The Role of Probiotics on the Microbiota: Effect on Obesity

Efficacy of Probiotics in Overweight and Obesity Control: An Umbrella Review and Subgroup Meta-Analysis

Numerous primary and secondary studies have consistently demonstrated that probiotics, including lactobacillus and Bifidobacterium, possess a potential anti-obesity effect. However, it is worth noting that some studies have yielded contrasting results. Considering this, our study aims to present a comprehensive overview of published systematic reviews and meta-analyses, focusing on the efficacy and safety of probiotics in managing obesity. To achieve this objective, we conducted an umbrella review following the PRISMA protocol and Cochrane guidelines. We searched databases such as Embase, PubMed, Cochrane Library, and Google Scholar for relevant systematic reviews and meta-analyses published in English, without imposing any date restrictions. Our inclusion criteria encompassed studies evaluating the anti-obesity impact of probiotics, with a specific focus on changes in body mass index (BMI), fat mass percentage (FMP), body weight (BW), and body fat mass (BFM). These studies were meticulously reviewed by two independent reviewers. Our analysis included five systematic reviews and 18 meta-analyses that met the predefined inclusion and exclusion criteria. The meta-analyses revealed statistically significant reductions in the following parameters: BMI, a decrease of 0.30 kg/m2 (p < 0.00001, 95% CI - 0.36 to - 0.25); BFM, a reduction of 0.86 kg (p < 0.00001, 95% CI - 1.02 to - 0.71); BW, a decrease of 0.59 kg (p < 0.00001, 95% CI - 0.74 to - 0.44); and FMP, a substantial decline of 78% (p < 0.00001, 95% CI - 1.02 to - 0.54). In summary, our umbrella review suggests that existing evidence supports the potential benefits of probiotics in managing obesity and overweight. However, it is essential to acknowledge that the credibility of this evidence is somewhat limited due to the inclusion of studies with poor-quality designs and relatively small participant numbers. To establish the true efficacy of probiotics in obesity management, we recommend conducting robust studies involving larger participant cohorts.

Investigation of the probiotic supplement's effect on obese adults demonstrated a reduction in fasting insulin levels: a double-blind randomized clinical trial

Purpose

Regarding the importance of obesity concerns and trying to help obese individuals, we planned to develop an effective probiotic formula for weight control. So, this double-blind randomized clinical trial study investigated the impact of probiotics supplementation on anthropometric and biochemical parameters in obese adults.

Methods

In this study, 66 obese patients with BMI in the range of 30-40 kg/m2, were enrolled and randomly assigned to either the probiotic or placebo group. They all received advice to maintain a reduction in daily caloric intake and for 3 months received two unlabeled placebo or probiotic (Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus casei and Bifidobacterium langum) capsules per day. For each participant demographic and medical history questionnaire, semi-quantitative food frequency questionnaire (FFQ), and modifiable activity questionnaire (MAQ) were completed at the beginning of the study and anthropometric and biochemical measurements were done before and after intervention.

Results

At the end of the trial 25 subjects in the probiotic group and 26 subjects in the placebo group were analyzed. After the intervention, in the probiotic group, the level of fasting insulin was reduced significantly (P < 0.05). Weight, body mass index, waist circumference, and hip circumference decreased within both groups. This reduction amount's mean was higher in the probiotic group. Also, total cholesterol, triglycerides, and LDL levels were decreased, but not statistically significant.

Conclusion

This study may suggest the potential of this combined probiotic supplement for treating obesity and related metabolic disorders. However, further researches are warranted for a definitive determination of its properties.

Gut microbiome in the Graves' disease: Comparison before and after anti-thyroid drug treatment

While several studies have proposed a connection between the gut microbiome and the pathogenesis of Graves's disease (GD), there has been a lack of reports on alteration in microbiome following using anti-thyroid drug treatment (ATD) to treat GD. Stool samples were collected from newly diagnosed GD patients provided at baseline and after 6 months of ATD treatment. The analysis focused on investigating the association between the changes in the gut microbiome and parameter including thyroid function, thyroid-related antibodies, and the symptom used to assess hyperthyroidism before and after treatment. A healthy control (HC) group consisting of data from 230 healthy subjects (110 males and 120 females) sourced from the open EMBL Nucleotide Sequence Database was included. Twenty-nine GD patients (14 males and 15 females) were enrolled. The analysis revealed a significant reduction of alpha diversity in GD patients. However, after ATD treatment, alpha diversity exhibited a significant increase, restored to levels comparable to the HC levels. Additionally, GD patients displayed lower levels of Firmicutes and higher levels of Bacteroidota. Following treatment, there was an increased in Firmicutes and a decrease in Bacteroidota, resembling levels found in the HC levels. The symptoms of hyperthyroidism were negatively associated with Firmicutes and positively associated with Bacteroidota. GD had significantly lower levels of Roseburia, Lachnospiraceaea, Sutterella, Escherichia-shigella, Parasuterella, Akkermansia, and Phascolarctobacterium compared to HC (all p < 0.05). Post-treatment, Subdoligranulum increased (p = 0.010), while Veillonella and Christensenellaceaea R-7 group decreased (p = 0.023, p = 0.029, respectively). Anaerostipes showed a significant association with both higher smoking pack years and TSHR-Ab levels, with greater abundantce observed in smokers among GD (p = 0.16). Although reduced ratio of Firmicutes/Bacteroidetes was evident in GD, this ratio recovered after treatment. This study postulates the involvement of the gut microbiome in the pathogenesis of GD, suggesting potential restoration after treatment.

Eight Weeks of Bifidobacterium lactis BL-99 Supplementation Improves Lipid Metabolism and Sports Performance through Short-Chain Fatty Acids in Cross-Country Skiers: A Preliminary Study

(1) Background: Probiotics in the form of nutritional supplements are safe and potentially useful for strategic application among endurance athletes. Bifidobacterium animalis lactis BL-99 (BL-99) was isolated from the intestines of healthy Chinese infants. We combined plasma-targeted metabolomics and fecal metagenomics to explore the effect of 8 weeks of BL-99 supplementation on cross-country skiers' metabolism and sports performance. (2) Methods: Sixteen national top-level male cross-country skiers were recruited and randomly divided into a placebo group (C) and a BL-99 group (E). The participants took the supplements four times/day (with each of three meals and at 21:00) consistently for 8 weeks. The experiment was conducted in a single-blind randomized fashion. The subject's dietary intake and total daily energy consumption were recorded. Blood and stool samples were collected before and after the 8-week intervention, and body composition, muscle strength, blood biochemical parameters, plasma-targeted metabolomic data, and fecal metagenomic data were then analyzed. (3) Results: The following changes occurred after 8 weeks of BL-99 supplementation: (a) There was no significant difference in the average total daily energy consumption and body composition between the C and E groups. (b) The VO2max and 60°/s and 180°/s knee joint extensor strength significantly increased in both the C and E groups. By the eighth week, the VO2max and 60 s knee-joint extensor strength were significantly higher in the E group than in the C group. (c) The triglyceride levels significantly decreased in both the C and E groups. In addition, the LDL-C levels significantly decreased in the E group. (d) The abundance of Bifidobacterium animalis increased two-fold in the C group and forty-fold in the E group. (e) Plasma-targeted metabolomic analysis showed that, after eight weeks of BL-99 supplementation, the increases in DHA, adrenic acid, linoleic acid, and acetic acid and decreases in glycocholic acid and glycodeoxycholic acid in the E group were significantly higher than those in the C group. (f) Spearman correlation analysis showed that there was a significant positive correlation between Bifidobacterium animalis' abundance and SCFAs, PUFAs, and bile acids. (g) There was a significant correlation between the most significantly regulated metabolites and indicators related to sports performance and lipid metabolism. (4) Conclusions: Eight weeks of BL-99 supplementation combined with training may help to improve lipid metabolism and sports performance by increasing the abundance of Bifidobacterium, which can promote the generation of short-chain fatty acids and unsaturated fatty acids, and inhibit the synthesis of bile acids.

