Gut microbiota and obesity: Involvement of the adipose tissue

Veterinary Drug Residues in the Food Chain as an Emerging Public Health Threat: Sources, Analytical Methods, Health Impacts, and Preventive Measures

Veterinary medications are necessary for both contemporary animal husbandry and food production, but their residues can linger in foods obtained from animals and pose a dangerous human risk. In this review, we aim to highlight the sources, occurrence, human exposure pathways, and human health effects of drug residues in food-animal products. Following the usage of veterinary medications, pharmacologically active compounds known as drug residues can be found in food, the environment, or animals. They can cause major health concerns to people, including antibiotic resistance development, the development of cancer, teratogenic effects, hypersensitivity, and disruption of normal intestinal flora. Drug residues in animal products can originate from variety of sources, including water or food contamination, extra-label drug use, and ignoring drug withdrawal periods. This review also examines how humans can be exposed to drug residues through drinking water, food, air, and dust, and discusses various analytical techniques for identifying these residues in food. Furthermore, we suggest some potential solutions to prevent or reduce drug residues in animal products and human exposure pathways, such as implementing withdrawal periods, monitoring programs, education campaigns, and new technologies that are crucial for safeguarding public health. This review underscores the urgency of addressing veterinary drug residues as a significant and emerging public health threat, calling for collaborative efforts from researchers, policymakers, and industry stakeholders to develop sustainable solutions that ensure the safety of the global food supply chain.

Gut microbiota differences in stunted and normal-lenght children aged 36-45 months in East Nusa Tenggara, Indonesia

The role of the gut microbiota in energy metabolism of the host has been established, both in overweight/obesity, as well as in undernutrition/stunting. Dysbiosis of the gut microbiota may predispose to stunting. The aim of this study was to compare the gut microbiota composition of stunted Indonesian children and non-stunted children between 36 and 45 months from two sites on the East Nusa Tenggara (ENT) islands. Fecal samples were collected from 100 stunted children and 100 non-stunted children in Kupang and North Kodi. The gut microbiota composition was determined by sequencing amplicons of the V3-V4 region of the 16S rRNA gene. Moreover, fecal SCFA concentrations were analyzed. The microbiota composition was correlated to anthropometric parameters and fecal metabolites. The phyla Bacteroidetes (Bacteroidota; q = 0.014) and Cyanobacteria (q = 0.049) were significantly higher in stunted children. Three taxa at genus levels were consistently significantly higher in stunted children at both sampling sites, namely Lachnoclostridium, Faecalibacterium and Veillonella (q < 7 * 10-4). These and 9 other taxa positively correlated to the z-score length-for-age (zlen), while 11 taxa negatively correlated with zlen. Several taxa also correlated with sanitary parameters, some of which were also significantly different between the two groups. All three fecal SCFA concentrations (acetate, propionate and butyrate) and their total were lower in stunted children compared to non-stunted children, although not significant for butyrate, indicating lower energy-extraction by the gut microbiota. Also, since SCFA have been shown to be involved in gut barrier function, barrier integrity may be affected in the stunted children. It remains to be seen if the three taxa are involved in stunting, or are changed due to e.g. differences in diet, hygiene status, or other factors. The observed differences in this study do not agree with our previous observations in children on Java, Indonesia. There are differences in infrastructure facilities such as clean water and sanitation on ENT and Java, which may contribute to the differences observed. The role of the gut microbiota in stunting therefore requires more in depth studies. Trial registration: the trial was registered at ClinicalTrials.gov with identifier number NCT05119218.

Dietary lysozyme improves growth performance and intestinal barrier function of weaned piglets

