Bacteroidetes Ratio Research Articles

Oral Administration of Latilactobacillus sakei ADM14 Improves Lipid Metabolism and Fecal Microbiota Profile Associated With Metabolic Dysfunction in a High-Fat Diet Mouse Model.

Effects of Latilactobacillus sakei ADM14 on changes in lipid metabolism and fecal microbiota composition were studied in high-fat diet (HFD) mouse model. The mice were divided into three groups: normal diet (ND), high-fat diet (HD), and HFD plus L. sakei ADM14 (HDA). Oral administration of L. sakei ADM14 daily for 10weeks decreased body weight gain, fat tissue mass, and liver weight in mice and reduced the size of histologically stained liver adipocytes. In addition, serum total cholesterol, triglycerides, and blood glucose decreased significantly. Latilactobacillus sakei ADM14 regulated the expression of genes related to lipid metabolism in epididymal adipose tissue and liver and induced changes in the composition of fecal microbiota, thereby improving energy harvests and changing metabolic disorder-related taxa. A significant decrease (p<0.05) in the Firmicutes to Bacteroidetes ratio was found in the HDA group compared to the HD group, particularly due to the difference in the relative abundance of the Bacteroidetes between the two groups over 10weeks. Differences in proportions of some taxa reported to have correlation with obesity were also found between HD and HDA groups. These results suggest that L. sakei ADM14 can have a positive effect on metabolic disorders such as obesity and fatty liver through effective regulation of host lipid metabolism and gut microbiota.

Long-term chronic exposure to di-(2-ethylhexyl)-phthalate induces obesity via disruption of host lipid metabolism and gut microbiota in mice

BackgroundNumerous epidemiological findings have shown that di-(2-ethylhexyl)-phthalate (DEHP), one of industrial plasticizers with endocrine-disrupting properties, positively contributes to high incidence of obesity. However, potential pathogenesis of dietary DEHP exposure-induced obesity remains largely unknown. MethodsChronic DEHP exposure at different doses (0.05 and 5 mg/kg body weight) to mice had been continuously lasted for 14 weeks through the diet. A combination of targeted quantitative metabolomics (LC/GC-MS) with global 1H NMR-based metabolic profiling to explore the effects of dietary DEHP exposure with different doses on host lipid metabolism of mice. Metagenomics (16S rRNA gene sequencing) was also employed to examine the alterations of gut microbiota composition in the cecal contents of mice after dietary DEHP exposure. ResultsDietary exposure to DEHP at both doses induced weight gain and hepatic lipogenesis of mice by promoting the uptake of fatty acids and disrupting phospholipids and choline metabolism. Dietary DEHP exposure altered the gut microbiota community with disruption of intestinal morphology and reduction of Firmicutes to Bacteroidetes ratio in the cecal contents of mice. Furthermore, DEHP exposure activated gut microbiota fermentation process producing excess short chain fatty acids of mice. ConclusionThese findings provide systematic evidence that long-term chronic DEHP exposure induces obesity through disruption of host lipid metabolism and gut microbiota in mice, which not only confirm the epidemiological results, but also expand our understanding of metabolic diseases caused by environmental pollutants exposure.

Gut Microbiome Composition and Metabolic Status Are Differently Affected by Early Exposure to Unhealthy Diets in a Rat Model

Childhood is a critical stage of development during which diet can have profound influence on the microbiota–host interactions, leading to potentially lifelong impacts. This study aimed to investigate whether the consumption of cafeteria diet (CAFD) and sugary drinks during early rat life alters the structure of the gut microbial community and the metabolic activity. Four-week-old male Wistar rats (n = 27) were fed a standard chow diet with ad libitum access to water (CD) or to sucrose solution (HSD), and a third group was fed with CAFD and a sucrose solution for 14 weeks. HSD and CAFD consumption induced alterations in Firmicutes to Bacteroidetes ratio, Proteobacteria, and Verrucomicrobia. HSD increased the abundance of Barnesiella, whereas CAFD induced a depletion of Saccharibacteria. CAFD increased total white adipose tissue (WAT) weight (p < 0.0005) compared to CD. When CAFD was compared to HSD, a significant difference was found only for retroperitoneal WAT (p < 0.0005). Unhealthy diet-fed groups presented higher glucose (p < 0.0005), total cholesterol and creatinine serum levels (p < 0.005) compared to the CD rats. Early-life consumption of HSD, and of CAFD even more so, can have long-lasting negative effects on metabolic function. The gut microbiota communities were distinctively perturbed by diet composition.