Plant-based dietary index in relation to gut microbiota in Arab women

Plant-based foods may influence gut microbiota profiles and contribute to overall human health. However, not all plant-based diets are nutritionally equivalent. We aimed to assess the association between a plant-based dietary index (PDI), specifically unhealthy PDI and healthy PDI (hPDI), and gut microbial composition and diversity in young women in Saudi Arabia. This observational study included 92 healthy women aged 18 to 25 years. Dietary and anthropometric data were collected. Fecal samples were analyzed using a novel whole-genome shotgun sequencing technique. Alpha and beta diversities measured the richness and composition of the gastrointestinal system. Relationships were examined with Pearson correlation, linear regression, and Wilcoxon Rank-Sum tests. Participants with higher PDI had higher levels of Bacteroides_u_s than those with lower PDI. hPDI was positively correlated with Bifidobacterium pseudocatenulatum, Bifidobacterium longum, Oscillibacter, and Lactobacillus acidophilus and inversely correlated with Clostridioides difficile (P < .05). Unhealthy plant-based dietary index was inversely correlated with B pseudocatenulatum, B longum, and L acidophilus and positively correlated with C difficile (P < .05) and other species of interest. In conclusion, hPDI scores were significantly associated with microbiota species linked with favorable health outcomes, independent of body mass index and gut microbial richness and composition in Arab women. Future studies should investigate the modulating effect of plant-based diets on the species identified in the current study.

Effects of probiotic administration on overweight or obese children: a meta-analysis and systematic review

BACKGROUND

This paper aimed to examine the effects of probiotics on eight factors in overweight or obese children by meta-analysis, namely, body mass index (BMI), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), adiponectin, leptin and tumor necrosis factor-α (TNF-α) and summarize the mechanisms of action of probiotics based on the existing researches.

METHODS

Six databases (PubMed, Web of Science, Embase, Cochrane Library, SinoMed and CNKI) were searched until March 2023. Review Manager 5.4 was used for meta-analysis. The data were analysed using weighted mean differences (WMDs) or standardized mean differences (SMDs) under a fixed effect model or random effect model to observe the effects of probiotic administration on the included indicators.

RESULTS

Four publications with a total of 206 overweight or obesity children were included. According to the meta-analysis, probiotics were able to significantly decrease the levels of HDL-C (MD, 0.06; 95% CI 0.03, 0.09; P = 0.0001), LDL-C (MD, - 0.06; 95% CI - 0.12, - 0.00; P = 0.04), adiponectin (MD, 1.39; 95% CI 1.19, 1.59; P < 0.00001), leptin (MD, - 2.72; 95% CI - 2.9, - 2.54; P < 0.00001) and TNF-α (MD, - 4.91; 95% CI - 7.15, - 2.67; P < 0.0001) compared to those in the placebo group. Still, for BMI, the palcebo group seemed to be better than the probiotic group (MD, 0.85; 95% CI 0.04, 1.66; P = 0.04). TC (MD, - 0.05; 95% CI - 0.12, 0.02; P = 0.14) and TG (MD, - 0.16; 95% CI - 0.36, 0.05; P = 0.14) were not different between two groups.

CONCLUSIONS

This review drew that probiotics might act as a role in regulating HDL-C, LDL-C, adiponectin, leptin and TNF-α in overweight or obesity children. Additionally, our systematic review yielded that probiotics might regulate lipid metabolism and improve obese associated symptoms by some paths. This meta-analysis has been registered at PROSPERO with ID: CRD42023408359.

Position statement on nutrition therapy for overweight and obesity: nutrition department of the Brazilian association for the study of obesity and metabolic syndrome (ABESO-2022)

Obesity is a chronic disease resulting from multifactorial causes mainly related to lifestyle (sedentary lifestyle, inadequate eating habits) and to other conditions such as genetic, hereditary, psychological, cultural, and ethnic factors. The weight loss process is slow and complex, and involves lifestyle changes with an emphasis on nutritional therapy, physical activity practice, psychological interventions, and pharmacological or surgical treatment. Because the management of obesity is a long-term process, it is essential that the nutritional treatment contributes to the maintenance of the individual's global health. The main diet-related causes associated with excess weight are the high consumption of ultraprocessed foods, which are high in fats, sugars, and have high energy density; increased portion sizes; and low intake of fruits, vegetables, and grains. In addition, some situations negatively interfere with the weight loss process, such as fad diets that involve the belief in superfoods, the use of teas and phytotherapics, or even the avoidance of certain food groups, as has currently been the case for foods that are sources of carbohydrates. Individuals with obesity are often exposed to fad diets and, on a recurring basis, adhere to proposals with promises of quick solutions, which are not supported by the scientific literature. The adoption of a dietary pattern combining foods such as grains, lean meats, low-fat dairy, fruits, and vegetables, associated with an energy deficit, is the nutritional treatment recommended by the main international guidelines. Moreover, an emphasis on behavioral aspects including motivational interviewing and the encouragement for the individual to develop skills will contribute to achieve and maintain a healthy weight. Therefore, this Position Statement was prepared based on the analysis of the main randomized controlled studies and meta-analyses that tested different nutrition interventions for weight loss. Topics in the frontier of knowledge such as gut microbiota, inflammation, and nutritional genomics, as well as the processes involved in weight regain, were included in this document. This Position Statement was prepared by the Nutrition Department of the Brazilian Association for the Study of Obesity and Metabolic Syndrome (ABESO), with the collaboration of dietitians from research and clinical fields with an emphasis on strategies for weight loss.

