Gut microbiome approaches to treat obesity in humans

Cereal-based fermented foods as microbiota-directed products for improved child nutrition and health in sub-Saharan Africa

Several strategies, programs and policies have long been developed and implemented to alleviate child malnutrition in sub-Saharan African countries. However, stunting and wasting still persist at an alarming rate, suggesting that alternative strategies are needed to induce faster progress toward the 2030 SDGs targets of reducing malnutrition. Gut microbiota-directed intervention is now being recognized as an unconventional powerful approach to mitigate malnutrition and improve overall child health. In an African setting, manufactured probiotic and synbiotic foods or supplements may not be successful owing to the non-affordability and high attachment of African populations to their food tradition. This review analyses the potential of indigenous fermented cereal-based products including porridges, doughs, beverages, bread- and yoghurt-like products, to be used as microbiota-directed foods for over 6 months children. The discussion includes relevant strategies to effectively enhance the beneficial effects of these products on gut microbiota composition for improved child health and nutrition in sub-Saharan Africa. Characterization of probiotic features and general safety of food processing in sub-Saharan Africa as well as randomized clinical studies are still lacking to fully ascertain the health effects and suitability of these fermented foods in preventing and treating child malnutrition and diarrhea.

Long-term efficacy of washed microbiota transplantation in overweight patients

BACKGROUND

Faecal microbiota transplantation holds promise in mitigating fat accumulation and improving obesity. This study aimed to evaluate the long-term efficacy of washed microbiota transplantation (WMT) among overweight patients.

METHODS

The clinical data pertaining to the treatment of patients with WMT were collected retrospectively. Compared alterations in body mass index (BMI), blood glucose, blood lipids and blood pressure prior to and following WMT treatment. Comprehensive efficacy evaluation and atherosclerosis cardiovascular disease (ASCVD) grading evaluation were carried out, with an analysis of gut microbiota composition before and after WMT.

RESULTS

A total of 186 patients were included (80 overweight, 106 normal weight). WMT not only had the effect of improving overweight patients to the normal weight patients (p < .001), but also could significantly reduce BMI in the long term by restoring gut microbiota homeostasis (p < .001). In addition, the BMI improvement value of multi course was more significant than that of single course or double course. WMT had a significant ASCVD downgrade effect on the high-risk and medium-risk groups outside 1 year, while it did not increase the risk of upgrading ASCVD for low-risk group.

CONCLUSIONS

WMT could significantly reduce the BMI of overweight patients and still had an improvement effect in the long term.

The effects of inulin on solubilizing and improving anti-obesity activity of high polymerization persimmon tannin

High polymerization persimmon tannin has been reported to have lipid-lowering effects. Unfortunately, the poor solubility restricts its application. This research aimed to investigate the effect and mechanism of inulin on solubilizing of persimmon tannin. Furthermore, we examined whether the addition of inulin would affect the attenuated obesity effect of persimmon tannin. Transmission electron microscope (TEM), Isothermal titration calorimetry (ITC) and Fourier transform infrared spectroscopy (FT-IR) results demonstrated that inulin formed a gel-like network structure, which enabled the encapsulation of persimmon tannin through hydrophobic and hydrogen bond interactions, thereby inhibiting the self-aggregation of persimmon tannin. The turbidity of the persimmon tannin solution decreased by 56.2 %, while the polyphenol content in the supernatant increased by 60.0 %. Furthermore, biochemical analysis and 16s rRNA gene sequencing technology demonstrated that persimmon tannin had a significant anti-obesity effect and improved intestinal health in HFD-fed mice. Moreover, inulin was found to have a positive effect on enhancing the health benefits of persimmon tannin, including improving hepatic steatosis and gut microbiota dysbiosis. it enhanced the abundance of beneficial core microbes while decreasing the abundance of harmful bacteria. Our findings expand the applications of persimmon tannin in the food and medical sectors.

Targeting Non-Alcoholic Fatty Liver Disease with Hawthorn Ethanol Extract (HEE): A Comprehensive Examination of Hepatic Lipid Reduction and Gut Microbiota Modulation

Recent studies have highlighted the lipid-lowering ability of hawthorn ethanol extract (HEE) and the role played by gut flora in the efficacy of HEE. Our study sought to explore the effects of HEE on non-alcoholic fatty liver disease (NAFLD) in normal flora and pseudo germ-free mice. The results showed that HEE effectively diminished hepatic lipid accumulation, ameliorated liver function, reduced inflammatory cytokine levels and blood lipid profiles, and regulated blood glucose levels. HEE facilitated triglyceride breakdown, suppressed fatty acid synthesis, and enhanced intestinal health by modulating the diversity of the gut microbiota and the production of short-chain fatty acids in the gut. In addition, HEE apparently helps to increase the presence of beneficial genera of bacteria, thereby influencing the composition of the gut microbiota, and the absence of gut flora affects the efficacy of HEE. These findings reveal the potential of hawthorn for the prevention and treatment of NAFLD and provide new perspectives on the study of functional plants to improve liver health.