Lysozyme (LZ) is a purely natural, nonpolluting and nonspecific immune factor, which has beneficial effects on the healthy development of animals. In this study, the influences of LZ on the growth performance and intestinal barrier of weaned piglets were studied. A total of 48 weaned piglets (Landrace × Yorkshire, 22 d old) were randomly divided into a control group (basal diet) and a LZ group (0.1% LZ diet) for 19 d. The results showed that LZ could significantly improve the average daily gain (ADG, P < 0.05) and average daily feed intake (ADFI, P < 0.05). LZ also improved the intestinal morphology and significantly increased the expression of occludin in the jejunum (P < 0.05). In addition, LZ down-regulated the expression of interleukin-1β (IL-1β, P < 0.05) and tumor necrosis factor-α (TNF-α, P < 0.05), and inhibited the expression of the genes in the nuclear factor-k-gene binding (NF-κB, P < 0.05) signaling pathway. More importantly, the analysis of intestinal flora showed LZ increased the abundance of Firmicutes (P < 0.05) and the ratio of Firmicutes to Bacteroidota (P = 0.09) at the phylum level, and increased the abundance of Clostridium_sensu_stricto_1 (P < 0.05) and reduced the abundance of Olsenella and Prevotella (P < 0.05) at the genus level. In short, this study proved that LZ could effectively improve the growth performance, relieve inflammation and improve the intestinal barrier function of weaned piglets. These findings provided an important theoretical basis for the application of LZ in pig production.

Nutrition and the state of the intestinal microflora in the formation of the metabolic syndrome

The literature review presents the results of modern studies of the relationship between diet and intestinal microbiota in the regulation of metabolic disorders. Metabolic syndrome, which is a symptom complex that combines abdominal obesity, insulin resistance, hyperglycemia, dyslipidemia and arterial hypertension, remains an important problem, being a risk factor for cardiovascular, neurodegenerative, oncological diseases and the development of type 2 diabetes mellitus. Although the pathogenesis of the metabolic syndrome has not yet been fully elucidated, it is known that visceral obesity and its associated complications, such as dyslipidemia and increased levels of pro-inflammatory cytokines, play a central role. The article presents data on the impact of the consumption of certain food products, the inclusion of plant biologically active substances (flavonoids, polyphenols, etc.) in the diet, as well as the use of elimination diets with the exclusion of carbohydrates or fats from the diet, on reducing the risk of cardiovascular accidents, levels of fasting glucose, total cholesterol, LDL, triglycerides, C-reactive protein, leptin, insulin, reduction in body weight and waist circumference, reduction in the level of circulating endotoxins and changes in the activity of immunocompetent cells. Data are presented on the possible influence of the intestinal microbiota in maintaining inflammation and the formation of degenerative changes in the body. The role of changes in the ratio of the levels of pathogenic microflora, bifidobacteria and lactobacilli in the formation of a pathological condition is shown.

Baicalin attenuate diet-induced metabolic syndrome by improving abnormal metabolism and gut microbiota

In this work, we examined whether baicalin (BC), a bioactive flavonoid in Scutellaria baicalensis Georgi, can reduce high-fat diet (HFD)-induced metabolic syndrome (MetS) in mice. The UPLC-QTOF/MS was used for metabolome profiles analysis, and an analysis of bacterial 16S rDNA in feces was used to examine the effects of BC on gut microbiota composition. Our results showed that BC (400 mg/kg) could reduce the body weight gain, decrease hepatic fat accumulation and abnormal blood lipids, and increase insulin sensitivity after 8 weeks of treatment. BC could reverse the alteration of 7 metabolites induced by HFD and the metabolic pathways responsive to BC intervention including citrate cycle, alanine, aspartate and glutamate metabolism, glycerophospholipid metabolism, and aminoacyl-tRNA biosynthesis. 16S rDNA analysis demonstrated that BC altered the composition and function of gut microbiota in MetS mice. Notably, we found that the change in succinic acid was negatively associated with the changes in Bacteroides and Sutterella, and positively associated with the change in Mucispirillum. Moreover, we confirmed that succinic acid displayed a metabolic protective effect on MetS mice. The antibiotic treatment verified that BC exerts metabolic protection through gut microbiota. Our findings suggested BC may be a potential therapeutic drug to ameliorate diet induced MetS and gut microbiome may be a novel mechanistic target of BC for treatment of MetS.

A Citrus Fruit Extract High in Polyphenols Beneficially Modulates the Gut Microbiota of Healthy Human Volunteers in a Validated In Vitro Model of the Colon

The effect of a Citrus Fruit Extract high in the polyphenols hesperidin and naringin (CFE) on modulation of the composition and activity of the gut microbiota was tested in a validated, dynamic in vitro model of the colon (TIM-2). CFE was provided at two doses (250 and 350 mg/day) for 3 days. CFE led to a dose-dependent increase in Roseburia, Eubacterium ramulus, and Bacteroides eggerthii. There was a shift in production of short-chain fatty acids, where acetate production increased on CFE, while butyrate decreased. In overweight and obesity, acetate has been shown to increase fat oxidation when produced in the distal gut, and stimulate secretion of appetite-suppressive neuropeptides. Thus, the data in the in vitro model point towards mechanisms underlying the effects of the polyphenols in CFE with respect to modulation of the gut microbiota, both in composition and activity. These results should be confirmed in a clinical trial.

