Changes in serum zonulin in individuals with morbid obesity after weight-loss interventions: a prospective cohort study

Oleuropein, a Component of Extra Virgin Olive Oil, Improves Liver Steatosis and Lobular Inflammation by Lipopolysaccharides-TLR4 Axis Downregulation

Gut-dysbiosis-induced lipopolysaccharides (LPS) translocation into systemic circulation has been suggested to be implicated in nonalcoholic fatty liver disease (NAFLD) pathogenesis. This study aimed to assess if oleuropein (OLE), a component of extra virgin olive oil, lowers high-fat-diet (HFD)-induced endotoxemia and, eventually, liver steatosis. An immunohistochemistry analysis of the intestine and liver was performed in (i) control mice (CTR; n = 15), (ii) high-fat-diet fed (HFD) mice (HFD; n = 16), and (iii) HFD mice treated with 6 µg/day of OLE for 30 days (HFD + OLE, n = 13). The HFD mice developed significant liver steatosis compared to the controls, an effect that was significantly reduced in the HFD + OLE-treated mice. The amount of hepatocyte LPS localization and the number of TLR4+ macrophages were higher in the HFD mice in the than controls and were lowered in the HFD + OLE-treated mice. The number of CD42b+ platelets was increased in the liver sinusoids of the HFD mice compared to the controls and decreased in the HFD + OLE-treated mice. Compared to the controls, the HFD-treated mice showed a high percentage of intestine PAS+ goblet cells, an increased length of intestinal crypts, LPS localization and TLR4+ expression, and occludin downregulation, an effect counteracted in the HFD + OLE-treated mice. The HFD-fed animals displayed increased systemic levels of LPS and zonulin, but they were reduced in the HFD + OLE-treated animals. It can be seen that OLE administration improves liver steatosis and inflammation in association with decreased LPS translocation into the systemic circulation, hepatocyte localization of LPS and TLR4 downregulation in HFD-induced mouse model of NAFLD.

Decreased expression of the NLRP6 inflammasome is associated with increased intestinal permeability and inflammation in obesity with type 2 diabetes

BACKGROUND

Obesity-associated dysfunctional intestinal permeability contributes to systemic chronic inflammation leading to the development of metabolic diseases. The inflammasomes constitute essential components in the regulation of intestinal homeostasis. We aimed to determine the impact of the inflammasomes in the regulation of gut barrier dysfunction and metabolic inflammation in the context of obesity and type 2 diabetes (T2D).

METHODS

Blood samples obtained from 80 volunteers (n = 20 normal weight, n = 21 OB without T2D, n = 39 OB with T2D) and a subgroup of jejunum samples were used in a case-control study. Circulating levels of intestinal damage markers and expression levels of inflammasomes as well as their main effectors (IL-1β and IL-18) and key inflammation-related genes were analyzed. The impact of inflammation-related factors, different metabolites and Akkermansia muciniphila in the regulation of inflammasomes and intestinal integrity genes was evaluated. The effect of blocking NLRP6 by using siRNA in inflammation was also studied.

RESULTS

Increased circulating levels (P < 0.01) of the intestinal damage markers endotoxin, LBP, and zonulin in patients with obesity decreased (P < 0.05) after weight loss. Patients with obesity and T2D exhibited decreased (P < 0.05) jejunum gene expression levels of NLRP6 and its main effector IL18 together with increased (P < 0.05) mRNA levels of inflammatory markers. We further showed that while NLRP6 was primarily localized in goblet cells, NLRP3 was localized in the intestinal epithelial cells. Additionally, decreased (P < 0.05) mRNA levels of Nlrp1, Nlrp3 and Nlrp6 in the small intestinal tract obtained from rats with diet-induced obesity were found. NLRP6 expression was regulated by taurine, parthenolide and A. muciniphila in the human enterocyte cell line CCL-241. Finally, a significant decrease (P < 0.01) in the expression and release of MUC2 after the knockdown of NLRP6 was observed.

CONCLUSIONS

The increased levels of intestinal damage markers together with the downregulation of NLRP6 and IL18 in the jejunum in obesity-associated T2D suggest a defective inflammasome sensing, driving to an impaired epithelial intestinal barrier that may regulate the progression of multiple obesity-associated comorbidities.