Probiotic-Induced Modulation of Microbiota Composition and Antibiotic Resistance Genes Load, an In Vitro Assessment

The imbalance of the gut microbiota (GM) is known as dysbiosis and is associated with disorders such as obesity. The increasing prevalence of microorganisms harboring antibiotic resistance genes (ARG) in the GM has been reported as a potential risk for spreading multi-drug-resistant pathogens. The objective of this work was the evaluation, in a fecal culture model, of different probiotics for their ability to modulate GM composition and ARG levels on two population groups, extremely obese (OB) and normal-weight (NW) subjects. Clear differences in the basal microbiota composition were observed between NW and OB donors. The microbial profile assessed by metataxonomics revealed the broader impact of probiotics on the OB microbiota composition. Also, supplementation with probiotics promoted significant reductions in the absolute levels of tetM and tetO genes. Regarding the blaTEM gene, a minor but significant decrease in both donor groups was detected after probiotic addition. A negative association between the abundance of Bifidobacteriaceae and the tetM gene was observed. Our results show the ability of some of the tested strains to modulate GM. Moreover, the results suggest the potential application of probiotics for reducing the levels of ARG, which constitutes an interesting target for the future development of probiotics.

Association between dietary patterns and chronic kidney disease combined with hyperuricemia

Background and aims: Chronic kidney disease (CKD) combined with hyperuricemia is a concerning health issue, but the association between this condition and dietary patterns remains poorly understood. The aim of this study was to assess the associations between dietary patterns and CKD combined with hyperuricemia. Methods: This cross-sectional study was conducted involving 12 318 participants aged 18-79 years during 2018-2020. Dietary intake information was collected using a validated 110-item food frequency questionnaire. Factor analysis was used to identify major dietary patterns. CKD was defined as the presence of albuminuria or an estimated glomerular filtration rate <60 mL min-1 1.73 m-2. Hyperuricemia was defined as serum uric acid levels >420 μmol L-1 both in men and women. Logistic regression models were applied to assess the association between dietary patterns and the risk of CKD combined with hyperuricemia. Results: Five major dietary patterns were identified: 'healthy pattern', 'traditional pattern', 'animal foods pattern', 'sweet foods pattern', and 'tea-alcohol pattern', which together explained 38.93% of the variance in the diet. After adjusting for potential confounders, participants in the highest quartile of the traditional pattern had a lower risk of CKD combined with hyperuricemia (OR = 0.49, 95% CI: 0.32-0.74, Pfor trend < 0.01). Conversely, participants in the highest quartile of the sweet foods pattern had a higher risk compared to those in the lowest quartile (OR = 1.69, 95% CI: 1.18-2.42, Pfor trend < 0.01). However, no significant association was observed between the healthy pattern, animal foods pattern and tea-alcohol pattern and the risk of CKD combined with hyperuricemia. Conclusions: Our results suggest that the traditional pattern is associated with a reduced risk of CKD combined with hyperuricemia, whereas the sweet foods pattern is associated with an increased risk.

The gut microbiome in the fight against obesity: The potential of dietary factors

Obesity as a global public health burden has experienced a drastic growing trend recently. The management of obesity is challenging because of its complex etiology, and various factors are involved in its development, such as genetic and environmental factors. Different approaches are available to treat and/or manage obesity, including diet, physical activity, lifestyle changes, medications, and surgery. However, some of these approaches have inherent limitations and are closely associated with adverse effects. Therefore, probing into a novel/safe approach to treat and/or manage obesity is of fundamental importance. One such approach gaining renewed interest is the potential role of gut microbiota in obesity and its effectiveness in treating this condition. However, there is a dearth of comprehensive compilation of data on the potential role of the gut microbiome in obesity, particularly regarding dietary factors as a therapeutic approach. Therefore, this review aims to provide an updated overview of the role of gut microbiota in obesity, further highlighting the importance of dietary factors, particularly diet, prebiotics, and probiotics, as potential complementary and/or alternative therapeutic options. Moreover, the association of gut microbiota with obese or lean individuals has also been discussed.

Ameliorating effects of L-carnitine and synbiotic co-supplementation on anthropometric measures and cardiometabolic traits in women with obesity: a randomized controlled clinical trial

Background

Obesity, a multifactorial disorder with pandemic dimensions, is conceded a major culprit of morbidity and mortality worldwide, necessitating efficient therapeutic strategies. Nutraceuticals and functional foods are considered promising adjuvant/complementary approaches for weight management in individuals with obesity who have low adherence to conventional treatments. Current literature supports the weight-reducing efficacy of pro/pre/synbiotics or L-carnitine; however, the superiority of the nutraceutical joint supplementation approach over common single therapies to counter obesity and accompanying comorbidities is well documented. This study was designed to assess the effects of L-carnitine single therapy compared with L-carnitine and multistrain/multispecies synbiotic co-supplementation on anthropometric and cardiometabolic indicators in women with obesity.

Methods

The current placebo-controlled double-blind randomized clinical trial was performed on 46 women with obesity, randomly allocated to either concomitant supplementation [L-carnitine tartrate (2 × 500 mg/day) + multistrain/multispecies synbiotic (1 capsule/day)] or monotherapy [L-carnitine tartrate (2 × 500 mg/day) + maltodextrin (1 capsule/day)] groups for 8 weeks. Participants in both groups received healthy eating dietary advice.