A Novel Symbiotic Beverage Based on Sea Buckthorn, Soy Milk and Inulin: Production, Characterization, Probiotic Viability, and Sensory Acceptance

Nowadays, vegan consumers demand that food products have more and more properties that contribute to the prevention of some diseases, such as lower fat content, increased mineral content (calcium, iron, magnesium, and phosphorus), pleasant flavor, and low calorie values. Therefore, the beverage industry has tried to offer consumers products that include probiotics, prebiotics, or symbiotics with improved flavor and appearance and beneficial effects on health. The possibility of producing beverages based on soy milk with sea buckthorn syrup or sea buckthorn powder supplemented with inulin and fermented with the Lactobacillus casei ssp. paracasei strain was examined. The aim of this study was to obtain a novel symbiotic product that exploits the bioactive potential of sea buckthorn fruits. Tests were carried out in the laboratory phase by fermenting soy milk, to which was added sea buckthorn syrup (20%) or sea buckthorn powder (3%) and inulin in proportions of 1% and 3%, with temperature variation of fermentation (30 and 37 °C). During the fermentation period, the survivability of prebiotic bacteria, pH, and titratable acidity were measured. The storage time of beverages at 4 °C ± 1 °C was 14 days, and the probiotic viability, pH, titratable acidity, and water holding capacity were determined. Novel symbiotic beverages based on sea buckthorn syrup or powder, inulin, and soy milk were successfully obtained using the Lactobacillus casei ssp. paracasei strain as a starter culture. Moreover, the inulin added to the novel symbiotic beverage offered microbiological safety and excellent sensory attributes as well.

Effects of Lactobacillus acidophilus administration to anorexigenic neuropeptides and some biochemical parameters on rats fed with a high-fat diet

AIM

One of the rapidly rising global public health concern is obesity. Over the past three decades, the prevalence of obesity has doubled/tripled in several nations around the world, most likely as a result of urbanization, sedentary lifestyles, and increased intake of high-calorie processed foods. In this study, it was aimed to investigate the effects of Lactobacillus acidophilus administration on rats exposed to high-fat diet experimentally on anorexigenic peptides in the brain and some biochemical parameters in the serum.

METHODS

In the study, 4 different experimental groups were formed. Group 1 was designated as the control group and fed with a standard rat chow (SD). Group 2 was designated as the high-fat diet (HFD) fed group. Group 3 fed with SD and L. acidophilus probiotic administered. Group 4 fed with HFD and L. acidophilus probiotic administered. At the end of the experiment, leptin, serotonin, glucagon-like peptide-1 (GLP-1) levels were measured in the brain tissue and serum. Glucose, total cholesterol (TC), triglyceride (TG), total protein (TP), albumin, uric acid, aspartate transaminase (AST), alanine aminotransferase (ALT) levels were determined in the serum.

RESULTS

At the end of the study, it was found that there was an increase in body weight and body mass index in Group 2 compared to Group 1. It was determined that the levels of AST, ALT, TG, TC, glucose, leptin in the serum were significantly high (P < 0.05). The levels of GLP-1 and serotonin in the serum and in the brain were significantly low (P < 0.05). There was a significant decrease in TG and TC in Groups 3 and 4 compared to Group 2 (P < 0.05). The leptin hormone levels in serum and brain were significantly higher in Group 2 than in other groups (P < 0.05). GLP-1 and serotonin levels were found to be significantly low (P < 0.05). The leptin levels in the serum of Groups 3 and 4 decreased significantly compared to Group 2 (P < 0.05).

CONCLUSION

It was found that probiotic supplementation in high-fat diet had positive effects on anorexigenic peptides. It was concluded that L. acidophilus probiotic can be recommended as a food supplement in the treatment of obesity.

Bacteria with potential: Improving outcomes through probiotic use following Roux-en-Y gastric bypass

Obesity impairs the gastrointestinal microbiome (GM) and may promote micronutrient deficiencies. Bariatric surgery (BS), the most efficacious treatment for severe obesity, produces sustained weight loss and improvements in obesity-related comorbidities, but might not fully restore microbial balance. Moreover, BS may result in deleterious consequences that affect weight loss and further intensify post-operative micronutrient deficiencies. To date, the use of probiotics appears to be associated with greater weight loss in bariatric patients, improved vitamin synthesis and availability, and decreased instances of small intestinal bacterial overgrowth. Thus, manipulation of the GM through probiotics represents a promising therapeutic approach in bariatric patients. This review aims to highlight the benefits of using probiotics in bariatric surgical patients by addressing the impact of probiotics on the GM, how BS impacts the microbial environment, associations between gastrointestinal dysbiosis and negative health outcomes, how BS contributes to dysbiosis, and how probiotics may prove efficacious in treating patients who undergo Roux-en-Y gastric bypass (RYGB). Based on currently available data, the role of microbial manipulation post-RYGB through probiotics has shown great potential, but a further clinical investigation is warranted to better understand their efficacy.

Combined effects of yacon flour and probiotic yogurt on the metabolic parameters and inflammatory and insulin signaling proteins in high-fat-diet-induced obese mice

BACKGROUND

Prebiotics and probiotics may be effective dietary components that can alter the gut microbiota of the host and, consequently, overcome imbalances associated with obesity. This work aimed to evaluate the synergistic and isolated effects and mechanisms by which probiotic yogurt containing Bifidobacterium animalis and/or Lactobacillus acidophilus and yacon flour alter metabolic parameters and inflammatory and insulin signaling proteins in diet-induced obese mice. Swiss mice were fed a high-fat diet (n = 48) or a standard diet (control; n = 6) for 56 days. The 42 mice that gained the most weight were selected and divided into seven groups that received different combinations of probiotic yogurt and yacon flour. After 30 days, biochemical parameters (blood glucose, serum total cholesterol, and triacylglycerols), crude fat excretion in feces, and periepididymal fat were assessed and an immunoblotting analysis of insulin signaling proteins and interleukin-1β was conducted.

RESULTS

The combination of yacon flour and a yogurt with two strains of probiotics exerted positive effects on the parameters evaluated, such as decreased body weight (-6.5%; P < 0.05), fasting glucose (-23.1%; P < 0.05), and triacylglycerol levels (-21.4%; P < 0.05) and decreased periepididymal fat accumulation (-44.2%; P < 0.05). There was a decrease in inflammatory markers (P < 0.001) and an improvement in insulin signaling (P < 0.001).

CONCLUSIONS

The combination of a prebiotic with two strains of probiotics in a food matrix may exert a protective effect against obesity-associated inflammation, improving insulin resistance, even in the short term. © 2022 Society of Chemical Industry.