The Effect of Oxidative Stress on the Chicken Ovary: Involvement of Microbiota and Melatonin Interventions.

The poultry ovary is used as a classic model to study ovarian biology and ovarian cancer. Stress factors induced oxidative stress to cause follicle atresia, which may be a fundamental reason for the reduction in fertility in older laying hens or in aging women. In the present study, we set out to characterize the relationships between oxidative stress and ovarian function. Layers (62 weeks of age; BW = 1.42 ± 0.12 kg) were injected with tert-butyl hydroperoxide (tBHP) at 0 (CON) and 800 μmol/kg BW (oxidative stress group, OS) for 24 days and the role of melatonin (Mel) on tBHP-induced ovary oxidative stress was assessed through ovary culture in vitro. The OS (800 μmol/kg BW tert-butyl hydroperoxide) treatment decreased the reproduction performance and ovarian follicle numbers. OS decreased the expression of SIRT1 and increased the P53 and FoxO1 expression of the ovary. A decreased Firmicutes to Bacteroidetes ratio, enriched Marinifilaceae (family), Odoribacter (genus) and Bacteroides_plebeius (species) were observed in the cecum of the OS group. Using Mel in vitro enhanced the follicle numbers and decreased the ovary cell apoptosis induced by tBHP. In addition, it increased the expression of SIRT1 and decreased the P53 and FoxO1 expression. These findings indicated that oxidative stress could decrease the laying performance, ovarian function and influence gut microbiota and body metabolites in the layer model, while the melatonin exerts an amelioration the ovary oxidative stress through SIRT1-P53/FoxO1 pathway.

Maternal 3,3-Dimethyl-1-Butanol Therapy Protects Adult Male Rat Offspring against Hypertension Programmed by Perinatal TCDD Exposure.

Maternal exposure to environmental pollutants affects fetal development, which can result in hypertension in adulthood. Gut microbiota-derived metabolite trimethylamine (TMA), trimethylamine-N-oxide (TMAO), and short chain fatty acids (SCFAs) have been associated with hypertension. We tested a hypothesis that maternal 3,3-Dimethyl-1-butanol (DMB, a TMA inhibitor) therapy prevents 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure-induced hypertension in adult offspring relevant to alterations of gut microbiota-derived metabolites, the mediation of aryl hydrocarbon receptor (AHR) signaling, and the renin-angiotensin system (RAS). Pregnant Sprague-Dawley rats were given weekly oral dose of TCDD 200 ng/kg for four doses (T), 1% DMB in drinking water (D), TCDD + DMB (TD), or vehicle (C) in pregnancy and lactation periods. Male progeny (n = 8/group) were sacrificed at the age of 12 weeks. Perinatal TCDD exposure caused hypertension in adult male offspring coinciding with reduced α-diversity, increased the Firmicutes to Bacteroidetes ratio, less abundant beneficial bacteria, impaired SCFA receptors’ expression, the activation of AHR signaling, and the aberrant activation of the RAS. Treatment with DMB during pregnancy and lactation rescued hypertension induced by perinatal TCDD exposure. This was accompanied by reshaping gut microbiota, mediating TMA-TMAO metabolic pathway, increasing acetic acid and its receptors, and restoring the AHR and RAS pathway. Our data provide new insights into the therapeutic potential of DMB, a microbiome-based metabolite treatment, for the prevention of hypertension of developmental origins.

Treatment with a spore-based probiotic containing five strains of Bacillus induced changes in the metabolic activity and community composition of the gut microbiota in a SHIME® model of the human gastrointestinal system

MegaSporeBiotic™ is an oral, spore-based probiotic comprised of five Bacillus spp. (Bacillus indicus HU36, Bacillus subtilis HU58, Bacillus coagulans SC208, Bacillus licheniformis SL307, and Bacillus clausii SC109). The effects of MegaSporeBiotic™ on gut microbiota activity and community composition were evaluated for the first time using an in vitro model of the human gastrointestinal tract, the simulator of the human intestinal microbial ecosystem (SHIME®), under healthy conditions. Following a stabilization period and a control period (2 weeks each), the reactor feed was supplemented with daily MegaSporeBiotic™ for 3 weeks (treatment period). Changes in microbial community activity and composition between the control and treatment periods were evaluated for each colon compartment (ascending [AC], transverse [TC], and descending colon [DC]). Propionate levels increased significantly in the TC (week 2, P = 0.02; week 3, P = 0.0019) and DC (week 2, P = 0.03) with treatment while lactate levels significantly decreased in the TC (week 3, P = 0.03). Ammonium levels were significantly decreased during the final week of treatment (TC, P = 0.02; DC, P = 0.03). Overall, Akkermansia muciniphila, Bifidobacteria spp., and Firmicutes increased with treatment while Lactobacillus spp. and Bacteroidetes decreased. The Firmicutes:Bacteroidetes ratio increased with treatment in the AC compartment. MegaSporeProbiotic™ treatment resulted in changes in metabolism and increased bacterial diversity.

