Data on microRNA expression, predicted gene targets and pathway analysis in response to different concentrations of a cranberry proanthocyanidin-rich extract and its metabolite 3-(4-hydroxyphenyl)-propionic acid in intestinal Caco-2BBe1 cells.

Cranberry-derived proanthocyanidin (PAC) is processed by the gut microbiota to produce 3-(4-hydroxyphenyl)-propionic acid (HPPA), among other metabolites. These data are in support of the article entitled, "Cranberry proanthocyanidin and its microbial metabolite 3,4-dihydroxyphenylacetic acid, but not 3-(4-hydroxyphenyl)-propionic acid, partially reverse pro-inflammatory microRNA responses in human intestinal epithelial cells," published in Molecular Nutrition and Food Research [1]. Here we describe data generated by nCounterⓇ Human v3 miRNA Expression Panel of RNA obtained from Caco-2BBe1 cells exposed to two different concentrations of cranberry extract rich in PAC (50 µg/ml or 100 µg/ml) or 3-(4-hydroxyphenyl)-propionic acid (5 µg/ml or 10 µg/ml) for 24 h, then stimulated with 1 ng/ml of IL-1ß or not (mock) for three hours. The raw data are publicly available at the NCBI GEO database GSE237078. This work also includes descriptive methodological procedures, treatment-responsive microRNA (miRNA) expression profiles in Caco-2BBe1 cells, and in silico mRNA gene target and pathway enrichment analyses of significantly differentially expressed miRNAs (q < 0.001). Cranberry and its components have recognized health benefits, particularly in relation to combatting inflammation and pathogenic bacterial adhesion. These data will be valuable as a reference to study the response of intestinal cells to other polyphenol-rich food sources, analyze gut microbial responses to cranberry and its metabolites in different cell lines and mammalian hosts to elucidate individualized effects, and to delineate the role of the gut microbiota in facilitating the benefits of cranberry. Moreover, these data will aid in expanding our knowledge on the mechanisms underlying the benefits of cranberry and its components.

Links between gut microbiome, metabolome, clinical variables and non-alcoholic fatty liver disease severity in bariatric patients.

BACKGROUND AND AIMS: Bacterial species and microbial pathways along with metabolites and clinical parameters may interact to contribute to non-alcoholic fatty liver disease (NAFLD) and disease severity. We used integrated machine learning models and a cross-validation approach to assess this interaction in bariatric patients. METHODS: 113 patients undergoing bariatric surgery had clinical and biochemical parameters, blood and stool metabolite measurements as well as faecal shotgun metagenome sequencing to profile the intestinal microbiome. Liver histology was classified as normal liver obese (NLO; n = 30), simple steatosis (SS; n = 41) or non-alcoholic steatohepatitis (NASH; n = 42); fibrosis was graded F0 to F4. RESULTS: We found that those with NASH versus NLO had an increase in potentially harmful E. coli, a reduction of potentially beneficial Alistipes putredinis and an increase in ALT and AST. There was higher serum glucose, faecal 3-(3-hydroxyphenyl)-3-hydroxypropionic acid and faecal cholic acid and lower serum glycerophospholipids. In NAFLD, those with severe fibrosis (F3-F4) versus F0 had lower abundance of anti-inflammatory species (Eubacterium ventriosum, Alistipes finegoldii and Bacteroides dorei) and higher AST, serum glucose, faecal acylcarnitines, serum isoleucine and homocysteine as well as lower serum glycerophospholipids. Pathways involved with amino acid biosynthesis and degradation were significantly more represented in those with NASH compared to NLO, with severe fibrosis having an overall stronger significant association with Superpathway of menaquinol-10 biosynthesis and Peptidoglycan biosynthesis IV. CONCLUSIONS: In bariatric patients, NASH and severe fibrosis were associated with specific bacterial species, metabolic pathways and metabolites that may contribute to NAFLD pathogenesis and disease severity.

Cecal microbiota and mammary gland microRNA signatures are related and modifiable by dietary flaxseed with implications for breast cancer risk.

