVE: The study aimed at comparing how changes in the gut microbiota are associated to the beneficial effects of the most clinically efficient hypoabsorptive bariatric procedures, namely Roux-en-Y gastric bypass (RYGB), biliopancreatic diversion with duodenal switch (BPD-DS) and single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S). METHODS: Diet-induced obese (DIO) male Wistar rats were divided into seven groups. In addition to the groups subjected to RYGB, BPD-DS and SADI-S, the following four control groups were included: SHAM-operated rats fed a high-fat diet (SHAM HF), SHAM fed a low-fat diet (SHAM LF), SHAM HF-pair-weighed to BPD-DS (SHAM HF-PW) and sleeve-gastrectomy (SG) rats. Body weight, food intake, glucose tolerance, insulin sensitivity/resistance, and L-cell secretion were assessed. The gut microbiota (16 S ribosomal RNA gene sequencing) as well as the fecal and cæcal contents of short-chain fatty acids (SCFAs) were also analyzed prior to, and after the surgeries. RESULTS: The present study demonstrates the beneficial effect of RYGB, BPD-DS and SADI-S on fat mass gain and glucose metabolism in DIO rats. These benefits were proportional to the effect of the surgeries on food digestibility (BPD-DS > SADI-S > RYGB). Notably, hypoabsorptive surgeries led to consonant microbial signatures characterized by decreased abundance of the Ruminococcaceae (Oscillospira and Ruminococcus), Oscillospiraceae (Oscillibacter) and Christensenellaceae, and increased abundance of the Clostridiaceae (Clostridium), Sutterellaceae (Sutterella) and Enterobacteriaceae. The gut bacteria following hypoabsorptive surgeries were associated with higher fecal levels of propionate, butyrate, isobutyrate and isovalerate. Increases in the fecal SCFAs were in turn positively and strongly correlated with the levels of peptide tyrosine-tyrosine (PYY) and with the beneficial effects of the surgery. CONCLUSION: The present study emphasizes the consistency with which the three major hypoabsorptive bariatric procedures RYGB, BPD-DS and SADI-S create a gut microbial environment capable of producing a SCFA profile favorable to the secretion of PYY and to beneficial metabolic effects.

Dietary fat and low fiber in purified diets differently impact the gut-liver axis to promote obesity-linked metabolic impairments.

Selecting the most relevant control diet is of critical importance for metabolic and intestinal studies in animal models. Chow and LF-purified diet differentially impact metabolic and gut microbiome outcomes resulting in major changes in intestinal integrity in LF-fed animals which contributes to altering metabolic homeostasis. Dietary fat and low fiber both contribute to the deleterious metabolic effect of purified HF diets through both selective and overlapping mechanisms.

The Concentration of Organic Acids in Cranberry Juice Modulates the Gut Microbiota in Mice.

A daily consumption of cranberry juice (CJ) is linked to many beneficial health effects due to its richness in polyphenols but could also awake some intestinal discomforts due to its organic acid content and possibly lead to intestinal inflammation. Additionally, the impact of such a juice on the gut microbiota is still unknown. Thus, this study aimed to determine the impacts of a daily consumption of CJ and its successive deacidification on the intestinal inflammation and on the gut microbiota in mice. Four deacidified CJs (DCJs) (deacidification rates of 0, 40, 60, and 80%) were produced by electrodialysis with bipolar membrane (EDBM) and administered to C57BL/6J mice for four weeks, while the diet (CHOW) and the water were ad libitum. Different parameters were measured to determine intestinal inflammation when the gut microbiota was profiled. Treatment with a 0% DCJ did not induce intestinal inflammation but increased the gut microbiota diversity and induced a modulation of its functions in comparison with control (water). The effect of the removal of the organic acid content of CJ on the decrease of intestinal inflammation could not be observed. However, deacidification by EDBM of CJ induced an additional increase, in comparison with a 0% DCJ, in the Lachnospiraceae family which have beneficial effects and functions associated with protection of the intestine: the lower the organic acid content, the more bacteria of the Lachnospiraceae family and functions having a positive impact on the gut microbiota.

Blueberry proanthocyanidins and anthocyanins improve metabolic health through a gut microbiota-dependent mechanism in diet-induced obese mice.

