Gut microbiota of obese subjects with Prader-Willi syndrome is linked to metabolic health

Sucrose-preferring gut microbes prevent host obesity by producing exopolysaccharides

Commensal bacteria affect host health by producing various metabolites from dietary carbohydrates via bacterial glycometabolism; however, the underlying mechanism of action remains unclear. Here, we identified Streptococcus salivarius as a unique anti-obesity commensal bacterium. We found that S. salivarius may prevent host obesity caused by excess sucrose intake via the exopolysaccharide (EPS) -short-chain fatty acid (SCFA) -carbohydrate metabolic axis in male mice. Healthy human donor-derived S. salivarius produced high EPS levels from sucrose but not from other sugars. S. salivarius abundance was significantly decreased in human donors with obesity compared with that in healthy donors, and the EPS-SCFA bacterial carbohydrate metabolic process was attenuated. Our findings reveal an important mechanism by which host-commensal interactions in glycometabolism affect energy regulation, suggesting an approach for preventing lifestyle-related diseases via prebiotics and probiotics by targeting bacteria and EPS metabolites.

IMPROVE 2022 International Meeting on Pathway-Related Obesity: Vision of Excellence

Nearly 90 clinicians and researchers from around the world attended the first IMPROVE 2022 International Meeting on Pathway-Related Obesity. Delegates attended in person or online from across Europe, Argentina and Israel to hear the latest scientific and clinical developments in hyperphagia and severe, early-onset obesity, and set out a vision of excellence for the future for improving the diagnosis, treatment, and care of patients with melanocortin-4 receptor (MC4R) pathway-related obesity. The meeting co-chair Peter Kühnen, Charité Universitätsmedizin Berlin, Germany, indicated that change was needed with the rapidly increasing prevalence of obesity and the associated complications to improve the understanding of the underlying mechanisms and acknowledge that monogenic forms of obesity can play an important role, providing insights that can be applied to a wider group of patients with obesity. World-leading experts presented the latest research and led discussions on the underlying science of obesity, diagnosis (including clinical and genetic approaches such as the role of defective MC4R signalling), and emerging clinical data and research with targeted pharmacological approaches. The aim of the meeting was to agree on the questions that needed to be addressed in future research and to ensure that optimised diagnostic work-up was used with new genetic testing tools becoming available. This should aid the planning of new evidence-based treatment strategies for the future, as explained by co-chair Martin Wabitsch, Ulm University Medical Center, Germany.

Gut microbiota, a potential cause of higher insulin sensitivity in children with Prader-Willi syndrome

PURPOSE

Obesity is the main driving factor for comorbidities in Prader-Willi syndrome (PWS) patients due to overeating behaviors. The gut microbiota has been implicated in the etiology of obesity and associated comorbidities. The purpose of the present study was to characterize the fecal microbiota in Chinese patients with PWS and compare it to that of patients with obesity as well as healthy controls.

METHODS

We conducted a cross-sectional study with 35 PWS patients (PWS), 35 patients with obesity (OB), and 35 healthy controls (HC). Metagenomic sequencing was performed in stool samples.

RESULTS

The composition of the fecal microbiota in PWS patients differed from that of participants in the OB and HC groups. It was characterized by increased Akkermansia Eubacterium, Eubacterium rectale, and Roseburia intestinalis and decreased Parabacteroides and Phascolarctobacterium. Additionally, the homeostatic model assessment of insulin resistance (HOMA-IR) was lower in PWS patients than in patients with obesity. Spearman rank correlation analysis showed that Achromobacter, Acidiphilium, Xylophilus, and Frisingicoccus were significantly negatively correlated with HOMA-IR.

CONCLUSION

The composition of the gut microbiota in Chinese PWS patients differed from that in patients with obesity, which might contribute to higher insulin sensitivity in PWS patients.

Erchen Decoction alleviates obesity-related hepatic steatosis via modulating gut microbiota-drived butyric acid contents and promoting fatty acid β-oxidation

ETHNOPHARMACOLOGICAL RELEVANCE

Erchen decoction (ECD) is a traditional Chinese medicine formula comprising six distinct herbs and has been documented to possess a protective effect against obesity. The study conducted previously demonstrated that ECD has the potential to effectively modulate the composition of gut microbiota and levels of short-chain fatty acids (SCFAs) in obese rat. However, the regulatory mechanism of ECD on gut microbiota and SCFAs and further improvement of obesity have not been thoroughly explained.

AIM OF THE STUDY

The objective of this study was to examine the therapeutic effect and molecular mechanism of ECD in a rat model of high-fat diet (HFD) feeding.

MATERIALS AND METHODS

Rats with HFD-induced obesity were treated with ECD. Upon completion of the study, serum and liver samples were procured to conduct biochemical, pathological, and Western blotting analyses. The investigation of alterations in the gut microbiota subsequent to ECD treatment was conducted through the utilization of 16S rRNA sequencing. The metabolic alterations in the cecal contents were examined through the utilization of mass spectrometry-ultraperformance liquid chromatography.

RESULTS

ECD treatment improved lipid metabolic disorders and reduced hepatic steatosis in HFD-induced obese rats. Obese rat treated with ECD showed a higher abundance of SCFA-producing bacteria, including Lactobacillus, Bifidobacterium, and Butyricicoccus, and lower abundance of disease-related bacteria, such as Bacteroides, Parabacteroides, and Sediminibacterium. Additionally, ECD caused an increase in total SCFAs levels; in particular, butyric acid was dramatically increased in the HFD group. Rats treated with ECD also exhibited significantly increased butyric acid concentrations in the serum and liver. The subsequent reduction in histone deacetylase 1 expression and increase in acetyl-histone 3-lysine 9 (H3K9ac) levels contributed to the promotion of fatty acid β-oxidation (FAO) in liver by ECD.