Results

Anthropometric, lipid, and glycemic indices significantly improved in both intervention groups; however, L-carnitine + synbiotic co-administration elicited a greater reduction in the anthropometric measures including body mass index (BMI), body weight, and neck, waist, and hip circumferences (p < 0.001, <0.001, <0.001, = 0.012, and =0.030, respectively) after adjusting for probable confounders. Moreover, L-carnitine + synbiotic joint supplementation resulted in a greater reduction in fasting blood sugar (FBS), insulin (though marginal), and homeostatic model assessment of insulin resistance (HOMA-IR) and more increment in quantitative insulin sensitivity check index (QUICKI; p = 0.014, 0.051, 0.024, and 0.019, respectively) compared with the L-carnitine + placebo monosupplementation. No significant intergroup changes were found for the lipid profile biomarkers, except for a greater increase in high-density lipoprotein-cholesterol concentrations (HDL-C) in the L-carnitine + synbiotic group (p = 0.009).

Conclusion

L-carnitine + synbiotic co-supplementation was more beneficial in ameliorating anthropometric indices as well as some cardiometabolic parameters compared with L-carnitine single therapy, suggesting that it is a promising adjuvant approach to ameliorate obesity or associated metabolic complications through potential synergistic or complementary mechanisms. Further longer duration clinical trials in a three-group design are demanded to verify the complementary or synergistic mechanisms.

Clinical trial registration

www.irct.ir, Iranian Registry of Clinical Trials IRCT20080904001197N13.

The Effect of Probiotic Supplementation on Glucolipid Metabolism in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

PURPOSE

Type 2 diabetes mellitus (T2DM) is a persistent metabolic condition with an unknown pathophysiology. Moreover, T2DM remains a serious health risk despite advances in medication and preventive care. Randomised controlled trials (RCTs) have provided evidence that probiotics may have positive effects on glucolipid metabolism. Therefore, we performed a meta-analysis of RCTs to measure the effect of probiotic therapy on glucolipid metabolism in patients with T2DM.

METHODS

With no constraints on the language used in the literature, Excerpta Medica Database, PubMed, the Cochrane Library, and the Web of Science were searched for pertinent RCTs published between the date of creation and 18 August 2022. Stringent inclusion and exclusion criteria were applied by two reviewers to independently examine the literature. The risk of bias associated with the inclusion of the original studies was assessed using the Cochrane risk-of-bias tool, and Stata 15.0 was used to perform the meta-analysis.

RESULTS

Thirty-seven publications containing a total of 2502 research participants were included in the meta-analysis. The results showed that after a probiotic intervention, the experimental group showed a significant decrease in body mass index (standardised mean difference (SMD) = -0.42, 95% confidence interval (CI) [-0.76, -0.08]), fasting glucose concentration (SMD = -0.73, 95% CI [-0.97, -0.48]), fasting insulin concentration (SMD = -0.67, 95% CI [-0.99, -0.36]), glycated haemoglobin concentration (SMD = -0.55, 95% CI [-0.75, -0.35]), Homeostatic Model Assessment for Insulin Resistance score (SMD = -0.88, 95% CI [-1.17, -0.59]), triglyceride concentration (SMD = -0.30, 95% CI [-0.43, -0.17]), total cholesterol concentration (SMD = -0.27, 95% CI [-0.43, -0.11]), and low-density lipoprotein concentration (SMD = -0.20, 95% CI [-0.37, -0.04]), and an increase in high-density lipoprotein concentration (SMD = 0.31, 95% CI [0.08, 0.54]). Moreover, subgroup analyses showed that patients with a longer intervention time, or those who were treated with multiple strains of probiotics, may benefit more than those with a shorter intervention time or those who were treated with a single probiotic strain, respectively.

CONCLUSION

Probiotic supplementation improves glucolipid metabolism in patients with T2DM, offering an alternative approach for the treatment of these patients.

The Effect of Exercise Prescription on the Human Gut Microbiota and Comparison between Clinical and Apparently Healthy Populations: A Systematic Review

This study systematically reviewed all human longitudinal exercise interventions that reported changes in the gut microbiota; frequency, intensity, duration and type of exercise were assessed to determine the influence of these variables on changes to the gut microbiota in both healthy individuals and clinical populations (PROPERO registration: CRD42022309854). Using PRISMA guidelines, trials analysing gut microbiota change with exercise interventions were included independent of trial randomisation, population, trial duration or analysis technique. Studies were excluded when microbiota abundance was not reported or when exercise was combined with other interventions. Twenty-eight trials were included, of which twelve involved healthy populations only and sixteen involved mixed or clinical-only populations. The findings show that participation in exercise of moderate to high-intensity for 30-90 min ≥3 times per week (or between 150-270 min per week) for ≥8 weeks is likely to produce changes in the gut microbiota. Exercise appears to be effective in modifying the gut microbiota in both clinical and healthy populations. A more robust methodology is needed in future studies to improve the certainty of the evidence.