Lipocalin 2 Deficiency Restrains Aging-Related Reshaping of Gut Microbiota Structure and Metabolism.

Gut microbiota modulate age-associated changes in metabolism, innate immune responses, and cognitive function. However, the involvement of host factors in the regulation of age-dependent gut microbial structure and intestinal inflammation is largely unknown. Lipocalin 2 (Lcn2) has previously been identified as an adipocytokine and characterized as an important regulator of diet-induced obesity and inflammation. Previous studies have shown that Lcn2 plays a role in high fat diet-induced reshaping of gut microbiota and intestinal inflammation. However, the role of Lcn2 in the regulation of aging-related reshaping of gut microbiota is unclear. Herein, we demonstrate that fecal levels of Lcn2 are reduced during aging. Age reshaped gut microbiota composition in wild-type (WT) mice. Interestingly, Lcn2 deficiency diminished this effect of aging in Lcn2 knockout (LKO) mice, leading to decreased bacterial diversity and increased Firmicutes to Bacteroidetes (F to B) ratio. Specifically, we identified 16 bacteria at the family level that were differentially abundant between WT and LKO mice at old age. Several health-promoting bacteria, including SCFA-producing bacteria, were significantly less prevalent in old LKO mice compared to WT mice, indicating that Lcn2 deficiency shifts the aging-related gut microbial community towards an unhealthy population and lowers microbial butyrate production. Our results provide a line of evidence that Lcn2 plays a role in the control of aging-related reshaping of gut microbiota composition and metabolites.

A randomized double-blind placebo controlled pilot study of probiotics in adolescents with severe obesity.

The purpose of the study is to assess the effect of probiotic supplementation on gut microbiota and insulin resistance in adolescents with severe obesity. Through a randomized, double blind, placebo-controlled, 12-week pilot clinical trial, 15 adolescents with severe obesity received either an oral probiotic 'Visbiome®' (n = 8) or placebo (n = 7). Anthropometry, fasting glucose, insulin, hs-CRP and stool for microbiome and calprotectin were collected at baseline (week 0) and 12weeks after intervention. Among completers (n = 4 in each of the two groups), mean change in fasting glucose was significantly lower in the probiotic group (0 ± 4mg/dL) as compared to the placebo group (6.3 ± 1.7mg/dL) (p = 0.028). Gut microbial Firmicutes to Bacteroidetes (F/B) ratio had a greater decline from week 0 to week 12 in the probiotic group (mean 17.7 ± 25.1 to 2.39 ± 2.0, respectively) but was not statistically significant (p = 0.06) as compared to in the placebo group (mean 12.8 ± 18.2 to 6.9 ± 5.61, respectively) (p = 0.89). Weight and BMI (mean ± SD) trended to remain stable in the treatment group (-1.07 ± 6.1kg and -0.3 ± 2.2kg/m2 respectively) as compared to the placebo group (3.9 ± 5.1kg, 1.0 ± 1.6kg/m2) but was not significant (p = 0.12 for weight and 0.38 for BMI). No significant change in the fasting insulin, HOMA-IR, or serum and stool inflammatory markers were noted between the two groups (p > 0.05). One participant in the treatment arm reported adverse effects of gastrointestinal intolerance. Probiotic therapy with Visbiome® may improve the fasting glucose and possibly decrease the gut microbial F/B ratio as compared to placebo in adolescents with severe obesity. Future larger studies are required to confirm these findings.U.S. Clinical Trial Registry number: NCT03109587. The online version contains supplementary material available at 10.1007/s40200-021-00855-7.