Blueberry consumption can prevent obesity-linked metabolic diseases, and it has been proposed that the polyphenol content of blueberries may contribute to these effects. Polyphenols have been shown to favorably impact metabolic health, but the role of specific polyphenol classes and whether the gut microbiota is linked to these effects remain unclear. We aimed to evaluate the impact of whole blueberry powder and blueberry polyphenols on the development of obesity and insulin resistance and to determine the potential role of gut microbes in these effects by using fecal microbiota transplantation (FMT). Sixty-eight C57BL/6 male mice were assigned to one of the following diets for 12 wk: balanced diet (Chow); high-fat, high-sucrose diet (HFHS); or HFHS supplemented with whole blueberry powder (BB), anthocyanidin (ANT)-rich extract, or proanthocyanidin (PAC)-rich extract. After 8 wk, mice were housed in metabolic cages, and an oral glucose tolerance test (OGTT) was performed. Sixty germ-free mice fed HFHS diet received FMT from one of the above groups biweekly for 8 wk, followed by an OGTT. PAC-treated mice were leaner than HFHS controls although they had the same energy intake and were more physically active. This observation was reproduced in germ-free mice receiving FMT from PAC-treated mice. PAC- and ANT-treated mice showed improved insulin responses during OGTT, and this finding was also reproduced in germ-free mice following FMT. These results show that blueberry PAC and ANT polyphenols can reduce diet-induced body weight and improve insulin sensitivity and that at least part of these beneficial effects are explained by modulation of the gut microbiota.

In vivo screening of multiple bacterial strains identifies Lactobacillus rhamnosus Lb102 and Bifidobacterium animalis ssp. lactis Bf141 as probiotics that improve metabolic disorders in a mouse model of obesity.

Given the growing evidence that gut dysfunction, including changes in gut microbiota composition, plays a critical role in the development of inflammation and metabolic diseases, the identification of novel probiotic bacteria with immunometabolic properties has recently attracted more attention. Herein, bacterial strains were first isolated from dairy products and human feces and then screened in vitro for their immunomodulatory activity. Five selected strains were further analyzed in vivo, using a mouse model of diet-induced obesity. C57BL/6 mice were fed a high-fat high-sucrose diet, in combination with 1 of 3 Lactobacillus strains (Lb38, L. plantarum; L79, L. paracasei/casei; Lb102, L. rhamnosus) or Bifidobacterium strains (Bf26, Bf141, 2 different strains of B. animalis ssp. lactis species) administered for 8 wk at 109 colony-forming units/d. Whereas 3 strains showed only modest (Lb38, Bf26) or no (L79) effects, Lb102 and Bf141 reduced diet-induced obesity, visceral fat accretion, and inflammation, concomitant with improvement of glucose tolerance and insulin sensitivity. Further analysis revealed that Lb102 and Bf141 enhanced intestinal integrity markers in association with selective changes in gut microbiota composition. We have thus identified 2 new potential probiotic bacterial strains with immunometabolic properties to alleviate obesity development and associated metabolic disturbances.-Le Barz, M., Daniel, N., Varin, T. V., Naimi, S., Demers-Mathieu, V., Pilon, G., Audy, J., Laurin, E., Roy, D., Urdaci, M. C., St-Gelais, D., Fliss, I, Marette, A. In vivo screening of multiple bacterial strains identifies Lactobacillus rhamnosus Lb102 and Bifidobacterium animalis ssp. lactis Bf141 as probiotics that improve metabolic disorders in a mouse model of obesity.

Treatment with camu camu (Myrciaria dubia) prevents obesity by altering the gut microbiota and increasing energy expenditure in diet-induced obese mice.

OBJECTIVE: The consumption of fruits is strongly associated with better health and higher bacterial diversity in the gut microbiota (GM). Camu camu (Myrciaria dubia) is an Amazonian fruit with a unique phytochemical profile, strong antioxidant potential and purported anti-inflammatory potential. DESIGN: By using metabolic tests coupled with 16S rRNA gene-based taxonomic profiling and faecal microbial transplantation (FMT), we have assessed the effect of a crude extract of camu camu (CC) on obesity and associated immunometabolic disorders in high fat/high sucrose (HFHS)-fed mice. RESULTS: Treatment of HFHS-fed mice with CC prevented weight gain, lowered fat accumulation and blunted metabolic inflammation and endotoxaemia. CC-treated mice displayed improved glucose tolerance and insulin sensitivity and were also fully protected against hepatic steatosis. These effects were linked to increased energy expenditure and upregulation of uncoupling protein 1 mRNA expression in the brown adipose tissue (BAT) of CC-treated mice, which strongly correlated with the mRNA expression of the membrane bile acid (BA) receptor TGR5. Moreover, CC-treated mice showed altered plasma BA pool size and composition and drastic changes in the GM (eg, bloom of Akkermansia muciniphila and a strong reduction of Lactobacillus). Germ-free (GF) mice reconstituted with the GM of CC-treated mice gained less weight and displayed higher energy expenditure than GF-mice colonised with the FM of HFHS controls. CONCLUSION: Our results show that CC prevents visceral and liver fat deposition through BAT activation and increased energy expenditure, a mechanism that is dependent on the GM and linked to major changes in the BA pool size and composition.