San-Huang-Yi-Shen Capsule Ameliorates Diabetic Nephropathy in Rats Through Modulating the Gut Microbiota and Overall Metabolism

San-Huang-Yi-Shen capsule (SHYS) has been used in the treatment of diabetic nephropathy (DN) in clinic. However, the mechanisms of SHYS on DN remain unknown. In this study, we used a high-fat diet (HFD) combined with streptozotocin (STZ) injection to establish a DN rat model. Next, we used 16S rRNA sequencing and untargeted metabolomics to study the potential mechanisms of SHYS on DN. Our results showed that SHYS treatment alleviated the body weight loss, hyperglycemia, proteinuria, pathological changes in kidney in DN rats. SHYS could also inhibite the oxidative stress and inflammatory response in kidney. 16S rRNA sequencing analysis showed that SHYS affected the beta diversity of gut microbiota community in DN model rats. SHYX could also decrease the Firmicutes to Bacteroidetes (F to B) ratio in phylum level. In genus level, SHYX treatment affected the relative abundances of Lactobacillus, Ruminococcaceae UCG-005, Allobaculum, Anaerovibrio, Bacteroides and Candidatus_Saccharimonas. Untargeted metabolomics analysis showed that SHYX treatment altered the serum metabolic profile in DN model rats through affecting the levels of guanidineacetic acid, L-kynurenine, prostaglandin F1α, threonine, creatine, acetylcholine and other 21 kind of metabolites. These metabolites are mainly involved in glycerophospholipid metabolism, tryptophan metabolism, alanine, aspartate and glutamate metabolism, arginine biosynthesis, tricarboxylic acid (TCA) cycle, tyrosine metabolism, arginine and proline metabolism, arginine and proline metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, and D-glutamine and D-glutamate metabolism pathways. Spearman correlation analysis showed that Lactobacillus, Candidatus_Saccharimonas, Ruminococcaceae UCG-005, Anaerovibrio, Bacteroides, and Christensenellaceae_R-7_group were closely correlated with most of physiological data and the differential metabolites following SHYS treatment. In conclusion, our study revealed multiple ameliorative effects of SHYS on DN including the alleviation of hyperglycemia and the improvement of renal function, pathological changes in kidney, oxidative stress, and the inflammatory response. The mechanism of SHYS on DN may be related to the improvement of gut microbiota which regulates arginine biosynthesis, TCA cycle, tyrosine metabolism, and arginine and proline metabolism.

Acute and short-term effects of Lactobacillus paracasei subsp. paracasei 431 and inulin intake on appetite control and dietary intake: A two-phases randomized, double blind, placebo-controlled study

This study aims to examine the acute and short-term effects of prebiotics, probiotics, and their combination on appetite, energy intake and satiety related hormones in two phases. The first phase was a randomized, double blind, placebo controlled crossover study. Prebiotic (16 g inulin), probiotic (Lactobacillus paracasei subsp. paracasei 431 (L. casei 431) (>10⁶ cfu/ml), synbiotic (their combination) and control (16 g maltodextrin) dairy drinks were consumed by 16 healthy men with a standard breakfast on four separate test days, and the following satiety responses and ad libitum food intake at lunch and over 24 h were assessed. In the second phase, the effects of 21 days of synbiotic (n = 10) or control (n = 11) drink consumption on appetite sensation, energy intake, serum glucose, insulin, peptide YY, ghrelin, obestatin and adiponectin concentration were assessed in a randomized double-blind placebo-controlled design. In the first phase, energy intake values during ad libitum lunch were the lowest in the prebiotic drink, followed by probiotic, synbiotic and control drinks, respectively (p = 0.017); also the rest of the day and 24-h dietary energy intake was lower by prebiotic and probiotic drinks compared to the control drink (p < 0.05 for each). For short-term effects, no significant difference in anthropometric measurements, hunger-satiety scores and serum glucose, insulin, PYY, ghrelin, obestatin and adiponectin concentrations were recorded. Despite the potential of prebiotics and probiotics to reduce energy intake, further studies are required for a better understanding of their role in satiety related mechanisms.

Short-Chain Inulin Modulates the Cecal Microbiota Structure of Leptin Knockout Mice in High-Fat Diet

The aim of this study was to explore the effect of short-chain inulin on cecal microbiota of high-fat diet-fed leptin knockout mice and the different influences of cecal microbiota on wild-type and leptin knockout mice. A total of 18 specific pathogen-free male C57BL/6J wild-type mice and 18 C57BL/6J leptin knockout mice (OB/OB mice) were selected. Mice were divided into six groups according to their genotype: wild-type mice have three groups, including the normal diet group (CT), 60% high-fat diet group (CH), and 60% high fat with 10% short-chain inulin group (CHI); OB/OB mice were also divided into three groups, including the normal diet group (OT), 60% high-fat diet group (OH), and 60% high fat with 10% short-inulin group (OHI). The mice were fed for 8 weeks to analyze the diversity of cecal microbiota. The results show that compared with CH and OH, the variety of cecal microbiota was significantly reduced in CH and OH and further reduced in CHI and OHI. Bifidobacterium and Lactobacillus are the biomarkers in genus level. Dietary short-chain inulin significantly enhanced Bifidobacterium in OHI compared with OH (p < 0.01) and significantly reduced in CHI and compared with CH (p < 0.01). Lactobacillus was significantly enhanced in CHI and OHI compared with CH and OH, respectively (p < 0.01). Blautia was significantly enhanced in CH and OH compared with other groups (p < 0.01). Both Escherichia-Shigella and Enterococcus were significantly reduced in CHI and OHI, compared with CH and OH, respectively (p < 0.05). Escherichia-Shigella was even lower than CT and OT in CHI and OHI. Functional prediction of microbial communities showed that the abundance of amino acid sugar and nucleotide sugar metabolism pathways were significantly enhanced (p < 0.05) in CH and OH, and OH was significantly higher than CH (p < 0.05). Among the leptin knockout groups, PICRUSt2 function prediction showed that the fatty acid metabolism pathway significantly reduced (p < 0.05) in OHI and OT compared with OH. In conclusion, short-chain inulin modulated the dysbiosis induced by high-fat diet, improved probiotics growth and inhibited conditioned pathogenic bacteria, and the influences were significantly different in wild-type and leptin knockout mice.

The beneficial effects of the composite probiotics from camel milk on glucose and lipid metabolism, liver and renal function and gut microbiota in db/db mice

Background

Probiotics may have beneficial effects on patients with type 2 diabetes mellitus (T2DM). We separated 4 lactobacillus and 1 saccharomycetes from traditional fermented cheese whey (TFCW) and prepared composite probiotics from camel milk (CPCM) and investigated their effects on glucose and lipid metabolism, liver and renal function and gut microbiota in db/db mice.

Methods

CPCM was prepared in the laboratory and 40 db/db mice were randomly divided into 4 groups as metformin, low-dose and high-dose group and model group, and treated for 6 weeks. In addition, 10 C57BL/Ks mice as normal control group were used for comparison. Fasting blood glucose (FBG), body weight (BW), oral glucose tolerance test (OGTT), glycated hemoglobin (HbAlc), C-peptide (CP), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), 24 h urinary microalbumin (24 h malb), urine ketone, urine sugar, pancreas and liver tissue and intestinal flora were tested.

Results

Compared to diabetic group, high dose CPCM significantly decreased FBG, OGTT, HbAlc and IRI, plasma TC, TG, LDL-C, 24 h malb, urine ketone and urine sugar, increased CP, HDL-C levels, improved the liver and kidney function, protected the function of islets, also increased intestinal tract lactic acid bacteria and Bifidobacterium, decreased Escherichia in db/db mice.

