Gut Microbiota and Obesity: A Role for Probiotics. Nutrients. 2019;11:2690. [PMID: 31703257 PMCID: PMC6893459 DOI: 10.3390/nu11112690]

Resveratrol Butyrate Esters Inhibit Obesity Caused by Perinatal Exposure to Bisphenol A in Female Offspring Rats

Resveratrol butyrate esters (RBE) are derivatives of resveratrol (RSV) and butyric acid and exhibit biological activity similar to that of RSV but with higher bioavailability. The aim of this study was designed as an animal experiment to explore the effects of RBE on the serum biochemistry, and fat deposits in the offspring rats exposed to bisphenol A (BPA), along with the growth and decline of gut microbiota. We constructed an animal model of perinatal Bisphenol A (BPA) exposure to observe the effects of RBE supplementation on obesity, blood lipids, and intestinal microbiota in female offspring rats. Perinatal exposure to BPA led to weight gain, lipid accumulation, high levels of blood lipids, and deterioration of intestinal microbiota in female offspring rats. RBE supplementation reduced the weight gain and lipid accumulation caused by BPA, optimised the levels of blood lipids, significantly reduced the Firmicutes/Bacteroidetes (F/B) ratio, and increased and decreased the abundance of S24-7 and Lactobacillus, respectively. The analysis of faecal short-chain fatty acid (SCFA) levels revealed that BPA exposure increased the faecal concentration of acetate, which could be reduced via RBE supplementation. However, the faecal concentrations of propionate and butyrate were not only significantly lower than that of acetate, but also did not significantly change in response to BPA exposure or RBE supplementation. Hence, RBE can suppress BPA-induced obesity in female offspring rats, and it demonstrates excellent modulatory activity on intestinal microbiota, with potential applications in perinatological research.

The Link between Obesity, Microbiota Dysbiosis, and Neurodegenerative Pathogenesis

Current research in medicine in several parts of the world has attempted to establish a link between the occurrence of neurodegenerative pathologies, microbiota dysbiosis, and the incidence of obesity. The body’s response to different physicochemical factors has also been influenced by the proper assimilation of bioactive compounds contained in the food that is ingested. Oxidative stress is one of the major factors that directly affects the functioning of the human microbiota. The body’s reaction to this imbalance is crucial to the progression of inflammatory processes, which are based on molecular mechanisms. Microbial dysbiosis can result in a possibly permanent alteration in the physiological response. This review aims to highlight recent contributions made to alleviating human dysbiosis in degenerative diseases, especially for neurodegenerative pathologies based on the rising prevalence of obesity. We discuss the significance of both microbiota modulation and possible alleviations of pathologies by a modulatory function. We argue that pre- and probiotics (including phenolic compounds stimulating the favorable strain from the microbiota) are an effective alternative that can support the microbiota pattern’s modulation over time and the attenuation of indirect causes that determine dysbiosis. Molecular aspects are presented in support of the modulating role of the microbiota following the use of probiotics.

Unhealthy Lifestyle and Gut Dysbiosis: A Better Understanding of the Effects of Poor Diet and Nicotine on the Intestinal Microbiome

The study of the intestinal or gut microbiome is a newer field that is rapidly gaining attention. Bidirectional communication between gut microbes and the host can impact numerous biological systems regulating immunity and metabolism to either promote or negatively impact the host's health. Habitual routines, dietary choices, socioeconomic status, education, host genetics, medical care and environmental factors can all contribute to the composition of an individual's microbiome. A key environmental factor that may cause negative outcomes is the consumption of nicotine products. The effects of nicotine on the host can be exacerbated by poor dietary choices and together can impact the composition of the gut microbiota to promote the development of metabolic disease including non-alcoholic fatty liver disease. This review explores the contribution of nicotine, poor dietary choices and other unhealthy lifestyle factors to gut dysbiosis.

Genetic and environmental factors influencing the interaction between the gut microbiota and the human host: implications for gastrointestinal disorders and treatment approaches

The growing knowledge on the microbiota hosted in the human intestine has allowed researchers and clinicians to discover a critical role for these microorganisms in the pathogenesis of several human disorders. In particular, perturbation in the microbiotic strains populating the gastrointestinal tract has been associated with several conditions affecting the digestive system. The composition of the human gut microbiota is influenced by both genetic factors, like the human and the microbiotic genomes, and environmental ones, such as diet or drugs. Alteration of the interaction between the gut microbiota and the human host has been proven to be associated with several gastrointestinal disorders as well as potential effects on pharmacological therapies.

The Influence of Gut Microbiota on the Cardiovascular System Under Conditions of Obesity and Chronic Stress

PURPOSE OF REVIEW

Based on the available data, it can be assumed that microbiota is an integral part of the human body. The most heavily colonized area of the human body is the gut, with bacterial accumulation ranging from 101-103 cells/g in the upper intestine to 1011-1012 cells/g in the colon. However, colonization of the gut is not the same throughout, as it was shown that there are differences between the composition of the microbiota in the intestine lumen and in the proximity of the mucus layer.

RECENT FINDINGS

Gut microbiota gradient can be differentially regulated by factors such as obesity and chronic stress. In particular, a high fat diet influences the gut microbial composition. It was also found that chronic stress may cause the development of obesity and thus change the organization of the intestinal barrier. Recent research has shown the significant effect of intestinal microflora on cardiovascular function. Enhanced absorption of bacterial fragments, such as lipopolysaccharide (LPS), promotes the onset of "metabolic endotoxemia," which could activate toll-like receptors, which mediates an inflammatory response and in severe cases could cause cardiovascular diseases. It is presumed that the intestinal microbiota, and especially its metabolites (LPS and trimethylamine N-oxide (TMAO)), may play an important role in the pathogenesis of arterial hypertension, atherosclerosis, and heart failure. This review focuses on how gut microbiota can change the morphological and functional activity of the cardiovascular system in the course of obesity and in conditions of chronic stress.

Allobaculum Involves in the Modulation of Intestinal ANGPTLT4 Expression in Mice Treated by High-Fat Diet

Increasing studies have shown that obesity is the primary cause of cardiovascular diseases, non-alcoholic fatty liver diseases, type 2 diabetes, and a variety of cancers. The dysfunction of gut microbiota was proved to result in obesity. Recent research indicated ANGPTL4 was a key regulator in lipid metabolism and a circulating medium for gut microbiota and fat deposition. The present study was conducted to investigate the alteration of gut microbiota and ANGPTL4 expression in the gastrointestinal tract of mice treated by the high-fat diet. Ten C57BL/6J mice were randomly allocated to two groups and fed with a high-fat diet (HFD) containing 60% fat or a normal-fat diet (Control) containing 10% fat. The segments of ileum and colon were collected for the determination of ANGPTL4 expression by RT-qPCR and immunohistochemical analysis while the ileal and colonic contents were collected for 16S rRNA gene sequencing. The results showed HFD significantly increased mice body weight, epididymal fat weight, perirenal fat weight, liver weight, and the lipid content in the liver (P < 0.05). The relative expression of ANGPTL4 and the ANGPTL4-positive cells in the ileum and colon of mice was significantly increased by HFD treatment. Furthermore, 16S rRNA gene sequencing of the ileal and colonic microbiota suggested that HFD treatment changed the composition of the gut microbiota. The ratio of Firmicutes to Bacteroidetes and the abundance of Allobaculum was significantly higher in the HFD group than in the Control group while the abundance of Adlercreutzia, Bifidobacterium, Prevotellaceae UCG-001, and Ruminococcus was significantly decreased. Interestingly, the abundance of Allobaculum was positively correlated with the expression of ANGPTL4. These findings provide a theoretical foundation for the development of strategies to control the obesity and related diseases by the regulation of ANGPTL4 and gut microbiota.

