Probiotics may delay the progression of nonalcoholic fatty liver disease by restoring the gut microbiota structure and improving intestinal endotoxemia

Auricularia auricula Melanin Protects against Alcoholic Liver Injury and Modulates Intestinal Microbiota Composition in Mice Exposed to Alcohol Intake

The potential effects of Auricularia auricula melanin (AAM) on the intestinal flora and liver metabolome in mice exposed to alcohol intake were investigated for the first time. The results showed that oral administration of AAM significantly reduced the abnormal elevation of serum total triglyceride (TG), cholesterol (TC), low density lipoprotein cholesterol (LDL-C), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and significantly inhibited hepatic lipid accumulation and steatosis in mice exposed to alcohol intake. Besides, the abnormally high levels of bile acids (BAs) and lactate dehydrogenase (LDH) in the liver of mice with alcohol intake were significantly decreased by AAM intervention, while the hepatic levels of glutathione (GSH) and superoxide dismutase (SOD) were appreciably increased. Compared with the model group, AAM supplementation significantly changed the composition of intestinal flora and up-regulated the levels of Akkermansia, Bifidobacterium, Romboutsia, Muribaculaceae, Lachnospiraceae_NK4A136_group, etc. Furthermore, liver metabolomics demonstrated that AAM had a significant regulatory effect on the composition of liver metabolites in mice with alcohol intake, especially the metabolites involved in phosphatidylinositol signaling system, ascorbate and aldarate metabolism, starch and sucrose metabolism, galactose metabolism, alpha-linolenic acid metabolism, glycolysis/gluconeogenesis, and biosynthesis of unsaturated fatty acids. At the gene level, AAM treatment regulated the mRNA levels of lipid metabolism and inflammatory response related genes in liver, including ACC-1, FASn, CPT-1, CD36, IFN-γ, LDLr and TNF-α. Conclusively, these findings suggest that AAM has potential beneficial effects on alleviating alcohol-induced liver injury and is expected to become a new functional food ingredient.

Phenolic Compounds Promote Diversity of Gut Microbiota and Maintain Colonic Health

The role of non-energy-yielding nutrients on health has been meticulously studied, and the evidence shows that a compound can exert significant effects on health even if not strictly required by the organism. Phenolic compounds are among the most widely studied molecules that fit this description; they are found in plants as secondary metabolites and are not required by humans for growth or development, but they can influence a wide array of processes that modulate health across multiple organs and systems. The lower gastrointestinal tract is a prime site of action of phenolic compounds, namely, by their effects on gut microbiota and colonic health. As with humans, phenolic compounds are not required by most bacteria but can be substrates of others; in fact, some phenolic compounds exert antibacterial actions. A diet rich in phenolic compounds can lead to qualitative and quantitative effects on gut microbiota, thereby inducing indirect health effects in mammals through the action of these microorganisms. Moreover, phenolic compounds may be fermented by the gut microbiota, thereby modulating the compounds bioactivity. In the colon, phenolic compounds promote anti-inflammatory, anti-oxidant and antiproliferative actions. The aim of the present review is to highlight the role of phenolic compounds on maintaining or restoring a healthy microbiota and overall colonic health. Mechanisms of action that substantiate the reported evidence will also be discussed.

Multidirectional facets of obesity management in the metabolic syndrome population after liver transplantation

The obesity pandemic has resulted in an increasing demand for liver transplantation and has significantly altered the profile of liver transplant candidates in addition to affecting posttransplantation outcomes. In this review, we discuss a broad range of clinical approaches that warrant attention to provide comprehensive and patient‐centred medical care to liver transplant recipients, and to be prepared to confront the rapidly changing clinical challenges and ensuing dilemmas. Adipose tissue is a complex and metabolically active organ. Visceral fat deposition is a key predictor of overall obesity‐related morbidity and mortality. Limited pharmacological options are available for the treatment of obesity in the liver transplant population. Bariatric surgery may be an alternative in eligible patients. The rapidly increasing prevalence of nonalcoholic fatty liver disease (NAFLD) is a global concern; NAFLD affects both pre‐ and posttransplantation outcomes. Numerous studies have investigated pharmacological and nonpharmacological management of NAFLD and some of these have shown promising results. Liver transplant recipients are constantly exposed to numerous factors that result in intestinal microbiota alterations, which were linked to the development of obesity, diabetes type 2, metabolic syndrome (MS), NAFLD, and hepatocellular cancer. Microbiota modifications with probiotics and prebiotics bring gratifying results in the management of metabolic complications. Fecal microbiota transplantation (FMT) is successfully performed in many medical indications. However, the safety and efficacy profiles of FMT in immunocompromised patients remain unclear. Obesity together with immunosuppressive treatment, may affect the pharmacokinetic and/or pharmacodynamic properties of coadministered medications. Individualized immunosuppressive regimens are recommended following liver transplantation to address possible metabolic concerns. Effective and comprehensive management of metabolic complications is shown to yield multiple beneficial results in the liver transplant population and may bring gratifying results in improving long‐term survival rates.

Probiotics maintain the gut microbiome homeostasis during Indian Antarctic expedition by ship

Ship voyage to Antarctica is a stressful journey for expedition members. The response of human gut microbiota to ship voyage and a feasible approach to maintain gut health, is still unexplored. The present findings describe a 24-day long longitudinal study involving 19 members from 38th Indian Antarctic Expedition, to investigate the impact of ship voyage and effect of probiotic intervention on gut microbiota. Fecal samples collected on day 0 as baseline and at the end of ship voyage (day 24), were analyzed using whole genome shotgun sequencing. Probiotic intervention reduced the sea sickness by 10% compared to 44% in placebo group. The gut microbiome in placebo group members on day 0 and day 24, indicated significant alteration compared to a marginal change in the microbial composition in probiotic group. Functional analysis revealed significant alterations in carbohydrate and amino acid metabolism. Carbohydrate-active enzymes analysis represented functional genes involved in glycoside hydrolases, glycosyltransferases and carbohydrate binding modules, for maintaining gut microbiome homeostasis. Suggesting thereby the possible mechanism of probiotic in stabilizing and restoring gut microflora during stressful ship journey. The present study is first of its kind, providing a feasible approach for protecting gut health during Antarctic expedition involving ship voyage.

Live Combined B. subtilis and E. faecium Alleviate Liver Inflammation, Improve Intestinal Barrier Function, and Modulate Gut Microbiota in Mice with Non-Alcoholic Fatty Liver Disease

Background

Non-alcoholic fatty liver disease (NAFLD) is a chronic, progressive liver disease with an increasing incidence rate. This study investigated the protective effects of live combined Bacillus subtilis and Enterococcus faecium (LCBE) on NAFLD, and its possible mechanisms.

Material/Methods

Five-week-old C57BL/6 mice were randomly divided into 3 groups: chow, HFD, and HFD+LCBE groups. The levels of serum biochemical markers, glucose tolerance, insulin, the inflammatory cytokines IL-1β, IL-6, and TNF-α, LPS, and histological staining were measured using commercial kits. qPCR was used to examine the mRNA expression levels of inflammatory cytokines in the liver. Western blotting was used to determine the protein levels of TLR4, NF-κB p65, PPAR-α, and CPT-1 in the liver, and occludin and Claudin1 in the intestine. The intestinal flora of the mice was analyzed by high-throughput sequencing of the V3–V4 region of 16S rDNA.

Results

LCBE significantly lowered the body weight, liver/body weight ratio, and serum glucose level, and increased the serum insulin level in NAFLD mice. In addition, LCBE treatment improved the liver function and lipid profile, decreased the levels of LPS and inflammatory cytokines, and downregulated the expression of TLR4 and NF-κB p65. Moreover, LCBE enhanced the intestinal barrier function by increasing the expression of occludin and Claudin1. Furthermore, LCBE modulated the composition of the gut microbiota by reducing the Firmicutes to Bacteroidetes ratio, and the proportion of inflammation-related and LPS-producing bacteria, thus re-arranging the structure of the gut microbiota.

Conclusions

LCBE protects against NAFLD by alleviating inflammation, restoring the intestinal barrier, and modulating gut microbiota composition.

Effect of Lycium barbarum polysaccharide supplementation in non-alcoholic fatty liver disease patients: study protocol for a randomized controlled trial

BACKGROUND

Non-alcohol fatty liver disease (NAFLD) is the most common chronic liver disease in the world, with a high incidence and no effective treatment. At present, the targeted therapy of intestinal microbes for NAFLD is highly valued. Lycium barbarum polysaccharide (LBP), as the main active ingredient of Lycium barbarum, is considered to be a new type of prebiotic substance, which can improve NAFLD by regulating the gut microbiota. The purpose of this study is to evaluate the safety and efficacy of LBP supplementation in modulating gut microbiota for NAFLD patients.