Conclusion

CPCM decreased FBG, OGTT and HbAlc, increased CP, modulated lipid metabolism and improved liver and kidney protected injury in db/db mice, which may be related to various probiotics acting through protecting the function of islets and regulating intestinal flora disturbance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03303-4.

Obese Animals as Models for Numerous Diseases: Advantages and Applications

With the advances in obesity research, a variety of animal models have been developed to investigate obesity pathogenesis, development, therapies and complications. Such obese animals would not only allow us to explore obesity but would also represent models to study diseases and conditions that develop with obesity or where obesity represents a risk factor. Indeed, obese subjects, as well as animal models of obesity, develop pathologies such as cardiovascular diseases, diabetes, inflammation and metabolic disorders. Therefore, obese animals would represent models for numerous diseases. Although those diseases can be induced in animals by chemicals or drugs without obesity development, having them developed as consequences of obesity has numerous advantages. These advantages include mimicking natural pathogenesis processes, using diversity in obesity models (diet, animal species) to study the related variabilities and exploring disease intensity and reversibility depending on obesity development and treatments. Importantly, therapeutic implications and pharmacological tests represent key advantages too. On the other hand, obesity prevalence is continuously increasing, and, therefore, the likelihood of having a patient suffering simultaneously from obesity and a particular disease is increasing. Thus, studying diverse diseases in obese animals (either induced naturally or developed) would allow researchers to build a library of data related to the patterns or specificities of obese patients within the context of pathologies. This may lead to a new branch of medicine specifically dedicated to the diseases and care of obese patients, similar to geriatric medicine, which focuses on the elderly population.

Liraglutide modulates gut microbiome and attenuates nonalcoholic fatty liver in db/db mice

AIMS

Liraglutide, a glucagon-like peptide-1(GLP-1) analog, is effective for the treatment of type II diabetes and nonalcoholic fatty liver disease (NAFLD). It was proved that gut microbiome plays a role in the development of NAFLD. This study aims to observe the therapeutic effect of liraglutide on nonalcoholic fatty liver (NAFL) in mice and effect on the gut microbial community.

MAIN METHODS

The db/db mice were used as the NAFL model, and lactulose was used as the positive control drug. Hepatic triglyceride, liver histopathology, and indices of glucolipid metabolism, including fasting blood glucose, fasting insulin, insulin resistance index and blood lipids were evaluated after treatment of liraglutide or lactulose for four weeks. The colonic microbiome of the mice was analyzed by 16S rRNA gene sequencing.

KEY FINDINGS

Liraglutide significantly reduced the hepatic triglyceride (TG) content, alanine aminotransferase (ALT) activity, fasting blood glucose, insulin resistance and serum low density lipoprotein (LDL) in the db/db mice. In terms of hepatic pathologies, hepatic steatosis was significantly improved after liraglutide treating. Microbiome analysis revealed that liraglutide significantly increased the abundance of Akkermansia, Romboutsia, norank_f_Bacteroidales_S24-7_group, and decreased the abundance of Klebsiella, Anaerotruncus, Bacteroides, Lachnospiraceae_UCG-001, Lachnospiraceae_NK4A136_group, Ruminiclostridium, uncultured_f__Ruminococcaceae, and Desulfovibrio.

SIGNIFICANCE

The results of the present study suggested that liraglutide had a certain therapeutic effect on fatty liver in db/db mice and had an impact on the composition of the intestinal microflora, especially some bacteria related to glucolipid metabolism and intestinal inflammation. Affecting gut microbiome might be a potential mechanism of liraglutide in treating NAFL.

Effects of a high-fat-diet supplemented with probiotics and ω3-fatty acids on appetite regulatory neuropeptides and neurotransmitters in a pig model

The pig is a valuable animal model to study obesity in humans due to the physiological similarity between humans and pigs in terms of digestive and associated metabolic processes. The dietary use of vegetal protein, probiotics and omega-3 fatty acids is recommended to control weight gain and to fight obesity-associated metabolic disorders. Likewise, there are recent reports on their beneficial effects on brain functions. The hypothalamus is the central part of the brain that regulates food intake by means of the production of food intake-regulatory hypothalamic neuropeptides, as neuropeptide Y (NPY), orexin A and pro-opiomelanocortin (POMC), and neurotransmitters, such as dopamine and serotonin. Other mesolimbic areas, such as the hippocampus, are also involved in the control of food intake. In this study, the effect of a high fat diet (HFD) alone or supplemented with these additives on brain neuropeptides and neurotransmitters was assessed in forty-three young pigs fed for 10 weeks with a control diet (T1), a high fat diet (HFD, T2), and HFD with vegetal protein supplemented with Bifidobacterium breve CECT8242 alone (T3) or in combination with omega-3 fatty acids (T4). A HFD provoked changes in regulatory neuropeptides and 3,4-dihydroxyphenylacetic acid (DOPAC) in the hypothalamus and alterations mostly in the dopaminergic system in the ventral hippocampus. Supplementation of the HFD with B. breve CECT8242, especially in combination with omega-3 fatty acids, was able to partially reverse the effects of HFD. Correlations between productive and neurochemical parameters supported these findings. These results confirm that pigs are an appropriate animal model alternative to rodents for the study of the effects of HFD on weight gain and obesity. Furthermore, they indicate the potential benefits of probiotics and omega-3 fatty acids on brain function.

Probiotics for the Treatment of Overweight and Obesity in Humans-A Review of Clinical Trials

The World Health Organization (WHO) reports that 400 million people are obese, and over 1.6 billion adults are overweight worldwide. Annually, over 2.8 million people die from obesity-related diseases. The incidence of overweight and obesity is steadily increasing, and this phenomenon is referred to as a 21st-century pandemic. The main reason for this phenomenon is an easy access to high-energy, processed foods, and a low-activity lifestyle. These changes lead to an energy imbalance and, as a consequence, to the development of body fat. Weight gain contributes to the development of heart diseases, skeletal system disorders, metabolic disorders such as diabetes, and certain types of cancer. In recent years, there have been many works linking obesity with intestinal microbiota. Experiments on germ-free animals (GFs) have provided much evidence for the contribution of bacteria to obesity. The composition of the gut microbiota (GM) changes in obese people. These changes affect the degree of energy obtained from food, the composition and secretory functions of adipose tissue, carbohydrate, and lipid metabolism in the liver, and the activity of centers in the brain. The study aimed to present the current state of knowledge about the role of intestinal microbiota in the development of obesity and the impact of supplementation with probiotic bacteria on the health of overweight and obese patients.