Nutritional Status and the Critically Ill Patient: Gut Microbiota and Immuno-Nutrition in I.C.U. at the Time of SARS-COV 2 Pandemic

Background: Gut microbiota is a complex ecosystem of bacteria, viruses, archaea, protozoa and yeasts in our intestine. It has several functions, including maintaining human body equilibrium. Microbial “dysbiosis” can be responsible for outbreak of local and systemic infections, especially in critically ill patients. Methods: to build a narrative review, we performed a Pubmed, Medline and EMBASE search for English language papers, reviews, meta-analyses, case series and randomized controlled trials (RCTs) by keywords and their associations: critically ill patient; nutrition; gut microbiota; probiotics; gut virome; SARS-COV 2. Results: Over the antibiotic-based “selective decontamination”, potentially responsible for drug-resistant microorganisms development, there is growing interest of scientists and the pharmaceutical industry for pre-, probiotics and their associations as safe and reliable remedies restoring gut microbial “eubiosis”. Very first encouraging evidences link different gut microbiota profiles with SARS-COV 2 disease stage and gravity. Thus, there is frame for a probiotic therapeutic approach of COVID-19. Conclusions: gut microbiota remodulation seems to be a promising and safe therapeutic approach to prevent local and systemic multi-resistant bug infections in the intensive care unit (ICU) patients. This approach deserves more and more attention at the time of SARS-COV 2 pandemic.

Probiotics and gut health

BACKGROUND

Gut microbiota is a complex ecosystem of bacteria, viruses, archea, protozoa and yeasts in our intestine. It has several functions maintaining human body equilibrium. Microbial " dysbiosis " can be responsible for several gastrointestinal diseases.

METHODS

to build a narrative review we performed a Pubmed, Medline, EMBASE search for English language papers, reviews, meta-analyses, case series, and randomized controlled trials (RCTs) by keywords and their associations: gut microbiota, dysbiosis, gastrointestinal diseases, probiotics.

RESULTS

gut microbiota is altered in several gastrointestinal diseases with very different pathophysiology. They range from multi-factorial diseases such as irritable bowel syndrome (IBS), non-alcoholic fatty liver disease (NAFLD) and gastric and colorectal cancers, immunemediated such as celiac disease, inflammatory bowel diseases (IBD), antibioticrelated such as Clostridium Difficile infection (CDI). Microbial dysbiosis re-modulation by probiotics is feasible and safe in some of them.

CONCLUSIONS

gut microbial dysbiosis is statistically associated with several gastro-intestinal diseases, affecting their pathophysiology. Its reverse by probiotics has some promising evidences of efficacy.

The Role of the Microbiome in Liver Cancer

Hepatocellular carcinoma (HCC) is the most common malignancy occuring in the context of chronic liver disease and is one of the main causes of cancer-derived death worldwide. The lack of effective treatments, together with the poor prognosis, underlines the urge to develop novel and multidisciplinary therapeutics. An increasing body of evidence shows that HCC associates with changes in intestinal microbiota abundance and composition as well as with impaired barrier function, leading to the release of bacteria and their metabolites to the liver. These factors trigger a cascade of inflammatory responses contributing to liver cirrhosis and constituting an ideal environment for the progression of HCC. Interestingly, the use of bacteriotherapy in human and preclinical studies of chronic liver disease and HCC has been shown to successfully modify the microbiota composition, reducing overall inflammation and fibrosis. In this review, we explore the existing knowledge on the characterisation of the intestinal microbial composition in humans and experimental murine chronic liver disease and HCC, as well as the use of antibiotics and bacteriotherapy as therapeutic options.

Harmful Effects of COVID-19 on Major Human Body Organs: A Review

The world experienced the outbreak of a new pandemic disease in 2019, known as coronavirus (CoV) disease 2019 (COVID-19), which is caused by the novel severe acute respiratory syndrome-CoV-2 (SARS-CoV-2). The respiratory system is the organ system most commonly affected by COVID-19; however, several other organ systems have been reported to be affected. The SARS-CoV-2 RNA found in infected stub samples can cause lung contagion by binding to the angiotensin-converting enzyme-2 (ACE-2) receptor of the alveolar epithelial cells. The gut microbiota (GM) promote immunity, indicating that the alignment of the microbiota and corresponding metabolic processes in COVID-19 can help to identify novel biomarkers and new therapeutic targets for this disease. The cause of kidney damage in COVID-19 patients is possibly multifactorial, involving a complex mechanism that involves complement dysregulation and thrombotic microangiopathy, as well as the occurrence of a “cytokine storm” syndrome, which are immune responses that are abandoned and dysfunctional with unfavorable prognosis in severe COVID-19 cases. Furthermore, COVID-19 involves a continuous proliferation and activation of macrophages and lymphocytes. SARS-CoV-2 can also bind to the ACE-2 receptor expressed in the cerebral capillary endothelial cells that can invade the blood-brain wall, to penetrate the brain parenchyma. However, in the ongoing pandemic, there has been a surge in studies on a wide range of topics, including causes of respiratory failure, asymptomatic patients, intensive care patients, and survivors. This review briefly describes the damaging effects of COVID-19 on vital human organs and the inhibitory function of the ACE-2 receptor on the GM, which causes gut dysbiosis, and thus, this review discusses topics that have an opportunity for further investigation.

Study Protocol of a Multicenter Randomized Controlled Trial to Tackle Obesity through a Mediterranean Diet vs. a Traditional Low-Fat Diet in Adolescents: The MED4Youth Study

Youth obesity is a strong predictor of adult obesity, which has well-known negative health consequences. Thus, addressing adult obesity requires tackling youth obesity. MED4Youth's main objective is to strengthen the link between the Mediterranean Diet (MD) and the health benefits against youth obesity and associated cardiovascular disease (CVD) risk factors, identifying positive effects exerted by an MD including sourdough bread and healthy products from the Mediterranean basis (chickpeas/hummus, nuts, and pomegranate juice). For this purpose, a multicenter randomized controlled trial in which an MD-based intervention will be compared to a traditional low-fat diet intervention will be carried out with 240 overweight and obese adolescents (13-17 years) from Spain, Portugal, and Italy. Both interventions will be combined with an educational web-application addressed to engage the adolescents through a learning-through-playing approach, using both educational materials and games. To assess the interventions, adherence to the MD, dietary records, physical activity, food frequency, sociodemographic, and quality of life questionnaires as well as classical anthropometric and biochemical parameters will be evaluated. Furthermore, an omics approach will be performed to elucidate whether the interventions can shape the gut microbiota and gut-derived metabolites to gain knowledge on the mechanisms through which the MD can exert its beneficial effects.