METHODS

This randomized, double-blind, placebo-control study will be conducted in the physical examination center of the Ningxia Hui Autonomous Region People's Hospital. A total of 50 patients with NAFLD confirmed by abdominal ultrasound, laboratory tests, and questionnaire surveys will be recruited and randomly assigned into the control group (maltodextrin placebo capsules) and the intervention group (LBP supplementation capsules) for 3 months. Neither patients, nor investigators, nor data collectors will know the contents in each capsule and the randomization list. The primary outcome measure is the level of ALT concentration relief after the intervention. Secondary outcomes include gut microbiota abundance and diversity, intestinal permeability, patient's characteristic demographic data and body composition, adverse effects, and compliance from patients.

DISCUSSION

LBPs are potential prebiotics with the property of regulating host gut microbiota. Our previous studies have documented that LBP supplement can improve the liver damage and the gut microflora dysbiosis in NAFLD rats. This treatment would provide a more in-depth understanding of the effect of this LBP supplementation.

TRIAL REGISTRATION

Chinese Clinical Trial Register, ChiCTR2000034740 . Registered on 17 July 2020.

Heat-sterilized Bifidobacterium breve prevents depression-like behavior and interleukin-1β expression in mice exposed to chronic social defeat stress

Major depressive disorder (MDD) is a common and serious psychiatric disease that involves brain inflammation. Bifidobacterium breve is commonly used as a probiotic and was shown to improve colitis and allergic diseases by suppressing the inflammatory response. Heat-sterilized B. breve has beneficial effects on inflammation. We hypothesize, therefore, that this probiotic might reduce depression symptoms. We tested this is a mouse model of social defeat stress. C57BL/6J mice exposed to chronic social defeat stress (CSDS) for five consecutive days developed a mild depression-like behavior characterized by a social interaction impairment. CSDS also altered the gut microbiota composition, such as increased abundance of Bacilli, Bacteroidia, Mollicutes, and Verrucomicrobiae classes and decreased Erysipelotrichi class. The prophylactic effect of heat-sterilized B. breve as a functional food ingredient was evaluated on the depression-like behavior in mice. The supplementation started two weeks before and lasted two weeks after the last exposure to CSDS. Two weeks after CSDS, the mice showed deficits in social interaction and increased levels of inflammatory cytokines, including interleukin-1β (IL-1β) in the prefrontal cortex (PFC) and hippocampus (HIP). Heat-sterilized B. breve supplementation significantly prevented social interaction impairment, suppressed IL-1β increase in the PFC and HIP, and modulated the alteration of the gut microbiota composition induced by CSDS. These findings suggest that heat-sterilized B. breve prevents depression-like behavior and IL-1β expression induced by CSDS through modulation of the gut microbiota composition in mice. Therefore, heat-sterilized B. breve used as an ingredient of functional food might prevent MDD.

Effect of Microbiome on Non-Alcoholic Fatty Liver Disease and the Role of Probiotics, Prebiotics, and Biogenics

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of liver cirrhosis and hepatocellular carcinoma. NAFLD is associated with metabolic disorders such as obesity, insulin resistance, dyslipidemia, steatohepatitis, and liver fibrosis. Liver-resident (Kupffer cells) and recruited macrophages contribute to low-grade chronic inflammation in various tissues by modulating macrophage polarization, which is implicated in the pathogenesis of metabolic diseases. Abnormalities in the intestinal environment, such as the gut microbiota, metabolites, and immune system, are also involved in the pathogenesis and development of NAFLD. Hepatic macrophage activation is induced by the permeation of antigens, endotoxins, and other proinflammatory substances into the bloodstream as a result of increased intestinal permeability. Therefore, it is important to understand the role of the gut–liver axis in influencing macrophage activity, which is central to the pathogenesis of NAFLD and nonalcoholic steatohepatitis (NASH). Not only probiotics but also biogenics (heat-killed lactic acid bacteria) are effective in ameliorating the progression of NASH. Here we review the effect of hepatic macrophages/Kupffer cells, other immune cells, intestinal permeability, and immunity on NAFLD and NASH and the impact of probiotics, prebiotics, and biogenesis on those diseases.

Probiotics and Prebiotics as a Strategy for Non-Alcoholic Fatty Liver Disease, a Narrative Review

Non-alcoholic fatty liver disease (NAFLD) is a chronic non-communicable disease, with a prevalence of 25% worldwide. This pathology is a multifactorial illness, and is associated with different risks factors, including hypertension, hyperglycemia, dyslipidemia, and obesity. Beside these predisposing features, NAFLD has been related to changes in the microbiota, which favor the disease progression. In this context, the modulation of the gut microbiota has emerged as a new therapeutic target for the prophylaxis and treatment of NAFLD. This review describes the changes in the gut microbiota associated with NAFLD and the effect of probiotics, prebiotics, and synbiotics on the gut microbiota, liver damage, anthropometric parameters, blood lipids, inflammation markers and insulin resistance in these patients.

A rise in Proteobacteria is an indicator of gut-liver axis-mediated nonalcoholic fatty liver disease in high-fructose-fed adult mice

Current evidence suggests that high fructose intake results in gut dysbiosis, leading to endotoxemia and NAFLD onset. Thus, the hypothesis of the study was that an enhanced Proteobacteria proportion in the cecal microbiota could be the most prominent trigger of NAFLD through enhanced endotoxin (LPS) in adult high-fructose-fed C57BL/6 mice. Male C57BL/6 mice received a control diet (n = 10, C: 76% of energy as carbohydrates, 0% as fructose) or high-fructose diet (n = 10, HFRU: 76% of energy as carbohydrate, 50% as fructose) for 12 weeks. Outcomes included biochemical analyses, 16S rDNA PCR amplification, hepatic stereology, and RT-qPCR. The groups showed similar body masses during the whole experiment. However, the HFRU group showed greater water intake and blood pressure than the C group. The HFRU group showed a significantly lower amount of Bacteroidetes and a predominant rise in Proteobacteria, implying increased LPS. The HFRU group also showed enhanced de novo lipogenesis (Chrebp expression), while beta-oxidation was decreased (Ppar-alpha expression). These results agree with the deposition of fat droplets within hepatocytes and the enhanced hepatic triacylglycerol concentrations, as observed in the photomicrographs, where the HFRU group had a higher volume density of steatosis than the C group. Thus, we confirmed that a rise in the Proteobacteria phylum proportion was the most prominent alteration in gut-liver axis-induced hepatic steatosis in HFRU-fed C57BL/6 mice. Gut dysbiosis and fatty liver were observed even in the absence of overweight in this dietary adult mouse model.

Patchouli alcohol ameliorates acute liver injury via inhibiting oxidative stress and gut-origin LPS leakage in rats

Alcoholism represents a predisposing factor for liver-related morbidity and mortality worldwide. Pogostemon cablin has been widely used in China for the treatment of digestive system diseases. Patchouli oil, the major active fraction of Pogostemon cablin, can ameliorate alcohol-induced acute liver injury (ALI). However, patchouli alcohol (PA),a principal bioactive ingredient of PO, exerts a protection against ALI remains elusive. Thepresentwork focused on the hepatoprotection of PA against acute ethanol-induced hepatotoxicity in rats. In this study, male Wistar rats orally received PA (10, 20, or 40 mg/kg), PO (400 mg/kg) and silymarin (200 mg/kg) for ten days. On the 8th day, the rats orally received 65% ethanol (10 mL/kg, 6.5 g/kg) every 12 h for 3 days. Results showed that PA wasfound to reduce alcohol-induced ALI, as evidenced bysignificantly alleviated histopathologicalalterations, decreased the elevation ofALT and AST levels, and enhancedthe alcoholdehydrogenase(ADH) andaldehyde dehydrogenase (ALDH) activities. Additionally, PA markedly suppressed ROS levels and increased antioxidant enzyme activities via the CYP2E1/ROS/Nrf2/HO-1 pathway. PA regulated lipid accumulation by markedly inhibiting the expression of lipogenesis-related genes and stimulating that of lipolysis-relatedgenes, which were associated with the activation of theAMPKpathway. What's more, PA pretreatment also restored acute alcohol-inducedalterationsin gut barrier function, colonic histopathology, and gut microbiota richness and evenness. PA pretreatment alleviated gut-origin LPS-inducedinflammation by inhibiting the MyD88/TLR4/NF-κB signal pathway. In general, PA ameliorates ethanol-induced ALI via restoration of CYP2E1/ROS/Nrf2/HO-1-mediatedoxidativestressand AMPK-mediated fat accumulation, as well as alleviation of gut-LPS-leakage-induced inflammation regulated by the MyD88/TLR4/NF-κB signaling pathway.