CONCLUSION

This study demonstrates that ECD regulates the gut microbiota and promotes butyric acid production to ameliorate obesity-related hepatic steatosis. The mechanism might be related to the promotion of FAO via a butyric acid-mediated increase in H3K9ac levels in the liver.

Desulfovibrio in the Gut: The Enemy within?

Desulfovibrio (DSV) are sulfate-reducing bacteria (SRB) that are ubiquitously present in the environment and as resident commensal bacteria within the human gastrointestinal tract. Though they are minor residents of the healthy gut, DSV are opportunistic pathobionts that may overgrow in the setting of various intestinal and extra-intestinal diseases. An increasing number of studies have demonstrated a positive correlation between DSV overgrowth (bloom) and various human diseases. While the relationship between DSV bloom and disease pathology has not been clearly established, mounting evidence suggests a causal role for these bacteria in disease development. As DSV are the most predominant genera of SRB in the gut, this review summarizes current knowledge regarding the relationship between DSV and a variety of diseases. In this study, we also discuss the mechanisms by which these bacteria may contribute to disease pathology.

Fecal microbiota transplantation holds the secret to youth

Aging shows itself not just at the cellular level, with shortened telomeres and cell cycle arrest, but also at the organ and organismal level, with diminished brainpower, dry eyes, intestinal inflammation, muscular atrophy, wrinkles, etc. When the gut microbiota, often called the "virtual organ of the host," fails to function normally, it can lead to a cascade of health problems including, but not limited to, inflammatory bowel disease, obesity, metabolic liver disease, type II diabetes, cardiovascular disease, cancer, and even neurological disorders. An effective strategy for restoring healthy gut bacteria is fecal microbiota transplantation (FMT). It can reverse the effects of aging on the digestive system, the brain, and the vision by transplanting the functional bacteria found in the excrement of healthy individuals into the gut tracts of patients. This paves the way for future research into using the microbiome as a therapeutic target for disorders associated with aging.

Combing fecal microbial community data to identify consistent obesity-specific microbial signatures and shared metabolic pathways

Obesity is associated with altered gut microbiome composition but data across different populations remain inconsistent. We meta-analyzed publicly available 16S-rRNA sequence datasets from 18 different studies and identified differentially abundant taxa and functional pathways of the obese gut microbiome. Most differentially abundant genera (Odoribacter, Oscillospira, Akkermansia, Alistipes, and Bacteroides) were depleted in obesity, indicating a deficiency of commensal microbes in the obese gut microbiome. From microbiome functional pathways, elevated lipid biosynthesis and depleted carbohydrate and protein degradation suggested metabolic adaptation to high-fat, low-carbohydrate, and low-protein diets in obese individuals. Machine learning models trained on the 18 studies were modest in predicting obesity with a median AUC of 0.608 using 10-fold cross-validation. The median AUC increased to 0.771 when models were trained in eight studies designed for investigating obesity-microbiome association. By meta-analyzing obesity-associated microbiota signatures, we identified obesity-associated depleted taxa that may be exploited to mitigate obesity and related metabolic diseases.

The potential of tailoring the gut microbiome to prevent and treat cardiometabolic disease

Despite milestones in preventive measures and treatment, cardiovascular disease (CVD) remains associated with a high burden of morbidity and mortality. The protracted nature of the development and progression of CVD motivates the identification of early and complementary targets that might explain and alleviate any residual risk in treated patients. The gut microbiota has emerged as a sentinel between our inner milieu and outer environment and relays a modified risk associated with these factors to the host. Accordingly, numerous mechanistic studies in animal models support a causal role of the gut microbiome in CVD via specific microbial or shared microbiota-host metabolites and have identified converging mammalian targets for these signals. Similarly, large-scale cohort studies have repeatedly reported perturbations of the gut microbial community in CVD, supporting the translational potential of targeting this ecological niche, but the move from bench to bedside has not been smooth. In this Review, we provide an overview of the current evidence on the interconnectedness of the gut microbiome and CVD against the noisy backdrop of highly prevalent confounders in advanced CVD, such as increased metabolic burden and polypharmacy. We further aim to conceptualize the molecular mechanisms at the centre of these associations and identify actionable gut microbiome-based targets, while contextualizing the current knowledge within the clinical scenario and emphasizing the limitations of the field that need to be overcome.

Dietary pattern interfered with the impacts of pesticide exposure by regulating the bioavailability and gut microbiota

Dietary intake is an essential way for pesticides to enter the human body. The effects of dietary pattern on the risks of pesticides and what diet can reduce the damage are largely unknown. Here, it is found that Mediterranean diet and Vegetarian diet could alleviate insulin resistance and obesity induced by chlorpyrifos, while Western diet could aggravate that. Gut microbiota and chlorpyrifos bioavailability mediated by the diets were involved in these effects. Both the dietary pattern and chlorpyrifos could change the composition of gut microbiota. Chlorpyrifos caused gut dysbacteriosis which was an important reason for the induced metabolic syndrome. Mediterranean diet and Vegetarian diet could maintain gut microbiota homeostasis and increase intestinal bacteria producing short-chain fatty acids, repair the gut microbiota and intestinal barrier damaged by chlorpyrifos. High dietary fat intake increased the bioavailability of chlorpyrifos, which aggravated the gut dysbacteriosis and destruction of intestinal integrity. Thus, the amount of endotoxin entering the blood increased and caused low-grade inflammation, which was also an important pathway of metabolic syndrome. The results suggested that although it was almost impossible to avoid the exposure to pesticides in modern life, healthy diets could regulate beneficial gut microbiota and alleviate the risk of pesticide exposure.

Hypothalamic integrity is necessary for sustained weight loss after bariatric surgery: A prospective, cross-sectional study

OBJECTIVE

The hypothalamus is the main integrator of peripheral and central signals in the control of energy homeostasis. Its functional relevance for the effectivity of bariatric surgery is not entirely elucidated. Studying the effects of bariatric surgery in patients with hypothalamic damage might provide insight.