Hepatitis C subtype distribution in chronically infected patients with mild liver fibrosis in France: the GEMHEP study.

Treatment options for Hepatitis C infection have greatly improved with direct-acting antiviral (DAA) combinations achieving high cure rates. Nevertheless, the cost of this treatment is still high and access to treatment in many countries has been preferentially reserved for patients with more severe fibrosis (F3 and F4). In this French nationwide study, we investigated the epidemiological characteristics and genotype distribution of hepatitis C virus (HCV) in treatment-naive patients with METAVIR fibrosis stages between F0 and F2 in order to identify patient profiles that became eligible for unrestricted treatment in a second period. Between 2015 and 2016 we collected data from nine French university hospitals on a total of 584 HCV positive patients with absent, mild or moderate liver fibrosis. The most represented genotypes were genotype 1b (159/584; 27.2%), followed by genotype 1a (150/584; 25.7%); genotype 3 (87/584: 14.9%); genotype 4 (80/584; 13.7%). Among genotype 4: 4a was predominantly encountered with 22 patients (27.5% of genotype 4). Genotypes 1b and 1a are currently the most frequent virus types present in treatment-naive patients with mild fibrosis in France. They can be readily cured using the available DAA. Nevertheless, non-a/non-d genotype 4 is also frequent in this population and clinical data on the efficacy of DAA on these subtypes is missing. The GEMHEP is the French group for study and evaluation of viral hepatitis on a national scale. Data collection on epidemiological and molecular aspects of viral hepatitis is performed on a regular basis in all main French teaching hospitals and serves as a basis for surveillance of these infections. Analysis and trends are regularly published on behalf of the GEMHEP group. Data collection was performed retrospectively over the 2015-2016 period, covering nine main university hospitals in France. A total of 584 hepatitis C positive patients were included in this study. Genotyping of the circulating viruses showed a high prevalence of genotypes 1b and 1a in our population. The epidemiology of hepatitis C is slowly changing in France, particularly as a consequence of the rise of 'non-a non-d' genotype 4 viruses mainly originating from African populations. More data concerning treatment efficacy of these genotypes is needed in order to guide clinical care.

Arctic berry extracts target the gut-liver axis to alleviate metabolic endotoxaemia, insulin resistance and hepatic steatosis in diet-induced obese mice.

AIMS/HYPOTHESIS: There is growing evidence that fruit polyphenols exert beneficial effects on the metabolic syndrome, but the underlying mechanisms remain poorly understood. In the present study, we aimed to analyse the effects of polyphenolic extracts from five types of Arctic berries in a model of diet-induced obesity. METHODS: Male C57BL/6 J mice were fed a high-fat/high-sucrose (HFHS) diet and orally treated with extracts of bog blueberry (BBE), cloudberry (CLE), crowberry (CRE), alpine bearberry (ABE), lingonberry (LGE) or vehicle (HFHS) for 8 weeks. An additional group of standard-chow-fed, vehicle-treated mice was included as a reference control for diet-induced obesity. OGTTs and insulin tolerance tests were conducted, and both plasma insulin and C-peptide were assessed throughout the OGTT. Quantitative PCR, western blot analysis and ELISAs were used to assess enterohepatic immunometabolic features. Faecal DNA was extracted and 16S rRNA gene-based analysis was used to profile the gut microbiota. RESULTS: Treatment with CLE, ABE and LGE, but not with BBE or CRE, prevented both fasting hyperinsulinaemia (mean ± SEM [pmol/l]: chow 67.2 ± 12.3, HFHS 153.9 ± 19.3, BBE 114.4 ± 14.3, CLE 82.5 ± 13.0, CRE 152.3 ± 24.4, ABE 90.6 ± 18.0, LGE 95.4 ± 10.5) and postprandial hyperinsulinaemia (mean ± SEM AUC [pmol/l × min]: chow 14.3 ± 1.4, HFHS 31.4 ± 3.1, BBE 27.2 ± 4.0, CLE 17.7 ± 2.2, CRE 32.6 ± 6.3, ABE 22.7 ± 18.0, LGE 23.9 ± 2.5). None of the berry extracts affected C-peptide levels or body weight gain. Levels of hepatic serine phosphorylated Akt were 1.6-, 1.5- and 1.2-fold higher with CLE, ABE and LGE treatment, respectively, and hepatic carcinoembryonic antigen-related cell adhesion molecule (CEACAM)-1 tyrosine phosphorylation was 0.6-, 0.7- and 0.9-fold increased in these mice vs vehicle-treated, HFHS-fed mice. These changes were associated with reduced liver triacylglycerol deposition, lower circulating endotoxins, alleviated hepatic and intestinal inflammation, and major gut microbial alterations (e.g. bloom of Akkermansia muciniphila, Turicibacter and Oscillibacter) in CLE-, ABE- and LGE-treated mice. CONCLUSIONS/INTERPRETATION: Our findings reveal novel mechanisms by which polyphenolic extracts from ABE, LGE and especially CLE target the gut-liver axis to protect diet-induced obese mice against metabolic endotoxaemia, insulin resistance and hepatic steatosis, which importantly improves hepatic insulin clearance. These results support the potential benefits of these Arctic berries and their integration into health programmes to help attenuate obesity-related chronic inflammation and metabolic disorders. DATA AVAILABILITY: All raw sequences have been deposited in the public European Nucleotide Archive server under accession number PRJEB19783 ( https://www.ebi.ac.uk/ena/data/view/PRJEB19783 ).

