Effects of a Diet-Based Weight-Reducing Program with Probiotic Supplementation on Satiety Efficiency, Eating Behaviour Traits, and Psychosocial Behaviours in Obese Individuals

Unlocking the Potential of Probiotics: A Comprehensive Review on Research, Production, and Regulation of Probiotics

This review provides a comprehensive overview of the current state of probiotic research, covering a wide range of topics, including strain identification, functional characterization, preclinical and clinical evaluations, mechanisms of action, therapeutic applications, manufacturing considerations, and future directions. The screening process for potential probiotics involves phenotypic and genomic analysis to identify strains with health-promoting properties while excluding those with any factor that could be harmful to the host. In vitro assays for evaluating probiotic traits such as acid tolerance, bile metabolism, adhesion properties, and antimicrobial effects are described. The review highlights promising findings from in vivo studies on probiotic mitigation of inflammatory bowel diseases, chemotherapy-induced mucositis, dysbiosis, obesity, diabetes, and bone health, primarily through immunomodulation and modulation of the local microbiota in human and animal models. Clinical studies demonstrating beneficial modulation of metabolic diseases and human central nervous system function are also presented. Manufacturing processes significantly impact the growth, viability, and properties of probiotics, and the composition of the product matrix and supplementation with prebiotics or other strains can modify their effects. The lack of regulatory oversight raises concerns about the quality, safety, and labeling accuracy of commercial probiotics, particularly for vulnerable populations. Advancements in multi-omics approaches, especially probiogenomics, will provide a deeper understanding of the mechanisms behind probiotic functionality, allowing for personalized and targeted probiotic therapies. However, it is crucial to simultaneously focus on improving manufacturing practices, implementing quality control standards, and establishing regulatory oversight to ensure the safety and efficacy of probiotic products in the face of increasing therapeutic applications.

The Effect of Probiotics on Obesity with Comorbid Depression: A Systematic Review and Meta-Analysis

Aims/Background Obesity and depression frequently co-occur, and the relationship between them is bidirectional. Being obese or overweight increases the risk of depression, and conversely, depression increases the risk of obesity or overweight. Emerging clinical research has shown that probiotics may be effective in treating obesity and associated depression. Modulating gut microbiota with probiotics may improve obesity-related depression, but current evidence is inconsistent. Methods We systematically searched PubMed, EMBASE, Web of Science, and Cochrane Library for randomized controlled trials examining probiotics for depression in obese adults. Mean difference (MD) in depression scores between probiotic and placebo groups was pooled across studies using random-effects models. Heterogeneity was assessed using I2 to explain heterogeneity in meta-regression analysis. To detect the publication bias of the included studies, a funnel plot, and Begg and Egger tests, were used. Possible heterogeneity moderators were detected by subgroup and sensitivity analyses, Galbraith plot, and graphic display of study heterogeneity (GOSH) analysis. Leave-one-out and Influence analyses were performed to assess sensitivity. Results Five trials (n = 488) were included. Overall, probiotics did not significantly improve depressive symptoms versus placebo (MD = 0.08, 95% confidence interval [CI] = -0.63 to 0.79, p = 0.82). Considerable heterogeneity among studies was observed (I2 = 63%). In subgroup analyses, probiotics significantly reduced depression as measured by the Edinburgh Postnatal Depression Scale (MD = -0.60, 95% CI = -1.17 to -0.03, p = 0.04) with no heterogeneity (I2 = 0%). Probiotics also decreased depressive symptoms after 12 weeks of supplementation (MD = -0.78, 95% CI = -1.58 to -0.01, p = 0.05) versus placebo. No publication bias was found using Begg and Egger tests. The GOSH diagnostics revealed three outliers, among the clusters identified by K-means, DBSCAN (Density-based spatial clustering of applications with noise algorithm), and GMM (Gaussian Mixture Model) analyses. Conclusion Overall, probiotics did not improve depressive symptoms in obesity. However, beneficial effects were observed with the Edinburgh Postnatal Depression Scale and short-term use of probiotic. Additional rigorous randomized controlled trials are warranted to elucidate the therapeutic potential of probiotics for obesity-related depression.

Research progress of probiotics regulating intestinal micro-ecological environment in obese patients after bariatric surgery

Bariatric surgery may cause intestinal microecological environment imbalance due to changes in gastrointestinal anatomy. Some patients may have complications, even regain weight. Probiotics can act on intestinal mucosa, epithelium and gut-associated lymphoid tissue to improve the intestinal microecological environment of obese patients after bariatric surgery. Probiotics can promote the production of intestinal antibacterial substances, bind specifically to receptors, decrease intestinal pH value, reduce the inflammatory factors, thus helping patients lose weight and lower blood sugar levels after bariatric surgery. Probiotics can produce lactic acid, acetic acid, lactase, etc., inhibit the growth of harmful bacteria, improve gastrointestinal symptoms of patients after bariatric surgery. Probiotics can activate the AMP-activated protein kinase signaling pathway, improve lipid metabolism, and promote the recovery of symptom indicators of nonalcoholic fatty liver disease after bariatric surgery. Probiotics can regulate the release of neurotransmitters or metabolites by the microbiota through the gut-brain axis to affect brain activity and behavior, thus helping patients improve bad mood after bariatric surgery. This article describes the intestinal microecological environment of obese patients and the change mechanism after bariatric surgery and summarizes the effects and possible mechanisms of probiotics in improving the intestinal microecological environment of obese patients after bariatric surgery, in order to provide references for promoting the clinical application of probiotics.