Effects of Regular Kefir Consumption on Gut Microbiota in Patients with Metabolic Syndrome: A Parallel-Group, Randomized, Controlled Study

Several health-promoting effects of kefir have been suggested, however, there is limited evidence for its potential effect on gut microbiota in metabolic syndrome This study aimed to investigate the effects of regular kefir consumption on gut microbiota composition, and their relation with the components of metabolic syndrome. In a parallel-group, randomized, controlled clinical trial setting, patients with metabolic syndrome were randomized to receive 180 mL/day kefir (n = 12) or unfermented milk (n = 10) for 12 weeks. Anthropometrical measurements, blood samples, blood pressure measurements, and fecal samples were taken at the beginning and end of the study. Fasting insulin, HOMA-IR, TNF-α, IFN-γ, and systolic and diastolic blood pressure showed a significant decrease by the intervention of kefir (p ≤ 0.05, for each). However, no significant difference was obtained between the kefir and unfermented milk groups (p > 0.05 for each). Gut microbiota analysis showed that regular kefir consumption resulted in a significant increase only in the relative abundance of Actinobacteria (p = 0.023). No significant change in the relative abundance of Bacteroidetes, Proteobacteria or Verrucomicrobia by kefir consumption was obtained. Furthermore, the changes in the relative abundance of sub-phylum bacterial populations did not differ significantly between the groups (p > 0.05, for each). Kefir supplementation had favorable effects on some of the metabolic syndrome parameters, however, further investigation is needed to understand its effect on gut microbiota composition.

Obesity and severe asthma

Obesity is an important global health issue for both children and adults. Obesity increases the prevalence and incidence of asthma and also increases the risk for severe asthma. Here we describe the features of severe asthma phenotypes for which obesity is a defining characteristic, including steroid resistance, airway inflammation, and co-morbidities. We also review current concepts regarding the mechanistic basis for the impact of obesity in severe asthma, including possible roles for vitamin D deficiency, systemic inflammation, and the microbiome. Finally, we describe data indicating a role for diet, weight loss, and exercise in the treatment of severe asthma with obesity. Better understanding of the mechanistic basis for the role of obesity in severe asthma could lead to new therapeutic options for this population.

Strain-level diversity of commercial probiotic isolates of Bacillus, Lactobacillus, and Saccharomyces species illustrated by molecular identification and phenotypic profiling

Probiotic products are becoming more prevalent as awareness of the role of beneficial microbes in health increases. Ingredient labels of these products often omit identifications at the strain level, making it difficult to track down applicable published research. In this study, we investigated whether products labeled with the same species name contained different strains of those species. From 21 commercially available probiotic supplements and beverages, we cultured five main species: Bacillus coagulans, Bacillus subtilis, Lactobacillus plantarum, Lactobacillus rhamnosus, and the yeast Saccharomyces boulardii. To confirm the identity of each bacterial isolate, we applied standard molecular approaches: 16S rRNA gene sequencing and Matrix Assisted Laser Desorption Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS). Phenotypic profiling and identification were performed with the Biolog Microbial Identification system. All of the bacterial isolates were correctly identified by at least one approach. Sequencing the 16S rRNA gene led to 82% of species identifications matching the product label, with 71% of isolates identified by MALDI-TOF MS and 60% identified correctly with the Biolog system. Analysis of the Biolog phenotypic profiles revealed different patterns of carbon source usage by each species, with sugars preferentially utilized by all except B. subtilis. To assess the strain-level differences, we compared strains of the same species and found variability in carbohydrate utilization and tolerance to environmental stressors (salt, acidity, antibiotics). By demonstrating that products listing the same species often contain strains with different 16S sequences and phenotypes, this study highlights that current labels of probiotic supplements do not sufficiently convey the strain diversity in these products.

Reduced-Fat Response of Lactobacillus casei subsp. casei SY13 on a Time and Dose-Dependent Model

A reduced-fat effect of probiotics was primarily derived functionally rather than structurally, and we investigated the ultra-structural aspect of the gut mucosa in Syrian golden hamsters with high-fat diet by feeding with Lactobacillus casei subsp. casei SY13 (Lc SY13). 36 adult-male Syrian golden hamsters were randomly grouped into four; control group (G1), high-fat group (G2), high-dose group (G3), and low-dose group (G4). The G1 hamsters were fed a standard normal chow diet, while those in other groups were fed a high-fat chow diet for duration of 8 weeks. With the use of oral gavage, G1 hamsters were administered 1 mL of skim milk/hamster/day, while G3 and G4 hamsters were administered Lc SY13 at 4.1 × 10¹⁰ or 4.1 × 10⁸ cells/hamster/day. At 14, 28, and 56 days consecutively, three golden hamsters from each group were sacrificed by carotid, taking blood from eyeball for quantitative detection of hamsters serum total cholesterol (TC), triacylglycerol (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL). At 56 days, Taqman-MGB fluorescence probe was used for the quantitative detection of Lc SY13 in the intestinal mucosal, and their ileum was viewed using transmission electron microscopy (TEM). Screening of the ileum microvilli of the hamsters showed that at 56 days, G3 was significantly (P < 0.05) bigger than other groups while its serum TC, TG, and TDL decreased. Lc SY13 was detected in the intestines, and was significantly (P < 0.05) higher in the ileum of G3 than those of G4. In conclusion, Lc SY13 may play a remarkable reduced-fat response role by improving high-fat uptake as well as its metabolism and transport; most especially in G3. The reduced-fat response of the Lc SY13 differed in a time and dose-dependent manner. These findings indicated that probiotic strains of Lc SY13 can reduce fat level, thus suggesting its potential in ameliorating obesity-related diseases.

POSTOPERATIVE CHANGES IN INTESTINAL MICROBIOTA AND USE OF PROBIOTICS IN ROUX-EN-Y GASTRIC BYPASS AND SLEEVE VERTICAL GASTRECTOMY: AN INTEGRATIVE REVIEW

Introduction:

Studies suggest that weight loss induced by bariatric surgery and the remission of some comorbidities may be related to changes in the microbiota profile of individuals undergoing this procedure. In addition, there is evidence that manipulation of the intestinal microbiota may prove to be a therapeutic approach against obesity and metabolic diseases.

Objective:

To verify the changes that occur in the intestinal microbiota of patients undergoing bariatric surgery, and the impact of the usage of probiotics in this population.

Methods:

Articles published between 2007 and 2017 were searched in Medline, Lilacs and Pubmed with the headings: bariatric surgery, microbiota, microbiome and probiotics, in Portuguese, English and Spanish. Of the 166 articles found, only those studies in adults subjected to either Roux-en-Y gastric bypass or sleeve vertical gastrectomy published in original articles were enrolled. In the end, five studies on the change of intestinal microbiota composition, four on the indirect effects of those changes and three on the probiotics administration on this population were enrolled and characterized.

Conclusion:

Bariatric surgery provides changes in intestinal microbiota, with a relative increase of the Bacteroidetes and Proteobacteria phyla and reduction of Firmicutes. This is possibly due to changes in the gastro-intestinal flux, coupled with a reduction in acidity, in addition to changes in eating habits. The usage of probiotics seems to reduce the gastro-intestinal symptoms in the post-surgery, favor the increase of vitamin B12 synthesis, as well as potentiate weight loss.