Dietary Moutan Cortex Radicis Improves Serum Antioxidant Capacity and Intestinal Immunity and Alters Colonic Microbiota in Weaned Piglets

Background:Moutan cortex radicis (MCR), as a common traditional Chinese medicine, has been widely used as an antipyretic, antiseptic, and anti-inflammatory agent in China.

Objectives: This study aimed to investigate the effects of dietary MCR supplementation on the antioxidant capacity and intestinal health of the pigs and to explore whether MCR exerts positive effects on intestinal health via regulating nuclear factor kappa-B (NF-κB) signaling pathway and intestinal microbiota.

Methods: MCR powder was identified by LC-MS analysis. Selected 32 weaned piglets (21 d of age, 6.37 ± 0.10 kg average BW) were assigned (8 pens/diet, 1 pig/pen) to 4 groups and fed with a corn-soybean basal diet supplemented with 0, 2,000, 4,000, and 8,000 mg/kg MCR for 21 d. After the piglets were sacrificed, antioxidant indices, histomorphology examination, and inflammatory signaling pathway expression were assessed. The 16s RNA sequencing was used to analyze the effects of MCR on the intestinal microbiota structure of piglets.

Results: Supplemental 4,000 mg/kg MCR significantly increased (P < 0.05) the average daily weight gain (ADG), average daily feed intake (ADFI), total antioxidative capability, colonic short-chain fatty acids (SCFA) concentrations, and the crypt depth in the jejunum but decreased (P < 0.05) the mRNA expression levels of interferon γ, tumor necrosis factor-α, interleukin-1β, inhibiting kappa-B kinase β (IKKβ), inhibiting nuclear factor kappa-B (IκBα), and NF-κB in the jejunum and ileum. Microbiota sequencing identified that MCR supplementation significantly increased the microbial richness indices (Chao1, ACE, and observed species, P < 0.05) and the relative abundances of Firmicutes and Lactobacillus (P < 0.05), decreased the relative abundances of Bacteroides, Parabacteroides, unidentified_Lachnospiraceae, and Enterococcus (P < 0.05) and had no significant effects on the diversity indices (Shannon and Simpson, P > 0.05). Microbial metabolic phenotypes analysis also showed that the richness of aerobic bacteria and facultative anaerobic bacteria, oxidative stress tolerance, and biofilm forming were significantly increased (P < 0.05), and the richness of anaerobic bacteria and pathogenic potential of gut microbiota were reduced (P < 0.05) by MCR treatment. Regression analysis showed that the optimal MCR supplemental level for growth performance, serum antioxidant capacity, and intestinal health of weaned piglets was 3,420 ~ 4,237 mg/kg.

Conclusions: MCR supplementation improved growth performance and serum antioxidant capacity, and alleviated intestinal inflammation by inhibiting the IKKβ/IκBα/NF-κB signaling pathway and affecting intestinal microbiota in weaned piglets.

Gut microbiota profile of Indonesian stunted children and children with normal nutritional status