Effect of Probiotic Supplementation on Intestinal Permeability in Overweight and Obesity: A Systematic Review of Randomized Controlled Trials and Animal Studies

Overweight and obesity are associated with increased intestinal permeability, characterized by loss of gut epithelial integrity, resulting in unregulated passage of lipopolysaccharide (LPS) and other inflammatory triggers into circulation, i.e., metabolic endotoxemia. In obesity, shifts in the gut microbiome negatively impact intestinal permeability. Probiotics are an intervention that can target the gut microbiome by introducing beneficial microbial species, potentially restoring gut barrier integrity. Currently, the role of probiotic supplementation in ameliorating obesity- and overweight-associated increases in gut permeability has not been reviewed. This systematic review aimed to summarize findings from both animal and clinical studies that evaluated the effect of probiotic supplementation on obesity-induced impairment in intestinal permeability (International Prospective Register of Systematic Reviews, CRD42022363538). A literature search was conducted using PubMed (Medline), Web of Science, and CAB Direct from origin until August 2023 using keywords of intestinal permeability, overweight or obesity, and probiotic supplementation. Of 920 records, 26 eligible records were included, comprising 12 animal and 14 clinical studies. Clinical trials ranged from 3 to 26 wk and were mostly parallel-arm (n = 13) or crossover (n = 1) design. In both animal and clinical studies, plasma/serum LPS was the most common measure of intestinal permeability. Eleven of 12 animal studies reported a positive effect of probiotic supplementation in reducing intestinal permeability. However, results from clinical trials were inconsistent, with half reporting reductions in serum LPS and half reporting no differences after probiotic supplementation. Bifidobacterium, Lactobacillus, and Akkermansia emerged as the most common genera in probiotic formulations among the animal and clinical studies that yielded positive results, suggesting that specific bacteria may be more effective at reducing intestinal permeability and improving gut barrier function. However, better standardization of strain use, dosage, duration, and the delivery matrix is needed to fully understand the probiotic impact on intestinal permeability in individuals with overweight and obesity.

Short chain fatty acids and GIT hormones mitigate gut barrier disruption in high fat diet fed rats supplemented by synbiotics

High fat diet (HFD) predisposes to many metabolic changes; it may disrupt gut barrier integrity and gut microbiota composition. Synbiotic supplementation may promote host’s metabolic health by selective activation of the healthy microorganisms. This study aimed to probe the interaction between synbiotic supplementation, gut microbiota and gut hormones in HFD states. Twenty-seven adult male albino rats, 3 groups, group I: control, group II: HFD received HFD for 12 weeks and group III: synbiotic-supplemented HFD received synbiotic in the last 6 weeks. The anthropometric measurments were measured. Liver transaminases, lipid profile, parameters of insulin resistance, serum serotonin, glucagon like polypeptide-1 (GLP-1), oxidant/antioxidant markers (MDA/GPx), zonulin levels and quantitative cecal short chain fatty acids (SCFA) were assessed. Samples of liver and colon were employed for histopathological studies. Compared to HFD group, synbiotic led to a significant reduction in anthropometric measurements, liver enzymes, atherogenic index, HOMA-IR and MDA denoting improved dyslipidemia, insulin resistance and oxidative state. Moreover, synbiotic supplementation decreased serum zonulin and increased both serum serotonin, GLP-1 and cecal SCFAs. Synbiotic supplementation ameliorated the metabolic derangements and the disturbed integrity of the intestinal barrier induced by HFD. As synbiotics can increase gut hormones (serum GLP-1&serotonin) and SCFAs.

Hyperglycemia is associated with duodenal dysbiosis and altered duodenal microenvironment

The gut microbiome influences the pathogenesis and course of metabolic disorders such as diabetes. While it is likely that duodenal mucosa associated microbiota contributes to the genesis and progression of increased blood sugar, including the pre-diabetic stage, it is much less studied than stool. We investigated paired stool and duodenal microbiota in subjects with hyperglycemia (HbA1c ≥ 5.7% and fasting plasma glucose > 100 mg/dl) compared to normoglycemic. We found patients with hyperglycemia (n = 33) had higher duodenal bacterial count (p = 0.008), increased pathobionts and reduction in beneficial flora compared to normoglycemic (n = 21). The microenvironment of duodenum was assessed by measuring oxygen saturation using T-Stat, serum inflammatory markers and zonulin for gut permeability. We observed that bacterial overload was correlated with increased serum zonulin (p = 0.061) and higher TNF-α (p = 0.054). Moreover, reduced oxygen saturation (p = 0.021) and a systemic proinflammatory state [increased total leukocyte count (p = 0.031) and reduced IL-10 (p = 0.015)] characterized the duodenum of hyperglycemic. Unlike stool flora, the variability in duodenal bacterial profile was associated with glycemic status and was predicted by bioinformatic analysis to adversely affect nutrient metabolism. Our findings offer new understanding of the compositional changes in the small intestine bacteria by identifying duodenal dysbiosis and altered local metabolism as potentially early events in hyperglycemia.