L-Carnitine and synbiotic co-supplementation: beneficial effects on metabolic-endotoxemia, meta-inflammation, and oxidative-stress biomarkers in obese patients: a double blind, randomized, controlled clinical trial

Obesity, a chronic pandemic disease, is characterized by low-grade chronic inflammation, accompanied by over-expression of pro-inflammatory cytokines, thereby contributing to metabolic disorders pathogenesis. Oxidative-stress, an adverse cellular response to adipocyte hypertrophy, promotes inflammation. Furthermore, gut-microbiota dysbiosis may induce oxidative-stress, low-grade inflammation, and metabolic-endotoxemia as major drivers of obesity. Functional-foods/nutraceuticals have attracted extensive attention due to their plausible anti-inflammatory/anti-oxidative properties; evidence supports the superiority of the nutraceutical combined-supplementation approach versus conventional mono-therapies. Current data suggest the anti-oxidative/anti-inflammatory properties of either L-carnitine or pre/pro/synbiotics. This trial compared the effects of co-supplementing L-carnitine and multi-species/multi-strain synbiotic versusL-carnitine mono-therapy on inflammatory/anti-inflammatory, oxidative-stress, and metabolic-endotoxemia biomarkers in 46 female obese patients, receiving either co-supplementation (L-carnitine-tartrate (2 × 500 mg d^-1) + multi-species/multi-strain synbiotic (1 capsule per day)) or mono-therapy (L-carnitine-tartrate (2 × 500 mg d^-1) + maltodextrin (1 capsule per day)) for eight weeks. L-Carnitine + synbiotic co-supplementation significantly decreased interleukin-6 (IL-6, -33.98%), high-sensitivity-C-reactive-protein (hs-CRP, -10%), tumor-necrosis-factor-alpha (TNF-α, -18.73%), malondialdehyde (MDA, -21.73%), and lipopolysaccharide (LPS, -10.14%), whereas the increase in interleukin-10 (IL-10, 7.69%) and total-antioxidant-capacity (TAC, 4.13%) levels was not significant. No significant changes were observed for the above-mentioned parameters in the L-carnitine + placebo group, except for a significant reduction in IL-10 (-17.59%) and TNF-α (-14.78%); however, between-group differences did not reach the significant threshold. Co-supplementing L-carnitine + multi-strain synbiotic led to significant amelioration of inflammatory, oxidative, and metabolic-endotoxemia responses in female obese patients; nevertheless, no improving effects were observed in patients receiving single-supplementation, suggesting that L-carnitine + synbiotic co-supplementation might represent an adjuvant approach to improve oxidative-stress/pro-inflammatory indicators in women with obesity, possibly through beneficial effects of the synbiotic alone. Further longer duration studies with higher doses of L-carnitine in a three-group setting are warranted to elucidate the possibility of synergistic or complementary mechanisms.

Regular consumption of pickled vegetables and fermented bean curd reduces the risk of diabetes: a prospective cohort study

Objective

The global incidence of diabetes is rising, in part due to the widespread adoption of poor dietary habits. Fermented vegetables have numerous health benefits and are generally affordable. Here, we examined whether regular consumption of pickled vegetables or fermented bean curd reduces the risk of diabetes.

Methods

A total of 9,280 adults (≥18 years of age) were recruited via multi-stage sampling from 48 townships in China between 2010 and 2012 for this 10-year prospective study. In addition to demographic information, monthly consumption levels of pickled vegetables and fermented bean curd were recorded. Participants were then monitored for diabetes onset. After the final follow-up, logistic regression analyses with multiple covariant corrections were conducted to estimate the changes in diabetes risk associated with consumption of pickled vegetables and fermented bean curd compared to non-consumption.

Results

A total of 6,640 subjects without diabetes at the start of the study were followed up for a median period of 6.49 years, among whom 714 were diagnosed with diabetes during the study. According to a regression model with multivariable adjustment, diabetes risk was significantly reduced by consumption of 0-0.5 kg/month of pickled vegetables (OR = 0.77, 95% CI: 0.63, 0.94) and further reduced by consumption of >0.5 kg/month of pickled vegetables (OR = 0.37, 95% CI: 0.23, 0.60) compared to no consumption (both P-trend < 0.001). Consumption of fermented bean curd also reduced diabetes risk (OR = 0.68, 95% CI: 0.55, 0.84).

Conclusion

Regular consumption of pickled vegetables and/or fermented bean curd can reduce the long-term risk of diabetes.

Modeling interaction networks between host, diet, and bacteria predicts obesogenesis in a mouse model

Host-microbiome interactions are known to have substantial effects on human health, but the diversity of the human microbiome makes it difficult to definitively attribute specific microbiome features to a host phenotype. One approach to overcoming this challenge is to use animal models of host-microbiome interaction, but it must be determined that relevant aspects of host-microbiome interactions are reflected in the animal model. One such experimental validation is an experiment by Ridura et al. In that experiment, transplanting a microbiome from a human into a mouse also conferred the human donor’s obesity phenotype. We have aggregated a collection of previously published host-microbiome mouse-model experiments and combined it with thousands of sequenced and annotated bacterial genomes and metametabolomic pathways. Three computational models were generated, each model reflecting an aspect of host-microbiome interactions: 1) Predict the change in microbiome community structure in response to host diet using a community interaction network, 2) Predict metagenomic data from microbiome community structure, and 3) Predict host obesogenesis from modeled microbiome metagenomic data. These computationally validated models were combined into an integrated model of host-microbiome-diet interactions and used to replicate the Ridura experiment in silico. The results of the computational models indicate that network-based models are significantly more predictive than similar but non-network-based models. Network-based models also provide additional insight into the molecular mechanisms of host-microbiome interaction by highlighting metabolites and metabolic pathways proposed to be associated with microbiome-based obesogenesis. While the models generated in this study are likely too specific to the animal models and experimental conditions used to train our models to be of general utility in a broader understanding of obesogenesis, the approach detailed here is expected to be a powerful tool of investigating multiple types of host-microbiome interactions.