A polyphenol-rich cranberry extract protects from diet-induced obesity, insulin resistance and intestinal inflammation in association with increased Akkermansia spp. population in the gut microbiota of mice.

OBJECTIVE: The increasing prevalence of obesity and type 2 diabetes (T2D) demonstrates the failure of conventional treatments to curb these diseases. The gut microbiota has been put forward as a key player in the pathophysiology of diet-induced T2D. Importantly, cranberry (Vaccinium macrocarpon Aiton) is associated with a number of beneficial health effects. We aimed to investigate the metabolic impact of a cranberry extract (CE) on high fat/high sucrose (HFHS)-fed mice and to determine whether its consequent antidiabetic effects are related to modulations in the gut microbiota. DESIGN: C57BL/6J mice were fed either a chow or a HFHS diet. HFHS-fed mice were gavaged daily either with vehicle (water) or CE (200 mg/kg) for 8 weeks. The composition of the gut microbiota was assessed by analysing 16S rRNA gene sequences with 454 pyrosequencing. RESULTS: CE treatment was found to reduce HFHS-induced weight gain and visceral obesity. CE treatment also decreased liver weight and triglyceride accumulation in association with blunted hepatic oxidative stress and inflammation. CE administration improved insulin sensitivity, as revealed by improved insulin tolerance, lower homeostasis model assessment of insulin resistance and decreased glucose-induced hyperinsulinaemia during an oral glucose tolerance test. CE treatment was found to lower intestinal triglyceride content and to alleviate intestinal inflammation and oxidative stress. Interestingly, CE treatment markedly increased the proportion of the mucin-degrading bacterium Akkermansia in our metagenomic samples. CONCLUSIONS: CE exerts beneficial metabolic effects through improving HFHS diet-induced features of the metabolic syndrome, which is associated with a proportional increase in Akkermansia spp.

Definition of an HBsAg to DNA international unit conversion factor by enrichment of circulating hepatitis B virus forms.

Hepatitis B (HBV) virus infection is characterized by the overproduction of subviral particles (SVP) over infectious Dane particles (VP). Precise regulation of the ratio between these forms is unknown, but its fluctuation may have a clinical impact. An enrichment method was applied to assess the SVP/VP ratio in chronically infected patients (CHB) and to compare the sensitivity of HBs antigen (HBsAg) and DNA detection methods. Plasmas from 9 genotype A-D CHB patients were fractionated on Nycodenz(®) gradients, and both HBV DNA and HBsAg were quantified in each collected fraction using standardized techniques expressed in IU/mL. Infection of primary human hepatocytes (PHHs) was performed with crude or fractionated plasma. Independently of the genotype, all plasmas showed a similar rate-zonal separation profile characterized by a bottom DNA-enriched peak surmounted by HBsAg-enriched fractions. Inoculation of PHH with plasma-derived VP-enriched fractions led to long-lasting production of virus in cell supernatants with a SVP/VP ratio similar to that observed in patient plasmas. In the VP fraction, one IU of HBsAg corresponded to approximately 5 million IU of HBV DNA. Rate-zonal gradient separation directly applied on patient plasma allows a better insight into the distribution of VP in HBeAg-positive CHB carriers. This study highlights the sensitivity difference of the techniques classically used to monitor HBV infection and indicates that VP-associated HBsAg contributes modestly to the overall amount of total circulating HBsAg in CHB. Such a fractionation approach should help to understand the fine regulation of HBsAg production over replication at different stages of CHB.