Low Grade Endotoxemia and Oxidative Stress in Offspring of Patients with Early Myocardial Infarction

Background and aims: Offspring of patients with early myocardial infarction are at higher cardiovascular risk, but the underlying physio-pathological mechanism is unclear. NADPH oxidase-type 2 (NOX-2) plays a pivotal role as mediator of oxidative stress and could be involved in activating platelets in these patients. Furthermore, altered intestinal permeability and serum lipopolysaccharide (LPS) could be a trigger to promote NOX-2 activation and platelet aggregation. This study aims to evaluate the behavior of low grade endotoxemia, oxidative stress and platelet activation in offspring of patients with early myocardial infarction. Methods: We enrolled, in a cross-sectional study, 46 offspring of patients with early myocardial infarction and 86 healthy subjects (HS). LPS levels and gut permeability (assessed by zonulin), oxidative stress (assessed by serum NOX-2-derived peptide (sNOX2-dp) release, hydrogen peroxide (H₂O₂) production and isoprostanes), serum nitric oxide (NO) bioavailability and platelet activation (by serum thromboxane B2 (TXB2) and soluble P-Selectin (sP-Selectin)) were analyzed. Results: Compared to HS, offspring of patients with early myocardial infarction had higher values of LPS, zonulin, serum isoprostanes, sNOX2-dp H₂O₂, TXB2, p-selectin and lower NO bioavailability. Logistic regression analysis showed that the variables associated with offspring of patients with early myocardial infarction were LPS, TXB2 and isoprostanes. The multiple linear regression analysis confirmed that serum NOX-2, isoprostanes, p-selectin and H₂O₂ levels were significantly associated to LPS. Furthermore, serum LPS, isoprostanes and TXB2 levels were significantly associated with sNOX-2-dp. Conclusions: Offspring of patients with early myocardial infarction have a low grade endotoxemia that could generate oxidative stress and platelet activation increasing their cardiovascular risk. Future studies are needed to understand the role of dysbiosis in this population.

Gut-derived low-grade endotoxaemia, atherothrombosis and cardiovascular disease

Systemic inflammation has been suggested to have a pivotal role in atherothrombosis, but the factors that trigger systemic inflammation have not been fully elucidated. Lipopolysaccharide (LPS) is a component of the membrane of Gram-negative bacteria present in the gut that can translocate into the systemic circulation, causing non-septic, low-grade endotoxaemia. Gut dysbiosis is a major determinant of low-grade endotoxaemia via dysfunction of the intestinal barrier scaffold, which is a prerequisite for LPS translocation into the systemic circulation. Experimental studies have demonstrated that LPS is present in atherosclerotic arteries but not in normal arteries. In atherosclerotic plaques, LPS promotes a pro-inflammatory status that can lead to plaque instability and thrombus formation. Low-grade endotoxaemia affects several cell types, including leukocytes, platelets and endothelial cells, leading to inflammation and clot formation. Low-grade endotoxaemia has been described in patients at risk of or with overt cardiovascular disease, in whom low-grade endotoxaemia was associated with atherosclerotic burden and its clinical sequelae. In this Review, we describe the mechanisms favouring the development of low-grade endotoxaemia, focusing on gut dysbiosis and changes in gut permeability; the plausible biological mechanisms linking low-grade endotoxaemia and atherothrombosis; the clinical studies suggesting that low-grade endotoxaemia is a risk factor for cardiovascular events; and the potential therapeutic tools to improve gut permeability and eventually eliminate low-grade endotoxaemia.

Weight loss via a low-carbohydrate diet improved the intestinal permeability marker, zonulin, in prostate cancer patients

BACKGROUND

Accumulating evidence suggest that gut microbiota may impact urologic health including prostate cancer (PC), potentially via affecting intestinal permeability (IP). Studies have indicated that disrupted IP may be improved by healthy diets and weight loss. In the Carbohydrate and Prostate Study 2 (CAPS2) clinical trial, which showed that a low-carbohydrate diet (LCD) reduced weight significantly in men with PC and suggestively slowed PC disease progression, we explored the impact of LCD on an IP marker, zonulin and an inflammation marker, high sensitivity C-reactive protein (hsCRP).