IMPORTANCE: Breast cancer is a leading cause of cancer mortality worldwide. There is a growing interest in using dietary approaches, including flaxseed (FS) and its oil and lignan components, to mitigate breast cancer risk. Importantly, there is recognition that pubertal processes and lifestyle, including diet, are important for breast health throughout life. Mechanisms remain incompletely understood. Our research uncovers a link between mammary gland miRNA expression and the gut microbiota in young female mice. We found that this relationship is modifiable via a dietary intervention. Using data from The Cancer Genome Atlas, we also show that the expression of miRNAs involved in these relationships is altered in breast cancer in humans. These findings highlight a role for the gut microbiome as a modulator, and thus a target, of interventions aiming at reducing breast cancer risk. They also provide foundational knowledge to explore the effects of early life interventions and mechanisms programming breast health.

Effect of faecal microbial transplant via colonoscopy in patients with severe obesity and insulin resistance: A randomized double-blind, placebo-controlled Phase 2 trial.

AIM: To assess the effects of faecal microbial transplant (FMT) from lean people to subjects with obesity via colonoscopy. MATERIAL AND METHODS: In a double-blind, randomized controlled trial, subjects with a body mass index ≥ 35 kg/m2 and insulin resistance were randomized, in a 1:1 ratio in blocks of four, to either allogenic (from healthy lean donor; n = 15) or autologous FMT (their own stool; n = 13) delivered in the caecum and were followed for 3 months. The main outcome was homeostatic model assessment of insulin resistance (HOMA-IR) and secondary outcomes were glycated haemoglobin levels, lipid profile, weight, gut hormones, endotoxin, appetite measures, intestinal microbiome (IM), metagenome, serum/faecal metabolites, quality of life, anxiety and depression scores. RESULTS: In the allogenic versus autologous groups, HOMA-IR and clinical variables did not change significantly, but IM and metabolites changed favourably (P < 0.05): at 1 month, Coprococcus, Bifidobacterium, Bacteroides and Roseburia increased, and Streptococcus decreased; at 3 months, Bacteroides and Blautia increased. Several species also changed significantly. For metabolites, at 1 month, serum kynurenine decreased and faecal indole acetic acid and butenylcarnitine increased, while at 3 months, serum isoleucine, leucine, decenoylcarnitine and faecal phenylacetic acid decreased. Metagenomic pathway representations and network analyses assessing relationships with clinical variables, metabolites and IM were significantly enhanced in the allogenic versus autologous groups. LDL and appetite measures improved in the allogenic (P < 0.05) but not in the autologous group. CONCLUSIONS: Overall, in those with obeisty, allogenic FMT via colonoscopy induced favourable changes in IM, metabolites, pathway representations and networks even though other metabolic variables did not change. LDL and appetite variables may also benefit.

MicroRNAs: A Link between Mammary Gland Development and Breast Cancer.

Breast cancer is among the most common cancers in women, second to skin cancer. Mammary gland development can influence breast cancer development in later life. Processes such as proliferation, invasion, and migration during mammary gland development can often mirror processes found in breast cancer. MicroRNAs (miRNAs), small, non-coding RNAs, can repress post-transcriptional RNA expression and can regulate up to 80% of all genes. Expression of miRNAs play a key role in mammary gland development, and aberrant expression can initiate or promote breast cancer. Here, we review the role of miRNAs in mammary development and breast cancer, and potential parallel roles. A total of 32 miRNAs were found to be expressed in both mammary gland development and breast cancer. These miRNAs are involved in proliferation, metastasis, invasion, and apoptosis in both processes. Some miRNAs were found to have contradictory roles, possibly due to their ability to target many genes at once. Investigation of miRNAs and their role in mammary gland development may inform about their role in breast cancer. In particular, by studying miRNA in development, mechanisms and potential targets for breast cancer treatment may be elucidated.

Data on mammary gland microRNAs expression, their predicted gene targets and corresponding pathway analysis in female mice receiving flaxseed or its oil and secoisolariciresinol diglucoside components.

Dietary flaxseed may act via microRNAs (miRNAs) to affect the health of the mammary gland. These data are in support of the article entitled "Effects of flaxseed and its components on mammary gland miRNome: identification of potential biomarkers to prevent breast cancer development" [1]. Here, we provide miRNA expression data obtained from NanoString nCounter® profiling of mammary gland RNA from C57BL/6 female mice who received a control diet or isocaloric diets containing 10% FS, 3.67% FSO, or 0.15% SDG for 21 days. The raw miRNA data were deposited at the NCBI Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE193847) under the accession number GSE193847. We also identified diet-associated miRNA-gene targets and corresponding enriched pathways. These data can be found at the HARVARD Dataverse (https://doi.org/10.7910/DVN/3ZNYES). These data will be valuable as a reference to understand the effects of FS versus its components and to study responses to these ingredients in hosts of different genetic backgrounds, sex and age. These data will contribute to future investigations regarding mechanisms underlying FS effects within the mammary gland.