Significance of African Diets in Biotherapeutic Modulation of the Gut Microbiome

Diet plays an essential role in human development and growth, contributing to health and well-being. The socio-economic values, cultural perspectives, and dietary formulation in sub-Saharan Africa can influence gut health and disease prevention. The vast microbial ecosystems in the human gut frequently interrelate to maintain a healthy, well-coordinated cellular and humoral immune signalling to prevent metabolic dysfunction, pathogen dominance, and induction of systemic diseases. The diverse indigenous diets could differentially act as biotherapeutics to modulate microbial abundance and population characteristics. Such modulation could prevent stunted growth, malnutrition, induction of bowel diseases, attenuated immune responses, and mortality, particularly among infants. Understanding the associations between specific indigenous African diets and the predictability of the dynamics of gut bacteria genera promises potential biotherapeutics towards improving the prevention, control, and treatment of microbiome-associated diseases such as cancer, inflammatory bowel disease, obesity, type 2 diabetes, and cardiovascular disease. The dietary influence of many African diets (especially grain-base such as millet, maize, brown rice, sorghum, soya, and tapioca) promotes gut lining integrity, immune tolerance towards the microbiota, and its associated immune and inflammatory responses. A fibre-rich diet is a promising biotherapeutic candidate that could effectively modulate inflammatory mediators' expression associated with immune cell migration, lymphoid tissue maturation, and signalling pathways. It could also modulate the stimulation of cytokines and chemokines involved in ensuring balance for long-term microbiome programming. The interplay between host and gut microbial digestion is complex; microbes using and competing for dietary and endogenous proteins are often attributable to variances in the comparative abundances of Enterobacteriaceae taxa. Many auto-inducers could initiate the process of quorum sensing and mammalian epinephrine host cell signalling system. It could also downregulate inflammatory signals with microbiota tumour taxa that could trigger colorectal cancer initiation, metabolic type 2 diabetes, and inflammatory bowel diseases. The exploitation of essential biotherapeutic molecules derived from fibre-rich indigenous diet promises food substances for the downregulation of inflammatory signalling that could be harmful to gut microbiota ecological balance and improved immune response modulation.

Antibiotic Followed by a Potential Probiotic Increases Brown Adipose Tissue, Reduces Biometric Measurements, and Changes Intestinal Microbiota Phyla in Obesity

The development of adjuvant therapies for obesity treatment is justified by the high prevalence of this disease worldwide, and the relationship between obesity and intestinal microbiota is a promising target for obesity treatment. Therefore, this study aimed at investigating the adjuvant treatment of obesity through the use of potential probiotics and antibiotics, either separately or sequentially. In the first phase of the experiment, animals had diet-induced obesity with consumption of a high saturated fat diet and a fructose solution. After this period, there was a reduction in caloric supply, that is the conventional treatment of obesity, and the animals were divided into 5 experimental groups: control group (G1), obese group (G2), potential probiotic group (G3), antibiotic group (G4), and antibiotic followed by potential probiotic group (G5). The adjuvant treatments lasted 4 weeks and were administered daily, via gavage: Animals in G1 and G2 received distilled water, the G3 obtained Lactobacillus gasseri LG-G12, and the G4 received ceftriaxone. The G5 received ceftriaxone for 2 weeks, followed by the offer of Lactobacillus gasseri LG-G12 for another 2 weeks. Parameters related to obesity, such as biometric measurements, food consumption, biochemical tests, histological assessments, short-chain fatty acids concentration, and composition of the intestinal microbiota, were analyzed. The treatment with caloric restriction and sequential supply of antibiotics and potential probiotics was able to reduce biometric measures, increase brown adipose tissue, and alter the intestinal microbiota phyla, standing out as a promising treatment for obesity.

Are Faecal Microbiota Analyses on Species-Level Suitable Clinical Biomarkers? A Pilot Study in Subjects with Morbid Obesity

BACKGROUND

An abnormal faecal microbiota could be a causal factor for disease. This study evaluated a new method for faecal microbiota analysis in subjects with obesity and irritable bowel syndrome.

METHODS

The study had a matched case-control design. Forty-six subjects with morbid obesity (defined as BMI > 40 or >35 kg/m² with obesity-related complications) of whom 23 had irritable bowel syndrome (IBS), were compared with 46 healthy volunteers. The faecal microbiota was analysed with Precision Microbiome Profiling (PMP™) which quantified 104 bacteria species. The primary aim was comparisons between the cases and controls.

RESULTS

Two men and 44 women with a mean age of 43.6 years were included in each of the groups; BMI in the groups was (mean and SD) 41.9 (3.5) and 22.5 (1.5) kg/m², respectively. Seventeen bacterial species showed statistically significant differences between the groups after adjusting for multiple testing. In a post hoc analysis, the sensitivity and specificity were 78%. Alpha diversity was lower in the group with obesity. In subjects with morbid obesity, no clinically significant differences were seen between subjects with and without IBS or from before to six months after bariatric surgery.

CONCLUSIONS

The results encourage further evaluation of the new microbiome profiling tool.

Gut Microbiota and Obesity in Adults and Children: The State of the Art

In recent decades, obesity has become a serious public health problem affecting both children and adults. Considering the multifactorial origin of obesity, including modifiable factors, childhood was identified as the golden age for investing in obesity prevention by both promoting proper lifestyles and actively intervening in possible triggers. The gut microbiota is at the center of the most recent scientific studies and plays a key role in obesity development because it is intimately linked to energetic-humoral variations in the host: its alterations can promote a state of excessive energy storage, and it can be manipulated to maintain energy homoeostasis. This review aims to offer a panoramic understanding of the interplay between obesity and the gut microbiota, focusing on the contribution that the gut microbiota could have to the prevention of childhood obesity and its complications in adulthood. Currently, the use of some specific probiotic strains has been shown to be able to act on some secondary metabolic consequences of obesity (such as liver steatosis and insulin resistance) without any effect on weight loss. Although definitive conclusions cannot be drawn on the real impact of probiotics and prebiotics, there is no doubt that they represent an exciting new frontier in the treatment of obesity and associated metabolic dysfunctions. Targeted studies randomized on specific populations and homogeneous for ethnicity, sex, and age are urgently needed to reach definitive conclusions about the influence of microbiota on weight. In particular, we still need more studies in the pediatric population to better understand when the switch to an obese-like gut microbiota takes place and to better comprehend the right timing of each intervention, including the use of pre/probiotics, to improve it.

Microbiota and their Influence in the Human Body

Scientists have invested considerable resources in the study of the microbiota of the human body. These microorganisms play pivotal roles in immunity and disease. Of which, probiotics are live beneficial microorganisms that keep your intestinal or lung microbiota healthy, and occupy a special role in combating the infections. Thus, it is critical to understand their contributions to these processes. Technology can facilitate advanced studies of the microbiota, including how it develops and its positive and negatives effects on the immune system. This paper investigates how several factors (e.g. birth delivery mode, metabolic activities, types of microorganisms, and immune system interactions) affect the microbiota, particularly in early life. The paper also discusses how gastrointestinal microbes in particular may be associated with certain disease processes, such as those related to schizophrenia, autism, and diabetes. Clinical studies show that certain probiotic strains, like Lactobacillus rhamnosus GG and Bifidobacterium animalis ssp. lactis help to prevent infection of pathogenic organisms (both bacterial and viral). This research may yield crucial contributions to disease prevention and public health. The dysbiosis may result in changes in the acquired immunity later on. The probiotic strains can prevent viral replication during SARS-CoV-2 or COVID-19 infection by reducing proinflammatory cytokines. There has been much interest into the intestinal flora as proposed by the diversity, volume, and proposed role in disease. Future research in the field of microbiome should be done in order to uncover their association to gut virome by noting both their influence on each other and relevant health and disease.