SUMMARY BACKGROUND DATA

Prospective study to analyze the effects of bariatric surgery in patients with hypothalamic obesity (HO) vs. matched patients with common obesity (CO) with and without bariatric surgery.

METHODS

65 participants were included (HO-surgery: n = 8, HO-control: n = 10, CO-surgery: n = 12, CO-control: n = 12, Lean-control: n = 23). Body weight, levels of anorexic hormones, gut microbiota, as well as subjective well-being/health status, eating behavior, and brain activity (via functional MRI) were evaluated.

RESULTS

Patients with HO lost significantly less weight after bariatric surgery than CO-participants (total body weight loss %: 5.5 % vs. 26.2 %, p = 0.0004). After a mixed meal, satiety and abdominal fullness tended to be lowest in HO-surgery and did not correlate with levels of GLP-1 or PYY. Levels of PYY (11,151 ± 1667 pmol/l/h vs. 8099 ± 1235 pmol/l/h, p = 0.028) and GLP-1 (20,975 ± 2893 pmol/l/h vs. 13,060 ± 2357 pmol/l/h, p = 0.009) were significantly higher in the HO-surgery vs. CO-surgery group. Abundance of Enterobacteriaceae and Streptococcus was increased in feces of HO and CO after bariatric surgery. Comparing HO patients with lean-controls revealed an increased activation in insula and cerebellum to viewing high-caloric foods in left insula and cerebellum in fMRI.

CONCLUSIONS

Hypothalamic integrity is necessary for the effectiveness of bariatric surgery in humans. Peripheral changes after bariatric surgery are not sufficient to induce satiety and long-term weight loss in patients with hypothalamic damage.

Probiotic Influences on Motor Skills: A Review

The effects of probiotics have mostly been shown to be favorable on measures of anxiety and stress. More recent experiments indicate single- and multi-strain probiotics in treating motorrelated diseases. Initial studies in patients with Parkinson's disease and Prader-Willi syndrome are concordant with this hypothesis. In addition, probiotics improved motor coordination in normal animals and models of Parkinson's disease, multiple sclerosis, and spinal cord injury as well as grip strength in hepatic encephalopathy. Further studies should delineate the most optimal bacterial profile under each condition.

Analysis of gut microbiota diversity in Hashimoto's thyroiditis patients

BACKGROUND

Hashimoto's thyroiditis (HT) is an autoimmune disease. Recent studies have found that the gut microbiota may play an important role in inducing HT, but there are no systematic studies on the changes in the gut microbiota during the development of HT.

METHODS

In this study, 16S rDNA high-throughput sequencing technology in combination with the Kruskal-Wallis test, CCA/RDA analysis, Spearman correlation analysis, and other statistical methods were used to analyze the effects of age, gender, hormones, and other environmental factors on gut microbiota by comparing the differences in the microbiota at different stages of HT development.

RESULTS

The results showed that there were differences in the gut microbiota composition between healthy people (HCA) and in patients with HT. Lachnoclostridium, Bilophila, and Klebsiella were enriched in the HCA group, while Akkermansia, Lachnospiraceae, Bifidobacterium, Shuttleia, and Clostriworthdia were enriched in the HT group. Environmental factors analysis revealed that the Bifidobacterium and Klebsiella were two groups of bacteria that have undergone dramatic changes in HCA and HT, and mainly affected by gender. Romboutsia and Haemophilus regulated by the hormone of free triiodothyronine (FT3) may promote the development of HT, while Faecalibacterium and Lachnospiraceae regulated by free thyroxine (FT4) may protect the host.

CONCLUSIONS

Comprehensive studies have shown that gender is an important factor affecting gut microbial composition, but with the development of HT, hormones, age, and TSH begin to become dominant factors.

Precise strategies for selecting probiotic bacteria in treatment of intestinal bacterial dysfunctional diseases

Abundant microbiota resides in the organs of the body, which utilize the nutrition and form a reciprocal relationship with the host. The composition of these microbiota changes under different pathological conditions, particularly in response to stress and digestive diseases, making the microbial composition and health of the hosts body interdependent. Probiotics are living microorganisms that have demonstrated beneficial effects on physical health and as such are used as supplements to ameliorate symptoms of various digestive diseases by optimizing microbial composition of the gut and restore digestive balance. However, the supplementary effect does not achieve the expected result. Therefore, a targeted screening strategy on probiotic bacteria is crucial, owing to the presence of several bacterial strains. Core bacteria work effectively in maintaining microbiological homeostasis and stabilization in the gastrointestinal tract. Some of the core bacteria can be inherited and acquired from maternal pregnancy and delivery; others can be acquired from contact with the mother, feces, and the environment. Knowing the genera and functions of the core bacteria could be vital in the isolation and selection of probiotic bacteria for supplementation. In addition, other supporting strains of probiotic bacteria are also needed. A comprehensive strategy for mining both core and supporting bacteria before its clinical use is needed. Using metagenomics or other methods of estimation to discern the typically differentiated strains of bacteria is another important strategy to treat dysbiosis. Hence, these two factors are significant to carry out targeted isolation and selection of the functional strains to compose the resulting probiotic preparation for application in both research and clinical use. In conclusion, precise probiotic supplementation, by screening abundant strains of bacteria and isolating specific probiotic strains, could rapidly establish the core microbiota needed to confer resilience, particularly in bacterial dysfunctional diseases. This approach can help identify distinct bacteria which can be used to improve supplementation therapies.