The gut microbiota has been shown to play a role in energy metabolism of the host. Dysbiosis of the gut microbiota may predispose to obesity on the one hand, and stunting on the other. The aim of the study was to study the difference in gut microbiota composition of stunted Indonesian children and children of normal nutritional status between 3 and 5 years. Fecal samples and anthropometric measurements, in addition to economic and hygiene status were collected from 78 stunted children and 53 children with normal nutritional status in two regions in Banten and West Java provinces: Pandeglang and Sumedang, respectively. The gut microbiota composition was determined by sequencing amplicons of the V3-V4 region of the 16S rRNA gene. The composition was correlated to nutritional status and anthropometric parameters. Macronutrient intake was on average lower in stunted children, while energy-loss in the form of short-chain fatty acids (SCFA) and branched-chain fatty acids (BCFA) appeared to be higher in stunted children. In stunted children, at the phylum level the relative abundance of Bacteroidetes (44.4%) was significantly lower than in normal children (51.3%; p-value 2.55*10-4), while Firmicutes was significantly higher (45.7% vs. 39.8%; p-value 5.89*10-4). At the genus level, overall Prevotella 9 was the most abundant genus (average of 27%), and it was significantly lower in stunted children than in normal children (23.5% vs. 30.5%, respectively; q-value 0.059). Thirteen other genera were significantly different between stunted and normal children (q-value < 0.1), some of which were at low relative abundance and present in only a few children. Prevotella 9 positively correlated with height (in line with its higher relative abundance in normal children) and weight. In conclusion, Prevotella 9, which was the most abundant genus in the children, was significantly lower in stunted children. The abundance of Prevotella has been correlated with dietary fibre intake, which was lower in these stunted children. Since fibres are fermented by the gut microbiota into SCFA, and these SCFA are a source of energy for the host, increasing the proportion of Prevotella in stunted children may be of benefit. Whether this would prevent the occurrence of stunting or even has the potential to revert it, remains to be seen in follow up research.

The impact of intestinal microbiota on weight loss in Parkinson's disease patients: a pilot study

Background: There is increasing evidence of the association between microbiome dysfunction and Parkinson's disease (PD). Moreover, some PD patients suffer from unintentional weight loss (WL) which may precede the motor manifestations of the disease. Materials & methods: Gut microbiota profiling by 16S rRNA gene sequencing was performed in PD patients with an unintended WL, in steady weight patients (non-WL [NWL]) and in matched normal subjects. KEGG functional predictions were carried out. Results: Microbiota profiles revealed a dissimilarity between WL and NWL. Moreover, WL pathways were characterized by fatty acid biosynthesis, while NWL by inflammation pathways. Conclusion: The gut microbiota could participate in weight alteration observed in PD by the presence of bacteria involved in weight gain and inflammation, or conversely by bacteria implicated in energy expenditure.

Effect of banana pulp dietary fibers on metabolic syndrome and gut microbiota diversity in high-fat diet mice

Banana (Musa nana Lour.) have the effect of anti-obesity and lipid modulating properties. However, the influences of banana pulp dietary fibers (BP-DF) on metabolic syndrome (MetS) and gut microbiota (GM) are unknown. In this research, we explore a novel strategy for dietary BP-DF on attenuation of lipid metabolic disease, GM disorder, and associated mechanisms in high-fat diet (HFD) mice. BP-DF can strongly suppress on HFD caused body weight and epididymal fat mass gain, and significantly improved serum lipid profiles, liver lipid profiles, and intestinal function. BP-DF also significantly improved fecal short-chain fatty acids formation and fecal ammonia content. BP-DF impacted the intestinal microorganism at all kinds of taxonomic levels by increasing the proportions of beneficial Lactobacillus, Bacteroidales _S24_7_group, and Alloprevotella and decreasing the disease or obesity associated Sutterella, Streptococcaceae, and Erysipelotrichaceae. The experiments show that BP-DF may use as a functional ingredient for preventing obesity, MetS, and intestinal microorganism imbalance. PRACTICAL APPLICATIONS: Obesity result in many metabolic complications, and it poses a great threat to people's health. Nowadays, the introduction of DF may lead to the development of a new strategy in the treatment of obesity and its metabolic syndrome. Our experiments findings show that BP-DF may use as a functional ingredient for preventing obesity, MetS, and intestinal microorganism imbalance. Therefore, BP-DF can be applied to the development and production of functional food, and can also be used as an important food functional ingredient, which can be added to various food, such as bread, noodles, baked goods, cakes, etc., to improve its nutritional value.