Peg-IFNα/ribavirin/protease inhibitor combination in hepatitis C virus associated mixed cryoglobulinemia vasculitis: results at week 24.

BACKGROUND: The standard-of-care treatment of patients with hepatitis C virus (HCV)-mixed cryoglobulinemia (MC) vasculitis includes pegylated interferon α (PegIFN)-α plus ribavirin and/or rituximab. About 30-40% of patients are non-responders or relapsers to such combination. OBJECTIVE: To analyse the safety and efficacy of Peg-IFNα/ribavirin/protease inhibitor combination in HCV-MC vasculitis. PATIENTS AND METHODS: Open-label, prospective, cohort study including 23 patients with HCV-MC vasculitis. Peg-IFNα/ribavirin was associated to telaprevir (375 mg three times daily, for 12 weeks, (n=15)) or boceprevir (800 mg three times daily, for 44 weeks, (n=8)) for 48 weeks. RESULTS: The median age was 59 (52.5-66) years, with 48.8% women. Thirteen patients (56.5%) were complete clinical responders, and 10 (43.5%) were partial responders at week 24. The virological response (ie, HCV RNA negativation) was of 69.6% at week 24 (p=0.005). The cryoglobulin level decreased from 0.44 to 0.06 g/l (p=0.0006) and the C4 level increased from 0.09 to 0.15 g/l (p=0.045). Grades 3 and 4 adverse events (mainly anaemia, neutropenia and thrombocytopenia) were observed in 10 cases (43.5%). Twenty patients (87%) received erythropoietin, 9 (39.1%) had red cell transfusion, and 2 (8.7%) had granulocyte stimulating agents. Antiviral therapy discontinuation was required in 8 (34.7%) patients for virological non-response (n=5), virological relapse (n=2) and depression (n=1). CONCLUSIONS: Peg-IFNα/ribavirin/protease inhibitor combination seems highly effective in HCV-MC. Such therapeutic regimen should be administered cautiously considering the high rate of side effects.

Rebaudioside D decreases adiposity and hepatic lipid accumulation in a mouse model of obesity.

Overconsumption of added sugars has been pointed out as a major culprit in the increasing rates of obesity worldwide, contributing to the rising popularity of non-caloric sweeteners. In order to satisfy the growing demand, industrial efforts have been made to purify the sweet-tasting molecules found in the natural sweetener stevia, which are characterized by a sweet taste free of unpleasant aftertaste. Although the use of artificial sweeteners has raised many concerns regarding metabolic health, the impact of purified stevia components on the latter remains poorly studied. The objective of this project was to evaluate the impact of two purified sweet-tasting components of stevia, rebaudioside A and D (RebA and RebD), on the development of obesity, insulin resistance, hepatic health, bile acid profile, and gut microbiota in a mouse model of diet-induced obesity. Male C57BL/6 J mice were fed an obesogenic high-fat/high-sucrose (HFHS) diet and orally treated with 50 mg/kg of RebA, RebD or vehicle (water) for 12 weeks. An additional group of chow-fed mice treated with the vehicle was included as a healthy reference. At weeks 10 and 12, insulin and oral glucose tolerance tests were performed. Liver lipids content was analyzed. Whole-genome shotgun sequencing was performed to profile the gut microbiota. Bile acids were measured in the feces, plasma, and liver. Liver lipid content and gene expression were analyzed. As compared to the HFHS-vehicle treatment group, mice administered RebD showed a reduced weight gain, as evidenced by decreased visceral adipose tissue weight. Liver triglycerides and cholesterol from RebD-treated mice were lower and lipid peroxidation was decreased. Interestingly, administration of RebD was associated with a significant enrichment of Faecalibaculum rodentium in the gut microbiota and an increased secondary bile acid metabolism. Moreover, RebD decreased the level of lipopolysaccharide-binding protein (LBP). Neither RebA nor RebD treatments were found to impact glucose homeostasis. The daily consumption of two stevia components has no detrimental effects on metabolic health. In contrast, RebD treatment was found to reduce adiposity, alleviate hepatic steatosis and lipid peroxidation, and decrease LBP, a marker of metabolic endotoxemia in a mouse model of diet-induced obesity.