Gut microbiome and Clostridioides difficile infection: a closer look at the microscopic interface

The pathogenesis of Clostridioides difficile infection (CDI) was recognized with its link to the use of antimicrobials. Antimicrobials significantly alter gut microbiota structure and composition, which led to the discovery of the association of this gut perturbation with the development of CDI. A number of factors implicated in its pathogenesis, such as advancing age, proton-pump inhibitors, and gastrointestinal diseases, are linked to gut microbiota perturbations. In an effort to better understand CDI, a multitude of studies have tried to ascertain protective and predictive microbial footprints linked with CDI. It has further been realized that CDI in itself can alter the gut microbiome. Its spore-forming capability poses as an impediment in the management of the infection and contributes to its recurrence. Antibiotic therapies used for its management have also been linked to gut microbiota changes, making its treatment a little more challenging. In an effort to exploit and utilize this association, gut microbial restoration therapies, particularly in the form of fecal microbial transplant, are increasingly being put to use and are proving to be beneficial. In this review, we summarize the association of the gut microbiome and microbial perturbation with initial and recurrent CDI.

Is Probiotic Supplementation Useful for the Management of Body Weight and Other Anthropometric Measures in Adults Affected by Overweight and Obesity with Metabolic Related Diseases? A Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis is to assess the effectiveness of probiotics in inducing body weight loss in patients with overweight or obesity with related metabolic diseases. The research was carried out on PubMed and Scopus, focusing on studies reporting the effect on anthropometric measures (weight, body mass Index (BMI), waist circumference (WC), and hip circumference (HC) after administration of various probiotic strains compared to placebo. Twenty randomized controlled trials, that included 1411 patients, were considered. The meta-analyzed mean differences (MD) for random effects showed no significant decrease in body weight after probiotic supplementation (−0.26 kg [−075, 0.23], p = 0.30), while a significant BMI decrease was found (−0.73 kg/m² [−1.31, −0.16], p = 0.01). For WC and HC, the meta-analyzed MD for random effects showed a significant decrease (WC: −0.71 cm [−1.24; −0.19], p = 0.008 and HC: −0.73 cm [−1.16; −0.30], p = 0.0008). The risk of bias was also evaluated considering a high risk and a low risk according to PRISMA criteria. In conclusion, the results of this meta-analysis highlight a positive trend of probiotics supplementation on the amelioration of anthropometric measures of overweight and obese patients with related metabolic diseases. However, further research is needed before recommending the use of probiotics as a therapeutic strategy for these patients. The focus of the future research should be to evaluate the efficacy of different probiotic strains, the quantities to be administered, and the duration of the intervention.

The intestinal mycobiota and its relationship with overweight, obesity and nutritional aspects

BACKGROUND

The fungal community of the gastrointestinal tract has recently become of interest, and knowledge of its relationship with the development of obesity is scarce. The present study aimed to evaluate the cultivable fungal fraction from the microbiota and to analyze its relationship with obesity.

METHODS

Samples were taken from 99 participants with normal weight, overweight and obesity (n = 31, 34 and 34, respectively) and were cultivated in selective medium, and the cultivable yeasts were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Anthropometric and biochemical measures were also evaluated.

RESULTS

Eutrophic, overweight and obese groups presented concentrations of 1.6, 2.16 and 2.19 log₁₀  colony-forming units g^-1 yeast, respectively. Ascomycota and Basidiomycota were the two identified phyla. At the genus level, Candida spp. showed a relatively high prevalence, and 10 different species were detected: Candida glabrata, Candida orthopsilosis, Candida lambica, Candida kefyr, Candida albicans, Candida krusei, Candida valida, Candida parapsilosis, Candida utilis and Candida humilis (with relative abundances of 71.72%, 5.05%, 21.21%, 6.06%, 29.29%, 27.27%, 8.08%, 16.16%, 1.01% and 2.02%, respectively).

CONCLUSIONS

The obese group presented a higher prevalence of Candida albicans. Furthermore, Candida albicans, Candida kefyr and Rhodotorula mucilaginosa showed a high positive correlation with obesity, weight gain and fat mass and showed a negative correlation with high-density lipoprotein and lean mass, parameters related to weight loss.

Antiobesity Effect of Novel Probiotic Strains in a Mouse Model of High-Fat Diet-Induced Obesity

Obesity is one of the major causes of the development of metabolic diseases, particularly cardiovascular diseases and type-2 diabetes mellitus. Increased lipid accumulation and abnormal adipocyte growth, which is an increase in cell numbers and differentiation, have been documented as major pathological characteristics of obesity. Thus, the inhibition of adipogenic differentiation prevents and suppresses obesity. Recently, specific probiotic strains have been known to regulate lipid metabolism in vitro and/or in vivo. Previously, we demonstrated that Lactobacillus johnsonni 3121 and Lactobacillus rhamnosus 86 could act as novel probiotic strains and reduce cholesterol levels. Moreover, both strains significantly reduced lipid accumulation and inhibited adipocyte differentiation by downregulating the adipogenic transcription factor in 3T3-L1 adipocytes. Therefore, L. johnsonni 3121 and L. rhamnosus 86 were selected for in vivo evaluation of their anti-obesity effects using a high-fat diet-induced obese mouse model. Daily oral administration of L. johnsonni 3121 and L. rhamnosus 86 for 12 weeks significantly improved serum lipid profile and downregulated the expression of genes related to adipogenesis and lipogenesis in epididymal white adipose tissue of high-fat diet fed obese mice (p < 0.05). Fecal analysis also suggested that the two probiotic strains could normalize the altered obesity-related gut microbiota in high-fat diet-fed obese mice. These results collectively demonstrate that oral administration of L. johnsonni 3121 and L. rhamnosus 86 could prevent obesity, thereby improving metabolic health.

Impact of Microbial Metabolites on Microbiota-Gut-Brain Axis in Inflammatory Bowel Disease

The complex bidirectional communication system existing between the gastrointestinal tract and the brain initially termed the "gut-brain axis" and renamed the "microbiota-gut-brain axis", considering the pivotal role of gut microbiota in sustaining local and systemic homeostasis, has a fundamental role in the pathogenesis of Inflammatory Bowel Disease (IBD). The integration of signals deriving from the host neuronal, immune, and endocrine systems with signals deriving from the microbiota may influence the development of the local inflammatory injury and impacts also more distal brain regions, underlying the psychophysiological vulnerability of IBD patients. Mood disorders and increased response to stress are frequently associated with IBD and may affect the disease recurrence and severity, thus requiring an appropriate therapeutic approach in addition to conventional anti-inflammatory treatments. This review highlights the more recent evidence suggesting that alterations of the microbiota-gut-brain bidirectional communication axis may concur to IBD pathogenesis and sustain the development of both local and CNS symptoms. The participation of the main microbial-derived metabolites, also defined as "postbiotics", such as bile acids, short-chain fatty acids, and tryptophan metabolites in the development of IBD-associated gut and brain dysfunction will be discussed. The last section covers a critical evaluation of the main clinical evidence pointing to the microbiome-based therapeutic approaches for the treatment of IBD-related gastrointestinal and neuropsychiatric symptoms.