Effects of Different Treatment Methods of Dried Citrus Peel (Chenpi) on Intestinal Microflora and Short-Chain Fatty Acids in Healthy Mice

Chenpi is a kind of dried citrus peel from Citrus reticulata, and it is often used as traditional Chinese medicine to treat dyspepsia and respiratory tract inflammation. In this study, to determine which way of chenpi treatment plays a better effect on the prevention of obesity in healthy mice, we conducted 16S ribosomal RNA (rRNA) gene sequencing for intestinal microbiota and gas chromatography-mass spectrometry detector (GC/MSD) analysis for short-chain fatty acids (SCFAs) of female rats fed with either chenpi decoction or chenpi powder-based diet (n = 10 per group) for 3 weeks. Chenpi powder (CP) group significantly reduced abdominal adipose tissues, subcutaneous adipose tissue, and the serum level of total triacylglycerol (TG). At a deeper level, chenpi powder has a better tendency to increase the ratio of Bacteroidetes to Firmicutes. It alters the Muribaculaceae and Muribaculum in intestinal microbiota, though it is not significant. The concentrations of acetic acid, valeric acid, and butyric acid increased slightly but not significantly in the CP group. Chenpi decoction just reduced perirenal adipose tissues, but it shows better antioxidant activity. It has little effect on intestinal microbiota. No differences were found for SCFAs in the chenpi decoction (CD) group. The results indicated that chenpi powder has a better effect in preventing obesity in mice. It can provide a basis for the development of functional products related to chenpi powder.

Kaempferol Alleviates Murine Experimental Colitis by Restoring Gut Microbiota and Inhibiting the LPS-TLR4-NF-κB Axis.

Intestinal microbiota dysbiosis is an established characteristic of ulcerative colitis (UC). Regulating the gut microbiota is an attractive alternative UC treatment strategy, considering the potential adverse effects of synthetic drugs used to treat UC. Kaempferol (Kae) is an anti-inflammatory and antioxidant flavonoid derived from a variety of medicinal plants. In this study, we determined the efficacy and mechanism of action of Kae as an anti-UC agent in dextran sulfate sodium (DSS)-induced colitis mice. DSS challenge in a mouse model of UC led to weight loss, diarrhea accompanied by mucous and blood, histological abnormalities, and shortening of the colon, all of which were significantly alleviated by pretreatment with Kae. In addition, intestinal permeability was shown to improve using fluorescein isothiocyanate (FITC)–dextran administration. DSS-induced destruction of the intestinal barrier was also significantly prevented by Kae administration via increases in the levels of ZO-1, occludin, and claudin-1. Furthermore, Kae pretreatment decreased the levels of IL-1β, IL-6, and TNF-α and downregulated transcription of an array of inflammatory signaling molecules, while it increased IL-10 mRNA expression. Notably, Kae reshaped the intestinal microbiome by elevating the Firmicutes to Bacteroidetes ratio; increasing the linear discriminant analysis scores of beneficial bacteria, such as Prevotellaceae and Ruminococcaceae; and reducing the richness of Proteobacteria in DSS-challenged mice. There was also an evident shift in the profile of fecal metabolites in the Kae treatment group. Serum LPS levels and downstream TLR4-NF-κB signaling were downregulated by Kae supplementation. Moreover, fecal microbiota transplantation from Kae-treated mice to the DSS-induced mice confirmed the effects of Kae on modulating the gut microbiota to alleviate UC. Therefore, Kae may exert protective effects against colitis mice through regulating the gut microbiota and TLR4-related signaling pathways. This study demonstrates the anti-UC effects of Kae and its potential therapeutic mechanisms, and offers novel insights into the prevention of inflammatory diseases using natural products.

Assessing the relationship between the rumen microbiota and feed efficiency in Nellore steers

BackgroundRuminants rely upon a complex community of microbes in their rumen to convert host-indigestible feed into nutrients. However, little is known about the association between the rumen microbiota and feed efficiency traits in Nellore (Bos indicus) cattle, a breed of major economic importance to the global beef market. Here, we compare the composition of the bacterial, archaeal and fungal communities in the rumen of Nellore steers with high and low feed efficiency (FE) phenotypes, as measured by residual feed intake (RFI).ResultsThe Firmicutes to Bacteroidetes ratio was significantly higher (P < 0.05) in positive-RFI steers (p-RFI, low feed efficiency) than in negative-RFI (n-RFI, high feed efficiency) steers. The differences in bacterial composition from steers with high and low FE were mainly associated with members of the families Lachnospiraceae, Ruminococcaceae and Christensenellaceae, as well as the genus Prevotella. Archaeal community richness was lower (P < 0.05) in p-RFI than in n-RFI steers and the genus Methanobrevibacter was either increased or exclusive of p-RFI steers. The fungal genus Buwchfawromyces was more abundant in the rumen solid fraction of n-RFI steers (P < 0.05) and a highly abundant OTU belonging to the genus Piromyces was also increased in the rumen microbiota of high-efficiency steers. However, analysis of rumen fermentation variables and functional predictions indicated similar metabolic outputs for the microbiota of distinct FE groups.ConclusionsOur results demonstrate that differences in the ruminal microbiota of high and low FE Nellore steers comprise specific taxa from the bacterial, archaeal and fungal communities. Biomarker OTUs belonging to the genus Piromyces were identified in animals showing high feed efficiency, whereas among archaea, Methanobrevibacter was associated with steers classified as p-RFI. The identification of specific RFI-associated microorganisms in Nellore steers could guide further studies targeting the isolation and functional characterization of rumen microbes potentially important for the energy-harvesting efficiency of ruminants.