Impact of feeding regimens on the composition of gut microbiota and metabolite profiles of plasma and feces from Mongolian sheep

Mongolian sheep are an indigenous ruminant raised for wool and meat production in China. The gut microbial community plays an important role in animal performance and metabolism. The objective of this study was to investigate the effects of two feeding regimens on the diversity and composition of gut microbiota and metabolite profiles of feces and plasma from Mongolian sheep. A total of 20 Mongolian sheep were assigned to one of two feeding regimens: free grazing (FG) and barn confinement (BC). When samples were collected, the average live weights of the sheep were 31.28 ± 1.56 kg and 34.18 ± 1.87 kg for the FG and BC groups, respectively. At the genus level, the FG group showed higher levels of Bacteroides, RC9_gut_group, Alistipes, Phocaeicola, Barnesiella, and Oscillibacter, and lower levels of Succinivibrio, Treponema, and Prevotella, compared to the BC group. The butyric acid content in feces was lower in the FG group (P > 0.05). Higher levels of palmitic acid, oleic acid, alpha-linolenic acid, L-carnitine, L-citrulline, and L-histidine, and lower levels of L-tyrosine, L-phenylalanine, and L-kynurenine were found in the plasma of the FG sheep. Moreover, there were substantial associations between several gut microbiota genera and alterations in feces and plasma metabolites especially those involved in the metabolism of butyric acid, linolenic acid, and L-tyrosine. Feeding regimens can not only influence the composition of gut microbiota, but also alter metabolic homeaostasis in sheep.

Regular intake of white kidney beans extract (Phaseolus vulgaris L.) induces weight loss compared to placebo in obese human subjects

Scope

Phaseolus vulgaris L. is rich in alpha-amylase inhibitor and has been used for reducing glycemia and calories absorption through preventing or delaying the digestion of complex carbohydrate. A randomized, double-blinded, placebo-controlled study was conducted on obese volunteers to evaluate the degree of significate weight loss by regular intake Phaseolus vulgaris cultivated from Southwestern region of China.

Method

The volunteers were divided into two groups, homogeneous for age, gender, and body weight. Phaseolus vulgaris extract or placebo was given 2,400 mg per day before each daily meal for 35 consecutive days. Each subject's body weight, fat mass, body mass index, blood biochemical parameters, skinfold fat thickness, and waist/hip circumferences were monitored and analyzed.

Result and conclusion

As a result, the average amount of weight lost by the Phaseolus vulgaris extract group was 2.24 kg (average of 0.448 kg per week), compared with a 0.29 kg weight loss (average of 0.058 kg per week) in placebo group after 35 days. The differences between groups were significant (p < .01). The body mass index decreased by an average of 0.79, and the body fat decreased by 1.53% on average compared to baseline (p < .05). The thickness of subcutaneous fat was significantly reduced at the four measurement points, and the decrease of waist circumference and hip circumference was significant as well. No adverse or side effects were observed during the trial period. The results indicate that Phaseolus vulgaris extract can significantly induce weight loss in a short time period.

Long-Chain Bases from Sea Cucumber Alleviate Obesity by Modulating Gut Microbiota

This study evaluated the effects of long-chain bases from sea cucumber (SC-LCBs) on modulation of the gut microbiota and inhibition of obesity in high fat diet-fed mice. Results showed that SC-LCBs exerted significant antiobese effects, which were associated with the inhibition of hyperglycemia and lipid accumulation. SC-LCBs also regulated serum adipocytokines toward to normal levels. SC-LCBs caused significant decreases in Firmicutes, Actinobacteria phylum, and obesity-related bacteria (Desulfovibro, Bifidobacterium, Romboutsia etc. genus). SC-LCBs also elevated Bacteroidetes, Proteobacteria, Verrucomicrobia phylum, and short chain fatty acids (SCFAs)-producing bacteria (Bacteroides, Lactobacillus, Lachnospiraceae_NK4A136_group etc. genus). Moreover, serum and fecal lipoplysaccharide (LPS) concentrations and its dependent toll-line receptor 4 pathway were inhibited by SC-LCBs treatment. SC-LCBs caused increases in fecal SCFAs and their mediated G-protein-coupled receptors proteins. These suggest that SC-LCBs alleviate obesity by altering gut microbiota. Thus, it sought to indicate that SC-LCBs can be developed as food supplement for the obesity control and the human gut health.

Adipose tissue inflammation and metabolic syndrome. The proactive role of probiotics

PURPOSE

The first part of this review focuses on the role of cells and molecules of adipose tissue involved in metabolic syndrome-induced inflammation and in the maintenance of this pathology. In the second part of the review, the potential role of probiotics-modulating metabolic syndrome-related inflammatory components is summarized and discussed.