A study of the correlation between obesity and intestinal flora in school-age children

With the improvement of living standards and dietary changes, childhood obesity has increased worldwide. This study aimed to understand the differences of intestinal flora structure between obese and normal children at school-age. Using the next generation sequencing platform, Illumina Miseq, 16S rDNA high-throughput sequencing technology, we analyzed the diversity and relative abundance of intestinal flora in 39 obese and 38 normal control school-age children. First, we categorized gut bacteria on the basis of their Operational taxonomic units (OTUs) using the RDP 16s rRNA database in RDP classifier. The alpha (α) diversity was used to measure the diversity within a sample and is calculated as a value for each sample. The beta (β) diversity was used to compare different samples and to measure the dissimilarity between each other sample. Our results indicated that intestinal flora in obese children showed lower diversity than normal controls. Significant differences of relative abundance of intestinal flora were detected at multiple levels of classifications. Identification of intestinal flora with significant difference between obese and normal children may provide important information to uncover the roles of these specific bacteria in the development of obesity and find new strategy to prevent and treat obesity through intervening the intestinal flora.

Effects of Natural Flavonoid Isoorientin on Growth Performance and Gut Microbiota of Mice

Isoorientin (ISO) is a natural flavonoid, which is a 6- C-glucoside of luteolin, and has been demonstrated to possess multiple biological properties. In this study, the effects of ISO on the growth performance and gut microbiota of BALB/c mice were investigated. The results showed that ISO could promote food intake and body weight gain, increase the digestibility of crude proteins and utilization of the gross energy, and strengthen antioxidant capacity of mice. We also demonstrated it has no side effects on hepatic and renal functions. Moreover, ISO inhibited the growth of most bacteria in gut microbiota, especially the pathogenic genera of Alistipes, Helicobacter, and Oscillibacter, which could lead to inflammation. Metabolisms of epithelial cell signaling in Helicobacter pylori infection, lipopolysaccharide (LPS) biosynthesis, and LPS biosynthesis proteins in gut microbiota of the control group were more abundant than those in the ISO group, while lipid metabolism and vitamin B₆ metabolism were enriched in the ISO group. We found the changes in enrichments of metabolic pathways of the gut microbiota along with the ISO application were positively correlated with the antioxidation, anti-inflammation, and antibiosis. This work provided a fundamental basis for the future development of ISO-functional foods used for resistance to oxidation, inflammation, and pathogens.

Molecular Alteration Analysis of Human Gut Microbial Composition in Graves' disease Patients

The gut microbial association with host co-existence is critical for body homeostasis and pathogenicity. Graves' disease (GD) is an autoimmune disease manifested with hyperthyroidism and ophthalmopathy. However, we hypothesized that gut bacteria could affect an important role in GD pathogenicity. The current study aim was to characterize and investigate the intestinal bacterial composition of GD qualitatively and quantitatively. 27 GD and 11 healthy controls were enrolled for fecal sample collection. The PCR-DGGE of 16S rRNA gene by targeting V3 region and Real-time PCR for Lactobacillus, Bifidobacterium, Bacteroides vulgatus and Clostridium leptum, were performed. High-throughput sequencing of 16S rRNA gene with the V3+V4 site was perormed on Hiseq2500 platform on randomly 20 selected samples. The relative analysis of richness indices and diversity illustrated lesser diversification of intestinal bacteria in GD patients in contrast to controls. The data statistics shows the alteration in phyla of GD as compared to control. At the family taxonomic level, the relative abundance of Prevotellaceae and Pasteurellaceae were significantly higher in patients, while Enterobacteriaceae, Veillonellaceae, and Rikenellaceae were significantly lower in the diseased group as compared to control. At the genus level, a significant raised in genera count of the diseased group were Prevotella_9 and Haemophilus, while significantly decreased in the genera of the GD group were Alistipes and Faecalibacterium. The modulation in intestinal bacterial composition was checked at species level particularly H. parainfluenza abundance was raised in GD. The outcomes of the current study are aligned with the proposed hypothesis of gut microbial dysbiosis in GD. Statistically, alpha indices and differential abundance analyses of each intestinal bacterial community were significantly changed in GD. Therefore, the current study may provide a new insight into the GD pathogenesis and, in turn, explore its contribution in possible treatments.

Probiotics and nutraceuticals as a new frontier in obesity prevention and management

INTRODUCTION

The beneficial interaction between the microbiota and humans is how bacteria contained within the gut 'talk' to the immune system and in this landscape, probiotics and nutraceuticals play a major role. The study aims to determine whether probiotics plus nutraceuticals such as smectite or omega-3 are superior to probiotic alone on the monosodium glutamate (MSG) induced obesity model in rats.

METHODS

Totally, 75 rats divided into five groups were included (n = 15, in each). Rats in group I were intact. Newborn rats in groups II-V were injected with MSG. Group III (Symbiter) received 2.5 ml/kg of multiprobiotic "Symbiter" containing concentrated biomass of 14 probiotic bacteria genera. Groups IV (Symbiter-Omega) and V (Symbiter-Smectite) received a combination of probiotic biomass supplemented with flax and wheat germ oil (250 mg of each, concentration of omega-3 fatty acids 1-5%) or smectite gel (250 mg), respectively.

RESULTS

In all interventional groups, significant reductions of total body and visceral adipose tissue weight as compared to MSG-obesity were observed. However, the lowest prevalence of obesity was noted for Symbiter-Omega (20% vs 33.3% as compared to other interventional groups). Moreover, supplementation of probiotics with omega-3 lead to a more pronounced decrease in HOMA-IR (2.31 ± 0.13 vs 4.02 ± 0.33, p < 0.001) and elevation of adiponectin levels (5.67 ± 0.39 vs 2.61 ± 0.27, P < 0.001), compared to the obesity group.

CONCLUSION

Probiotics and nutraceuticals led to a significantly lower prevalence of obesity, reduction of insulin resistance, total and VAT weight. Our study demonstrated that supplementation of probiotics with omega-3 may have the most beneficial antiobesity properties.

Microbiota in obesity: interactions with enteroendocrine, immune and central nervous systems

Western diets, with high consumption of simple sugars and saturated fats, contribute to the rise in the prevalence of obesity. It now seems clear that high-fat diets cause obesity, at least in part, by modifying the composition and function of the microorganisms that colonize in the gastrointestinal tract, the microbiota. The exact pathways by which intestinal microbiota contribute to obesity remain largely unknown. High-fat diet-induced alterations in intestinal microbiota have been suggested to increase energy extraction, intestinal permeability and systemic inflammation while decreasing the capability to generate obesity-suppressing short-chain fatty acids. Moreover, by increasing systemic inflammation, microglial activation and affecting vagal nerve activity, 'obese microbiota' indirectly influence hypothalamic gene expression and promote overeating. Because the potential of intestinal microbiota to induce obesity has been recognized, multiple ways to modify its composition and function are being investigated to provide novel preventive and therapeutic strategies against diet-induced obesity.