The gut microbiome-prostate cancer crosstalk is modulated by dietary polyunsaturated long-chain fatty acids.

The gut microbiota modulates response to hormonal treatments in prostate cancer (PCa) patients, but whether it influences PCa progression remains unknown. Here, we show a reduction in fecal microbiota alpha-diversity correlating with increase tumour burden in two distinct groups of hormonotherapy naïve PCa patients and three murine PCa models. Fecal microbiota transplantation (FMT) from patients with high PCa volume is sufficient to stimulate the growth of mouse PCa revealing the existence of a gut microbiome-cancer crosstalk. Analysis of gut microbial-related pathways in mice with aggressive PCa identifies three enzymes responsible for the metabolism of long-chain fatty acids (LCFA). Supplementation with LCFA omega-3 MAG-EPA is sufficient to reduce PCa growth in mice and cancer up-grading in pre-prostatectomy PCa patients correlating with a reduction of gut Ruminococcaceae in both and fecal butyrate levels in PCa patients. This suggests that the beneficial effect of omega-3 rich diet is mediated in part by modulating the crosstalk between gut microbes and their metabolites in men with PCa.

Comparing Transgenic Production to Supplementation of ω-3 PUFA Reveals Distinct But Overlapping Mechanisms Underlying Protection Against Metabolic and Hepatic Disorders.

We compared endogenous ω-3 PUFA production to supplementation for improving obesity-related metabolic dysfunction. Fat-1 transgenic mice, who endogenously convert exogenous ω-6 to ω-3 PUFA, and wild-type littermates were fed a high-fat diet and a daily dose of either ω-3 or ω-6 PUFA-rich oil for 12 wk. The endogenous ω-3 PUFA production improved glucose intolerance and insulin resistance but not hepatic steatosis. Conversely, ω-3 PUFA supplementation fully prevented hepatic steatosis but failed to improve insulin resistance. Both models increased hepatic levels of ω-3 PUFA-containing 2-monoacylglycerol and N-acylethanolamine congeners, and reduced levels of ω-6 PUFA-derived endocannabinoids with ω-3 PUFA supplementation being more efficacious. Reduced hepatic lipid accumulation associated with the endocannabinoidome metabolites EPEA and DHEA, which was causally demonstrated by lower lipid accumulation in oleic acid-treated hepatic cells treated with these metabolites. While both models induced a significant fecal enrichment of the beneficial Allobaculum genus, mice supplemented with ω-3 PUFA displayed additional changes in the gut microbiota functions with a significant reduction of fecal levels of the proinflammatory molecules lipopolysaccharide and flagellin. Multiple-factor analysis identify that the metabolic improvements induced by ω-3 PUFAs were accompanied by a reduced production of the proinflammatory cytokine TNFα, and that ω-3 PUFA supplementation had a stronger effect on improving the hepatic fatty acid profile than endogenous ω-3 PUFA. While endogenous ω-3 PUFA production preferably improves glucose tolerance and insulin resistance, ω-3 PUFA intake appears to be required to elicit selective changes in hepatic endocannabinoidome signaling that are essential to alleviate high-fat diet-induced hepatic steatosis.

SARS-CoV-2 seroprevalence and antibodies persistence among health care workers after the first COVID-19 wave in nine hospitals in Western France.

OBJECTIVES: To estimate the SARS-CoV-2 IgG seroprevalence rate in healthcare workers (HCWs) from Western France after the first 2020 wave, its determinants and the kinetics of total SARS-CoV-2 antibodies. PATIENTS AND METHODS: Overall, 9,453 HCWs responded to a self-questionnaire and underwent a lateral flow immunoassay to assess SARS-CoV-2 IgG presence. For 72 HCWs who tested positive, total anti-nucleocapsid antibodies were assessed at day 0, 30, and 90. RESULTS: SARS-CoV-2 IgG seroprevalence rate was 1.06 % [0.86 %-1.27 %]. Factors associated with IgG presence were gender, performing upper respiratory tract samples, contact with HCWs or household members diagnosed with COVID-19. Total antibodies decreased between day 0 and day 90, with anosmia or ageusia, and were higher in HCWs older than 50 years. CONCLUSION: We reported a low prevalence rate of IgG and identified several risk factors associated with its presence and persistence of total antibodies. Additional studies are needed to confirm these observations.