Modulation of the gut microbiota and lipidomic profiles by black chokeberry (Aronia melanocarpa L.) polyphenols via the glycerophospholipid metabolism signaling pathway

Black chokeberry (Aronia melanocarpa L.) is rich in polyphenols with various physiological and pharmacological activities. However, the relationship between the modulation effect of black chokeberry polyphenols on obesity and the alteration of lipid metabolism is not clearly understood. This study aimed to investigate the beneficial effects of the black chokeberry polyphenols (BCPs) treatment on the structure of gut microbiota, lipid metabolism, and associated mechanisms in high-fat diet (HFD)-induced obese rats. Here, we found that a high-fat diet promoted body weight gain and lipid accumulation in rats, while oral BCPs supplementation reduced body weight, liver, and white adipose tissue weight and alleviated dyslipidemia and hepatic steatosis in HFD-induced obese rats. In addition, BCPs supplementation prevented gut microbiota dysbiosis by increasing the relative abundance of Bacteroides, Prevotella, Romboutsia, and Akkermansia and decreasing the relative abundance of Desulfovibrio and Clostridium. Furthermore, 64 lipids were identified as potential lipid biomarkers through lipidomics analysis after BCPs supplementation, especially PE (16:0/22:6), PE (18:0/22:6), PC (20:3/19:0), LysoPE (24:0), LysoPE (24:1), and LysoPC (20:0). Moreover, our studies provided new evidence that composition of gut microbiota was closely related to the alteration of lipid profiles after BCPs supplementation. Additionally, BCPs treatment could ameliorate the disorder of lipid metabolism by regulating the mRNA and protein expression of genes related to the glycerophospholipid metabolism signaling pathway in HFD-induced obese rats. The mRNA and protein expression of PPARα, CPT1α, EPT1, and LCAT were significantly altered after BCPs treatment. In conclusion, the results of this study indicated that BCPs treatment alleviated HFD-induced obesity by modulating the composition and function of gut microbiota and improving the lipid metabolism disorder via the glycerophospholipid metabolism signaling pathway.

Do patients with Prader-Willi syndrome have favorable glucose metabolism?

Background

In recent years, more studies have observed that patients with Prader–Willi syndrome have lower insulin levels and lower insulin resistance than body mass index-matched controls, which may suggest protected glucose metabolism.

Method

The PubMed and Web of Science online databases were searched to identify relevant studies published in the English language using the terms “Prader–Willi syndrome” with “glucose”, “insulin”, “diabetes mellitus”, “fat”, “adipo*”, “ghrelin”, “oxytocin”, “irisin” or “autonomic nervous system”.

Results

The prevalence of impaired glucose intolerance, type 2 diabetes mellitus and some other obesity-associated complications in patients with Prader–Willi syndrome tends to be lower when compared to that in general obesity, which is consistent with the hypothetically protected glucose metabolism. Factors including adipose tissue, adiponectin, ghrelin, oxytocin, irisin, growth hormone and the autonomic nervous system possibly modulate insulin sensitivity in patients with Prader–Willi syndrome.

Conclusion

Although lower insulin levels, lower IR and protected glucose metabolism are widely reported in PWS patients, the causes are still mysterious. Based on existing knowledge, we cannot determine which factor is of utmost importance and what are the underlying mechanisms, and further research is in urgent need.

Altered Salivary Microbiota Following Bifidobacterium animalis Subsp. Lactis BL-11 Supplementation Are Associated with Anthropometric Growth and Social Behavior Severity in Individuals with Prader-Willi Syndrome

To evaluate the influence of oral probiotic Bifidobacterium animalis subsp. lactis (BL-11) supplementation on salivary microbiota composition and the association with growth parameters, and behavioral symptoms in individuals with Prader-Willi syndrome (PWS). In this post hoc analysis, we included a subset of 36 PWS patients with available saliva samples from our original randomized, double-blinded, placebo-controlled trial (Chinese Clinical Trial Registry, ChiCTR1900022646, April 20, 2019). Among the 36 subjects, 17 subjects were allocated to the probiotic group for daily use of the BL-11 probiotic and 19 subjects were allocated to the placebo group. Groupwise and longitudinal differences in salivary microbiota abundances, biodiversity metrics, and height were analyzed. Linear correlations were found between identified differentially abundant salivary microbiota and clinical parameters. Salivary microbiome α-diversity was found to be higher in the probiotic-treated group at week 12 relative to placebo controls (P < 0.05). Leptotrichia, Paracoccus, and Faecalibacterium were found to be more abundant in the probiotic-treated group (P < 0.05). Salivary microbiota abundance and predicted functional profiling abundance correlations were found to be associated with anti-inflammation, anti-obesity, toxin degradation, and anti-oxidative injury effects (Q < 0.1). Several oral taxa also displayed correlations with social behavior severity scores in the probiotic-treated group (Q < 0.1). The findings suggest novel salivary microbiota compositional changes in response to the oral supplementation of BL-11 probiotic in individuals with PWS. The observed differentially abundant taxa between groups post-treatment were highly correlated with interventional effects on growth and social behaviors, although further investigation is warranted. Clinical Trial Registration The original clinical trial was registered under the Chinese Clinical Trial Registry with registration number ChiCTR1900022646 (April 20, 2019).

Relationship between gut microbiome characteristics and the effect of nutritional therapy on glycemic control in pregnant women with gestational diabetes mellitus

The purpose of this study was to explore the relationship between the characteristics of gut microbiome and the effect of medical nutrition therapy (MNT) on glycemic control in pregnant women with gestational diabetes mellitus (GDM). Seventy-four pregnant women newly diagnosed with GDM received MNT for one-week. The effect of glycemic control was evaluated by fasting and 2-hour postprandial blood glucose; and stool samples of pregnant women were collected to detect the gut microbiome before and after MNT. We used a nested case-control study design, with pregnant women with GDM who did not meet glycemic standards after MNT as the ineffective group and those with an age difference of ≤5 years, matched for pre-pregnancy body mass index (BMI) 1:1, and meeting glycemic control criteria as the effective group. Comparison of the gut microbiome characteristics before MNT showed that the ineffective group was enriched in Desulfovibrio, Aeromonadales, Leuconostocaceae, Weissella, Prevotella, Bacillales_Incertae Sedis XI, Gemella and Bacillales, while the effective group was enriched in Roseburia, Clostridium, Bifidobacterium, Bifidobacteriales, Bifidobacteriaceae, Holdemania and Proteus. After treatment, the effective group was enriched in Bifidobacterium and Actinomycete, while the ineffective group was enriched in Holdemania, Proteus, Carnobacteriaceae and Granulicatella. In conclusion, the decrease in the abundance of characteristic gut microbiome positively correlated with blood glucose may be a factor influencing the poor hypoglycemic effect of MNT in pregnant women with GDM. Abundance of more characteristic gut microbiome negatively correlated with blood glucose could help control blood glucose in pregnant women with GDM.