METHODS

CAPS2 was a 6-month randomized controlled trial testing a LCD intervention vs. control on PC progression using prostate-specific antigen doubling time (PSADT) as the marker. All 45 participants had prior primary PC treatment, PSADT >3 and <36 months, and body mass index (BMI) ≥24 kg/m².

RESULTS

At 6-month, zonulin decreased in the LCD arm (median -8.3%, IQR -16.6, 0.3%) while the control increased slightly (median 1.4%, IQR -3.0, 13.3%; p = .014). No changes were observed in hsCRP. Linear regression models showed that weight change was significantly associated with log(PSADT) such that the greater the weight loss, the longer the PSADT(p = .003). There was a similar inverse trend between change in zonulin and log(PSADT) (p = .050). Nevertheless, the mediation analysis showed that zonulin was not a significant intermediary mechanism of the effect of weight change on PSADT (p = .3).

CONCLUSION

Future studies are merited to examine further the potential association of IP with inflammation and to clarify if improvement in IP is associated with decreased PC progression. Trial registration: NCT01763944. KEY MESSAGESGut microbiota may impact urologic health including prostate cancer, potentially via affecting intestinal permeability.Weight loss significantly improved intestinal permeability in prostate cancer patients.Improvement in intestinal permeability was associated with slowed prostate cancer progression as indicated by the PSA doubling time.

Gut Barrier Damage and Gut Translocation of Pathogen Molecules in Lupus, an Impact of Innate Immunity (Macrophages and Neutrophils) in Autoimmune Disease

The gut barrier is a single cell layer that separates gut micro-organisms from the host, and gut permeability defects result in the translocation of microbial molecules from the gut into the blood. Despite the silent clinical manifestation, gut translocation of microbial molecules can induce systemic inflammation that might be an endogenous exacerbating factor of systemic lupus erythematosus. In contrast, circulatory immune-complex deposition and the effect of medications on the gut, an organ with an extremely large surface area, of patients with active lupus might cause gut translocation of microbial molecules, which worsens lupus severity. Likewise, the imbalance of gut microbiota may initiate lupus and/or interfere with gut integrity which results in microbial translocation and lupus exacerbation. Moreover, immune hyper-responsiveness of innate immune cells (macrophages and neutrophils) is demonstrated in a lupus model from the loss of inhibitory Fc gamma receptor IIb (FcgRIIb), which induces prominent responses through the cross-link between activating-FcgRs and innate immune receptors. The immune hyper-responsiveness can cause cell death, especially apoptosis and neutrophil extracellular traps (NETosis), which possibly exacerbates lupus, partly through the enhanced exposure of the self-antigens. Leaky gut monitoring and treatments (such as probiotics) might be beneficial in lupus. Here, we discuss the current information on leaky gut in lupus.

Intestinal barrier integrity in anorexia nervosa (a pilot study)

OBJECTIVE

There is no conclusive evidence for involvement of intestinal barrier alteration in the etiology of anorexia nervosa (AN). The aims of this pilot study were to identify serum markers of intestinal barrier integrity in patients with AN and to determine the relationships between those markers and body mass index (BMI), eating disorder symptoms, gastrointestinal complaints, and liver synthesis function (international normalized ratio [INR]).

METHOD

Twenty-five outpatients with AN prior to starting treatment and 28 healthy controls (HC) were assessed. BMI and serum markers of intestinal barrier integrity were measured, including zonulin family peptides (ZFP), lipopolysaccharide-binding protein (LBP), and intestinal fatty-acid-binding protein (i-FABP). Eating disorder symptoms and gastrointestinal complaints were evaluated via questionnaires.

RESULTS

The serum ZFP concentration was significantly lower in patients with AN than in HC (44.2 [7.4] vs. 49.2 [5.6] ng/ml, mean [standard deviation], p = .008). LBP and i-FABP did not differ between the two groups. In patients with AN, serum ZFP was significantly predicted by BMI (β = 0.479, p = .009), age (β = 0.411, p = .020), and INR (β = -0.388, p = .028). No such associations were found for either gastrointestinal complaints or eating disorder symptoms.