Influence of low FODMAP-gluten free diet on gut microbiota alterations and symptom severity in Iranian patients with irritable bowel syndrome

Background and objectiveRecently, dietary restriction of fermentable carbohydrates (a low-FODMAP diet) in combination with a gluten-free diet (GFD) has been proposed to reduce the symptoms in irritable bowel syndrome (IBS) patients. Different studies reported that IBS has been associated with dysbiosis in the gut microbiota. Additionally, a few studies have reported inflammation in the gastrointestinal (GI) system of adults with IBS. In this study, we aimed to investigate the effects of low FODMAP-gluten free diet (LF-GFD) on clinical symptoms, intestinal microbiota diversity, and fecal calprotectin (FC) level in Iranian patients with IBS.DesignIn this clinical trial study, 42 patients with IBS (Rome IV criteria) underwent LF-GFD intervention for 6 weeks. Symptoms were assessed using the IBS symptom severity scoring (IBS-SSS), and fecal samples were collected at baseline and after intervention and analyzed by quantitative 16 S rRNA PCR assay. The diversity of gut microbiota compared before and after 6 weeks of dietary intervention. FC was also analyzed by the ELISA method.ResultsThirty patients (mean age 37.8 ± 10.7 years) completed the 6-week diet. The IBS-SSS was significantly (P = 0.001) reduced after LF-GFD intervention compared to the baseline. Significant microbial differences before and after intervention were noticed in fecal samples. A significant increase was found in Bacteroidetes, and the Firmicutes to Bacteroidetes (F/B) ratio was significantly (P = 0.001) decreased after the dietary intervention. The value of FC was significantly decreased after 6 weeks of dietary intervention (P = 0.001).ConclusionsOur study suggests that patients with IBS under an LF-GFD had a significant improvement in IBS symptoms severity, with reduced FC level following normalization of their gut microbiota composition. Further rigorous trials are needed to establish a long-term efficacy and safety of this dietary intervention for personalized nutrition in IBS.Clinical Trial Registry Number: IRCT20100524004010N26.

Effects of Differences in Resistant Starch Content of Rice on Intestinal Microbial Composition.

The aim of this study was to evaluate the effects of resistant starch (RS) and fat levels on the gut microbiome in C57BL/6 mice. Three levels of RS from three varieties of rice were the major source of carbohydrates and fat levels were low (10%) and high (39%). We confirmed that RS decreased the Firmicutes to Bacteroidetes ratio, increased SCFA production by higher Bacteroidaceae and S24-7 abundance, and enriched predicted gene families of glycosidases and functional pathways associated with carbohydrate and glycan metabolism. We also found correlations between microbial taxa and tissue gene expression related to carbohydrate and lipid metabolism. Moreover, increasing RS levels resulted in a molecular ecological network with enhanced modularity and interspecific synergy, which is less sensitive to high fat intervention. Overall, RS as low as 0.44% from cooked rice can modulate gut microbiome in mice, which correlated to a protective effect against deleterious effects of an obesogenic diet.

Carbonate alkalinity and dietary protein levels affected growth performance, intestinal immune responses and intestinal microflora in Songpu mirror carp (Cyprinus carpio Songpu)