16S rRNA gene amplicon sequencing of gut microbiota in gestational diabetes mellitus and their correlation with disease risk factors

PURPOSE

Although the gut microbiota (GM) are associated with various diseases, their role in gestational diabetes mellitus (GDM) remains uncharacterized. Further study is urgently needed to expose the real relationship between GM and GDM.

METHODS

We performed a prospective study in 33 pregnant Chinese individuals [15, GDM; 18, normal glucose tolerance (NGT)] to observe the fecal microbiota by 16S rRNA gene amplicon sequencing at 24-28 weeks of gestational age after a standard 75 g oral glucose tolerance test. Linear regression analysis was employed to assess the relationships between the GM and GDM clinical parameters.

RESULTS

Sequencing showed no difference in the microbiota alpha diversity but a significant difference in the beta diversity between the GDM and NGT groups, with the relative abundances of Ruminococcus bromii, Clostridium colinum, and Streptococcus infantis being higher in the GDM group (P < 0.05). The quantitative PCR results validated the putative bacterial markers of R. bromii and S. infantis. Moreover, a strong positive correlation was found between S. infantis and blood glucose levels after adjusting for body mass index (P < 0.05).

CONCLUSION

Three abnormally expressed intestinal bacteria (R. bromii, C. colinum, and S. infantis) were identified in GDM patients. S. infantis may confer an increased risk of GDM. Hence, the GM may serve as a potential therapeutic target for GDM.

Targeting the Gut Microbiome in Prader-Willi Syndrome

Overwhelming evidence demonstrates an important role of the gut microbiome in the development of a wide range of diseases, including obesity, metabolic disorders, and mental health symptoms. Indeed, interventions targeting the gut microbiome are being actively investigated as a therapeutic strategy to tackle these diseases. Given that obesity and mental health symptoms are both hallmarks of Prader-Willi syndrome, targeting the gut microbiome may be a promising therapeutical strategy. Only a few studies have investigated the gut microbiome in the context of Prader-Willi syndrome and assessed the efficacy of probiotic supplementation as a therapeutic strategy for this disease. Here, we review the knowledge obtained to this date regarding the gut microbiome in individuals with Prader-Willi syndrome. The limited evidence available indicate that probiotic supplementation improves some metabolic and mental health aspects, however further studies are warranted to determine whether targeting the gut microbiome may constitute a safe and efficient strategy to treat individuals with Prader-Willi syndrome.

Standardized Astragalus Mongholicus Bunge-Curcuma Aromatica Salisb. Extract Efficiently Suppresses Colon Cancer Progression Through Gut Microbiota Modification in CT26-Bearing Mice

Altered gut microbiota and a damaged colon mucosal barrier have been implicated in the development of colon cancer. Astragalus mongholicus Bunge-Curcuma aromatica Salisb. (ACE) is a common herbal drug pair that widely used clinically to treat cancer. However, whether the anti-cancer effect of ACE is related to gut microbiota remains unclear yet. We standardized ACE and investigated the effects of ACE on tumour suppression and analyze the related mechanisms on gut microbiota in CT26 colon cancer-bearing mice in the present study. Firstly, four flavonoids (calycosin-7-glucoside, ononin, calycosin, formononetin) and three astragalosides (astragaloside A, astragaloside II, astragaloside I) riched in Astragalus mongholicus Bunge, three curcumins (bisdemethoxycurcumin, demethoxycurcumin, curcumin) and four essential oils (curdione, curzerene, germacrone and β-elemene) from Curcuma aromatica Salisb., in concentrations from 0.08 to 2.07 mg/g, were examined in ACE. Then the results in vivo studies indicated that ACE inhibited solid tumours, liver and spleen metastases of colon cancer while simultaneously reducing pathological tissue damage. Additionally, ACE regulated gut microbiota dysbiosis and the short chain fatty acid content in the gut, repaired intestinal barrier damage. ACE treatment suppressed the overgrowth of conditional pathogenic gut bacteria, including Escherichia-Shigella, Streptococcus and Enterococcus, while the probiotic gut microbiota like Lactobacillus, Roseburia, Prevotellaceae_UCG-001 and Mucispirillum were increased. More interestingly, the content level of SCFAs such as propionic acid and butyric acid was increased after ACE administration, which further mediates intestinal SDF-1/CXCR4 signalling pathway to repair the integrity of the intestinal barrier, decrease Cyclin D1 and C-myc expressions, eventually suppress the tumor the growth and metastasis of colon cancer. To sum up, the present study demonstrated that ACE could efficiently suppress colon cancer progression through gut microbiota modification, which may provide a new explanation of the mechanism of ACE against colon cancer.

Angiopoietin-like 8 (ANGPTL8) as a potential predictor of NAFLD in paediatric patients with Prader-Willi Syndrome

PURPOSE

Angiopoietin-like 8 (ANGPTL8) is a liver- and adipose tissue-produced protein that predicts non-alcoholic fatty liver disease (NAFLD) and altered metabolic homeostasis in the general population as well as in persons with common and genetic obesity, including the Prader-Willi syndrome (PWS). However, its metabolic correlate in paediatric patients with respect to PWS is unknown.

METHODS

This cross-sectional study investigated circulating ANGPTL8 and adipocytokines levels in 28 PWS and 28 age-, sex- and BMI-matched children and adolescents (age, 7.0-17.8y) in relation to NAFLD and metabolic homeostasis assessed by OGTT, paediatric metabolic index (PMI) and fatty liver index (FLI), liver ultrasonography (US), as well as dual-energy X-ray absorptiometry (DEXA) for analysis of fat (FM) and fat-free mass (FFM).