Temporal relationship among adiposity, gut microbiota, and insulin resistance in a longitudinal human cohort

BACKGROUND

The temporal relationship between adiposity and gut microbiota was unexplored. Whether some gut microbes lie in the pathways from adiposity to insulin resistance is less clear. Our study aims to reveal the temporal relationship between adiposity and gut microbiota and investigate whether gut microbiota may mediate the association of adiposity with insulin resistance in a longitudinal human cohort study.

METHODS

We obtained repeated-measured gut shotgun metagenomic and anthropometric data from 426 Chinese participants over ~3 years of follow-up. Cross-lagged path analysis was used to examine the temporal relationship between BMI and gut microbial features. The associations between the gut microbes and insulin resistance-related phenotypes were examined using a linear mixed-effect model. We examined the mediation effect of gut microbes on the association between adiposity and insulin resistance-related phenotypes. Replication was performed in the HMP cohort.

RESULTS

Baseline BMI was prospectively associated with levels of ten gut microbial species. Among them, results of four species (Adlercreutzia equolifaciens, Parabacteroides unclassified, Lachnospiraceae bacterium 3 1 57FAA CT1, Lachnospiraceae bacterium 7 1 58FAA) were replicated in the independent HMP cohort. Lachnospiraceae bacterium 3 1 57FAA CT1 was inversely associated with HOMA-IR and fasting insulin. Lachnospiraceae bacterium 3 1 57FAA CT1 mediated the association of overweight/obesity with HOMA-IR (FDR<0.05). Furthermore, Lachnospiraceae bacterium 3 1 57FAA CT1 was positively associated with the butyrate-producing pathway PWY-5022 (p < 0.001).

CONCLUSIONS

Our study identified one potentially beneficial microbe Lachnospiraceae bacterium 3 1 57FAA CT1, which might mediate the effect of adiposity on insulin resistance. The identified microbes are helpful for the discovery of novel therapeutic targets, as to mitigate the impact of adiposity on insulin resistance.

Probiotics and gut microbiome - Prospects and challenges in remediating heavy metal toxicity

The gut microbiome, often referred to as "super organ", comprises up to a hundred trillion microorganisms, and the species diversity may vary from person to person. They perform a decisive role in diverse biological functions related to metabolism, immunity and neurological responses. However, the microbiome is sensitive to environmental pollutants, especially heavy metals. There is continuous interaction between heavy metals and the microbiome. Heavy metal exposure retards the growth and changes the structure of the phyla involved in the gut microbiome. Meanwhile, the gut microbiome tries to detoxify the heavy metals by altering the physiological conditions, intestinal permeability, enhancing enzymes for metabolizing heavy metals. This review summarizes the effect of heavy metals in altering the gut microbiome, the mechanism by which gut microbiota detoxifies heavy metals, diseases developed due to heavy metal-induced dysbiosis of the gut microbiome, and the usage of probiotics along with advancements in developing improved recombinant probiotic strains for the remediation of heavy metal toxicity.

Probiotics Regulate Gut Microbiota: An Effective Method to Improve Immunity

Probiotics are beneficial active microorganisms that colonize the human intestines and change the composition of the flora in particular parts of the host. Recently, the use of probiotics to regulate intestinal flora to improve host immunity has received widespread attention. Recent evidence has shown that probiotics play significant roles in gut microbiota composition, which can inhibit the colonization of pathogenic bacteria in the intestine, help the host build a healthy intestinal mucosa protective layer, and enhance the host immune system. Based on the close relationship between the gut microbiota and human immunity, it has become an extremely effective way to improve human immunity by regulating the gut microbiome with probiotics. In this review, we discussed the influence of probiotics on the gut microbiota and human immunity, and the relationship between immunity, probiotics, gut microbiota, and life quality. We further emphasized the regulation of gut microflora through probiotics, thereby enhancing human immunity and improving people’s lives.

Porphyromonas gingivalis induces entero-hepatic metabolic derangements with alteration of gut microbiota in a type 2 diabetes mouse model

Periodontal infection induces systemic inflammation; therefore, aggravating diabetes. Orally administered periodontal pathogens may directly alter the gut microbiota. We orally treated obese db/db diabetes mice using Porphyromonas gingivalis (Pg). We screened for Pg-specific peptides in the intestinal fecal specimens and examined whether Pg localization influenced the intestinal microbiota profile, in turn altering the levels of the gut metabolites. We evaluated whether the deterioration in fasting hyperglycemia was related to the changes in the intrahepatic glucose metabolism, using proteome and metabolome analyses. Oral Pg treatment aggravated both fasting and postprandial hyperglycemia (P < 0.05), with a significant (P < 0.01) increase in dental alveolar bone resorption. Pg-specific peptides were identified in fecal specimens following oral Pg treatment. The intestinal Pg profoundly altered the gut microbiome profiles at the phylum, family, and genus levels; Prevotella exhibited the largest increase in abundance. In addition, Pg-treatment significantly altered intestinal metabolite levels. Fasting hyperglycemia was associated with the increase in the levels of gluconeogenesis-related enzymes and metabolites without changes in the expression of proinflammatory cytokines and insulin resistance. Oral Pg administration induced gut microbiota changes, leading to entero-hepatic metabolic derangements, thus aggravating hyperglycemia in an obese type 2 diabetes mouse model.