Bifidobacteria and its rice fermented products on diet induced obese mice: analysis of physical status, serum profile and gene expressions

Obesity is highly correlated with the dysbiosis of intestinal microbiota, and bifidobacteria are one of the soft targets of this metabolic syndrome. The aim of this study is to evaluate the efficacy of Bifidobacterium sp. MKK4 and rice-based fermented foods on physical, haematological, gut microbiota and lypogenic-lypolytic marker genes in diet-induced obese mice. Adult male mice (21±0.7 g) were randomly divided into four groups (n=10) according to the type of diet: normal diet (ND), high fat diet (HFD), HFD supplemented with Bifidobacterium sp. MKK4 and HFD supplemented with MKK4 associated rice-fermented food. 8 weeks of bacterial therapy in the obese mice resulted in significant reduction of body and organ weights, improved serum levels of glucose, triglyceride and cholesterol, the histological structure of the liver (steatosis), and re-establishment of gut Lactobacillus, Bifidobacterium and Bacteroides species. The bacterial therapy led to up-regulation of lipolytic transcription factors, such as peroxisome proliferator-activated receptor (PPAR)-α, PPAR-δ, and their regulated gene products in fatty acid metabolism and glucose uptake, such as acyl-CoA oxidase, carnitine palmitoyl-transferase-1, uncoupling protein-3 and glucose transporter-4. Concomitantly, both adipocytogenesis and fatty acid synthesis were arrested as reflected by the down-regulation of sterol regulatory element binding protein-1c, acetyl-CoA carboxylase, fatty acid synthase and tumour necrosis factor alpha genes. The effectiveness of the fermented product was more profound than the single bacterium. These data provide experimental support with regard to the use of Bifidobacterium sp. MKK4 as a natural therapeutic agent to control obesity.

Diet and microbiota linked in health and disease

Diet has shaped microbiota profiles through human evolution.

Citrus peel extracts attenuated obesity and modulated gut microbiota in mice with high-fat diet-induced obesity

Polymethoxyflavones (PMFs) and hydroxyl PMFs (HOPMFs) are mainly found in citrus peel and have shown anti-obesity potential in in vitro and in vivo studies.

Total fecal microbiota transplantation alleviates high-fat diet-induced steatohepatitis in mice via beneficial regulation of gut microbiota

Non-alcoholic steatohepatitis (NASH) is an epidemic metabolic disease with limited therapeutic strategies. Cumulative data support the pivotal role of gut microbiota in NASH. Here, we investigated the hypothesis regarding whether fecal microbiota transplantation (FMT) is effective in attenuating high-fat diet (HFD)-induced steatohepatitis in mice. Mice were randomized into control, HFD and HFD + FMT groups. After an 8-week HFD, FMT treatment was initiated and carried out for 8 weeks. The gut microbiota structure, butyrate concentrations of the cecal content, liver pathology and intrahepatic lipid and cytokines were examined. Our results showed that after FMT, the gut microbiota disturbance was corrected in HFD-fed mice with elevated abundances of the beneficial bacteria Christensenellaceae and Lactobacillus. FMT also increased butyrate concentrations of the cecal content and the intestinal tight junction protein ZO-1, resulting in relief of endotoxima in HFD-fed mice. Steatohepatitis was alleviated after FMT, as indicated by a significant decrease in intrahepatic lipid accumulation (reduced Oli-red staining, decreased intrahepatic triglyceride and cholesterol), intrahepatic pro-inflammatory cytokines, and the NAS score. Accordingly, intrahepatic IFN-γ and IL-17 were decreased, but Foxp3, IL-4 and IL-22 were increased after FMT intervention. These data indicate that FMT attenuated HFD-induced steatohepatitis in mice via a beneficial effect on the gut microbiota.

Sodium butyrate attenuates high-fat diet-induced steatohepatitis in mice by improving gut microbiota and gastrointestinal barrier

AIM

To investigate whether gut microbiota metabolite sodium butyrate (NaB) is an effective substance for attenuating non-alcoholic fatty liver disease (NAFLD) and the internal mechanisms.

METHODS

Male C57BL/6J mice were divided into three groups, normal control were fed standard chow and model group were fed a high-fat diet (HFD) for 16 wk, the intervention group were fed HFD for 16 wk and treated with NaB for 8 wk. Gut microbiota from each group were detected at baseline and at 16 wk, liver histology were evaluated and gastrointestinal barrier indicator such as zonula occluden-1 (ZO-1) were detected by immunohistochemistry and realtime-PCR, further serum or liver endotoxin were determined by ELISA and inflammation- or metabolism-associated genes were quantified by real-time PCR.

RESULTS

NaB corrected the HFD-induced gut microbiota imbalance in mice, while it considerably elevated the abundances of the beneficial bacteria Christensenellaceae, Blautia and Lactobacillus. These bacteria can produce butyric acid in what seems like a virtuous circle. And butyrate restored HFD induced intestinal mucosa damage, increased the expression of ZO-1 in small intestine, further decreased the levels of gut endotoxin in serum and liver compared with HF group. Endotoxin-associated genes such as TLR4 and Myd88, pro-inflammation genes such as MCP-1, TNF-α, IL-1, IL-2, IL-6 and IFN-γ in liver or epididymal fat were obviously downregulated after NaB intervention. Liver inflammation and fat accumulation were ameliorated, the levels of TG and cholesterol in liver were decreased after NaB intervention, NAS score was significantly decreased, metabolic indices such as FBG and HOMA-IR and liver function indicators ALT and AST were improved compared with HF group.

CONCLUSION

NaB may restore the dysbiosis of gut microbiota to attenuate steatohepatitis, which is suggested to be a potential gut microbiota modulator and therapeutic substance for NAFLD.

Gut Microbiota and Metabolic Health: The Potential Beneficial Effects of a Medium Chain Triglyceride Diet in Obese Individuals

Obesity and associated metabolic complications, such as non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D), are in constant increase around the world. While most obese patients show several metabolic and biometric abnormalities and comorbidities, a subgroup of patients representing 3% to 57% of obese adults, depending on the diagnosis criteria, remains metabolically healthy. Among many other factors, the gut microbiota is now identified as a determining factor in the pathogenesis of metabolically unhealthy obese (MUHO) individuals and in obesity-related diseases such as endotoxemia, intestinal and systemic inflammation, as well as insulin resistance. Interestingly, recent studies suggest that an optimal healthy-like gut microbiota structure may contribute to the metabolically healthy obese (MHO) phenotype. Here, we describe how dietary medium chain triglycerides (MCT), previously found to promote lipid catabolism, energy expenditure and weight loss, can ameliorate metabolic health via their capacity to improve both intestinal ecosystem and permeability. MCT-enriched diets could therefore be used to manage metabolic diseases through modification of gut microbiota.