RESULTS

At the set level of significance, PWS children showed lower values of FFM (p < 0.01) but healthier insulin profiles (p < 0.01) and PMI values (p < 0.05) than matched controls. By US, the prevalence of NAFLD was similar between groups but less severe in PWS than controls. Analysis of ANGPTL8 levels showed no difference between groups, yet only in PWS ANGPTL8 levels were associated with ALT levels, FLI values and NAFLD. In stepwise multivariable regression analysis on merged data, ANGPTL8 levels were independently predicted by BMI SDS, leptin levels and NAFLD.

CONCLUSION

ANGPTL8 levels are similar in PWS and controls and, overall, they are directly associated with the presence and severity of NAFLD in patients with PWS.

The Effects of Limosilactobacillus reuteri LR-99 Supplementation on Body Mass Index, Social Communication, Fine Motor Function, and Gut Microbiome Composition in Individuals with Prader-Willi Syndrome: a Randomized Double-Blinded Placebo-Controlled Trial

Prader-Willi syndrome (PWS) is a rare genetic disorder associated with developmental delay, obesity, and neuropsychiatric comorbidities. Limosilactobacillus reuteri (Lactobacillus reuteri, Lact. reuteri) has demonstrated anti-obesity and anti-inflammatory effects in previous studies. In the present study, we aim to evaluate the effects of Lact. reuteri supplementation on body mass index (BMI), social behaviors, and gut microbiota in individuals with PWS. We conducted a 12-week, randomized, double-blind, placebo-controlled trial in 71 individuals with PWS aged 6 to 264 months (64.4 ± 51.0 months). Participants were randomly assigned to either receive daily Lact. reuteri LR-99 probiotic (6 × 10¹⁰ colony forming units) or a placebo sachet. Groupwise differences were assessed for BMI, ASQ-3, and GARS-3 at baseline, 6 weeks, and 12 weeks into treatment. Gut microbiome data was analyzed with the QIIME2 software package, and predictive functional profiling was conducted with PICRUSt-2. We found a significant reduction in BMI for the probiotic group at both 6 weeks and 12 weeks relative to the baseline (P < 0.05). Furthermore, we observed a significant improvement in social communication and interaction, fine motor function, and total ASQ-3 score in the probiotics group compared to the placebo group (P < 0.05). Altered gut microbiota was observed in the probiotic group to favor weight loss and improve gut health. The findings suggest a novel therapeutic potential for Lact. reuteri LR-99 probiotic to modulate BMI, social behaviors, and gut microbiota in Prader-Willi syndrome patients, although further investigation is warranted.Trial registration Chinese Clinical Trial Registry: ChiCTR1900022646.

The Effects of Probiotic Supplementation on Anthropometric Growth and Gut Microbiota Composition in Patients With Prader-Willi Syndrome: A Randomized Double-Blinded Placebo-Controlled Trial

Background: Prader-Willi Syndrome (PWS) is a rare genetic disorder associated with developmental delay, obesity, and neuropsychiatric comorbidities. Bifidobacterium animalis subsp. lactis has demonstrated anti-obesity and anti-inflammatory effects in previous studies. Aim: To evaluate the effects of Bifidobacterium animalis subsp. lactis probiotics supplementation on anthropometric growth, behavioral symptoms, and gut microbiome composition in patients with PWS. Methods: Ethical Approval was issued by the Internal Review Board (IRB) of the Second Affiliated Hospital of Kunming Medical University (Review-YJ-2016-06). We conducted a 12-week, randomized, double-blind, placebo-controlled trial in 68 patients with Prader-Willi syndrome aged 11 months-16 years (mean = 4.2 years old) who were randomly assigned to receive daily B. lactis-11 probiotics (6 × 1010 CFUs) or a placebo sachet. Weight, height, ASQ-3, ABC, SRS-2, and CGI-I were compared between the two groups at baseline and at 6 and 12 weeks into treatment. Gut microbiome data were analyzed with the QIIME 2 software package, and functional gene analysis was conducted with PICRUSt-2. Results: We found a significant increase in height (mean difference = 2.68 cm, P < 0.05) and improvement in CGI-I (P < 0.05) in the probiotics group compared to the placebo group. No significant change in weight or psychological measures were observed. Probiotic treatment altered the microbiome composition to favor weight loss and gut health and increased the abundance of antioxidant production-related genes. Conclusions: The findings suggest a novel therapeutic potential for Bifidobacterium animalis subsp. lactis probiotics in Prader-Willi syndrome patients, although further investigation is warranted.

Adults with Prader-Willi syndrome exhibit a unique microbiota profile

Objective

Adults with Prader–Willi syndrome (PWS) require less energy intake to maintain body weight than the general adult population. This, combined with their altered gastrointestinal transit time, may impact microbiota composition. The aim of the study was to determine if the fecal microbiota composition of adults with PWS differed from non-affected adults. Using usual diet/non-interventional samples, fecal microbiota composition was analyzed using 16S rRNA gene amplicon sequencing and data from adults with PWS were merged with four other adult cohorts that differed by geographical location and age. QIIME 2™ sample-classifier, machine learning algorithms were used to cross-train the samples and predict from which dataset the taxonomic profiles belong. Taxa that most distinguished between all datasets were extracted and a visual inspection of the R library PiratePlots was performed to select the taxa that differed in abundance specific to PWS.

Results

Fecal microbiota composition of adults with PWS showed low Blautia and enhanced RF39 (phyla Tenericutes), Ruminococcaceae, Alistipes, Erysipelotrichacaea, Parabacteriodes and Odoribacter. Higher abundance of Tenericutes, in particular, may be a signature characteristic of the PWS microbiota although its relationship, if any, to metabolic health is not yet known.