Dietary Polyphenols and Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), which is emerging as a major public health issue worldwide, is characterized by a wide spectrum of liver disorders, ranging from simple fat accumulation in hepatocytes, also known as steatosis, to non-alcoholic steatohepatitis (NASH) and cirrhosis. At present, the pharmacological treatment of NAFLD is still debated and dietary strategies for the prevention and the treatment of this condition are strongly considered. Polyphenols are a group of plant-derived compounds whose anti-inflammatory and antioxidant properties are associated with a low prevalence of metabolic diseases, including obesity, hypertension, and insulin resistance. Since inflammation and oxidative stress are the main risk factors involved in the pathogenesis of NAFLD, recent studies suggest that the consumption of polyphenol-rich diets is involved in the prevention and treatment of NAFLD. However, few clinical trials are available on human subjects with NAFLD. Here, we reviewed the emerging existing evidence on the potential use of polyphenols to treat NAFLD. After introducing the physiopathology of NAFLD, we focused on the most investigated phenolic compounds in the setting of NAFLD and described their potential benefits, starting from basic science studies to animal models and human trials.

What Role Does the Endocannabinoid System Play in the Pathogenesis of Obesity?

The endocannabinoid system (ECS) is an endogenous signaling system formed by specific receptors (cannabinoid type 1 and type 2 (CB₁ and CB₂)), their endogenous ligands (endocannabinoids), and enzymes involved in their synthesis and degradation. The ECS, centrally and peripherally, is involved in various physiological processes, including regulation of energy balance, promotion of metabolic process, food intake, weight gain, promotion of fat accumulation in adipocytes, and regulation of body homeostasis; thus, its overactivity may be related to obesity. In this review, we try to explain the role of the ECS and the impact of genetic factors on endocannabinoid system modulation in the pathogenesis of obesity, which is a global and civilizational problem affecting the entire world population regardless of age. We also emphasize that the search for potential new targets for health assessment, treatment, and the development of possible therapies in obesity is of great importance.

Obesogenic Programming Effects during Lactation: A Narrative Review and Conceptual Model Focusing on Underlying Mechanisms and Promising Future Research Avenues

Animal studies have consistently demonstrated that maternal obesity and a high-fat diet during lactation enhances obesity risk in the offspring. However, less is known about these potential obesogenic programming effects in obese humans. We propose three important pathways that may explain obesogenic programming effects of human breastmilk. First, human milk components and hormones may directly affect child eating and satiety characteristics. Second, human milk constituents can affect child microbiota that, in turn, may influence child eating and weight outcomes. Third, human milk composition may affect child eating and weight outcomes through flavor exposure. We reviewed a few very recent findings from well-powered longitudinal or experimental human research with regard to these three pathways. Moreover, we provide a research agenda for future intervention research with the overarching aim to prevent excessive pediatric weight gain during lactation and beyond. The ideas presented in this paper may represent important “black box” constructs that explain obesogenic programming effects during lactation. It should be noted, however, that given the scarcity of studies, findings should be seen as working hypotheses to further test in future research.

Obesity and gut microbiome: review of potential role of probiotics

Obesity prevalence has increased worldwide over the years, with pandemic levels being already reached, besides to its huge economic and health impacts. The multifactorial pathogenesis of obesity partly explains the important challenge posed to health policy regarding its clinical treatment, with increasing evidences have shown that obesity and metabolic disturbances are closely linked to variations in gut microbiota (GM) function and composition. Indeed, GM play a key contribution in energy metabolism, with GM modulation being increasingly linked to changes in body weight and body mass index. In such matter, probiotics have been proposed as a promising new therapeutic strategy to treat/prevent obesity. Thus, this review aims to provide an overview on the clinical impact and effectiveness of probiotics in obese individuals.

Probiotics as a therapeutic strategy in obesity and overweight: a systematic review

Obesity and overweight are two of the most health challenges with an increasing prevalence in recent years, in which several complications have been identified to have a high impact in patients' health conditions. In this vein, an increasing interest in the gut microbiota has emerged as a target for therapeutic strategies in obesity and overweight due to its direct relation with the aforementioned health conditions and complications. Thus, the aim of this study was to evaluate the efficacy of probiotics as a therapeutic strategy in the management of obesity and overweight. A systematic review of randomised controlled trials was carried out in 6 databases until May 2019 to assess the use of probiotics in obesity and overweight patients. The Jadad Scale was used to assess the quality of the clinical trials. Twenty-three clinical trials published between 2000 and 2019 met the inclusion criteria. The role of probiotics in reducing body mass index and weight as well as changing the visceral abdominal fat area, waist and hip circumference were shown in 14 of 23 trials (60.87%); 14 trials (60.87%) showed changes on patients' fatty acids and biomarkers; and 4 trials (17.39%) studied the role of the gut microbiota in obese and overweight patients. Some probiotics strains are shown to be effective in reducing body mass index and hip circumference. This review provides evidence of successful results in weight loss using probiotic groups.

Metasequencing of V3-V4 Variable Regions of 16S rRNA Gene in Opportunistic Microbiota and Gut Biocenosis in Obese Adolescents

Opportunistic microorganisms in the gut biocenosis were studied in adolescents with normal body weight and obesity (patients consulted at the Clinical Department of Research Center of Family Health and Human Reproduction Problems). The biological material was studied by standard bacteriological methods, representatives of Enterobacteriaceae family were also characterized using metagenomic sequencing of V3-V4 variable regions of 16S gene rRNA. Gut microbiota of obese adolescents was unbalanced and was characterized by low levels of bifido- and lactoflora representatives, a spectrum of E. coli associations, and high prevalence of opportunistic microorganisms and their associations. Representatives of Enterobacteriaceae family were most often found in the gut microbiota of obese adolescents.

Effect of probiotic Lactobacillus plantarum Dad-13 powder consumption on the gut microbiota and intestinal health of overweight adults

BACKGROUND

Shifting on lifestyle, diet, and physical activity contributed on increasing number of obese people around the world. Multiple factors influence the development of obesity. Some research suggested that gut microbiota (GM) plays an important role in nutrient absorption and energy regulation of individuals, thus affecting their nutritional status. Report of Indonesia Basic Health Research showed that the prevalence of obesity in every province tended to increase. Although the root cause of obesity is excessive calorie intake compared with expenditure, the differences in gut microbial ecology between healthy and obese humans may affect energy homeostasis. GM affect body weight, especially obesity. Probiotics that are consumed while alive and able to colonize in the intestine are expected to increase the population of good bacteria, especially Bifidobacteria and Lactobacilli, and suppress pathogens such as Enterobacteriaceae and Staphylococcus. The strain of L. plantarum Dad-13 has been demonstrated to survive and colonize in the gastrointestinal tract of healthy Indonesian adults who consume fermented milk containing L. plantarum Dad-13. The consumption of probiotic L. plantarum Dad-13 powder decreased E. coli and non-E. coli coliform bacteria in school-aged children in Indonesia. L. plantarum is a dominant bacterium in the average Indonesian’s GM. For this reason, this bacterium is probably a more suitable probiotic for Indonesians.