METHODS

The search for the current scientific literature was carried out using ScienceDirect, PubMed, and Google Scholar search engines. The keywords used were: metabolic syndrome, obesity, insulin resistant, adipose tissue, adipose tissue inflammation, chronic low-grade inflammation, immune cells, adipokines, cytokines, probiotics, and gut microbiota.

RESULTS AND CONCLUSIONS

Chronic low-grade inflammation that characterized metabolic syndrome can contribute to the development of the metabolic dysfunctions involved in the pathogenesis of its comorbidities. Adipose tissue is a complex organ that performs metabolic and immune functions. During metabolic syndrome, an imbalance in the inflammatory components of adipose tissue (immune cells, cytokines, and adipocytokines), which shift from an anti-inflammatory to a pro-inflammatory profile, can provoke metabolic syndrome linked complications. Further knowledge concerning the immune function of adipose tissue may contribute to finding better alternatives for the treatment or prevention of such disorders. The control of inflammation could result in the management of many of the pathologies related to metabolic syndrome. Due to the strong evidence that gut microbiota composition plays a role modulating the body weight, adipose tissue, and the prevalence of a low-grade inflammatory status, probiotics emerge as valuable tools for the prevention of metabolic syndrome and health recovery.

Reshaped fecal gut microbiota composition by the intake of high molecular weight persimmon tannin in normal and high-cholesterol diet-fed rats

It has been proposed that the gut microbiome may be related to obesity, and diet-induced obesity may induce changes in the gut microbiota composition. Our previous studies suggested that persimmon tannin (PT), which is highly polymerized and non-absorbable in the intestine, showed anti-hyperlipidemic and cholesterol-lowering effects in animal models. Considering that the possible composition modification effects of PT on intestinal bacteria might contribute to its anti-hyperlipidemic and cholesterol-lowering effects in vivo, in this study, we determined whether the PT administration could modify the gut microbiota in both normal diet-fed and high-cholesterol (HC) diet-fed rats, and how PT altered the bacterial composition in both normal and HC fed rats. Sprague-Dawley rats were randomly divided into eight groups, and fed with either a normal or an HC diet supplemented with or without a low/medium/high dose of PT (50 (LPT), 100 (MPT), 200 (HPT) mg per kg body weight (BW) per day, respectively) for 4 weeks. On days 0, 7, 14, 21 and 28, feces were collected and prepared for the microbiota and physicochemical analysis. The results showed that LPT and MPT supplementation significantly altered the gut microbiota composition by increasing the Bacteroidetes/Proteobacteria ratio in both normal diet-fed and HC diet-fed rats. LPT also decreased the Firmicutes/Bacteroidetes ratio in normal diet-fed rats and MPT decreased the Firmicutes/Bacteroidetes ratio in HC diet-fed rats. Both LPT and MPT supplementation induced a significant alteration in specific bacterial species after 14 days of treatment. The relative abundance of Bifidobacterium sp. and Lactobacillus sp. was increased by both LPT and MPT treatment, and that of Escherichia coli and Enterococcus was reduced. Our data also indicate that there is a correlation between the changes in bacterial composition and the changes in short-chain fatty acid (SCFA) metabolism. However, HPT supplementation altered the gut microbiota at the phylum and species levels in an adverse way.

Nanocomposite of Half-Fin Anchovy Hydrolysates/Zinc Oxide Nanoparticles Exhibits Actual Non-Toxicity and Regulates Intestinal Microbiota, Short-Chain Fatty Acids Production and Oxidative Status in Mice