Investigating causality with fecal microbiota transplantation in rodents: applications, recommendations and pitfalls

In recent years, studies investigating the role of the gut microbiota in health and diseases have increased enormously - making it essential to deepen and question the research methodology employed. Fecal microbiota transplantation (FMT) in rodent studies (either from human or animal donors) allows us to better understand the causal role of the intestinal microbiota across multiple fields. However, this technique lacks standardization and requires careful experimental design in order to obtain optimal results. By comparing several studies in which rodents are the final recipients of FMT, we summarize the common practices employed. In this review, we document the limitations of this method and highlight different parameters to be considered while designing FMT Studies. Standardizing this method is challenging, as it differs according to the research topic, but avoiding common pitfalls is feasible. Several methodological questions remain unanswered to this day and we offer a discussion on issues to be explored in future studies.

A Universal Gut-Microbiome-Derived Signature Predicts Cirrhosis

Dysregulation of the gut microbiome has been implicated in the progression of non-alcoholic fatty liver disease (NAFLD) to advanced fibrosis and cirrhosis. To determine the diagnostic capacity of this association, we compared stool microbiomes across 163 well-characterized participants encompassing non-NAFLD controls, NAFLD-cirrhosis patients, and their first-degree relatives. Interrogation of shotgun metagenomic and untargeted metabolomic profiles by using the random forest machine learning algorithm and differential abundance analysis identified discrete metagenomic and metabolomic signatures that were similarly effective in detecting cirrhosis (diagnostic accuracy 0.91, area under curve [AUC]). Combining the metagenomic signature with age and serum albumin levels accurately distinguished cirrhosis in etiologically and genetically distinct cohorts from geographically separated regions. Additional inclusion of serum aspartate aminotransferase levels, which are increased in cirrhosis patients, enabled discrimination of cirrhosis from earlier stages of fibrosis. These findings demonstrate that a core set of gut microbiome species might offer universal utility as a non-invasive diagnostic test for cirrhosis.

Microbiota profile and efficacy of probiotic supplementation on laxation in adults affected by Prader-Willi Syndrome: A randomized, double-blind, crossover trial

Background

Probiotics may provide a benefit for adults with Prader‐Willi syndrome (PWS) experiencing constipation. The primary aim was to determine if Bifidobacterium animalis ssp. lactis B94 (B. lactis B94) improves stool frequency, with secondary aims of stool form and gastrointestinal symptoms. Exploratory aims included diet quality and fecal microbiota composition.

Methods

Following a 4‐week baseline, 25 adults with PWS were randomized to consume B. lactis B94 by capsule (15 billion) or placebo for 4 weeks, followed by 4‐week washout in a double‐blind, crossover design. Stool frequency and Bristol Stool Form (BSF) were assessed daily, and Gastrointestinal Symptom Rating Scale (GSRS) and dietary intake (7‐days food records), per period. Fecal microbiota per period was analyzed using 16S rRNA gene amplicon sequencing and taxa of interest by qPCR (n = 24).

Results

No adverse events were reported. Stool frequency at baseline (n = 25; 2.0 ± 0.1 stools/day), GSRS syndromes, and microbiota composition did not differ with the probiotic intervention overall; however, a delayed, carry‐over effect on BSF types 6 and 7 was seen. Diet quality by HEI‐2015 was 65.4 ± 8.5.

Conclusion

In adults with PWS, B. lactis B94 exhibited little effect on laxation over 4 weeks; however, further research is needed.

Effects of Bifidobacterium animalis Subsp. lactis (BPL1) Supplementation in Children and Adolescents with Prader-Willi Syndrome: A Randomized Crossover Trial

Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by a wide range of clinical manifestations, including obesity, hyperphagia, and behavioral problems. Bifidobacterium animalis subsp. lactis strain BPL1 has been shown to improve central adiposity in adults with simple obesity. To evaluate BPL1's effects in children with PWS, we performed a randomized crossover trial among 39 patients (mean age 10.4 years). Participants were randomized to placebo-BPL1 (n = 19) or BPL1-placebo (n = 20) sequences and underwent a 12-week period with placebo/BPL1 treatments, a 12-week washout period, and a 12-week period with the crossover treatment. Thirty-five subjects completed the study. The main outcome was changes in adiposity, measured by dual-energy X-ray absorptiometry. Secondary outcomes included lipid and glucose metabolism, hyperphagia, and mental health symptoms. Generalized linear modeling was applied to assess differences between treatments. While BPL1 did not modify total fat mass compared to placebo, BPL1 decreased abdominal adiposity in a subgroup of patients older than 4.5 years (n = 28). BPL1 improved fasting insulin concentration and insulin sensitivity. Furthermore, we observed modest improvements in some mental health symptoms. A follow-up trial with a longer treatment period is warranted to determine whether BPL1 supplementation can provide a long-term therapeutic approach for children with PWS (ClinicalTrials.gov NCT03548480).

Characterization of Fecal Microbiota with Clinical Specimen Using Long-Read and Short-Read Sequencing Platform

Accurate and rapid identification of microbiotic communities using 16S ribosomal (r)RNA sequencing is a critical task for expanding medical and clinical applications. Next-generation sequencing (NGS) is widely considered a practical approach for direct application to communities without the need for in vitro culturing. In this report, a comparative evaluation of short-read (Illumina) and long-read (Oxford Nanopore Technologies (ONT)) platforms toward 16S rRNA sequencing with the same batch of total genomic DNA extracted from fecal samples is presented. Different 16S gene regions were amplified, bar-coded, and sequenced using the Illumina MiSeq and ONT MinION sequencers and corresponding kits. Mapping of the sequenced amplicon using MinION to the entire 16S rRNA gene was analyzed with the cloud-based EPI2ME algorithm. V3–V4 reads generated using MiSeq were aligned by applying the CLC genomics workbench. More than 90% of sequenced reads generated using distinct sequencers were accurately classified at the genus or species level. The misclassification of sequenced reads at the species level between the two approaches was less substantial as expected. Taken together, the comparative results demonstrate that MinION sequencing platform coupled with the corresponding algorithm could function as a practicable strategy in classifying bacterial community to the species level.