Role of the Gut Microbiota in Regulating Non-alcoholic Fatty Liver Disease in Children and Adolescents

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease in children and adolescents. Although obesity is the leading cause of NAFLD, the etiologies of NAFLD are multifactorial (e.g., high-fat diet, a lack of exercise, gender, maternal obesity, the antibiotic use), and each of these factors leads to dysbiosis of the gut microbiota community. The gut microbiota is a key player in the development and regulation of the gut mucosal immune system as well as the regulation of both NAFLD and obesity. Dysbiosis of the gut microbiota promotes the development of NAFLD via alteration of gut-liver homeostasis, including disruption of the gut barrier, portal transport of bacterial endotoxin (lipopolysaccharide) to the liver, altered bile acid profiles, and decreased concentrations of short-chain fatty acids. In terms of prevention and treatment, conventional approaches (e.g., dietary and exercise interventions) against obesity and NAFLD have been confirmed to recover the dysbiosis and dysbiosis-mediated altered metabolism. In addition, increased understanding of the importance of gut microbiota-mediated homeostasis in the prevention of NAFLD suggests the potential effectiveness of gut microbiota-targeted preventive and therapeutic strategies (e.g., probiotics and fecal transplantation) against NAFLD in children and adolescents. This review comprehensively summarizes our current knowledge of the gut microbiota, focusing on its interaction with NAFLD and its potential therapeutic role in obese children and adolescents with this disorder.

Diet-Regulating Microbiota and Host Immune System in Liver Disease

The gut microbiota has been known to modulate the immune responses in chronic liver diseases. Recent evidence suggests that effects of dietary foods on health care and human diseases are related to both the immune reaction and the microbiome. The gut-microbiome and intestinal immune system play a central role in the control of bacterial translocation-induced liver disease. Dysbiosis, small intestinal bacterial overgrowth, translocation, endotoxemia, and the direct effects of metabolites are the main events in the gut-liver axis, and immune responses act on every pathways of chronic liver disease. Microbiome-derived metabolites or bacteria themselves regulate immune cell functions such as recognition or activation of receptors, the control of gene expression by epigenetic change, activation of immune cells, and the integration of cellular metabolism. Here, we reviewed recent reports about the immunologic role of gut microbiotas in liver disease, highlighting the role of diet in chronic liver disease.

Lactobacillus casei YRL577 combined with plant extracts reduce markers of non-alcoholic fatty liver disease in mice

Probiotics and plant extracts are considered to prevent the development of non-alcoholic fatty liver disease (NAFLD). The present study explores the effects of using both probiotics and plant extracts on NAFLD. The present study evaluated the effects of plant extracts on lipid droplet accumulation and the growth of probiotics in vitro. A C57BL/6 mouse model was used to examine the effects of probiotics and plant extracts on NAFLD. Body weight and food intake were measured. The levels of serum lipids, oxidative stress and the liver injury index were determined using commercial kits. Haematoxylin and eosin staining, GC and real-time PCR were also used for analysis. The results revealed that administration of Lactobacillus casei YRL577 and L. paracasei X11 with resveratrol (RES) or tea polyphenols (TP) significantly reduced the levels of total cholesterol, TAG and LDL-cholesterol and increased the level of the HDL-cholesterol. The groups of L. casei YRL577 with RES and TP also regulated the liver structure, oxidative stress and injury. Furthermore, L. casei YRL577 with TP exhibited a more positive effect towards improving the NAFLD and increased the concentrations of the butyric acid than other three combined groups. L. casei YRL577 with TP up-regulated the mRNA levels of the farnesoid X receptor and fibroblast growth factor 15 and decreased the mRNA levels of the apical Na-dependent bile acid transporter. These findings showed that L. casei YRL577 + TP-modified genes in the intestinal bile acid pathway improved markers of NAFLD.

Lactobacillus fermentum CQPC06 in naturally fermented pickles prevents non-alcoholic fatty liver disease by stabilizing the gut-liver axis in mice

Herein, we used a HFD/F to induce NAFLD in mice and intervened with CQPC06 to determine the preventive effect of CQPC06 on NAFLD and its potential regulatory mechanism. C57BL/6J mice were fed with LFD, HFD/F, HFD/F supplemented with CQPC06, and HFD/F supplemented with LDBS for 8 weeks to test the properties of the probiotic. Biochemical and molecular biology methods were used to determine the levels of related indexes in mouse serum, liver tissue, epididymal fat, small intestine tissue, and feces. The results showed that CQPC06 exhibited satisfactory probiotic properties, significantly inhibited mouse weight gain, and decreased the liver index and serum lipid levels, including ALT, AKP, AST, TC, TG, LDL-C, LPS, and HDL-C levels. The HOMA-IR index calculated based on the blood glucose levels and serum insulin levels showed that the HOMA-IR index of NAFLD mice treated with CQPC06 significantly decreased. From the molecular biology level, CQPC06 significantly increased the mRNA and protein expression of PPAR-α, CYP7A1, CPT1, and LPL in NAFLD mouse livers, and decreased the expression of PPAR-γ and C/EBP-α. Furthermore, CQPC06 enhanced the expression of ZO-1, occludin, and claudin-1 in the small intestine of NAFLD mice, and decreased the expression of CD36. CQPC06 decreased the level of Firmicutes and increased the levels of Bacteroides and Akkermansia in the feces of NAFLD mice, and the ratio of Firmicutes/Bacteroides was significantly decreased. CQPC06 is highly resistant in vitro and survived in the gastrointestinal tract and exerted its probiotic effect, altered the intestinal microecology of NAFLD mice, and played an important role in NAFLD prevention through the unique anatomical advantages of the gut-liver axis. There was a clear preventive effect with high concentrations of CQPC06 and it was stronger than that of l-carnitine.

Lycium barbarum polysaccharide combined with aerobic exercise ameliorated nonalcoholic fatty liver disease through restoring gut microbiota, intestinal barrier and inhibiting hepatic inflammation

Gut microbiota and intestinal permeability have been demonstrated to be the key players in the gut-liver cross talk in nonalcoholic fatty liver disease (NAFLD). Lycium barbarum polysaccharides (LBPs), which seem to be a potential prebiotic, and aerobic exercise (AE) have shown protective effects on NAFLD. However, their combined effects on intestinal microecology remain unclear. This study evaluated the effects of LBP, AE, and its combination (LBP + AE) on gut microbiota composition, intestinal barrier, and hepatic inflammation in NAFLD. LBP + AE showed high abundance and diversity of gut microbiota, restored the gut microbiota composition, increased some Bacteroidetes, short chain fatty acids, but decreased Proteobacteria and the ratio of Firmicutes/Bacteroidetes. Simultaneously, LBP, AE, and LBP + AE could restore the colonic and ileum tight junctions by increasing the expression of zonula occludens-1 and occludin. They also downregulated gut-derived lipopolysaccharides (LPSs), hepatic LPS-binding proteins, inflammatory factors, and related indicators of the LPS/TLR4/NF-κB signaling pathway for the liver. Our results implied that LBP could be considered a prebiotic agent, and LBP + AE might be a promising treatment for NAFLD because it could maintain gut microbiota balance, thereby restoring intestinal barrier and exerting hepatic benefits.

Inhibitory Effect of Lactococcus lactis subsp. lactis HFY14 on Diphenoxylate-Induced Constipation in Mice by Regulating the VIP-cAMP-PKA-AQP3 Signaling Pathway

Aim

The naturally fermented yak yogurt of pastoralists in the Tibetan Plateau, China, because of its unique geographical environment and the unique lifestyle of Tibetan pastoralists, is very different from other kinds of sour milk, and the microorganisms it contains are special. Lactococcus lactis subsp. lactis HFY14 (LLSL-HFY14) is a new lactic acid bacterium isolated from naturally fermented yak yogurt. The purpose of this study was to study the inhibitory effect of the bacterium on constipation.

Methods

Constipation was induced in ICR mice with diphenoxylate, and the constipated mice were treated with LLSL-HFY14. The weight and feces of the mice were visually detected. Colonic tissues were observed on hematoxylin and eosin-stained sections. Serum indices were detected with kits. mRNA expression in the colon was determined by quantitative polymerase chain reaction assay.

Results

Constipation caused weight loss, the number of defecation granules, defecation weight, fecal water content decreased, and the first black stool excretion time increased. LLSL-HFY14 alleviated these symptoms, and the effects were similar to those of lactulose (drug). The pathological examination revealed that constipation caused pathological changes in the colon, and LLSL-HFY14 effectively alleviated the disease. LLSL-HFY14 increased serum levels of motilin, gastrin, endothelin, substance P, acetylcholinesterase, and vasoactive intestinal peptide (VIP) and decreased serum levels of somatostatin in constipated mice. In addition, LLSL-HFY14 upregulated VIP, cAMP, protein kinase A, and aquaporin 3 expression in colonic tissues of constipated mice in a dose-dependent manner.

Conclusion

LLSL-HFY14 inhibited constipation, similar to lactulose, and has the potential to become a biological agent.