AIM

To determine the effect of the consumption of indigenous probiotic Lactobacillus plantarum Dad-13 powder in overweight adults in Yogyakarta (Indonesia).

METHODS

Sixty overweight volunteers with a body mass index (BMI) equal to or greater than 25 consume indigenous probiotic powder L. plantarum Dad-13 (2 × 10⁹ CFU/gram/sachet) for 90 d. The study was a randomized, double-blind, placebo-controlled study. The volunteers filled in a diary on a daily basis, which consisted of questions on study product intake (only during ingestion period), other food intake, number of bowel movements, fecal quality (consistency and color), any medications received, and any symptom of discomfort, such as diarrhea, constipation, vomiting, gassing, sensation of illness, etc. Fecal samples and the subjects’ diaries were collected on the morning of day 10 + 1, which was marked as the end of the baseline period and the start of the ingestion period. During the ingestion period (from day 11 to day 101), several parameters to measure and analyze the results included body weight and height (once a month), the lipid profile, GM analysis using MiSeq, short-chain fatty acid (SCFA) analysis using gas chromatography, and the measurement of fecal pH using a pH meter.

RESULTS

The consumption of indigenous probiotic powder L. plantarum Dad-13 caused the average body weight and BMI of the probiotic group to decrease from 84.54 ± 17.64 kg to 83.14 ± 14.71 kg and 33.10 ± 6.15 kg/m² to 32.57 ± 5.01 kg/m², respectively. No significant reduction of body weight and BMI in the placebo group was observed. An analysis of the microbiota showed that the number of Bacteroidetes, specifically Prevotella, increased significantly, while that of Firmicutes significantly decreased. No significant change in lipid profile in both groups was found. Also, no significant change in SCFAs (e.g., butyrate, propionate, acetic acid) and pH level was found after the consumption of the probiotic.

CONCLUSION

No significant differences in pH before and after ingestion were observed in both the probiotic and placebo groups as well as in the lipid profile of both cholesterol and triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and the LDL/HDL ratio. In addition, no significant changes in the concentration of SCFAs (e.g., acetic acid, propionate, and butyrate) were found after con-sumption. Interestingly, a significant decrease in body weight and BMI (P < 0.05) was determined in the treatment group. An analysis of GM shows that L. plantarum Dad-13 caused the Firmicutes population to decrease and the Bacteroidetes population (especially Prevotella) to increase.

Effect of probiotic Lactobacillus plantarum Dad-13 powder consumption on the gut microbiota and intestinal health of overweight adults

BACKGROUND

Shifting on lifestyle, diet, and physical activity contributed on increasing number of obese people around the world. Multiple factors influence the development of obesity. Some research suggested that gut microbiota (GM) plays an important role in nutrient absorption and energy regulation of individuals, thus affecting their nutritional status. Report of Indonesia Basic Health Research showed that the prevalence of obesity in every province tended to increase. Although the root cause of obesity is excessive calorie intake compared with expenditure, the differences in gut microbial ecology between healthy and obese humans may affect energy homeostasis. GM affect body weight, especially obesity. Probiotics that are consumed while alive and able to colonize in the intestine are expected to increase the population of good bacteria, especially Bifidobacteria and Lactobacilli, and suppress pathogens such as Enterobacteriaceae and Staphylococcus. The strain of L. plantarum Dad-13 has been demonstrated to survive and colonize in the gastrointestinal tract of healthy Indonesian adults who consume fermented milk containing L. plantarum Dad-13. The consumption of probiotic L. plantarum Dad-13 powder decreased E. coli and non-E. coli coliform bacteria in school-aged children in Indonesia. L. plantarum is a dominant bacterium in the average Indonesian's GM. For this reason, this bacterium is probably a more suitable probiotic for Indonesians.

AIM

To determine the effect of the consumption of indigenous probiotic Lactobacillus plantarum Dad-13 powder in overweight adults in Yogyakarta (Indonesia).

METHODS

Sixty overweight volunteers with a body mass index (BMI) equal to or greater than 25 consume indigenous probiotic powder L. plantarum Dad-13 (2 × 10⁹ CFU/gram/sachet) for 90 d. The study was a randomized, double-blind, placebo-controlled study. The volunteers filled in a diary on a daily basis, which consisted of questions on study product intake (only during ingestion period), other food intake, number of bowel movements, fecal quality (consistency and color), any medications received, and any symptom of discomfort, such as diarrhea, constipation, vomiting, gassing, sensation of illness, etc. Fecal samples and the subjects' diaries were collected on the morning of day 10 + 1, which was marked as the end of the baseline period and the start of the ingestion period. During the ingestion period (from day 11 to day 101), several parameters to measure and analyze the results included body weight and height (once a month), the lipid profile, GM analysis using MiSeq, short-chain fatty acid (SCFA) analysis using gas chromatography, and the measurement of fecal pH using a pH meter.

RESULTS

The consumption of indigenous probiotic powder L. plantarum Dad-13 caused the average body weight and BMI of the probiotic group to decrease from 84.54 ± 17.64 kg to 83.14 ± 14.71 kg and 33.10 ± 6.15 kg/m² to 32.57 ± 5.01 kg/m², respectively. No significant reduction of body weight and BMI in the placebo group was observed. An analysis of the microbiota showed that the number of Bacteroidetes, specifically Prevotella, increased significantly, while that of Firmicutes significantly decreased. No significant change in lipid profile in both groups was found. Also, no significant change in SCFAs (e.g., butyrate, propionate, acetic acid) and pH level was found after the consumption of the probiotic.

CONCLUSION

No significant differences in pH before and after ingestion were observed in both the probiotic and placebo groups as well as in the lipid profile of both cholesterol and triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and the LDL/HDL ratio. In addition, no significant changes in the concentration of SCFAs (e.g., acetic acid, propionate, and butyrate) were found after con-sumption. Interestingly, a significant decrease in body weight and BMI (P < 0.05) was determined in the treatment group. An analysis of GM shows that L. plantarum Dad-13 caused the Firmicutes population to decrease and the Bacteroidetes population (especially Prevotella) to increase.

Daily supplementation with the Lab4P probiotic consortium induces significant weight loss in overweight adults

This 9-month randomised, parallel, double-blind, single-centre, placebo-controlled study (PROBE, ISRCTN18030882) assessed the impact of probiotic supplementation on bodyweight. Seventy overweight Bulgarian participants aged 45-65 years with BMI 25-29.9 kg/m² received a daily dose of the Lab4P probiotic comprising lactobacilli and bifidobacteria (50 billion cfu/day). Participants maintained their normal diet and lifestyle over the duration of the study. The primary outcome was change from baseline in body weight and secondary outcomes included changes in waist circumference, hip circumference and blood pressure. A significant between group decrease in body weight (3.16 kg, 95% CI 3.94, 2.38, p < 0.0001) was detected favouring the probiotic group. Supplementation also resulted in significant between group decreases in waist circumference (2.58 cm, 95% CI 3.23, 1.94, p < 0.0001) and hip circumference (2.66 cm, 95% CI 3.28, 2.05, p < 0.0001) but no changes in blood pressure were observed. These findings support the outcomes of a previous shorter-term Lab4P intervention study in overweight and obese participants (PROMAGEN, ISRCTN12562026). We conclude that Lab4P has consistent weight modulation capability in free-living overweight adults.