Cranberry Proanthocyanidin and Its Microbial Metabolite 3,4-Dihydroxyphenylacetic Acid, but Not 3-(4-Hydroxyphenyl)-Propionic Acid, Partially Reverse Pro-Inflammatory microRNA Responses in Human Intestinal Epithelial Cells.

SCOPE: The molecular basis underlying the anti-inflammatory and anticarcinogenic properties of cranberries is incompletely understood. The effects of a cranberry proanthocyanidin-rich extract (PAC) and two of its gut microbial metabolites, 3,4-dihydroxyphenylacetic acid (DHPAA) and 3-(4-hydroxyphenyl)-propionic acid (HPPA), on intestinal epithelial cells microRNA (miRNA) expression and their downstream pathways at homeostasis and in inflammatory conditions, are investigated. METHODS AND RESULTS: The expression of 799 miRNAs is quantitatively assessed in differentiated Caco-2BBe1 cells pre-treated with PAC, DHPAA, or HPPA and stimulated with interleukin (IL)-1ß or not. PAC, DHPAA, and HPPA generate subsets of shared and distinct miRNA responses. At homeostasis, miRNAs affected by the metabolites, but not PAC, targeted genes enriched in kinase, Wnt, and growth factor signaling, cell growth and proliferation, apoptosis, and specific cancer pathways. In an inflammatory environment, PAC and DHPAA, but not HPPA, reverses the expression of 16 and two IL-1ß-induced miRNAs, respectively, regulating inflammatory and cancer pathways. CONCLUSION: miRNA modulation is a novel mechanism for PAC bioactivity in the gut. The gut microbiota may be necessary to unlock these effects at homeostasis and partially in inflammation.

Data on cecal and fecal microbiota and predicted metagenomes profiles of female mice receiving whole flaxseed or its oil and secoisolariciresinol diglucoside components.

Dietary flaxseed (FS) and its components including FS oil (FSO), secoisolariciresinol diglucoside (SDG) and fiber, are processed by the gut microbiota. These data are in support of the article entitled "Discriminatory and cooperative effects within the mouse gut microbiota in response to flaxseed and its oil and lignan components", Journal of Nutritional Biochemistry [1]. Here we describe data generated by 16S rRNA sequencing of DNA obtained from cecum contents and feces of C57BL/6 female mice fed either a basal diet (BD, AIN93G), or isocaloric diets containing 10% FS, or 10% FS-equivalent amounts of FSO or SDG for 21 days. These include bacterial community composition and inferred KEGG pathways; the raw data are publicly available at the NCBI SRA database (BioProject ID PRJNA683934). Furthermore, this work includes detailed experimentation procedures, total bacterial counts (qPCR) in the cecum content and feces, and correlation analysis between a selected bacterial genus, Bacteroides and a predicted metabolic pathway. FS is utilized worldwide, especially for the prevention and/or treatment of diseases including cardiovascular diseases, diabetes and cancer. These data will be valuable as a reference to study different FS cultivars and SDG- or FSO- enriched products on the gut microbiota, to study gut microbial responses to FS and its components in different mouse strains and mammalian hosts to elucidate individualized effects, and to understand the importance of the gut microbiota for FS benefits.

Discriminatory and cooperative effects within the mouse gut microbiota in response to flaxseed and its oil and lignan components.

Gut microbial processing of dietary flaxseed (FS) contributes to its health benefits, but the relative effects of its bioactive components (lignans, omega-3 fatty acids, fiber) on the microbiota are unclear. We investigated the gut microbial compositional and functional responses to whole FS and its isolated components, FS oil (FSO) and secoisolariciresinol diglucoside (SDG) (precursor to microbial-derived enterolignans) to help understand their contribution to whole FS benefits. Cecum content and fecal samples were collected from C57BL/6 female mice fed a basal diet (AIN93G) or isocaloric diets containing 10% FS or 10% FS-equivalent amounts of FSO or SDG for 21 days. Cecal and fecal microbiota composition and predicted genomic functions, and their relationship with serum enterolignans were evaluated. Only FS modified the community structure. Shared- and diet-specific enriched taxa and functions were identified. Carbohydrate and protein processing functions were enriched in FS mice, and there was a positive correlation between select enriched taxa, encompassing fiber degraders and SDG metabolizers, and serum enterolignans. This was not observed in mice receiving isolated FSO and SDG, suggesting that FS fiber supports SDG microbial metabolism. In conclusion, the cooperative activities of a diverse microbiota are necessary to process FS components and, when administered at the amount present in FS, these components may act together to affect SDG-derived enterolignans production. This has implications for the use of FS, FSO and SDG in clinical practice.