DISCUSSION

Abnormal levels of serum ZFP were observed in patients with AN. Further studies with other assessment methods are warranted to examine intestinal barrier function in AN.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02745067.

Plasma and fecal zonulin are not altered by a high green leafy vegetable dietary intervention: secondary analysis of a randomized control crossover trial

BACKGROUND

Zonulin is observed in animal models to regulate intestinal permeability and influenced by dietary intake, gut microbiota, and inflammation. We conducted a secondary analysis of a randomized controlled crossover trial (NCT03582306) in individuals with a BMI greater than 30 kg/m² and high habitual red meat intake and low habitual green leafy vegetable (GLV) intake.

METHODS

Participants were provided with frozen GLV during the first or last four weeks (immediate or delayed intervention) of the twelve-week trial. Biological and anthropometric measures were taken at the beginning and at each four-week interval. A subset of 20 participants was selected for this secondary analysis of the intestinal permeability and inflammation-related biomarkers: serum and fecal zonulin; serum lipopolysaccharide binding protein (LBP), Alpha-1-acid glycoprotein 1 (ORM-1), tumor necrosis factor α (TNFα), interleukin-6 (IL-6), and C-reactive protein; 8-hydroxy-2'-deoxyguanosine (8OHdG) and plasma Vitamin K1 as a marker of protocol adherence. Nutrient and food group intake from two-24-h dietary recalls collected at each time point were assessed. Fecal microbiota was measured by 16 s rRNA PCR sequencing. Changes in biological markers, dietary factors, and microbial taxa were assessed with Wilcoxon Sign Ranks Tests. Exploratory analyses of the relationship between changes in outcome variables were conducted with Spearman correlations.

RESULTS

No changes in serum and fecal zonulin and serum LBP were observed. Plasma Vitamin K (p = 0.005) increased, while plasma 8OHdG (p = 0.023) decreased during the intervention compared to the control. The only dietary factors that changed significantly were increases during intervention in Vitamin K and Dark GLV (p < 0.001 for both) compared to control. Fecal microbiota did not change significantly across all times points; however, change in serum zonulin was associated with change in Proteobacteria (ρ = - 0.867, p = 0.001) in females and Bifidobacterium (ρ = - 0.838, p = 0.009) and Bacteroidaceae (ρ = 0.871, p = 0.005) in men.

CONCLUSIONS

A high GLV dietary intervention increased serum zonulin levels and had no effect on fecal zonulin. Lack of concordance between several inflammation-associated biomarkers and zonulin corroborate recent reports of limited utility of zonulin in obese adults free of lower gastrointestinal disease. Trial Registration information: https://clinicaltrials.gov/ct2/show/NCT03582306 (NCT03582306) registered on 07/11/2018.

The association of weight loss with changes in the gut microbiota diversity, composition, and intestinal permeability: a systematic review and meta-analysis

The gut microbiome may be a mediator between obesity and health outcomes. However, it is unclear how intentional weight loss changes the gut microbiota and intestinal permeability. We aimed to systematically review and quantify this association. We searched Medline, Embase, CINAHL, Cochrane databases, and trial registries until June 2020 (PROSPERO: CRD42020205292). We included trials of weight loss interventions (energy-restricted diets, pharmacotherapy, bariatric surgery) reporting on the microbiome. Two reviewers independently completed screening, extraction, and risk assessment with the ROBINS-I tool. Pooled standardized mean differences (SMDs) were obtained from random-effects meta-analyses. Forty-seven trials with 1,916 participants (81% female) and a median follow-up of 6 months (range: 2-24) were included. Based on imprecise evidence but with fairly consistent direction of effect, weight loss was associated with a statistically significant increase in α-diversity [SMD: 0.4 (95% CI: 0.2, 0.6], p < .0001, I² = 70%, n = 30 studies) and a statistically significant reduction in intestinal permeability [SMD: -0.7 (95% CI: -0.9, -0.4), p < .0001, I² = 83%, n = 17 studies]. Each kg of weight loss was associated with a 0.012 (95% CI: 0.0003, 0.024, p = .045) increase in α-diversity and a -0.017 (95% CI: -0.034, -0.001, p = .038) reduction in intestinal permeability. There was clear evidence of increases in the relative abundance of Akkermansia, but no clear evidence of changes in individual phyla, species, or fecal short-chain fatty acids. Restricting the analyses to the studies with lower risk of bias did not materially alter the estimates. Increasing weight loss is positively associated with increases in gut microbiota α-diversity and reductions in intestinal permeability.