Effect of Food Endotoxin on Infant Health

Endotoxin is a complex molecule derived from the outer membrane of Gram-negative bacteria, and it has strong thermal stability. The processing of infant food can kill pathogenic bacteria but cannot remove endotoxin. Because the intestinal structure of infants is not fully developed, residual endotoxin poses a threat to their health by damaging the intestinal flora and inducing intestinal inflammation, obesity, and sepsis, among others. This paper discusses the sources and contents of endotoxin in infant food and methods for preventing endotoxin from harming infants. However, there is no clear evidence that endotoxin levels in infant food cause significant immune symptoms or even diseases in infants. However, in order to improve the safety level of infant food and reduce the endotoxin content, this issue should not be ignored. The purpose of this review is to provide a theoretical basis for manufacturers and consumers to understand the possible harm of endotoxin content in infant formula milk powder and to explore how to reduce its level in infant formula milk powder. Generally, producers should focus on cleaning the milk source, securing the cold chain, avoiding long-distance transportation, and shortening the storage time of raw milk to reduce the level of bacteria and endotoxin. After production and processing, the endotoxin content should be measured as an important index to test the quality of infant formula milk powder so as to provide high-quality infant products for the healthy growth of newborns.

Gut microbiota and non-alcoholic fatty liver disease: a narrative review

The gastrointestinal tract of the adult human represents the habitat of the ecological community of commensal, symbiotic and pathogenic microorganisms, defined as the gut microbiota, which has more than 100 trillion microorganisms representing one of the most complex ecosystems. Colonization of the gastrointestinal tract by microorganisms begins at the time of birth. Contrary to what was previously hypothesized, a large number of fundamental functions for the host are attributed to the gut microbiota to date. The gut microbiota, therefore, does not represent a passive set of microbes hosted inside the human organism but plays a crucial role in the balance of the organism itself. An alteration of the microbiota is a phenomenon known as dysbiosis. The latter can be implicated in the development of complex liver diseases like non-alcoholic fatty liver disease. The aim of this review is to describe the most interesting data linking the development of non-alcoholic fatty liver disease with the gut microbiota and, therefore, to underline the importance of the microbiota itself, as a potential therapeutic target in the treatment of non-alcoholic fatty liver disease.

Effect of probiotics on diversity and function of gut microbiota in Moschus berezovskii

The forest musk deer, Moschus berezovskii, is a nationally protected species of economic importance in China. However, in captive breeding programmes, they usually die as a result of diarrhoea. In this study, six M. berezovskii were randomly selected and divided into two groups: probiotics group (n = 3) and placebo (control) group (n = 3). The two groups were fed a basal diet that included 2 g probiotics (probiotic group) or 2 g whey powder (placebo group) for 30 days. Faecal samples were collected at day 0, 15 and 30 and evaluated for microbial diversity, species richness and metabolic function. Probiotic intervention significantly improved gut health in M. berezovskii by changing the overall community structure of the gut microbiota. Intake of probiotics reduced the relative abundance of pathogenic bacteria such as Escherichia coli and Citrobacter freundii in the intestinal flora and increased the relative abundance of beneficial Bifidobacterium species and other lactic acid bacteria. At the same time, gut microbiota in the probiotics group were involved in regulating degradation of phenylacetic acid and in dTDP-L-rhamnose synthesis; these processes have the potential to enhance immunity in M. berezovskii. This preliminary study revealed the beneficial effects of probiotics on the gut microbiota of M. berezovskii, which the potential to significantly improve the health, wellbeing and economic value of M. berezovskii.

Relationship between Nutrient Intake and Human Gut Microbiota in Monozygotic Twins

Background and Objectives: The gut microbiota is associated with human health and dietary nutrition. Various studies have been reported in this regard, but it is difficult to clearly analyze human gut microbiota as individual differences are significant. The causes of these individual differences in intestinal microflora are genetic and/or environmental. In this study, we focused on differences between identical twins in Japan to clarify the effects of nutrients consumed on the entire gut microbiome, while excluding genetic differences. Materials and Methods: We selected healthy Japanese monozygotic twins for the study and confirmed their zygosity by matching 15 short tandem repeat loci. Their fecal samples were subjected to 16S rRNA sequencing and bioinformatics analyses to identify and compare the fluctuations in intestinal bacteria. Results: We identified 12 genera sensitive to environmental factors, and found that Lactobacillus was relatively unaffected by environmental factors. Moreover, we identified protein, fat, and some nutrient intake that can affect 12 genera, which have been identified to be more sensitive to environmental factors. Among the 12 genera, Bacteroides had a positive correlation with retinol equivalent intake (rs = 0.38), Lachnospira had a significantly negative correlation with protein, sodium, iron, vitamin D, vitamin B6, and vitamin B12 intake (rs = −0.38, −0.41, −0.39, −0.63, −0.42, −0.49, respectively), Lachnospiraceae ND3007 group had a positive correlation with fat intake (rs = 0.39), and Lachnospiraceae UCG-008 group had a negative correlation with the saturated fatty acid intake (rs = −0.45). Conclusions: Our study is the first to focus on the relationship between human gut microbiota and nutrient intake using samples from Japanese twins to exclude the effects of genetic factors. These findings will broaden our understanding of the more intuitive relationship between nutrient intake and the gut microbiota and can be a useful basis for finding useful biomarkers that contribute to human health.

Mechanisms by Which Probiotic Bacteria Attenuate the Risk of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the second leading cause of cancer-related deaths worldwide. Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV), alcoholic liver disease (ALD), and non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) are the major extrinsic risk factors of HCC development. Genetic background is pivotal in HCC pathogenesis, and both germline mutations and single nucleotide polymorphism (SNP) are intrinsic risk factors of HCC. These HCC risk factors predispose to hepatic injury and subsequent activation of fibrogenesis that progresses into cirrhosis and HCC. Probiotic bacteria can mitigate HCC risk by modulating host gut microbiota (GM) to promote growth of beneficial microbes and inhibit HCC-associated dysbiosis, thus preventing pathogen-associated molecular patterns (PAMPs)-mediated hepatic inflammation. Probiotics have antiviral activities against HBV and HCV infections, ameliorate obesity and risk of NAFLD/NASH, and their antioxidant, anti-proliferative, anti-angiogenic, and anti-metastatic effects can prevent the HCC pathogenesis. Probiotics also upregulate the expression of tumor suppressor genes and downregulate oncogene expression. Moreover, metabolites generated by probiotics through degradation of dietary phytochemicals may mitigate the risk of HCC development. These multiple anticancer mechanisms illustrate the potential of probiotics as an adjuvant strategy for HCC risk management and treatment.

Perfluorooctanoic acid-induced liver injury is potentially associated with gut microbiota dysbiosis

Perfluorooctanoic acid (PFOA), an environmental pollutant, is widely engaged in industrial products and tends to accumulate in the liver. Emerging evidence has suggested that the gut microbiome is a pivotal player in maintaining animal health and can potentially altered by xenobiotic. However, few studies explored whether PFOA-induced liver injury is associated with gut microbiota dysbiosis. In the present study, the effects of subacute and subchronic PFOA exposure on liver and gut microbiota in C57BL/6J mice were investigated. Our findings showed that both subacute and subchronic exposure to PFOA induced the liver inflammation, disrupted antioxidative homeostasis and caused liver histological abnormalities with detectable hepatomegaly, ultimately triggering liver injury. Besides, 16S rRNA sequencing analysis revealed that subacute PFOA exposure caused significant changes in the abundances of intestinal flora known to contribute to liver inflammation and oxidative stress, such as the Dehalobacterium and Bacteroides genera. Exposure to subchronic toxicity mainly induced the decrease in commensal probiotics including Lactobacillus and Bifidobacterium genera, which are potentially beneficial to liver damage, compared with that in the untreated group. They also resulted in disturbed functional capabilities of the microbial communities by a Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis. Additionally, the levels of short-chain fatty acids (SCFAs), especially butyric acid, were significantly reduced by PFOA administration. Collectively, our observations suggested that liver damage induced by both subacute and subchronic PFOA exposures probably partly related to the gut microbiota dysbiosis and provided a new insight into the role of PFOA in liver injury.

Co-Treatment with Cefotaxime and High-Fructose Diet Inducing Nonalcoholic Fatty Liver Disease and Gut Microbial Dysbiosis in Mice

High fructose diet causes metabolic syndrome and induces host gut microbial dysbiosis and related obesity and nonalcoholic fatty liver disease (NAFLD). Several antibiotic treatments could prevent fatty liver. However, there are studies that have demonstrated that a high-fructose diet could influence the gut microbial dysbiosis and induce fatty liver. The purpose of this study was performed to partially modify the gut bacterial composition with a single cefotaxime treatment, which might affect the fructose-induced NAFLD severity. The C57BL/6JNarl male mice were divided into four groups including vehicle/chow diet (VE-CD), vehicle/high-fructose diet (VE-FD), antibiotic (cefotaxime (CF))/CD, and CF/FD. The results showed that body weight gain, moderate hepatic steatosis severity, epididymal white adipose tissue hypertrophy, and insulin resistance occurrence with NAFLD-related symptoms were observed only in the CF-FD group. The raised protein expression of hepatic lipogenesis was observed in the CF-FD group, but lipolysis protein expression was no difference. The diversity and composition of microbiota were significantly reduced in the CF-FD group. The Erysipelatoclostridium, Enterobacteriaceae, Lachnospiraceae, and Escherichia Shigella were in increased abundance in the feces of CF-FD group compared with VE-FD group. The novel model reveals that particular antibiotics such as cefotaxime co-treatment with high-fructose diet may affect the gut microbiota accelerating the NAFLD and obesity.