An eight week 3 × 2 two-factorial experiment was conducted to investigate the interaction between carbonate alkalinity levels at 0 and 15 mmol/L, and dietary protein levels at 310, 340 and 370 g/kg on the growth rate, digestive ability and the intestinal immunity, physical barrier function and microflora of Songpu mirror carp (Cyprinus carpio songpu). Fish at an initial average weight of 17.86 ± 0.19 g were randomly allotted to 18 aquariums each with 30 fish. Results revealed that weight gain rate (WGR) significantly decreased as carbonate alkalinity levels increased (p < 0.05), whereas the feed conversion ratio (FCR) of fish significantly increased (p < 0.05). Amylase activity in the intestine significantly decreased with increasing carbonate alkalinity levels (p < 0.05). A carbonate alkalinity of 15 mmol/L significantly reduced the superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) activities, elevated the malondialdehyde (MDA) contents in the intestine and hepatopancreas and decreased the contents of Complement 3 (C3), Complement (C4) and Ig M (p < 0.05). The relative expressions of occludin, claudin3, claudin7, myosin light chain kinase (MLCK) and interleukin 10 (IL-10) in the intestine were significantly down-regulated with increasing carbonate alkalinity levels (p < 0.05), whereas the relative expressions of interleukin 6 (IL-6), interleukin 8 (IL-8) and tumor necrosis factor (TNF-α) in the intestine were significantly up-regulated (p < 0.05). The Proteobacteria abundance significantly increased with increasing carbonate alkalinity level (p < 0.05). The WGR significantly decreased as dietary protein levels increased (p < 0.05). The MDA contents in intestine and hepatopancreas also showed a significant rise with increasing dietary protein levels (p < 0.05). Increments in dietary protein levels significantly reduced the C3 and C4 contents of fish intestine (p < 0.05). Fish in the 370 g/kg diet protein level group showed a significantly lower relative expression of occludin and TNF-α (p < 0.05). There was an effect on the C3 content, the relative expression of occludin, the abundance of Firmicutes and Firmicutes: Bacteroidetes ratio between carbonate alkalinity and dietary proteins over time (p < 0.05).In summary, under the long-term carbonate alkalinity stress of 15 mmol/L, dietary protein level for Songpu mirror carp should be controlled below 310 g/kg, which could effectively weaken the oxidative damage produced by carbonate alkalinity stress and further strengthen the growth and intestinal immune response of fish.

The Gut Microbiome of Heart Failure With Preserved Ejection Fraction

BackgroundRisk factors for heart failure with preserved ejection fraction (HFpEF) include hypertension, age, sex, and obesity. Emerging evidence suggests that the gut microbiota independently contributes to each one of these risk factors, potentially mediated via gut microbial‐derived metabolites such as short‐chain fatty acids. In this study, we determined whether the gut microbiota were associated with HFpEF and its risk factors.Methods and ResultsWe recruited 26 patients with HFpEF and 67 control participants from 2 independent communities. Patients with HFpEF were diagnosed by exercise right heart catheterization. We assessed the gut microbiome by bacterial 16S rRNA sequencing and food intake by the food frequency questionnaire. There was a significant difference in α‐diversity (eg, number of microbes) and β‐diversity (eg, type and abundance of microbes) between both cohorts of controls and patients with HFpEF (P=0.001). We did not find an association between β‐diversity and specific demographic or hemodynamic parameters or risk factors for HFpEF. The Firmicutes to Bacteroidetes ratio, a commonly used marker of gut dysbiosis, was lower, but not significantly so (P=0.093), in the patients with HFpEF. Compared with controls, the gut microbiome of patients with HFpEF was depleted of bacteria that are short‐chain fatty acid producers. Consistent with this, participants with HFpEF consumed less dietary fiber (17.6±7.7 versus 23.2±8.8 g/day; P=0.016).ConclusionsWe demonstrate key changes in the gut microbiota in patients with HFpEF, including the depletion of bacteria that generate metabolites known to be important for cardiovascular homeostasis. Further studies are required to validate the role of these gut microbiota and metabolites in the pathophysiology of HFpEF.

Abstract 2588: Oral administration of water extract from Euglena gracilis prevents lung carcinoma growth in mice by alteration of intestinal microbiota