Effects of Flaxseed and Its Components on Mammary Gland MiRNome: Identification of Potential Biomarkers to Prevent Breast Cancer Development.

Breast cancer is the most common cancer among women worldwide. We previously showed that early-life exposure to flaxseed (FS) or its components, FS oil (FSO) and secoisolariciresinol diglucoside (SDG), affects the mammary gland (MG) and is associated with the reduction of breast cancer risk during adulthood. However, the underlying mechanisms are not understood. This study aimed to investigate the effect of FS, FSO, and SDG on the MG miRNA signature at a late stage of development. Female C57BL/6 mice, 4-5 weeks of age, were randomized into four groups to receive: (i) basal AIN-93G, (ii) 10% FS, (iii) 3.67% FSO, or (iv) 0.15% SDG. After 21 days, the mice were sacrificed and MG miRNAs were profiled. Diet-specific MG miRNA signatures were identified. Deregulated miRNAs were associated with breast cancer and targeted genes involved in MG development, growth, and cancer. The study allowed for the identification of potential biomarkers or novel therapeutic targets to prevent and/or reduce the risk of breast cancer.

Cancer-related gene expression is associated with disease severity and modifiable lifestyle factors in non-alcoholic fatty liver disease.

OBJECTIVE: The aim of this study was to determine whether hepatic gene expression related to hepatocellular carcinoma (HCC) is associated with disease severity and modifiable lifestyle factors in non-alcoholic fatty liver disease (NAFLD). METHODS: In a cross-sectional study, the associations between hepatic gene expression and liver histology, insulin resistance, anthropometrics, diet, and physical activity were assessed in patients with non-alcoholic steatohepatitis (NASH; n = 19) or simple steatosis (SS; n = 20). In a group of patients with NASH, we then conducted a 1-y, single-arm, pilot study using ω-3 polyunsaturated fatty acid (PUFA) supplementation to determine whether changes in hepatic PUFA content would have a modulating effect on hepatic gene expression and would affect liver histology. RESULTS: In the cross-sectional study, histological features of disease severity correlated with AKR1B10, ANXA2, PEG10, SPP1, STMN2, MT1A, and MT1B in NASH and with EEF1A2, PEG10, and SPP1 in SS. In addition, PEG10, SPP1, ANXA2, and STMN2 expression correlated positively with insulin resistance in NASH. SPP1 and UBD correlated strongly with body mass index in SS. Associations between ENPP2, AKR1B10, SPP1, UBD, and waist circumference depended on sex and diagnosis. Several genes correlated with protein, fat, or carbohydrate intake. PEG10 correlated positively with physical activity in NASH and inversely with plasma vitamin C in both groups. Despite increased erythrocyte and hepatic ω-3 PUFA, supplementation did not alter hepatic gene expression and liver histology. CONCLUSIONS: HCC-related gene expression was associated with liver histology, body mass index, waist circumference, diet, and physical activity but was not affected by ω-3 PUFA supplementation.

Research in nutritional supplements and nutraceuticals for health, physical activity, and performance: moving forward 1.

This Horizons is part of a series that identifies key, forward-thinking research questions and challenges that need to be addressed. Specifically, this Horizons paper discusses research in nutritional supplements and nutraceuticals for health, physical activity, and performance, and is the product of a discussion by an expert panel that took place in January 2018 prior to the Canadian Nutrition Society Thematic Conference "Advances in Sport Nutrition from Daily Living to High Performance Sport". The objective of this Horizons paper was to identify core considerations for future studies for this research area, and how scientists can be leaders in the field to ensure the best quality science is available for decision makers. It is strongly recommended that the various elements highlighted throughout this Horizons paper will increase the awareness of the significant before-, during-, and after-research due-diligence required to produce research of the highest quality. While it is recognized that many scientists will not be able to meet all of these aspects, it is nonetheless important to consider the points outlined and to recognize that those elements that are not met in studies may be significant limitations. Highlights Research questions that are hypothesis-driven are the strongest, and when combined with careful planning of the study, the result will often be of the best quality. Studies with a strong experimental design help discern between evidence-based findings and those that have not been substantiated.