New insights into intestinal failure-associated liver disease in adults: A comprehensive review of the literature

Intestinal failure-associated liver disease (IFALD) remains one of the most common and serious complications of parenteral nutrition (PN), causing a wide spectrum of hepatic manifestations from steatosis and mild cholestasis to portal hypertension and end-stage liver failure. The prevalence of IFALD depends on the diagnostic criteria and ranges from 4.3% to 65%. Moreover, many factors are shown to contribute to its development, including nutrient deficiencies, toxicity of PN, infections, and alterations of bile acid metabolism and gut microbiota. Prevention and management of IFALD aim at ameliorating or eliminating the risk factors associated with IFALD. The use of PN formulations with a lower ratio omega-6-to-omega-3 polyunsaturated fatty acids, cycle PN, optimization of enteral stimulation and prevention and early treatment of infections constitute the main therapeutic targets. However, failure of improvement and severe IFALD with end-stage liver failure should be considered as the indications of intestinal transplantation. The aim of this review is to provide an update of the epidemiology, pathophysiology, and diagnosis of IFALD in the adult population as well as to present a clinical approach of the therapeutic strategies of IFALD and present novel therapeutic targets.

Understanding the Effects of Gut Microbiota Dysbiosis on Nonalcoholic Fatty Liver Disease and the Possible Probiotics Role: Recent Updates

Nonalcoholic fatty liver disease (NAFLD) is leading chronic liver syndrome worldwide. Gut microbiota dysbiosis significantly contributes to the pathogenesis and severity of NAFLD. However, its role is complex and even unclear. Treatment of NAFLD through chemotherapeutic agents have been questioned because of their side effects on health. In this review, we highlighted and discussed the current understanding on the importance of gut microbiota, its dysbiosis and its effects on the gut-liver axis and gut mucosa. Further, we discussed key mechanisms involved in gut dysbiosis to provide an outline of its role in progression to NAFLD and liver cirrhosis. In addition, we also explored the potential role of probiotics as a treatment approach for the prevention and treatment of NAFLD. Based on the latest findings, it is evident that microbiota targeted interventions mostly the use of probiotics have shown promising effects and can possibly alleviate the gut microbiota dysbiosis, regulate the metabolic pathways which in turn inhibit the progression of NAFLD through the gut-liver axis. However, very limited studies in humans are available on this issue and suggest further research work to identify a specific core microbiome association with NAFLD and to discover its mechanism of pathogenesis, which will help to enhance the therapeutic potential of probiotics to NAFLD.

Influence of the Intestinal Microbiota on Diabetes Management

In recent decades, there has been a very rapid increase in the prevalence of diabetes globally, with serious health and economic implications. Although today there are several therapeutic treatments for this disease, these do not address the causes of the disease and have serious side effects, so it is necessary to seek new treatments to replace or complement the existing ones. Among these complementary treatments, a strong link between the intestinal microbiota and diabetes has been demonstrated, which has focused attention on the use of biotherapy to regulate the function of the intestinal microbiota and, thus, treat diabetes. In this way, the main objective of this work is to provide a review of the latest scientific evidence on diabetes, gathering information about new trends in its management, and especially, the influence of the intestinal microbiota and microbiome on this pathology. It is possible to conclude that the relationship between the intestinal microbiota and diabetes is carried out through alterations in energy metabolism, the immune system, changes in intestinal permeability, and a state of low-intensity systemic inflammation. Although, currently, most of the experimental work, using probiotics for diabetes management, has been done on experimental animals, the results obtained are promising. Thus, the modification of the microbiota through biotherapy has shown to improve the symptoms and severity of diabetes through various mechanisms related to these alterations.

Endotoxins and Non-Alcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. It occurs with a prevalence of up to 25%, of which 10-20% cases progress to nonalcoholic steatohepatitis (NASH), cirrhosis, and liver cancer. The histopathology of NASH is characterized by neutrophilic infiltration, and endotoxins from gram-negative rods have been postulated as a contributing factor. Elevations in endotoxin levels in the blood can be classified as intestinal and hepatic factors. In recent years, leaky gut syndrome, which is characterized by impaired intestinal barrier function, has become a significant issue. A leaky gut may prompt intestinal bacteria dysbiosis and increase the amount of endotoxin that enters the liver from the portal vein. These contribute to persistent chronic inflammation and progressive liver damage. In addition, hepatic factors suggest that liver damage can be induced by low-dose endotoxins, which does not occur in healthy individuals. In particular, increased expression of CD14, an endotoxin co-receptor in the liver, may result in leptin-induced endotoxin hyper-responsiveness in obese individuals. Thus, elevated blood endotoxin levels contribute to the progression of NASH. The current therapeutic targets for NASH treat steatosis and liver inflammation and fibrosis. While many clinical trials are underway, no studies have been performed on therapeutic agents that target the intestinal barrier. Recently, a randomized placebo-controlled trial examined the role of the intestinal barrier in patients with NAFLD. To our knowledge, this study was the first of its kind and study suggested that the intestinal barrier may be a novel target in the future treatment of NAFLD.

Post-hoc analysis of a randomized controlled trial on the impact of pre-transplant use of probiotics on outcomes after liver transplantation

Perioperative use of probiotics serves as efficient prophylaxis against postoperative infections after liver transplantation, yet data on long-term effects of pre-transplant probiotic intake is lacking. The aim of this study was to assess the effects of pre-transplant probiotic administration on long-term results of liver transplantation. This was secondary analysis of a randomized trial. Patients were randomized to receive either 4-strain probiotic or placebo before liver transplantation. Five year graft survival was set as the primary end-point. Secondary end-points comprised serum bilirubin and C-reactive protein (CRP) concentration, international normalized ratio (INR), serum transaminases and gamma-glutamyl transferase (GGT) activity. Study group comprised 44 patients, of whom 21 received probiotics and 23 received placebo with 5-year graft survival of 81.0% and 87.0%, respectively (p = 0.591). Patients in the probiotic arm exhibited lower INR (p = 0.001) and CRP (p = 0.030) over the first 6 post-transplant months. In the absence of hepatitis B or C virus infection, pre-transplant administration of probiotics also reduced aspartate transaminase activity (p = 0.032). In the intervention arm, patients receiving probiotics for under and over 30 days had 5-year graft survival rates of 100% and 66.7%, respectively (p = 0.061). Duration of probiotic intake > 30 days was additionally associated with increased INR (p = 0.031), GGT (p = 0.032) and a tendency towards increased bilirubin (p = 0.074) over first 6 post-transplant months. Pre-transplant administration of probiotics has mild positive influence on 6-month allograft function, yet should not exceed 30 days due to potential negative effects on long-term outcomes. (ClinicalTrials.gov Identifier: NCT01735591).

Gut microbes in cardiovascular diseases and their potential therapeutic applications

Microbial ecosystem comprises a complex community in which bacteria interact with each other. The potential roles of the intestinal microbiome play in human health have gained considerable attention. The imbalance of gut microbial community has been looked to multiple chronic diseases. Cardiovascular diseases (CVDs) are leading causes of morbidity worldwide and are influenced by genetic and environmental factors. Recent advances have provided scientific evidence that CVD may also be attributed to gut microbiome. In this review, we highlight the complex interplay between microbes, their metabolites, and the potential influence on the generation and development of CVDs. The therapeutic potential of using intestinal microbiomes to treat CVD is also discussed. It is quite possible that gut microbes may be used for clinical treatments of CVD in the near future.