The nanocomposite of half-fin anchovy hydrolysates (HAHp) and zinc oxide nanoparticles (ZnO NPs) (named as HAHp(3.0)/ZnO NPs) demonstrated increased antibacterial activity compared to either HAHp(3.0) or ZnO NPs as per our previous studies. Also, reactive oxygen species (ROS) formation was detected in Escherichia coli cells after treatment with HAHp(3.0)/ZnO NPs. The aim of the present study was to evaluate the acute toxicity of this nanocomposite and to investigate its effect on intestinal microbiota composition, short-chain fatty acids (SCFAs) production, and oxidative status in healthy mice. The limit test studies show that this nanoparticle is non-toxic at the doses tested. The administration of HAHp(3.0)/ZnO NPs, daily dose of 1.0 g/kg body weight for 14 days, increased the number of goblet cells in jejunum. High-throughput 16S ribosomal RNA gene sequencing of fecal samples revealed that HAHp(3.0)/ZnO NPs increased Firmicutes and reduced Bacteriodetes abundances in female mice. Furthermore, the microbiota for probiotic-type bacteria, including Lactobacillus and Bifidobacterium, and SCFAs-producing bacteria in the Clostridia class, e.g., Lachnospiraceae_unclassified and Lachnospiraceae_UCG-001, were enriched in the feces of female mice. Increases of SCFAs, especially statistically increased propionic and butyric acids, indicated the up-regulated anti-inflammatory activity of HAHp(3.0)/ZnO NPs. Additionally, some positive responses in liver, like markedly increased glutathione and decreased malonaldehyde contents, indicated the improved oxidative status. Therefore, our results suggest that HAHp(3.0)/ZnO NPs could have potential applications as a safe regulator of intestinal microbiota or also can be used as an antioxidant used in food products.

Antiobesity molecular mechanisms of action: Resveratrol and pterostilbene

Obesity is a current global epidemic that has led to a marked increase in metabolic diseases. However, its treatment remains a challenge. Obesity is a multifactorial disease, which involves the dysfunction of neuropeptides, hormones, and inflammatory adipokines from the brain, gut, and adipose tissue. An understanding of the mechanisms and signal interactions in the crosstalk between organs and tissue in the coordination of whole-body energy metabolism would be helpful to provide therapeutic and putative approaches to the treatment and prevention of obesity and related complications. Resveratrol and pterostilbene are well-known stilbenes that provide various potential benefits to human health. In particular, their potential anti-obesity effects have been proven in numerous cell culture and animal studies. Both compounds act to regulate energy intake, adipocyte life cycle and function, white adipose tissue (WAT) inflammation, energy expenditure, and gut microbiota by targeting multiple molecules and signaling pathways as an intervention for obesity. Although the efficacy of both compounds in humans requires further investigation with respect to their oral bioavailability, promising scientific findings have highlighted their potential as candidates for the treatment of obesity and the improvement of obesity-related metabolic diseases. © 2018 BioFactors, 44(1):50-60, 2018.

Microbiota and Lipotoxicity

Obesity and metabolic syndrome is a multisystemic disorder, that is characterized by excess caloric intake and spillover lipotoxicity caused by ectopic lipid accumulation in non-adipose tissues. Low grade chronic inflammation and insulin resistance are the hallmarks of the disorder, which further aggravate the condition. Gut microbiota constitutes an indispensible part of human superorganism's energy harvesting apparatus. The dynamic composition of microbiota changes with age, life style and host metabolic background. The wealth of genetic repertoire provided by these microorganism enables to extend host's substrate processing and harvesting capability. Some of these compounds including short chain fatty acids and indole act as signalling molecules on mammalian cells and modulate their behaviour. Nonetheless, this symbiotic style of interaction is restrained by immune system. The role of chronic low grade inflammation in metabolic syndrome is well established. Treg cells are the key players that sense and reshape the composition of microbiota. In this regard, any disturbance in Treg functionality may aggravate the inflammation and shift the symbiotic balance towards dysbiosis, which is characterized by autoimmunity and insulin resistance. Thus, immune system is responsible for the modulation of host and microbiota metabolisms and Treg cells act as a bridge in between.

Gut microbiome and metabolic syndrome

The gut microbiome contributes approximately 2kg of the whole body weight, and recent studies suggest that gut microbiota has a profound effect on human metabolism, potentially contributing to several features of the metabolic syndrome. Metabolic syndrome is defined by a clustering of metabolic disorders that include central adiposity with visceral fat accumulation, dyslipidemia, insulin resistance, dysglycemia and non-optimal blood pressure levels. Metabolic syndrome is associated with an increased risk of cardiovascular diseases and type 2 diabetes. It is estimated that around 20-25 percent of the world's adult population has metabolic syndrome. In this manuscript, we have reviewed the existing data linking gut microbiome with metabolic syndrome. Existing evidence from studies both in animals and humans support a link between gut microbiome and various components of metabolic syndrome. Possible pathways include involvement with energy homeostasis and metabolic processes, modulation of inflammatory signaling pathways, interferences with the immune system, and interference with the renin-angiotensin system. Modification of gut microbiota via prebiotics, probiotics or other dietary interventions has provided evidence to support a possible beneficial effect of interventions targeting gut microbiota modulation to treat components or complications of metabolic syndrome.