Citrobacter rodentium alters the mouse colonic miRNome.

Citrobacter rodentium is a murine pathogen causing transmissible colonic hyperplasia and colitis with a pathogenic mechanism similar to foodborne enterohaemorrhagic Escherichia coli in humans. Mechanisms underlying intestinal responses to C. rodentium infection are incompletely understood. We identified 24 colonic microRNAs (miRNAs) as significantly deregulated in response to C. rodentium, including miR-7a, -17, -19a, -20a, -20b, -92a, -106a, -132, -200a, and -2137; most of these miRNAs belong to the oncogenic miR-17-92 clusters. Pathways involved in cell cycle, cancers, and immune responses were enriched among the predicted targets of these miRNAs. We further demonstrated that an apoptosis facilitator, Bim, is a candidate gene target of miRNA-mediated host response to the infection. These findings suggest that host miRNAs participate in C. rodentium pathogenesis and may represent novel treatment targets.

Altered hepatic genes related to retinol metabolism and plasma retinol in patients with non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD), especially non-alcoholic steatohepatitis (NASH) is a chronic liver disease commonly associated with hepatic fibrosis. NASH patients have an increased risk for hepatocellular carcinoma (HCC). An altered retinol metabolism is one of the pathways involved in the process of hepatic fibrosis, and enzymes involved in retinol metabolism have been associated with HCC. We aimed to determine the association between plasma retinol levels and hepatic expression of genes related to retinol metabolism, as well as to assess the hepatic expression of transcription factors regulated by retinoic acid in patients with NAFLD. Cross-sectional study where hepatic gene expression (Illumina microarray) and plasma retinol levels (HPLC) were measured in 17 patients with simple steatosis (SS), 15 with NASH, and 22 living liver donors (LD) as controls. Plasma retinol levels were higher in SS (1.53 ± 0.44 µmol/L) and NASH (1.51 ± 0.56 µmol/L) compared to LD (1.21 ± 0.38 µmol/L; p<0.05). AKR1B10 was highly overexpressed in NASH compared to SS (+6.2-fold) and LD (+9.9-fold; p = 4.89E-11). Retinaldehyde dehydrogenase 1 family, member A2 (ALDH1A2) and retinaldehyde dehydrogenase 1 family, member A3 (ALDH1A3), key enzymes for retinoic acid synthesis, were underexpressed in SS (-1.48 and -2.3-fold, respectively) and NASH (-1.47 and -2.6-fold, respectively) versus LD. In NASH, hepatic ALDH1A2 and ALDH1A3 were underexpressed and inversely correlated with plasma retinol levels, which may reduce retinoic acid in the liver. This, in addition to changes in expression of other genes involved in retinol metabolism, suggests a role for altered retinol homeostasis in NASH.

Markers of activated inflammatory cells are associated with disease severity and intestinal microbiota in adults with non­alcoholic fatty liver disease.

Several mechanisms contribute to the pathogenesis of non­alcoholic fatty liver disease (NAFLD). The intestinal microbiota (IM) and liver immune cells (LIC) may serve a role, but there has been no previous study assessing potential associations between IM and LIC. The aim of the present study was to investigate whether there are differences in LIC markers between patients with NAFLD and healthy controls (HC), and to determine whether these markers are associated with specific IM. The present prospective, cross­sectional study examined a cohort of adults with liver biopsy­confirmed NAFLD and HC. Clinical and laboratory data were collected. Fecal IM was assessed by quantitative polymerase chain reaction and LIC, by immunohistochemistry. NAFLD activity score (NAS) was used for disease severity. Liver immune cell counts were increased in patients with NAFLD (n=34) vs. HC (n=8) and this was associated with disease severity. Hematopoietic cell marker cluster of differentiation (CD)45+ and Kupffer cell marker CD163+ were higher in NAFLD compared with HC, and those with an NAS ≥5 had higher levels of CD20+ cells, a marker of B cells, vs. a NAS of 0 or 1­4. Additionally, from those patients (5 HC, 34 NAFLD), IM was measured. Specific immune cells in portal or lobular areas correlated with specific fecal IM, suggesting a potential association between IM and liver inflammation in patients with NAFLD. Specifically, Faecalibacterium prausnitzii was negatively correlated with CD45+ (r= ­0.394; P=0.015) and CD163+ (r= ­0.371; P=0.022) cells in the portal tract and Prevotella was negatively correlated with CD20+ (r= ­0.353; P=0.028) cells in the liver lobule. Other taxa exhibited no correlation. In conclusion, the present study demonstrated a potential association between IM and liver inflammation in NAFLD.