A narrative review of the role of gastrointestinal dysbiosis in the pathogenesis of polycystic ovary syndrome

Diet-induced gastrointestinal dysbiosis has been hypothesized to play a significant role in stimulating an increase in gastrointestinal permeability and activating systemic inflammation in women with polycystic ovary syndrome (PCOS). We reviewed the current proof-of-concept studies on the proposed mechanism of dysbiosis in the pathogenesis of PCOS. A literature search was performed to identify articles on changes in the intestinal microbiome (dysbiosis) and increased intestinal mucosal permeability involving lipopolysaccharide (LPS), LPS-binding protein (LPS-BP), and zonulin. We also searched for systematic reviews and meta-analyses that synthesized the results of studies on the therapeutic effects of prebiotics, probiotics, or synbiotics in women with PCOS. Our search was confined to human studies between 2012 and 2021 using the PubMed, Scopus, and Cochrane databases. Thirty-one studies met the inclusion criteria (14 microbiota, 1 LPS, 1 LPS-BP, 1 LPS and LPS-BP, 5 zonulin, 9 systematic reviews). Our analysis revealed that most studies reported reduced alpha diversity and dysbiosis in women with PCOS. Preliminary studies suggest that LPS, LPS-BP, and zonulin may be involved in the pathophysiology of increased intestinal permeability. Treatment of PCOS with prebiotics, probiotics, and synbiotics appears to have a range of beneficial effects on metabolic and biochemical profiles. This review highlights the need for continued research into the pathophysiological mechanisms of dysbiosis and the clinical efficacy of prebiotics, probiotics, and synbiotics in women with PCOS.

SERUM ZONULIN LEVELS IN HYPOTHYROID AND EUTHYROID PATIENTS WITH HASHIMOTO'S THYROIDITIS - A PILOT STUDY

CONTEXT

Human zonulin is a protein that regulates the intercellular tight junctions in various tissues and organs of the human body. Hashimoto's thyroiditis (HT) is one of the most common endocrine autoimmune disorder, but the role of increased intestinal permeability in its pathogenesis is still being studied.

OBJECTIVE AND DESIGN

This pilot cross-sectional study investigates serum zonulin concentration in adults with Hashimoto's thyroiditis and assesses the relationship between zonulin levels, clinical hormonal and immunological characteristics.

SUBJECTS AND METHODS

A group of 62 adults with HT participated in this study and were divided into three groups: hypothyroid (n=33) euthyroid (n=25) and hyperthyroid (n=4). Serum zonulin was determined using an ELISA method.

RESULTS

Age, gender and BMI were different between groups (hypothyroid and euthyroid ones). Serum zonulin values ranged from 2.6 to 198.0 ng/mL in participants. A direct positive correlation was found between serum zonulin levels and weight and BMI (r = 0.351, p = 0.008 and r = 0.236, p = 0.05, respectively).

CONCLUSIONS

There is no correlation between zonulin and thyroid hormones or autoantibodies in Hashimoto thyroiditis patients. There is a difference in zonulin levels between the studied groups, but they are not statistically significant.

Synbiotic Supplementation Improves Obesity Index and Metabolic Biomarkers in Thai Obese Adults: A Randomized Clinical Trial

The cluster of metabolic disorders includes obesity, dyslipidemia, hypertension, and glucose intolerance, increasing the risk of developing cardiovascular diseases and type 2 diabetes. Evolving proofs suggest an essential role of microbiota in human health and disease, including digestion, energy and glucose metabolism, immunomodulation, and brain function. The frequency of overweight is increasing, and the main causes for this are highly processed foods and less active lifestyles. Research is underway to unravel the probable relationship between obesity and intestinal microbiota. Here, we propose a method to understand and elucidate the synergistic function of prebiotics and probiotics in treating obesity. The biomarkers of obesity, such as cholesterol, gut permeability, oxidative stress, bacterial toxins, cytokines, and short-chain fatty acids, were analyzed in Thai obese individuals after being supplemented with a synbiotic preparation containing Lactobacillus paracasei, Bifidobacterium longum, Bifidobacterium breve, inulin, and fructooligosaccharide. The results reveal that the supplementation of synbiotics significantly altered the obesity-associated biomarkers in an appositive way. Further studies are warranted to use synbiotics as an adjuvant therapy for the management of obesity-related health issues.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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