Abstract Euglena gracilis, a single-celled alga, is rich in nutrients and thus, used as a nutritional dietary supplement. This alga can be found in both fresh and saltwater and possesses characteristics of both plants and animals. Euglena gracilis extracts have a wide range of medicinal properties including stimulation of anticancer immunity against multiple types of cancers; however, the anticancer mechanism has not yet been fully elucidated. Therefore, a water extract from Euglena gracilis devoid of water-insoluble mature paramylons was evaluated as an anticancer agent against lung carcinoma. Two different extracts were prepared using dried powder from whole Euglena gracilis. First, partially purified water extract (EWE) was prepared by suspending dry powder in PBS and centrifugation at 10,000g for 20 min followed by a filtration using a 0.22µm pore size membrane. Second, boiled EWE (bEWE) was prepared by immersing unfiltered EWE in boiling water for 12 min followed by centrifugation at 10,000g for 10 min and filtration using 0.22µm pore size membrane. Both EWE and bEWE treatments inhibited the growth of lung carcinoma cells in vitro in a dose- and time-dependent manner. Furthermore, both extracts significantly inhibited the three-dimensional growth of Lewis Lung Carcinoma (LLC) cells. Flow cytometry analysis showed that the EWE treatment attenuates granulocytic myeloid-derived suppressor cells (MDSCs) in bone marrow cell cultures. The in vivo study was conducted using a mouse LLC orthotopic allograft model. Oral administration of EWE and bEWE (100-200 mg/kg/day) three weeks prior to LLC cell inoculation attenuated the tumor growth in the lungs of immunocompetent mice while decreasing the peripheral granulocytes. However, this attenuation was not seen for the extract treatment initiated after LLC cell inoculation. The tumor growth attenuation was more efficient with the bEWE treatment than with EWE treatment. The fecal microbiomes of the mice were analyzed by 16s rRNA gene amplicon sequencing which revealed that alpha diversity in three groups (EWE, bEWE, and PBS control) was similar, however, the microbial compositions of the EWE- and bEWE-treated mouse groups were more diversified than in the PBS group. Specifically, an increase in the ratio of Bacteroidetes to Firmicutes was observed, and a significant increase in Akkermansia and Muribaculum was detected in EWE- and bEWE- treated mice compared to PBS treated mice. These studies suggest that oral administration of partially purified water extracts from Euglena gracilis altered the intestinal microbiome and the alteration may attenuate host MDSCs, thereby preventing lung carcinoma growth. This study was supported by 2016EUGLENA-RC1 (MT), 2017EUGLENA-RC2 (MT and JC), Kansas State University College of Veterinary Medicine SMILE award (MT and JC), and NIH grant P20 RR017686 (MT). Citation Format: Deepa Upreti, Susumu Ishiguro, Mayme Loyd, Nicole Robben, Paige Cote, Morgan Phillips, Ayaka Nakashima, Kengo Suzuki, Jeffrey Comer, Masaaki Tamura. Oral administration of water extract from Euglena gracilis prevents lung carcinoma growth in mice by alteration of intestinal microbiota [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2588.

How the Gut Microbiome Links to Menopause and Obesity, with Possible Implications for Endometrial Cancer Development.

Background: Interest is growing in the dynamic role of gut microbiome disturbances in human health and disease. No direct evidence is yet available to link gut microbiome dysbiosis to endometrial cancer. This review aims to understand any association between microbiome dysbiosis and important risk factors of endometrial cancer, high estrogen levels, postmenopause and obesity. Methods: A systematic search was performed with PubMed as primary database. Three separate searches were performed to identify all relevant studies. Results: Fifteen studies were identified as highly relevant and included in the review. Eight articles focused on the relationship with obesity and eight studies focused on the menopausal change or estrogen levels. Due to the heterogeneity in patient populations and outcome measures, no meta-analysis could be performed. Both the menopausal change and obesity were noted to enhance dysbiosis by reducing microbiome diversity and increasing the Firmicutes to Bacteroidetes ratio. Both also incurred estrobolome changes, leading to increased systemic estrogen levels, especially after menopause. Furthermore, microbiome dysbiosis was reported to be related to systemic inflammation through toll-like receptor signaling deficiencies and overexpression of pro-inflammatory cytokines. Conclusions: This review highlights that the female gut microbiome is intrinsically linked to estrogen levels, menopausal state and systemic inflammation, which indicates gut microbiome dysbiosis as a potential hallmark for risk stratification for endometrial cancer. Studies are needed to further define the role the gut microbiome plays in women at risk for endometrial cancer.

Effect of High-Fat Diet on the Intestinal Flora in Letrozole-Induced Polycystic Ovary Syndrome Rats.