Omega-3 Polyunsaturated Fatty Acids Time-Dependently Reduce Cell Viability and Oncogenic MicroRNA-21 Expression in Estrogen Receptor-Positive Breast Cancer Cells (MCF-7).

The omega-3 polyunsaturated fatty acid (n-3 PUFA), α-linolenic acid (ALA), and its metabolites, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), independently reduce the growth of breast cancer cells in vitro, but the mechanisms, which may involve microRNA (miRNA), are still unclear. The expression of the oncomiR, miR-21, is reduced by DHA treatment, but the effects of ALA on miR-21, alone or combined with EPA and DHA under physiologically relevant concentrations, have not been investigated. The effects of ALA alone and +/-EPA and DHA at the blood molar ratios seen in either humans (1.0:1.0:2.5, ALA:EPA:DHA) or mice (1.0:0.4:3.1, ALA:EPA:DHA) post flaxseed oil consumption (containing ALA) were assessed in vitro in MCF-7 breast cancer cells. Cell viability and the expression of miR-21 and its molecular target, phosphatase and tension homolog (PTEN, gene and protein), at different time points, were examined. At 1, 3, 48 and 96 h ALA alone and 24 h animal ratio treatments significantly reduced MCF-7 cell viability, while 1 and 3 h ALA alone and human and animal ratio treatments all significantly reduced miR-21 expression, and 24 h animal ratio treatment reduced miR-21 expression; these effects were not associated with changes in PTEN gene or protein expressions. We showed for the first time that ALA alone or combined with EPA and DHA at levels seen in human and animal blood post-ALA consumption can significantly reduce cell viability and modulate miR-21 expression in a time- and concentration-dependent manner, with the animal ratio containing higher DHA having a greater effect. The time dependency of miR-21 effects suggests the significance of considering time as a variable in miRNA studies, particularly of miR-21.

Nonalcoholic fatty liver disease is associated with dysbiosis independent of body mass index and insulin resistance.

This study aimed to determine if there is an association between dysbiosis and nonalcoholic fatty liver disease (NAFLD) independent of obesity and insulin resistance (IR). This is a prospective cross-sectional study assessing the intestinal microbiome (IM) of 39 adults with biopsy-proven NAFLD (15 simple steatosis [SS]; 24 nonalcoholic steatohepatitis [NASH]) and 28 healthy controls (HC). IM composition (llumina MiSeq Platform) in NAFLD patients compared to HC were identified by two statistical methods (Metastats, Wilcoxon). Selected taxa was validated using quantitative PCR (qPCR). Metabolites in feces and serum were also analyzed. In NAFLD, 8 operational taxonomic units, 6 genera, 6 families and 2 phyla (Bacteroidetes, Firmicutes) were less abundant and; 1 genus (Lactobacillus) and 1 family (Lactobacillaceae) were more abundant compared to HC. Lower abundance in both NASH and SS patients compared to HC were confirmed by qPCR for Ruminococcus, Faecalibacterium prausnitzii and Coprococcus. No difference was found between NASH and SS. This lower abundance in NAFLD (NASH+SS) was independent of BMI and IR. NAFLD patients had higher concentrations of fecal propionate and isobutyric acid and serum 2-hydroxybutyrate and L-lactic acid. These findings suggest a potential role for a specific IM community and functional profile in the pathogenesis of NAFLD.