Effects of High Carbohydrate Diet-Modulated Microbiota on Gut Health in Chinese Perch

High carbohydrate diet-induced damage in gut is linked to changes in gut permeability and microbiota. However, the mechanisms of action are not clear, especially in non-mammals. We performed the gut microbiota profiling in Chinese perch fed with different content of starch diets (0, 10, and 20%) by 16S rRNA sequencing. The gut permeability, metabolites, histological analysis, and inflammatory infiltration were evaluated. We found that gut microbial diversity, beneficial bacteria quantity, and lactic acid content were higher in C10 group than in the other groups. The lower level of gut microbial diversity was observed in C20 group, and mycoplasma was the overwhelmingly dominant species, but the butyric acid-producing bacteria and butyric acid level were significantly reduced. The gut permeability in C20 group was also increased due to the decreased mRNA expression levels of tight junction proteins caused by the butyric acid deficiency and gut lipid droplets accumulation. Then a large amount of LPS penetrated into the plasma, resulting in inflammation. These results suggested that high carbohydrate diet-induced damage in gut could be attributed to the endotoxemia, permeability, and gut microbiota, especially the role of mycoplasma and butyric acid-producing bacteria. In addition, predictive functional profiling of microbial communities by PICRUSt showed that C10 group enriched pathway related to membrane transport and down-regulated the pathways related to energy, coenzyme factor and vitamin metabolism, while C20 group exhibited reversed results. These data showed that the high-carbohydrate diet reversed the beneficial changes in gut microbial metabolism resulted from the medium-carbohydrate diet, and further demonstrated that microbiota played a key role in the gut damage caused by the high-carbohydrate diet. Our findings provide a reference for the targeted regulation of gut microbiota to mitigate the damage caused by the increase in starch content in fish feed (cost saving).

New Insights into the Pathogenesis of Non-Alcoholic Fatty Liver Disease: Gut-Derived Lipopolysaccharides and Oxidative Stress

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. The intricate NAFLD pathogenesis is summarized by the multiple-hits hypothesis, which combines all the environmental and genetic factors that promote the development of NAFLD into a single scenario. Among these, bacterial lipopolysaccharides (LPS) are derived from the overgrowth of Gram-negative bacteria and translocated mainly as a consequence of enhanced intestinal permeability. Furthermore, oxidative stress is increased in NAFLD as a consequence of reactive oxygen species (ROS) overproduction and a shortage of endogenous antioxidant molecules, and it is promoted by the interaction between LPS and the Toll-like receptor 4 system. Interestingly, oxidative stress, which has previously been described as being overexpressed in cardiovascular disease, could represent the link between LPS and the increased cardiovascular risk in NAFLD subjects. To date, the only effective strategy for the treatment of NAFLD and non-alcoholic steatohepatitis (NASH) is the loss of at least 5% body weight in overweight and/or obese subjects. However, the dose-dependent effects of multispecies probiotic supplementation on the serum LPS level and cardiometabolic profile in obese postmenopausal women were demonstrated. In addition, many antibiotics have regulatory effects on intestinal microbiota and were able to reduce serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and tumor necrosis factor alpha (TNF-α) in NASH animal models. Regarding the oxidant status, a Mediterranean diet has been reported to reduce oxidant stress, while vitamin E at high daily dosages induced the resolution of NASH in 36% of treated patients. Silymarin had the positive effect of reducing transaminase levels in NAFLD patients and long-term treatment may also decrease fibrosis and slow liver disease progression in NASH. Finally, the influence of nutraceuticals on gut microbiota and oxidant stress in NAFLD patients has not yet been well elucidated and there are insufficient data either to support or refuse their use in these subjects.

Bacterial antigen translocation and age as BMI-independent contributing factors on systemic inflammation in NAFLD patients

BACKGROUND & AIMS

Low-grade systemic inflammation is a crucial landmark in NAFLD favouring disease progression and comorbidities. We evaluated the input of circulating bacterial antigens on systemic markers of inflammation in NAFLD patients.

PATIENTS & METHODS

Multicenter cross-sectional study including consecutive patients with biopsy-proven NAFLD. Demographic, metabolic and fibrosis-related variables were collected. Circulating bacterial antigens were quantified in blood. Toll-like receptor SNPs were genotyped. Serum cytokine levels were evaluated. Peripheral blood mononuclear cell response to bacterial antigens was evaluated in vitro.

RESULTS

Three hundred and fifteen patients from five Spanish hospitals were distributed by BMI. At least, one bacterial antigenic type was found in 66 patients with BMI < 30 (63.4%) and 163 patients with BMI > 30 (77.3%) (P = .014). HOMA-IR was significantly higher in the presence of circulating antigens among patients with BMI < 30. NASH and significant fibrosis in non-obese patients were more frequent in the presence of at least two circulating antigenic types. Allelic frequencies of TLR variants were similar to controls and did not affect clinical or laboratory parameters. Pro-inflammatory cytokines were significantly increased in patients with bacterial antigens, regardless of BMI. TLR gene and protein expression levels were significantly increased in PBMCs from patients with bacterial antigens. Antigen concentrations independently influenced TNF-α and IL-6, in both BMI subgroups of patients. Age independently influenced TNF-α and IL-6 in non-obese patients, and TNF-α in obese patients.

CONCLUSION

Serum circulating bacterial antigens as well as age were BMI-independent factors related to increased systemic inflammation in NAFLD and provides insight on the multifaceted sources of inflammation in these patients.

Dietary Mannan-oligosaccharides potentiate the beneficial effects of Bifidobacterium bifidum in broiler chicken

This study investigated the effects of dietary Bifidobacterium bifidum (BFD) and mannan-oligosaccharide (MOS), as a synbiotic, on the production performance, gut microbiology, serum biochemistry, antioxidant profile and health indices of broiler chicken. Six dietary treatments were T1 (negative control), T2 (positive control-20 mg antibiotic BMD kg^-1 diet; BMD: bacitracin methylene disalicylate), T3 (0·1% MOS + 10⁶  CFU BFD per g feed), T4 (0·1% MOS + 10⁷  CFU BFD per g feed), T5 (0·2% MOS + 10⁶  CFU BFD per g feed) and T6 (0·2% MOS + 10⁷  CFU BFD per g feed). Significantly (P < 0·01) better growth performance and efficiency was observed in birds supplemented with 0·2% MOS along with 10⁶  CFU BFD per g of feed compared to BMD and control birds. Supplementation with 0·2% MOS along with either 10⁶ or 10⁷  CFU BFD per g feed reduced (P < 0·01) the gut coliform, Escherichia coli, total plate count, and Clostridium perfringens count and increased the Lactobacillus and Bifidobacterium count. Significantly (P < 0·01) higher serum and liver antioxidant enzyme pool, serum HDL cholesterol and lower serum glucose, triglyceride, total cholesterol, cardiac risk ratio, atherogenic coefficient and atherogenic index of plasma were observed in birds supplemented with 0·2% MOS along with 10⁶  CFU BFD per g of feed compared to control or BMD supplemented birds. Better production performance, gut microbial composition, serum biochemistry, antioxidant profile and health indices were depicted by broiler chicken supplemented with 0·2% MOS and 10⁶  CFU BFD per g of feed.

Constant Light Exposure Alters Gut Microbiota and Promotes the Progression of Steatohepatitis in High Fat Diet Rats

Background

Non-alcoholic fatty liver disease (NAFLD) poses a significant health concern worldwide. With the progression of urbanization, light pollution may be a previously unrecognized risk factor for NAFLD/NASH development. However, the role of light pollution on NAFLD is insufficiently understood, and the underlying mechanism remains unclear. Interestingly, recent studies indicate the gut microbiota affects NAFLD/NASH development. Therefore, the present study explored effects of constant light exposure on NAFLD and its related microbiotic mechanisms.

Materials and Methods

Twenty-eight SD male rats were divided into four groups (n = 7 each): rats fed a normal chow diet, and exposed to standard light-dark cycle (ND-LD); rats fed a normal chow diet, and exposed to constant light (ND-LL); rats fed a high fat diet, and exposed to standard light-dark cycle (HFD-LD); and rats on a high fat diet, and exposed to constant light (HFD-LL). Body weight, hepatic pathophysiology, gut microbiota, and short/medium chain fatty acids in colon contents, serum lipopolysaccharide (LPS), and liver LPS-binding protein (LBP) mRNA expression were documented post intervention and compared among groups.

Result

In normal chow fed groups, rats exposed to constant light displayed glucose abnormalities and dyslipidemia. In HFD-fed rats, constant light exposure exacerbated glucose abnormalities, insulin resistance, inflammation, and liver steatohepatitis. Constant light exposure altered composition of gut microbiota in both normal chow and HFD fed rats. Compared with HFD-LD group, HFD-LL rats displayed less Butyricicoccus, Clostridium, and Turicibacter, butyrate levels in colon contents, decreased colon expression of occludin-1 and zonula occluden−1 (ZO-1), and increased serum LPS and liver LBP mRNA expression.

Conclusion

Constant light exposure impacts gut microbiota and its metabolic products, impairs gut barrier function and gut-liver axis, promotes NAFLD/NASH progression in HFD rats.