Impact of Interplay between Obese Gut Microbiota and Diet in Developing Obesity in Synthetic Community Mice

This study aims at investigating the effects of cultured gut microbiota (GM) of obese human coupled high fat diet (HFD) or chow diet (CD) in development of obesity in mice. 20 stool samples were collected from obese patients and isolated bacteria were identified morphologically and biochemically. Identified isolates were mixed in equal proportions to synthesize obese GM. In vivo study was performed using obese GM combined with HFD/CD using mouse model for three months. Albino mice were treated with ampicillin from one week prior to birth until weaning of the pups at seven weeks of age and then inoculated with obese GM. Sixteen mice were divided into four groups: i.e. group 1 (G1) mice fed with CD, group 2 (G2) mice with HFD, group 3 (G3) mice with GM + HFD and group 4 (G4) mice with GM + CD. Mice from groups 3-4 were considered synthetic community (SC) mice due to transfer of synthesize human GM. 16S rRNA sequencing identified five abundant bacteria as Pseudomonas aeruginosa, Staphylococcus sp., Escherichia coli, Morganella morganii, and Klebsiella oxytoca (accession numbers: MZ150742-MZ150746). In vivo study indicated that GM combination with either HFD/CD caused significantly increased body weight in SC mice (BMI; Kg/m²) compared to HFD or CD fed mice groups. One way ANOVA revealed highly significant increase (p ≤ 0.001) in levels of total cholesterol (TC), triglycerides and low density lipoprotein (LDL) in GM coupled diet groups (G3-G4; SC mice) compared to significant increase in HFD group (G2) versus CD group (G1). Our study is first of its kind to report significant effects of using purified strains as obese GM plus diet (HFD/CD) in inducing obesity in SC mice and elevated serum liver parameters as metabolic indicators, hence providing strong evidence about significance of modified GM combination with HFD in developing obesity in SC mice.

Prebiotic inulin as a treatment of obesity related nonalcoholic fatty liver disease through gut microbiota: a critical review

The microbial-derived products, including short chain fatty acids, lipopolysaccharide and secondary bile acids, have been shown to participate in the regulation of hepatic lipid metabolism. Previous studies have demonstrated that prebiotics, such as oligosaccharide and inulin, have abilities to change the concentration of microbial-derived products through modulating the microbial community structure, thus controlling body weight and alleviating hepatic fat accumulation. However, recent evidence indicates that there are individual differences in host response upon inulin treatment due to the differences in host microbial composition before dietary intervention. Probably it is because of the multiple relationships among bacterial species (e.g., competition and mutualism), which play key roles in the degradation of inulin and the regulation of microbial structure. Thereby, analyzing the composition and function of initial gut microbiota is essential for improving the efficacy of prebiotics supplementation. Furthermore, considering that different structures of polysaccharides can be used by different microorganisms, the chemical structure of processed inulin should be tested before using prebiotic inulin to treat obesity related nonalcoholic fatty liver disease.

In Vitro Fecal Fermentation Patterns of Arabinoxylan from Rice Bran on Fecal Microbiota from Normal-Weight and Overweight/Obese Subjects

Arabinoxylan (AX) is a structural polysaccharide found in wheat, rice and other cereal grains. Diets high in AX-containing fiber may promote gut health in obesity through prebiotic function. Thus, the impact of soluble AX isolated from rice bran fiber on human gut microbiota phylogenetic composition and short-chain fatty acid (SCFA) production patterns from normal-weight and overweight/obese subjects was investigated through in vitro fecal fermentation. Results showed that rice bran arabinoxylan modified the microbiota in fecal samples from both weight classes compared to control, significantly increasing Collinsella, Blautia and Bifidobacterium, and decreasing Sutterella, Bilophila and Parabacteroides. Rice bran AX also significantly increased total and individual SCFA contents (p < 0.05). This study suggests that rice bran AX may beneficially impact gut health in obesity through prebiotic activities.

Tibet Kefir Milk Regulated Metabolic Changes Induced by High-Fat Diet via Amino Acids, Bile Acids, and Equol Metabolism in Human-Microbiota-Associated Rats

This study aimed to confirm the effects of Tibet kefir milk (TKM) on gut microbiota and metabolism. An obesity model was established by feeding a high-fat diet (HFD) to human-microbiota-associated rats. Next-generation sequencing and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry were applied for gut microbiota and untargeted metabolomics, respectively. After 8 weeks of feeding, the enterotype in the HFD group was switched from ET1 (Prevotella/Akkermansia-dominant) to ET2 (Bacteroides/Akkermansia-dominant). Branched-chain amino-acids- and aromatic amino-acids-metabolism increased, and taurine-conjugated bile acids decreased in the HFD group. Compared with the HFD group, taurocholic acid increased in the TKM1 group, while l-threonine decreased, and equol, taurochenodeoxycholate, and taurodeoxycholic acid increased in the TKM2 group. The metabolite alteration suggested restorative bile acid metabolism, modified metabolic pattern of amino acids, and elevation of anti-obesity factors in the TKM-intervened animals. It can be deduced that changes by TKM intervention in the host gut metabolites are the major contributors to reducing fat deposition.

Cross-sectional comparisons of gut microbiome and short-chain fatty acid levels among children with varied weight classifications

BACKGROUND

Limited studies associate changes in microbiota composition and metabolites among children and adolescents with obesity. Decreases in compositional diversity, increases in the proportion of Firmicutes and Bacteroidetes (F/B ratio) and increases in short-chain fatty acids (SCFAs) have been proposed as contributing factors in the pathophysiology of obesity.