Metabolism and Metabolic Disorders and the Microbiome: The Intestinal Microbiota Associated With Obesity, Lipid Metabolism, and Metabolic Health-Pathophysiology and Therapeutic Strategies

Changes in the intestinal microbiome have been associated with obesity and type 2 diabetes, in epidemiological studies and studies of the effects of fecal transfer in germ-free mice. We review the mechanisms by which alterations in the intestinal microbiome contribute to development of metabolic diseases, and recent advances, such as the effects of the microbiome on lipid metabolism. Strategies have been developed to modify the intestinal microbiome and reverse metabolic alterations, which might be used as therapies. We discuss approaches that have shown effects in mouse models of obesity and metabolic disorders, and how these might be translated to humans to improve metabolic health.

Gallstone Disease, Obesity and the Firmicutes/Bacteroidetes Ratio as a Possible Biomarker of Gut Dysbiosis

Obesity is a major risk factor for developing gallstone disease (GSD). Previous studies have shown that obesity is associated with an elevated Firmicutes/Bacteroidetes ratio in the gut microbiota. These findings suggest that the development of GSD may be related to gut dysbiosis. This review presents and summarizes the recent findings of studies on the gut microbiota in patients with GSD. Most of the studies on the gut microbiota in patients with GSD have shown a significant increase in the phyla Firmicutes (Lactobacillaceae family, genera Clostridium, Ruminococcus, Veillonella, Blautia, Dorea, Anaerostipes, and Oscillospira), Actinobacteria (Bifidobacterium genus), Proteobacteria, Bacteroidetes (genera Bacteroides, Prevotella, and Fusobacterium) and a significant decrease in the phyla Bacteroidetes (family Muribaculaceae, and genera Bacteroides, Prevotella, Alistipes, Paludibacter, Barnesiella), Firmicutes (genera Faecalibacterium, Eubacterium, Lachnospira, and Roseburia), Actinobacteria (Bifidobacterium genus), and Proteobacteria (Desulfovibrio genus). The influence of GSD on microbial diversity is not clear. Some studies report that GSD reduces microbial diversity in the bile, whereas others suggest the increase in microbial diversity in the bile of patients with GSD. The phyla Proteobacteria (especially family Enterobacteriaceae) and Firmicutes (Enterococcus genus) are most commonly detected in the bile of patients with GSD. On the other hand, the composition of bile microbiota in patients with GSD shows considerable inter-individual variability. The impact of GSD on the Firmicutes/Bacteroidetes ratio is unclear and reports are contradictory. For this reason, it should be stated that the results of reviewed studies do not allow for drawing unequivocal conclusions regarding the relationship between GSD and the Firmicutes/Bacteroidetes ratio in the microbiota.

Adipose Tissue and Endocrine-Disrupting Chemicals: Does Sex Matter?

Obesity and metabolic-related diseases, among which diabetes, are prominent public health challenges of the 21st century. It is now well acknowledged that pollutants are a part of the equation, especially endocrine-disrupting chemicals (EDCs) that interfere with the hormonal aspect. The aim of the review is to focus on adipose tissue, a central regulator of energy balance and metabolic homeostasis, and to highlight the significant differences in the endocrine and metabolic aspects of adipose tissue between males and females which likely underlie the differences of the response to exposure to EDCs between the sexes. Moreover, the study also presents an overview of several mechanisms of action by which pollutants could cause adipose tissue dysfunction. Indeed, a better understanding of the mechanism by which environmental chemicals target adipose tissue and cause metabolic disturbances, and how these mechanisms interact and sex specificities are essential for developing mitigating and sex-specific strategies against metabolic diseases of chemical origin. In particular, considering that a scenario without pollutant exposure is not a realistic option in our current societies, attenuating the deleterious effects of exposure to pollutants by acting on the gut-adipose tissue axis may constitute a new direction of research.

Gastric cancer: a comprehensive review of current and future treatment strategies

Gastric cancer remains a major unmet clinical problem with over 1 million new cases worldwide. It is the fourth most commonly occurring cancer in men and the seventh most commonly occurring cancer in women. A major fraction of gastric cancer has been linked to variety of pathogenic infections including but not limited to Helicobacter pylori (H. pylori) or Epstein Barr virus (EBV). Strategies are being pursued to prevent gastric cancer development such as H. pylori eradication, which has helped to prevent significant proportion of gastric cancer. Today, treatments have helped to manage this disease and the 5-year survival for stage IA and IB tumors treated with surgery are between 60 and 80%. However, patients with stage III tumors undergoing surgery have a dismal 5-year survival rate between 18 and 50% depending on the dataset. These figures indicate the need for more effective molecularly driven treatment strategies. This review discusses the molecular profile of gastric tumors, the success, and challenges with available therapeutic targets along with newer biomarkers and emerging targets.

The Influence of Probiotics on the Firmicutes/Bacteroidetes Ratio in the Treatment of Obesity and Inflammatory Bowel disease

The two most important bacterial phyla in the gastrointestinal tract, Firmicutes and Bacteroidetes, have gained much attention in recent years. The Firmicutes/Bacteroidetes (F/B) ratio is widely accepted to have an important influence in maintaining normal intestinal homeostasis. Increased or decreased F/B ratio is regarded as dysbiosis, whereby the former is usually observed with obesity, and the latter with inflammatory bowel disease (IBD). Probiotics as live microorganisms can confer health benefits to the host when administered in adequate amounts. There is considerable evidence of their nutritional and immunosuppressive properties including reports that elucidate the association of probiotics with the F/B ratio, obesity, and IBD. Orally administered probiotics can contribute to the restoration of dysbiotic microbiota and to the prevention of obesity or IBD. However, as the effects of different probiotics on the F/B ratio differ, selecting the appropriate species or mixture is crucial. The most commonly tested probiotics for modifying the F/B ratio and treating obesity and IBD are from the genus Lactobacillus. In this paper, we review the effects of probiotics on the F/B ratio that lead to weight loss or immunosuppression.

Gut microbiota and old age: Modulating factors and interventions for healthy longevity

Our gut microbiota is a complex and dynamic ecosystem with a paramount role in shaping our metabolic and immunological functions. Recent research suggests that aging may negatively affect the composition, diversity, and function of our microbiota mainly due to alterations in diet and immunologic reactivity (i.e. immunosenescence), and increased incidence of certain diseases and, therefore, increased exposure to certain medication (e.g. antibiotics, proton pump inhibitors). In turn, this aging-related gut dysbiosis may contribute to the initiation and/or progress of other metabolic diseases, and consequently, to a decrease in healthy longevity. On the positive side, promising therapeutic interventions, such as diet supplementation with prebiotics, probiotics and synbiotics, or fecal microbiota transplantation, aimed to counteract these aging-related deleterious consequences, could improve our health, and extend our healthy lifespan. In this context, the current review aims to assess the latest progress in identifying the key elements affecting the gut microbiota of the older adults and their mechanism of action, and the effectiveness of the therapeutic interventions aimed at restoring the diversity and healthy functions of the gut microbiota in older individuals.