Bile Acids and Dysbiosis in Non-Alcoholic Fatty Liver Disease.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) is characterized by dysbiosis. The bidirectional effects between intestinal microbiota (IM) and bile acids (BA) suggest that dysbiosis may be accompanied by an altered bile acid (BA) homeostasis, which in turn can contribute to the metabolic dysregulation seen in NAFLD. This study sought to examine BA homeostasis in patients with NAFLD and to relate that with IM data. METHODS: This was a prospective, cross-sectional study of adults with biopsy-confirmed NAFLD (non-alcoholic fatty liver: NAFL or non-alcoholic steatohepatitis: NASH) and healthy controls (HC). Clinical and laboratory data, stool samples and 7-day food records were collected. Fecal BA profiles, serum markers of BA synthesis 7-alpha-hydroxy-4-cholesten-3-one (C4) and intestinal BA signalling, as well as IM composition were assessed. RESULTS: 53 subjects were included: 25 HC, 12 NAFL and 16 NASH. Levels of total fecal BA, cholic acid (CA), chenodeoxycholic acid (CDCA) and BA synthesis were higher in patients with NASH compared to HC (p<0.05 for all comparisons). The primary to secondary BA ratio was higher in NASH compared to HC (p = 0.004), but ratio of conjugated to unconjugated BAs was not different between the groups. Bacteroidetes and Clostridium leptum counts were decreased in in a subset of 16 patients with NASH compared to 25 HC, after adjusting for body mass index and weight-adjusted calorie intake (p = 0.028 and p = 0.030, respectively). C. leptum was positively correlated with fecal unconjugated lithocholic acid (LCA) (r = 0.526, p = 0.003) and inversely with unconjugated CA (r = -0.669, p<0.0001) and unconjugated CDCA (r = - 0.630, p<0.0001). FGF19 levels were not different between the groups (p = 0.114). CONCLUSIONS: In adults with NAFLD, dysbiosis is associated with altered BA homeostasis, which renders them at increased risk of hepatic injury.

Mucin-Microbiota Interaction During Postnatal Maturation of the Intestinal Ecosystem: Clinical Implications.

The mucus layer and gut microbiota interplay contributes to host homeostasis. The mucus layer serves as a scaffold and a carbon source for gut microorganisms; conversely, gut microorganisms, including mucin degraders, influence mucin gene expression, glycosylation, and secretion. Conjointly they shield the epithelium from luminal pathogens, antigens, and toxins. Importantly, the mucus layer and gut microbiota are established in parallel during early postnatal life. During this period, the development of gut microbiota and mucus layer is coupled with that of the immune system. Developmental changes of different mucin types can impact the age-dependent patterns of intestinal infection in terms of incidence and severity. Altered mucus layer, dysbiotic microbiota, and abnormal mucus-gut microbiota interaction have the potential for inducing systemic effects, and accompany several intestinal diseases such as inflammatory bowel disease, colorectal cancer, and radiation-induced mucositis. Early life provides a pivotal window of opportunity to favorably modulate the mucus-microbiota interaction. The support of a health-compatible mucin-microbiota maturation in early life is paramount for long-term health and serves as an important opportunity for clinical intervention.

Altered hepatic gene expression in nonalcoholic fatty liver disease is associated with lower hepatic n-3 and n-6 polyunsaturated fatty acids.

UNLABELLED: In nonalcoholic fatty liver disease, hepatic gene expression and fatty acid (FA) composition have been reported independently, but a comprehensive gene expression profiling in relation to FA composition is lacking. The aim was to assess this relationship. In a cross-sectional study, hepatic gene expression (Illumina Microarray) was first compared among 20 patients with simple steatosis (SS), 19 with nonalcoholic steatohepatitis (NASH), and 24 healthy controls. The FA composition in hepatic total lipids was compared between SS and NASH, and associations between gene expression and FAs were examined. Gene expression differed mainly between healthy controls and patients (SS and NASH), including genes related to unsaturated FA metabolism. Twenty-two genes were differentially expressed between NASH and SS; most of them correlated with disease severity and related more to cancer progression than to lipid metabolism. Biologically active long-chain polyunsaturated FAs (PUFAs; eicosapentaenoic acid + docosahexaenoic acid, arachidonic acid) in hepatic total lipids were lower in NASH than in SS. This may be related to overexpression of FADS1, FADS2, and PNPLA3. The degree and direction of correlations between PUFAs and gene expression were different among SS and NASH, which may suggest that low PUFA content in NASH modulates gene expression in a different way compared with SS or, alternatively, that gene expression influences PUFA content differently depending on disease severity (SS versus NASH). CONCLUSION: Well-defined subjects with either healthy liver, SS, or NASH showed distinct hepatic gene expression profiles including genes involved in unsaturated FA metabolism. In patients with NASH, hepatic PUFAs were lower and associations with gene expression were different compared to SS.