OBJECTIVES

The aim of the current study was to characterize the faecal microbiota composition, diversity, F/B ratio and SCFA levels in different weight categories (lean, overweight, obesity classes 1-3) of children ages 5 to 12 years.

METHODS

We collected and processed 83 samples from different weight categories (27.7% lean, 11% overweight, 15%, 17% and 17% of obesity classes 1, 2, and 3, respectively). Microbiota content was determined by sequencing the V4 region of the 16S rRNA gene, and SCFA content was analyzed.

RESULTS

Microbiota compositions showed no significant differences in diversity or F/B ratios between weight categories. However, a relative abundance of Proteobacteria and lack of Verrucomicrobia were demonstrated when comparing severe obesity to the leaner groups. Faecal butyrate, propionate and isopentanoate concentrations increased progressively with weight category demonstrating significance in the class 3 obesity group.

CONCLUSIONS

Our results show that severe childhood obesity in our study population was associated with changes in gut microbiome composition correlated to previously reported cardiometabolic disease states in obesity. Increased SCFA levels correlate with obesity-related microbiome metabolic function without a reduction in diversity characterized at a phyla level. Further characterization of these specimens at a species level and longitudinal studies are needed to elucidate these relationships.

A Pilot Study on the Metabolic Impact of Mediterranean Diet in Type 2 Diabetes: Is Gut Microbiota the Key?

The Mediterranean diet (MD) has been recommended for type 2 diabetes (T2D) treatment. The impact of diet in shaping the gut microbiota is well known, particularly for MD. However, the link between MD and diabetes outcome improvement is not completely clear. This study aims to evaluate the role of microbiota modulation by a nonpharmacological intervention in patients with T2D. In this 12-week single-arm pilot study, nine participants received individual nutritional counseling sessions promoting MD. Gut microbiota, biochemical parameters, body composition, and blood pressure were assessed at baseline, 4 weeks, and 12 weeks after the intervention. Adherence to MD [assessed by Mediterranean Diet Adherence Screener (MEDAS) score] increased after the intervention. Bacterial richness increased after 4 weeks of intervention and was negatively correlated with fasting glucose levels and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). Prevotella to Bacteroides ratio also increased after 4 weeks. In contrast, glycated haemoglobin (HbA1c) and HOMA-IR were only decreased at the end of study. Alkaline phosphatase activity was assessed in fecal samples and was negatively correlated with HbA1c and positively correlated with bacterial diversity. The results of this study reinforce that MD adherence results in a better glycemic control in subjects with T2D. Changes in gut bacterial richness caused by MD adherence may be relevant in mediating the metabolic impact of this dietary intervention.

Adherence to a Supplemented Mediterranean Diet Drives Changes in the Gut Microbiota of HIV-1-Infected Individuals

Objective: The health effects of a supplemented Mediterranean diet (SMD) with extra-virgin olive oil (EVOO) and nuts are well documented in non-HIV-infected individuals. We hypothesised that the benefits of an SMD could be mediated by changes in the gut microbiota, even in those with an altered intestinal microbiota such as people living with HIV. Design: Individuals living with HIV (n = 102) were randomised to receive an SMD with 50 g/day of EVOO and 30 g/day of walnuts (SMD group) or continue with their regular diet (control group) for 12 weeks. Methods: Adherence to the Mediterranean diet was assessed using the validated 14-item MD-Adherence-Screener (MEDAS) from the PREDIMED study. A sub-study classifying the participants according to their MEDAS scores was performed. Results: The lipid profile was improved in the SMD group vs. that in the control group (delta-total cholesterol and delta-B-lipoprotein). The immune activation (CD4+HLADR+CD38+ and CD8+HLADR+CD38+ cells) and IFN-γ-producing T-cells significantly decreased at week 12 compared to the baseline in the SMD group but not in the control group. The gut microbiota in those from the high-adherence group presented significantly high diversity and richness at the end of the intervention. Succinivibrio and Bifidobacterium abundances were influenced by the adherence to the MD and significantly correlated with Treg cells. Conclusion: The Mediterranean diet improved metabolic parameters, immune activation, Treg function, and the gut microbiota composition in HIV-1-infected individuals. Further, Mediterranean diet increased the Bifidobacterium abundances after the intervention, and it was associated to a beneficial profile.

Vitamin D Modulates Intestinal Microbiota in Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal tract (GIT), including Crohn's disease (CD) and ulcerative colitis (UC), which differ in the location and lesion extensions. Both diseases are associated with microbiota dysbiosis, with a reduced population of butyrate-producing species, abnormal inflammatory response, and micronutrient deficiency (e.g., vitamin D hypovitaminosis). Vitamin D (VitD) is involved in immune cell differentiation, gut microbiota modulation, gene transcription, and barrier integrity. Vitamin D receptor (VDR) regulates the biological actions of the active VitD (1α,25-dihydroxyvitamin D3), and is involved in the genetic, environmental, immune, and microbial aspects of IBD. VitD deficiency is correlated with disease activity and its administration targeting a concentration of 30 ng/mL may have the potential to reduce disease activity. Moreover, VDR regulates functions of T cells and Paneth cells and modulates release of antimicrobial peptides in gut microbiota-host interactions. Meanwhile, beneficial microbial metabolites, e.g., butyrate, upregulate the VDR signaling. In this review, we summarize the clinical progress and mechanism studies on VitD/VDR related to gut microbiota modulation in IBD. We also discuss epigenetics in IBD and the probiotic regulation of VDR. Furthermore, we discuss the existing challenges and future directions. There is a lack of well-designed clinical trials exploring the appropriate dose and the influence of gender, age, ethnicity, genetics, microbiome, and metabolic disorders in IBD subtypes. To move forward, we need well-designed therapeutic studies to examine whether enhanced vitamin D will restore functions of VDR and microbiome in inhibiting chronic inflammation.