Protective effect of probiotics in patients with non-alcoholic fatty liver disease

To investigate the effects of probiotics on liver function, glucose and lipids metabolism, and hepatic fatty deposition in patients with non-alcoholic fatty liver disease (NAFLD).Totally 140 NAFLD cases diagnosed in our hospital from March 2017 to March 2019 were randomly divided into the observation group and control group, 70 cases in each. The control group received the diet and exercise therapy, while the observation group received oral probiotics based on the control group, and the intervention in 2 groups lasted for 3 months. The indexes of liver function, glucose and lipids metabolism, NAFLD activity score (NAS), and conditions of fecal flora in 2 groups were compared before and after the treatment.Before the treatment, there were no significant differences on alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamine transferase (GGT), total bilirubin (TBIL), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), insulin resistance index (HOMA-IR), NAFLD activity score (NAS), and conditions of fecal flora in 2 groups (P > .05). After the treatment, ALT, AST, GGT, TC, TG, HOMA-IR, NAS, and conditions of fecal flora in the observation group were better than those in the control group, and the observation group was better after treatment than before. All these above differences were statistically significant (P < .05).Probiotics can improve some liver functions, glucose and lipids metabolism, hepatic fatty deposition in patients with NAFLD, which will enhance the therapeutic effects of NAFLD.

Gut Microbiota Metabolites in NAFLD Pathogenesis and Therapeutic Implications

Gut microbiota dysregulation plays a key role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) through its metabolites. Therefore, the restoration of the gut microbiota and supplementation with commensal bacterial metabolites can be of therapeutic benefit against the disease. In this review, we summarize the roles of various bacterial metabolites in the pathogenesis of NAFLD and their therapeutic implications. The gut microbiota dysregulation is a feature of NAFLD, and the signatures of gut microbiota are associated with the severity of the disease through altered bacterial metabolites. Disturbance of bile acid metabolism leads to underactivation of bile acid receptors FXR and TGR5, causal for decreased energy expenditure, increased lipogenesis, increased bile acid synthesis and increased macrophage activity. Decreased production of butyrate results in increased intestinal inflammation, increased gut permeability, endotoxemia and systemic inflammation. Dysregulation of amino acids and choline also contributes to lipid accumulation and to a chronic inflammatory status. In some NAFLD patients, overproduction of ethanol produced by bacteria is responsible for hepatic inflammation. Many approaches including probiotics, prebiotics, synbiotics, faecal microbiome transplantation and a fasting-mimicking diet have been applied to restore the gut microbiota for the improvement of NAFLD.

Gastrointestinal Disorders and Metabolic Syndrome: Dysbiosis as a Key Link and Common Bioactive Dietary Components Useful for their Treatment

Gastrointestinal (GI) diseases, which include gastrointestinal reflux disease, gastric ulceration, inflammatory bowel disease, and other functional GI disorders, have become prevalent in a large part of the world population. Metabolic syndrome (MS) is cluster of disorders including obesity, hyperglycemia, hyperlipidemia, and hypertension, and is associated with high rate of morbidity and mortality. Gut dysbiosis is one of the contributing factors to the pathogenesis of both GI disorder and MS, and restoration of normal flora can provide a potential protective approach in both these conditions. Bioactive dietary components are known to play a significant role in the maintenance of health and wellness, as they have the potential to modify risk factors for a large number of serious disorders. Different classes of functional dietary components, such as dietary fibers, probiotics, prebiotics, polyunsaturated fatty acids, polyphenols, and spices, possess positive impacts on human health and can be useful as alternative treatments for GI disorders and metabolic dysregulation, as they can modify the risk factors associated with these pathologies. Their regular intake in sufficient amounts also aids in the restoration of normal intestinal flora, resulting in positive regulation of insulin signaling, metabolic pathways and immune responses, and reduction of low-grade chronic inflammation. This review is designed to focus on the health benefits of bioactive dietary components, with the aim of preventing the development or halting the progression of GI disorders and MS through an improvement of the most important risk factors including gut dysbiosis.

Altered nutrient status reprograms host inflammation and metabolic health via gut microbiota

The metabolism of macro- and micronutrients is a complex and highly regulated biological process. An imbalance in the metabolites and their signaling networks can lead to nonresolving inflammation and consequently to the development of chronic inflammatory-associated diseases. Therefore, identifying the accumulated metabolites and altered pathways during inflammatory disorders would not only serve as "real-time" markers but also help in the development of nutritional therapeutics. In this review, we explore recent research that has delved into elucidating the effects of carbohydrate/calorie restriction, protein malnutrition, lipid emulsions and micronutrient deficiencies on metabolic health and inflammation. Moreover, we describe the integrated stress response in terms of amino acid starvation and lipemia and how this modulates new age diseases such as inflammatory bowel disease and atherosclerosis. Lastly, we explain the latest research on metaflammation and inflammaging. This review focuses on multiple signaling pathways, including, but not limited to, the FGF21-β-hydroxybutryate-NLRP3 axis, the GCN2-eIF2α-ATF4 pathway, the von Hippel-Lindau/hypoxia-inducible transcription factor pathway and the TMAO-PERK-FoxO1 axis. Additionally, throughout the review, we explain how the gut microbiota responds to altered nutrient status and also how antimicrobial peptides generated from nutrient-based signaling pathways can modulate the gut microbiota. Collectively, it must be emphasized that metabolic starvation and inflammation are strongly regulated by both environmental (i.e., nutrition, gut microbiome) and nonenvironmental (i.e., genetics) factors, which can influence the susceptibility to inflammatory disorders.

Lactobacillus plantarum NA136 ameliorates nonalcoholic fatty liver disease by modulating gut microbiota, improving intestinal barrier integrity, and attenuating inflammation

Gut microbiota dysbiosis, associated with insulin resistance, weak intestinal barrier integrity, and inflammation, may also play a role in the development of dietary-induced nonalcoholic fatty liver disease (NAFLD). This study investigates the effects of dietary Lactobacillus plantarum NA136 administration on gut microbiota composition in an insulin-resistant C57BL/6J mouse NAFLD model. Comparison of mice with and without L. plantarum NA136 treatment revealed that L. plantarum NA136 treatment not only relieved insulin resistance but also significantly increased relative proportions of Desulfovibrio, Alistipes, Prevotella, and Enterorhabdus in gut microbiota of NAFLD mice. Meanwhile, L. plantarum NA136 administration also inhibited pathogenic bacterial growth, while promoting growth of probiotics such as Allobaculum, Lactobacillus, and, most markedly, Bifidobacterium. Moreover, L. plantarum NA136 treatment of NAFLD mice improved intestinal barrier integrity and attenuated high-fat and fructose diet (HFD/F)-induced inflammation. These results implicate gut-liver-axis-dependent microbiota modulation as the underlying mechanism for L. plantarum NA136-induced amelioration of NAFLD.Key points• L. plantarum NA136 corrects gut microbiota disorders caused by a high-fat and fructose diet. • L. plantarum NA136 strengthens the intestinal barrier and reduces inflammation in the liver. • L. plantarum NA136 relieves NAFLD by improving the gut-liver axis.

Dysregulated FXR-FGF19 signaling and choline metabolism are associated with gut dysbiosis and hyperplasia in a novel pig model of pediatric NASH

To investigate the role of bile acids (BAs) in the pathogenesis of diet-induced nonalcoholic steatohepatitis (NASH), we fed a "Western-style diet" [high fructose, high fat (HFF)] enriched with fructose, cholesterol, and saturated fat for 10 wk to juvenile Iberian pigs. We also supplemented probiotics with in vitro BA deconjugating activity to evaluate their potential therapeutic effect in NASH. Liver lipid and function, cytokines, and hormones were analyzed using commercially available kits. Metabolites, BAs, and fatty acids were measured by liquid chromatography-mass spectrometry. Histology and gene and protein expression analyses were performed using standard protocols. HFF-fed pigs developed NASH, cholestasis, and impaired enterohepatic Farnesoid-X receptor (FXR)-fibroblast growth factor 19 (FGF19) signaling in the absence of obesity and insulin resistance. Choline depletion in HFF livers was associated with decreased lipoprotein and cholesterol in serum and an increase of choline-containing phospholipids in colon contents and trimethylamine-N-oxide in the liver. Additionally, gut dysbiosis and hyperplasia increased with the severity of NASH, and were correlated with increased colonic levels of choline metabolites and secondary BAs. Supplementation of probiotics in the HFF diet enhanced NASH, inhibited hepatic autophagy, increased excretion of taurine and choline, and decreased gut microbial diversity. In conclusion, dysregulation of BA homeostasis was associated with injury and choline depletion in the liver, as well as increased biliary secretion, gut metabolism and excretion of choline-based phospholipids. Choline depletion limited lipoprotein synthesis, resulting in hepatic steatosis, whereas secondary BAs and choline-containing phospholipids in colon may have promoted dysbiosis, hyperplasia, and trimethylamine synthesis, causing further damage to the liver.NEW & NOTEWORTHY Impaired Farnesoid-X receptor (FXR)-fibroblast growth factor 19 (FGF19) signaling and cholestasis has been described in nonalcoholic fatty liver disease (NAFLD) patients. However, therapeutic interventions with FXR agonists have produced contradictory results. In a swine model of pediatric nonalcoholic steatohepatitis (NASH), we show that the uncoupling of intestinal FXR-FGF19 signaling and a decrease in FGF19 levels are associated with a choline-deficient phenotype of NASH and increased choline excretion in the gut, with the subsequent dysbiosis, colonic hyperplasia, and accumulation of trimethylamine-N-oxide in the liver.