Aim The aim of this study was to explore whether letrozole and high-fat diets (HFD) can induce obese insulin-resistant polycystic ovary syndrome (PCOS) with intestinal flora dysbiosis in a rat model. We compared the changes in the intestinal flora of letrozole-induced rats fed with HFD or normal chow, to explore the effects of HFD and letrozole independently and synergistically on the intestinal flora. Methods Five-week-old female Sprague Dawley (SD) rats were divided into four groups: control (C) group fed with regular diet; L1 group administered with letrozole and fed with regular diet; L2 group received letrozole and fed with HFD; and HFD group fed with HFD. At the end of the experiment, ovarian morphology, hormones, metabolism, oxidative stress, and inflammatory status of all rats were studied. 16S rDNA high-throughput sequencing was used to profile microbial communities, and various multivariate analysis approaches were used to quantitate microbial composition, abundance, and diversity. Results Compared to the C group, the increased plasma fasting insulin and glucose, HOMA-IR, triglyceride, testosterone, and malondialdehyde were significantly higher in the L2 group, while high-density lipoprotein cholesterol was significantly lower in the L1 group and L2 group. The indices of Chao1 and the Abundance-based Coverage Estimator (ACE) (α-diversity) in the L2 and HFD groups were significantly lower than that in the C group. Bray–Curtis dissimilarity based principal coordinate analysis (PCoA) plots and analysis of similarities (ANOSIM) test showed obvious separations between the L2 group and C group, between the HFD group and C group, and between the L2 and HFD groups. At the phylum level, Firmicutes and ratio of Firmicutes and Bacteroidetes (F/B ratio) were increased in the L2 group; Bacteroidetes was decreased in the L2 and HFD groups. No significant differences in bacterial abundance between the C group and L1 group were observed at the phylum level. Based on linear discriminant analysis (LDA) effect size (LEfSe) analysis, the bacterial genera (the relative abundance > 0.1%, LDA > 3, p < 0.05) were selected as candidate bacterial signatures. They showed that the abundance of Vibrio was significantly increased in the L1 group; Bacteroides and Phascolarctobacterium were enriched in the HFD group, and Bacteroides, Phascolarctobacterium, Blautia, Parabacteroides, Akkermansia [Ruminococcus]_torques_group, and Anaerotruncus were enriched in the L2 group. Conclusion The effect of letrozole on intestinal flora was not significant as HFD. HFD could destroy the balance of intestinal flora and aggravate the intestinal flora dysbiosis in PCOS. Letrozole-induced rats fed with HFD have many characteristics like human PCOS, including some metabolic disorders and intestinal flora dysbiosis. The dysbiosis was characterized by an increased Firmicutes/Bacteroidetes ratio, an expansion of Firmicutes, a contraction of Bacteroidetes, and the decreased microbial richness. Beta-diversity also showed significant differences in intestinal microflora, compared with control rats.

High-Fat Diet Induced Gut Microbiota Alterations Associating With Ghrelin/Jak2/Stat3 Up-Regulation to Promote Benign Prostatic Hyperplasia Development.

The role of high-fat diet (HFD) induced gut microbiota alteration and Ghrelin as well as their correlation in benign prostatic hyperplasia (BPH) were explored in our study. The gut microbiota was analyzed by 16s rRNA sequencing. Ghrelin levels in serum, along with Ghrelin and Ghrelin receptor in prostate tissue of mice and patients with BPH were measured. The effect of Ghrelin on cell proliferation, apoptosis, and induction of BPH in mice was explored. Our results indicated that BPH mice have the highest ratio of Firmicutes and Bacteroidetes induced by HFD, as well as Ghrelin level in serum and prostate tissue was significantly increased compared with control. Elevated Ghrelin content in the serum and prostate tissue of BPH patients was also observed. Ghrelin promotes cell proliferation while inhibiting cell apoptosis of prostate cells. The effect of Ghrelin on enlargement of the prostate was found almost equivalent to that of testosterone propionate (TP) which may be attenuated by Ghrelin receptor antagonist YIL-781. Ghrelin could up-regulate Jak2/pJak2/Stat3/pStat3 expression in vitro and in vivo. Our results suggested that Gut microbiota may associate with Ghrelin which plays an important role in activation of Jak2/Stat3 in BPH development. Gut microbiota and Ghrelin might be pathogenic factors for BPH and could be used as a target for mediation.

Effect of dark environment on intestinal flora and expression of genes related to liver metabolism in zebrafish (Danio rerio)

To explore the effects of dark environment on intestinal flora and expression of genes related to liver metabolism in zebrafish, a total of 60 zebrafish were fed for 21 days (24 h dark treatments or 14/10 h light/dark cycle), and the influence of dark environment on gut microbes and liver gene expression was studied using sequencing analysis of intestinal flora and liver. The results showed that the body weight of fish was significantly increased in the dark group than that in the control group (P < 0.05). Compared with the control group, dark environment treatment changed the composition of dominant flora, increased the abundance of unconventional bacteria and reduced probiotics in the intestine of zebrafish. Of these, the ratio of Bacteroidetes to Firmicutes in the intestine was reduced. The genome expression of the liver showed significant changes, and liver metabolites were also affected. Meanwhile, dark environment decreased gene expression associated with changes in blood glucose, lipid metabolism and immunization. Dark environment also caused liver steatosis as observed by histological study. This study shows that dark environment treatment has an important impact on liver metabolism and intestinal microbes in zebrafish.