Undaria pinnatifida improves obesity-related outcomes in association with gut microbiota and metabolomics modulation in high-fat diet-fed mice

Dietary fiber has beneficial effects on obesity-related diseases and gut microbiota, contributing a key role in the interaction between dietary metabolism and host metabolism. Our objective was to investigate the cause of the improvement in multiple types of physiological states with seaweed Undaria pinnatifida treatment on high-fat diet-fed mice and to evaluate whether its consequent anti-adiposity and anti-hyperlipidemic effects are associated with gut microbiota and its metabolomics regulation. U. pinnatifida administration in our experiment was shown to significantly decrease high-fat diet-induced body weight gain, as well as epididymal and abdominal adiposity. U. pinnatifida intake also significantly reduced liver weight and serum triacylglycerol accumulation. We also found that improving effects of U. pinnatifida on high-fat diet-induced metabolic dysfunctions were associated with significant increase in specific bacteria, such as Bacteroides acidifaciens and Bacteroides ovatus, as well as metabolites, including short-chain fatty acids and tricarboxylic acid cycle intermediates. Our result provides a cheap dietary strategy to host metabolism improvement and obesity management. KEY POINTS: • U. pinnatifida improved adipose accumulation and lipid metabolism. • B. acidifaciens and B. ovatus contributed to the beneficial effects of U. pinnatifida. • SCFAs and TCA cycle intermediates were critical to the metabolic outcomes. • Our study provides a cheap dietary strategy for obesity management.

Beneficial effects of mung bean seed coat on the prevention of high-fat diet-induced obesity and the modulation of gut microbiota in mice

PURPOSE

Our recent study has reported that whole mung bean showed better beneficial effects on high-fat diet (HFD)-induced obesity and gut microbiota disorders when compared with the decorticated mung bean at the same intervention dose level, suggesting that the mung bean seed coat (MBC) may play a crucial role in its health benefits. This study aims to investigate whether MBC has beneficial benefits on the prevention of HFD-induced obesity and the modulation of gut microbiota in mice when it was supplemented in HFD.

METHODS

Herein, male C57BL/6 J mice were fed with normal control diet, HFD, and HFD supplemented with MBC (3-6%, w/w) for 12 weeks. The changes in physiological, histological, biochemical parameters, serum endotoxin, proinflammatory cytokines, and gut microbiota composition of mice were determined to assess the ability of MBC to alleviate HFD-induced obesity and modulate gut microbiota disorders in mice.

RESULTS

MBC supplementation exhibited significant reductions in the HFD-induced adiposity, fat accumulation, serum lipid levels, lipopolysaccharide, and proinflammatory cytokines concentrations (P < 0.05), which was accompanied by improvements in hepatic steatosis and adipocyte size. Especially, the elevated fasting blood glucose and insulin resistance were also significantly improved by MBC supplementation (P < 0.05). Furthermore, high-throughput sequencing of the 16S rRNA gene revealed that MBC could normalize HFD-induced gut microbiota dysbiosis. MBC not only could promote the bloom of Akkermansia, but also restore several HFD-dependent taxa (Blautia, Ruminiclostridium_9, Bilophila, and unclassified_f_Ruminococcaceae) back to normal status, co-occurring with the decreases in obesity-related indices.

CONCLUSIONS

This study provides evidence that MBC may be mainly responsible for the beneficial effects of whole mung bean on preventing the HFD-induced changes, thus enlarging the application value of MBC.

Probiotic low-fat fermented goat milk with passion fruit by-product: In vitro effect on obese individuals' microbiota and on metabolites production

This study aimed to evaluate the impact of a two-week treatment period with probiotic low-fat fermented goat milk by Lactobacillus casei Lc-1, supplemented with passion fruit by-product (1%), on the modulation of gut microbiota from obese individuals using the Simulator of Human Intestinal Microbial Ecosystem (SHIME) system. The effects were carried out through the study of gut microbiota composition, using 16S rRNA next generation sequencing, quantification of short-chain fatty acids (SCFA) and ammonium ions. The microbiota composition changed across three vessels representing the colon regions, because of fermented milk treatment. Fermented goat milk administration caused a reduction of bacteria belonging to genera Prevotella, Megamonas and Succinivibrio, which can produce SCFA, and an increase of Lactobacillus and Bifidobacterium genera in all simulated colon regions. There was no effect on SCFA and on ammonium ions concentration during treatment period. Fermented milk shifted the obese donors' microbiota without changing metabolites production. It happens, possibly, due to a balance in abundances among bacterial genera that can produce or not SCFA, and among bacterial genera with high or low proteolytic activity. Our outcomes help to clarify the effects of the ingestion of a probiotic low-fat fermented goat milk product on colon microbiota composition.