Bifidobacterium animalis ssp. Lactis 420 Mitigates Autoimmune Hepatitis Through Regulating Intestinal Barrier and Liver Immune Cells

Autoimmune hepatitis (AIH) is an immune-mediated inflammatory liver disease of uncertain cause. Accumulating evidence shows that gut microbiota and intestinal barrier play significant roles in AIH thus the gut–liver axis has important clinical significance as a potential therapeutic target. In the present study, we found that Bifidobacterium animalis ssp. lactis 420 (B420) significantly alleviated S100-induced experimental autoimmune hepatitis (EAH) and modulated the gut microbiota composition. While the analysis of clinical specimens revealed that the fecal SCFA quantities were decreased in AIH patients, and B420 increased the cecal SCFA quantities in EAH mice. Remarkably, B420 application improved intestinal barrier function through upregulation of tight junction proteins in both vitro and vivo experiments. Moreover, B420 decreased the serum endotoxin level and suppressed the RIP3 signaling pathway of liver macrophages in EAH mice thus regulated the proliferation of Th17 cells. Nevertheless, the inhibition effect of B420 on RIP3 signaling pathway was blunted in vitro studies. Together, our results showed that early intervention with B420 contributed to improve the liver immune homeostasis and liver injury in EAH mice, which might be partly due to the protection of intestinal barrier. Our study suggested the potential efficacy of probiotics application against AIH and the promising therapeutic strategies targeting gut–liver axis for AIH.

The role of gut microbiota (GM) and GM-related metabolites in diabetes and obesity. A review of analytical methods used to measure GM-related metabolites in fecal samples with a focus on metabolites' derivatization step

Disruption of gut microbiota (GM) composition is increasingly related to the pathogenesis of various metabolic diseases. Additionally, GM is responsible for the production and transformation of metabolites involved in the development of metabolic disorders, such as obesity and type 2 diabetes mellitus (T2DM). The current state of knowledge regarding the composition of GM and GM-related metabolites in relation to the progress and development of obesity and T2DM is presented in this review. To understand the relationships between GM-related metabolites and the development of metabolic disorders, their accurate qualitative and quantitative measurement in biological samples is needed. Feces represent a valuable biological matrix which composition may reflect the health status of the lower gastrointestinal tract and the whole organism. Mass spectrometry (MS), mainly in combination with gas chromatography (GC) or liquid chromatography (LC), is commonly used to measure fecal metabolites. However, profiling metabolites in such a complex matrix as feces is challenging from both analytical chemistry and biochemistry standpoints. Chemical derivatization is one of the most effective methods used to overcome these problems. In this review, we provide a comprehensive summary of the derivatization methods of GM-related metabolites prior to GC-MS or LC-MS analysis, which have been published in the last five years (2015-2020). Additionally, analytical methods used for the analysis of GM-related metabolites without the derivatization step are also presented.

Efficacy of probiotics in patients with morbid obesity undergoing bariatric surgery: a systematic review and meta-analysis

Bariatric surgery is considered effective for morbid obesity, and probiotic supplementation might provide some benefits. We aimed to revise the evidence regarding probiotic supplementation in patients with morbid obesity undergoing bariatric surgery. MEDLINE, Embase, Web of Science, CENTRAL, and trial registers were searched up to April 1, 2020. We included randomized controlled trials and controlled clinical trials, and outcomes of interest were weight change, quality of life, gastrointestinal symptoms, and adverse events. All stages of the review were done by 2 authors independently and we followed Cochrane Handbook guidance. We screened 2541 references and included 5 studies. Probiotics may have minor to no effect regarding percentage excess weight loss (%EWL) at 6 weeks (mean difference [MD], .28; 95% CI, -9.53 to 10.09; 44 participants, 2 studies), 3 months (MD, 5.47; 95% CI, -3.22 to 14.17; 165 participants, 3 studies), 6 months (MD, .46; 95% CI, -8.14 to 9.07; 115 participants, 2 studies), and 12 months post surgery (MD, .35; 95% CI, -8.66 to 9.37; 123 participants, 2 studies). We observed short-term improvement in gastrointestinal symptoms. There was no important effect on quality of life and no meaningful adverse events. Because probiotic supplementation might provide some benefit with respect to weight loss, might alleviate some gastrointestinal symptoms, and is associated with minor or no adverse events, continuous supplementation might be worth considering in certain individuals. Our findings are based on the body of evidence of very low certainty, and further well-designed randomized controlled trials are required to elucidate the effect and strengthen the certainty in the estimates.

Gut Microbiota and Intestinal Trans-Epithelial Permeability

Constant remodeling of tight junctions to regulate trans-epithelial permeability is essential in maintaining intestinal barrier functions and thus preventing diffusion of small molecules and bacteria to host systemic circulation. Gut microbiota dysbiosis and dysfunctional gut barrier have been correlated to a large number of diseases such as obesity, type 2 diabetes and inflammatory bowel disease. This led to the hypothesis that gut bacteria-epithelial cell interactions are key regulators of epithelial permeability through the modulation of tight junctions. Nevertheless, the molecular basis of host-pathogen interactions remains unclear mostly due to the inability of most in vitro models to recreate the differentiated tissue structure and components observed in the normal intestinal epithelium. Recent advances have led to the development of a novel cellular model derived from intestinal epithelial stem cells, the so-called organoids, encompassing all epithelial cell types and reproducing physiological properties of the intestinal tissue. We summarize herein knowledge on molecular aspects of intestinal barrier functions and the involvement of gut bacteria-epithelial cell interactions. This review also focuses on epithelial organoids as a promising model for epithelial barrier functions to study molecular aspects of gut microbiota-host interaction.

ACE2 imbalance as a key player for the poor outcomes in COVID-19 patients with age-related comorbidities - Role of gut microbiota dysbiosis

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COVID-19 patients with pre-existing age-related comorbidities have poor outcomes.

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Gut microbiota dysbiosis is associated with ageing and age-related diseases.

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Viral-mediated ACE2 shedding favors poor outcomes by RAS-dependent mechanisms.

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Viral-mediated ACE2 shedding favors poor outcomes by RAS-independent gut dysbiosis.

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Potential of ACE2 and gut microbiota-based therapeutic opportunities for COVID-19.

Coronavirus disease 19 (COVID-19) is a pandemic condition caused by the new coronavirus SARS-CoV-2. The typical symptoms are fever, cough, shortness of breath, evolving to a clinical picture of pneumonia and, ultimately, death. Nausea and diarrhea are equally frequent, suggesting viral infection or transmission via the gastrointestinal-enteric system. SARS-CoV-2 infects human cells by using angiotensin converting enzyme 2 (ACE2) as a receptor, which is cleaved by transmembrane proteases during host cells infection, thus reducing its activities. ACE2 is a relevant player in the renin-angiotensin system (RAS), counterbalancing the deleterious effects of angiotensin II. Furthermore, intestinal ACE2 functions as a chaperone for the aminoacid transporter B⁰AT1. It has been suggested that B⁰AT1/ACE2 complex in the intestinal epithelium regulates gut microbiota (GM) composition and function, with important repercussions on local and systemic immune responses against pathogenic agents, namely virus. Notably, productive infection of SARS-CoV-2 in ACE2⁺ mature human enterocytes and patients’ GM dysbiosis was recently demonstrated. This review outlines the evidence linking abnormal ACE2 functions with the poor outcomes (higher disease severity and mortality rate) in COVID-19 patients with pre-existing age-related comorbidities and addresses a possible role for GM dysbiosis. The article culminates with the therapeutics opportunities based on these pathways.