The Gut Microbiota Profile in Children with Prader-Willi Syndrome

Although gut microbiota has been suggested to play a role in disease phenotypes of Prader-Willi syndrome (PWS), little is known about its composition in affected children and how it relates to hyperphagia. This cross-sectional study aimed to characterize the gut bacterial and fungal communities of children with PWS, and to determine associations with hyperphagia. Fecal samples were collected from 25 children with PWS and 25 age-, sex-, and body mass index-matched controls. Dietary intake data, hyperphagia scores, and relevant clinical information were also obtained. Fecal bacterial and fungal communities were characterized by 16S rRNA and ITS2 sequencing, respectively. Overall bacterial α-diversity and compositions of PWS were not different from those of the controls, but 13 bacterial genera were identified to be differentially abundant. Interestingly, the fungal community, as well as specific genera, were different between PWS and controls. The majority of the variation in the gut microbiota was not attributed to differences in dietary intake or the impact of genotype. Hyperphagia scores were associated with fungal α-diversity and relative abundance of several taxa, such as Staphylococcus, Clostridium, SMB53, and Candida. Further longitudinal studies correlating changes in the microbiome with the degree of hyperphagia and studies integrating multi-omics data are warranted.

Phase Angle: Could Be an Easy Tool to Detect Low-Grade Systemic Inflammation in Adults Affected by Prader-Willi Syndrome?

Prader-Willi syndrome (PWS) is the most common genetic inherited obesity syndrome. Obesity-related complications, mostly related to chronic low-grade systemic inflammation (LGI), are the commonest cause of mortality and morbidity in PWS adults. Phase angle (PhA) is an easy tool to screen a state of LGI in healthy subjects and in subjects with obesity and is obtained from bioelectrical impedance analysis (BIA). The aim of this study was to validate the PhA in PWS adults as a potential biomarker of LGI. In this single-center, cross-sectional study, fifteen PWS adults (six males, aged 19-41 years, and body mass index (BMI) 31.0-68.0 Kg/m2) and fifteen control subjects matched by gender, age, and BMI were evaluated. PhA values were significantly lower (p < 0.001), while high-sensitivity C-reactive protein (hs-CRP) levels were significantly higher (p < 0.001) in PWS adults compared with controls (p < 0.001), without a gender difference in the latter. After adjustment for gender, BMI, and waist circumference, significant correlation was found between PhA and hs-CRP levels (r = -0.69, p = 0.01). At the ROC analysis, the threshold value of PhA predicting the highest hs-CRP levels above the median value was found at PhA ≤ 4.8° (p = 0.01; AUC, 0.82; standard error, 0.12; 95% CI, 0.58 to 1.00). These results suggest that PWS adults had a significant higher degree of LGI compared with their counterparts. Moreover, our finding suggest that PhA is a valid biomarker of LGI also in PWS adults.

Specific Dietary Components and Gut Microbiota Composition are Associated with Obesity in Children and Adolescents with Prader-Willi Syndrome

Prader–Willi syndrome is a rare genetic disorder associated with impaired body composition, hyperphagia, and excessive weight gain. Strict dietary restrictions from an early age is crucial to prevent or delay the early onset of obesity, which is the main driver of comorbidities in these patients. The aim of this study was to identify dietary and gut microbiota components closely linked to weight status of these patients. We studied a cohort of children and adolescents with genetic diagnosis of Prader–Willi syndrome (N = 31), in which we determined adiposity by Dual-energy X-ray absorptiometry (DXA) and dietary composition with 4-day food records. Furthermore, we obtained fecal samples to assess microbiota composition by 16S sequencing. Multivariate regression models showed that body mass index standard deviation score (BMI-SDS) and body fat mass were directly associated with saturated fat intake and meat consumption, and inversely associated with fruit consumption. Furthermore, the gut microbiome from normal weight patients was characterized by higher phylogenetic diversity compared to those overweight or obese, with differential abundance of several genera, including Alistipes, Klebsiella, and Murimonas. Notably, Alistipes abundance was inversely correlated to adiposity, lipid and glucose homeostasis parameters, and meat intake. Our results suggest that limiting meat and increasing fruit intake might be beneficial for body weight management in children and adolescents with Prader–Willi syndrome.

The Composition of Gut Microbiota in Patients Bearing Hashimoto's Thyroiditis with Euthyroidism and Hypothyroidism

AIMS

Hashimoto's thyroiditis (HT), a type of autoimmune disease, occurs due to genetic predisposition and environmental factors. It is well known that thyroid function may affect the gut microbiota. However, the composition of gut microbiota in HT patients with different thyroid function status has been less highlighted. Therefore, we focused on the alterations in the composition of gut microbiota in HT patients with euthyroidism and hypothyroidism.

METHODS

We performed a cross-sectional study, including 45 HT patients with euthyroidism, 18 HT patients with hypothyroidism, and 34 healthy controls. Fecal samples were collected, and microbiota was examined by using 16S RNA ribosomal RNA gene sequencing. Then, we analyzed the possible pathways in relation to the enriched bacteria by linear discriminant analysis (LDA) effect size (LEfSe).

RESULTS

Compared with the controls, bacterial richness and diversity were significantly lower in patients with HT, especially in hypothyroidism. Moreover, Lachnospiraceae_incertae_sedis, Lactonifactor, Alistipes, and Subdoligranulum were more enriched in HT patients with euthyroidism, while Phascolarctobacterium was more abundant in those with hypothyroidism. Further analysis suggested that Phascolarctobacterium was negatively related to several pathways, including environmental information processing and metabolism.

CONCLUSION

In summary, our study demonstrated the altered composition of gut microbiota in HT patients with different thyroid function status. Moreover, Phascolarctobacterium may be involved in the development of HT.