Gut microbiota in health and disease: an overview focused on metabolic inflammation

In concern to the continuously rising global prevalence of obesity, diabetes and associated diseases, novel preventive and therapeutic approaches are urgently required. However, to explore and develop such innovative strategies, a meticulous comprehension of the biological basis of these diseases is extremely important. Past decade has witnessed an enormous amount of research investigation and advancement in the field of obesity, diabetes and metabolic syndrome, with the gut microbiota receiving a special focus in the triangle of nutrition, health and diseases. In particular, the role of gut microbiota in health and diseases has been one of the most vigorous and intriguing field of recent research; however, much still remains to be elucidated about its precise role in host metabolism and immune functions and its implication in the onset, progression as well as in the amelioration of metabolic ailments. Recent investigations have suggested a significant contribution of the gut microbiota in the regulation and impairment of energy homeostasis, thereby causing metabolic disorders, such as metabolic endotoxemia, insulin resistance and type 2 diabetes. Numerous inflammatory biomarkers have been found to be associated with obesity, diabetes and risk of other associated adverse outcomes, thereby suggesting that a persistent low-grade inflammatory response is a potential risk factor. In this milieu, this review intends to discuss potential evidences supporting the disturbance of the gut microbiota balance and the intestinal barrier permeability as a potential triggering factor for systemic inflammation in the onset and progression of obesity, type 2 diabetes and metabolic syndrome.

The Characterization of Novel Tissue Microbiota Using an Optimized 16S Metagenomic Sequencing Pipeline

Background

Substantial progress in high-throughput metagenomic sequencing methodologies has enabled the characterisation of bacteria from various origins (for example gut and skin). However, the recently-discovered bacterial microbiota present within animal internal tissues has remained unexplored due to technical difficulties associated with these challenging samples.

Results

We have optimized a specific 16S rDNA-targeted metagenomics sequencing (16S metabarcoding) pipeline based on the Illumina MiSeq technology for the analysis of bacterial DNA in human and animal tissues. This was successfully achieved in various mouse tissues despite the high abundance of eukaryotic DNA and PCR inhibitors in these samples. We extensively tested this pipeline on mock communities, negative controls, positive controls and tissues and demonstrated the presence of novel tissue specific bacterial DNA profiles in a variety of organs (including brain, muscle, adipose tissue, liver and heart).

Conclusion

The high throughput and excellent reproducibility of the method ensured exhaustive and precise coverage of the 16S rDNA bacterial variants present in mouse tissues. This optimized 16S metagenomic sequencing pipeline will allow the scientific community to catalogue the bacterial DNA profiles of different tissues and will provide a database to analyse host/bacterial interactions in relation to homeostasis and disease.

The art of targeting gut microbiota for tackling human obesity

Recently, a great deal of interest has been expressed regarding strategies to tackle worldwide obesity because of its accelerated wide spread accompanied with numerous negative effects on health and high costs. Obesity has been traditionally associated with an imbalance in energy consumed when compared to energy expenditure. However, growing evidence suggests a less simplistic event in which gut microbiota plays a key role. Obesity, in terms of microbiota, is a complicated disequilibrium that presents many unclear complications. Despite this, there is special interest in characterizing compositionally and functionally the obese gut microbiota with the help of in vitro, animal and human studies. Considering the gut microbiota as a factor contributing to human obesity represents a tool of great therapeutic potential. This paper reviews the use of antimicrobials, probiotics, fecal microbial therapy, prebiotics and diet to manipulate obesity through the human gut microbiota and reveals inconsistencies and implications for future study.

Does the Gut Microbiota Contribute to Obesity? Going beyond the Gut Feeling

Increasing evidence suggests that gut microbiota is an environmental factor that plays a crucial role in obesity. However, the aetiology of obesity is rather complex and depends on different factors. Furthermore, there is a lack of consensus about the exact role that this microbial community plays in the host. The aim of this review is to present evidence about what has been characterized, compositionally and functionally, as obese gut microbiota. In addition, the different reasons explaining the so-far unclear role are discussed considering evidence from in vitro, animal and human studies.