Changes to the gut microbiota in mice induced by infection with Toxoplasma gondii

Toxoplasma gondii (T. gondii) is a common parasite worldwide, which can cause encephalitis, enteritis and miscarriage in abortion women. This study examined the cecal microbiome of mice infected with T. gondii through analysis of 16S rRNA genes determined by Illumina sequencing. BALB/c mice were orally infected with sporulated T. gondii oocysts. Mice were killed after 13-days- and 21-days- post infection, respectively, then their cecal contents were extracted and examined to determine the composition of gut microflora by illumina sequencing of the V3 +V4 region of the 16S rRNA genes. Our results showed the alterations in the gut microbes of BALB/c mice infected with T. gondii infection, where we observed a significant shift in the relative abundance of cecal bacteria. In mice at 13 days post-infection, the relative abundance of Proteobacteria increased, along with that of harmful bacteria, such as Bilopha and Desulfovibrio. However, the abundance of Lactobacillus decreased. At 21 days post-infection, the abundance of Lactobacillus was more than that observed for the uninfected control, with harmful bacteria, such as Bilopha and Desulfovibrio being reduced. The mice at 21-days post-infection had more beneficial intestinal bacteria than the control group. Our results suggested that the gut microbiota play an important role in disease progression from acute infection to chronic infection.

Targeting the gut microbiota with resveratrol: a demonstration of novel evidence for the management of hepatic steatosis

Resveratrol is a natural polyphenol that has been reported to reduce the risk of obesity and nonalcoholic fatty liver disease (NAFLD). Recent evidence has demonstrated that the gut microbiota plays an important role in the protection against NAFLD and other metabolic diseases. The present study aimed to investigate the relationship between the gut microbiota and the beneficial effects of resveratrol on the amelioration of NAFLD in mice. We observed marked decreases in body weight and liver steatosis and improved insulin resistance in high-fat diet (HFD)-fed mice treated with resveratrol. Furthermore, we found that resveratrol treatment alleviated NAFLD in HFD-fed mice by improving the intestinal microenvironment, including gut barrier function and gut microbiota composition. On the one hand, resveratrol improved gut intestinal barrier integrity through the repair of intestinal mucosal morphology and increased the expression of physical barrier- and physiochemical barrier-related factors in HFD-fed mice. On the other hand, in HFD-fed mice, resveratrol supplementation modulated the gut bacterial composition. The resveratrol-induced gut microbiota was characterized by a decreased abundance of harmful bacteria, including Desulfovibrio, Lachnospiraceae_NK4A316_group and Alistipes, as well as an increased abundance of short-chain fatty acid (SCFA)-producing bacteria, such as Allobaculum, Bacteroides and Blautia. Moreover, transplantation of the HFDR-microbiota into HFD-fed mice sufficiently decreased body weight, liver steatosis and low-grade inflammation and improved hepatic lipid metabolism. Collectively, resveratrol would provide a potentially dietary intervention strategy against NAFLD through modulating the intestinal microenvironment.

Antibiotics can cause weight loss by impairing gut microbiota in mice and the potent benefits of lactobacilli

This study assessed whether antibiotics could alter gut microbiota to affect host growth and the possibility of alleviation by lactobacilli. We divided four-week-old BABL/c mice into control (Ctrl), antibiotic exposure (Abx), Lactobacillus plantarum PC-170 (PC), and Lactobacillus rhamnosus GG (LGG) group and the Abx, LGG, and PC group received an one-week antibiotic/antibiotic + probiotic treatment. The fecal microbiota and the expression of splenic cytokines were determined. Following the ceftriaxone treatment, the body weight gain of Abx was delayed compared with others. The ceftriaxone treatment significantly decreased the alpha-diversity of the fecal microbiota and altered the fecal microbiota but LGG and PC can partly alleviate the effect. At the end of the study, the microbial community of LGG and PC group were more similar to Ctrl compared with Abx group. The results indicated that ceftriaxone could significantly alter intestinal microbiota. Lactobacilli might alleviate the side effects of antibiotics by stabilizing the intestinal microbiota.

Lactic acid bacteria reduce diabetes symptoms in mice by alleviating gut microbiota dysbiosis and inflammation in different manners

LAB exhibiting hypoglycaemic effects reduced insulin resistance by contributing to the production of SCFAs and alleviation of inflammation. L. rhamnosus regulated blood lipid more efficiently than Bifidobacterium.

Lactobacillus acidophilus JCM 1132 Strain and Its Mutant with Different Bacteriocin-Producing Behaviour Have Various in Situ Effects on the Gut Microbiota of Healthy Mice

The production of bacteriocin is considered to be a probiotic trait of lactic acid bacteria (LAB). However, not all strains of LAB harbour bacteriocin genes, even within the same species. Moreover, the effects of bacteriocins on the host gut microbiota and on host physiological indicators are rarely studied. This study evaluated the effects of the bacteriocin-producing Lactobacillus acidophilus strain JCM1132 and its non-producing spontaneous mutant, L. acidophilus CCFM720, on the physiological statuses and gut microbiota of healthy mice. Mice that received the bacteriocin-producing strain JCM1132 exhibited reduced water and food intake. Furthermore, the administration of these strains induced significant changes in the compositional abundance of faecal microbiota at the phylum and genus levels, and some of these changes were more pronounced after one week of withdrawal. The effects of CCFM720 treatment on the gut microbiota seemed to favour the prevention of metabolic diseases to some extent. However, individuals that received JCM1132 treatment exhibited weaker inflammatory responses than those that received CCFM720 treatment. Our results indicate that treatment with bacteriocin-producing or non-producing strains can have different effects on the host. Accordingly, this trait should be considered in the applications of LAB.

Effects of Probiotics on Intestinal Failure-Associated Liver Disease in Adult Patients Receiving Prolonged Parenteral Support: A Tertiary Care Center Experience

BACKGROUND

It has been hypothesized that dysbiosis plays a significant role in the pathogenesis of intestinal failure-associated liver disease (IFALD). Therefore, we aimed to investigate the effect of probiotics on IFALD in patients receiving parenteral support, namely home parenteral nutrition (HPN) and home intravenous fluids (HIVFs).

METHODS

We retrospectively reviewed charts of patients with intestinal failure who received HPN or HIVF for >2 weeks at our tertiary center between January 2005 and August 2016. We excluded patients <18 years of age, patients with other causes of liver disease, patients who used probiotics for <30 days, patients with <6 months' follow-up, and those who had long-term antibiotic use (>30 days). Bivariable and multivariable logistic regression analyses were used in this study.

RESULTS

A total of 282 patients who received parenteral support were included. Eighty-five percent of our sample received PN. A total of 78 (27.7%) patients used probiotics. The prevalence of IFALD in patients who used probiotics was 35.9% vs 54.4% in patients who did not use probiotics, P = .005. In multivariable analysis, only small-bowel length of 10-90 cm and HPN use showed a significant impact on IFALD, odds ratio (OR) = 4.394 (95% confidence interval [CI], 1.635-11.814; P = .003) and OR = 4.502 (95% CI 1.412-14.351; P = .011), respectively.

CONCLUSION

Our study revealed that the prevalence of IFALD was comparable among the probiotic users and nonusers. Only small bowel length of 1090 cm and HPN use showed a significant impact on IFALD.

Natural Microbial Communities Can Be Manipulated by Artificially Constructed Biofilms

Biofouling proceeds in successive steps where the primary colonizers affect the phylogenetic and functional structure of a future microbial consortium. Using microbiologically influenced corrosion (MIC) as a study case, a novel approach for material surface protection is described, which does not prevent biofouling, but rather shapes the process of natural biofilm development to exclude MIC-related microorganisms. This approach interferes with the early steps of natural biofilm formation affecting how the community is finally developed. It is based on a multilayer artificial biofilm, composed of electrostatically modified bacterial cells, producing antimicrobial compounds, extracellular antimicrobial polyelectrolyte matrix, and a water-proof rubber elastomer barrier. The artificial biofilm is constructed layer-by-layer (LBL) by manipulating the electrostatic interactions between microbial cells and material surfaces. Field testing on standard steel coupons exposed in the sea for more than 30 days followed by laboratory analyses using molecular-biology tools demonstrate that the preapplied artificial biofilm affects the phylogenetic structure of the developing natural biofilm, reducing phylogenetic diversity and excluding MIC-related bacteria. This sustainable solution for material protection showcases the usefulness of artificially guiding microbial evolutionary processes via the electrostatic modification and controlled delivery of bacterial cells and extracellular matrix to the exposed material surfaces.