Effects of Probiotic Supplementation Added to a Weight Loss Program on Anthropometric Measures, Body Composition, Eating Behavior, and Related Hormone Levels in Patients with Food Addiction and Weight Regain After Bariatric Surgery: A Randomized Clinical Trial

PURPOSE

Weight regain after metabolic bariatric surgery is a common problem. Food addiction is an eating disorder that can be one of the reasons for weight regain in these patients. This study aimed to evaluate the effects of probiotic supplementation with a weight loss program and cognitive behavioral therapy (CBT) on anthropometric measures, eating behavior, food addiction, and related hormone levels, in patients with food addiction and weight regain after metabolic bariatric surgery.

MATERIALS AND METHODS

This randomized, triple-blind, placebo-controlled clinical trial was conducted on patients with food addiction and weight regain after metabolic bariatric surgery. Participants (n = 50) received a weight loss program and CBT plus probiotic, or placebo for 12 weeks. Then, anthropometric measurements, biochemical markers, eating behavior, and food addiction were assessed.

RESULTS

Weight and body mass index (BMI) decreased significantly in the probiotic group compared to placebo (p = 0.008, p = 0.001, respectively). Fat mass was significantly decreased in the probiotic group (p < 0.001). Moreover, a significant improvement was observed in the probiotic group's eating behavior and food addiction compared to the placebo group (p < 0.001). Serum levels of leptin decreased significantly (p = 0.02), and oxytocin serum levels increased significantly (p = 0.008) in the probiotic group compared to the placebo group.

CONCLUSION

Adding probiotic supplements to the weight loss program and CBT is superior to the weight loss program and CBT alone in improving weight loss, eating behavior, and food addiction in patients with food addiction and weight regain after metabolic bariatric surgery.

Preoperative Multistrain Probiotic Supplementation Does Not Affect Body Weight Changes or Cardiometabolic Risk Factors in Bariatrics: Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Emerging evidence suggests that microbiota plays a crucial role in the development, progression, and therapeutic options in obesity and its comorbidities. This study assessed preoperative probiotic therapy's impact on bariatric treatment outcomes. A 12-week randomized, double-blind, placebo-controlled trial with 48 patients undergoing bariatric surgery was conducted. Participants received probiotics-Sanprobi Barrier-which contained nine strains of bacteria: Bifidobacterium bifidum W23, Bifidobacterium lactis W51 and W52, Lactobacillus acidophilus W37, Levilactobacillus brevis W63, Lacticaseibacillus casei W56, Ligilactobacillus salivarius W24, Lactococcus lactis W19, and Lactococcus lactis W58. Primary outcomes included excess body weight loss, body weight loss, and excess body mass index loss, with secondary objectives focusing on metabolic profiles. Surgical treatment of obesity significantly improved anthropometric and metabolic parameters. No significant differences were observed in primary outcomes or in secondary outcomes between groups at any time point post-surgery. Preoperative probiotics administration did not affect clinical outcomes 1, 3, or 6 months following bariatric surgery.

The effect of a low-calorie diet on depressive symptoms in individuals with overweight or obesity: a systematic review and meta-analysis of interventional studies

BACKGROUND

Individuals with overweight or obesity are at a high risk for so-called 'atypical' or immunometabolic depression, with associated neurovegetative symptoms including overeating, fatigue, weight gain, and a poor metabolic profile evidenced e.g. by dyslipidemia or hyperglycemia. Research has generated preliminary evidence for a low-calorie diet (LCD) in reducing depressive symptoms. The aim of the current systematic review and meta-analysis is to examine this evidence to determine whether a LCD reduces depressive symptoms in people with overweight or obesity.

METHODS

Eligible studies were identified through PubMed, ISI Web of Science, and PsycINFO until August 2023. Standardized mean differences (SMDs) were derived using random-effects meta-analyses for (1) pre-post LCD comparisons of depression outcomes, and (2) LCD v. no-diet-control group comparisons of depression outcomes.

RESULTS

A total of 25 studies were included in the pre-post meta-analysis, finding that depression scores were significantly lower following a LCD (SMD = -0.47), which was not significantly moderated by the addition of exercise or behavioral therapy as a non-diet adjunct. Meta-regressions indicated that a higher baseline BMI and greater weight reduction were associated with a greater reduction in depression scores. The intervention-control meta-analysis (n = 4) found that overweight or obese participants adhering to a LCD showed a nominally lower depression score compared with those given no intervention (SMD = -0.29).

CONCLUSIONS

There is evidence that LCDs may reduce depressive symptoms in people with overweight or obesity in the short term. Future well-controlled intervention studies, including a non-active control group, and longer-term follow-ups, are warranted in order to make more definitive conclusions.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Human Gut Microbiota for Diagnosis and Treatment of Depression

Nowadays, depressive disorder is spreading rapidly all over the world. Therefore, attention to the studies of the pathogenesis of the disease in order to find novel ways of early diagnosis and treatment is increasing among the scientific and medical communities. Special attention is drawn to a biomarker and therapeutic strategy through the microbiota-gut-brain axis. It is known that the symbiotic interactions between the gut microbes and the host can affect mental health. The review analyzes the mechanisms and ways of action of the gut microbiota on the pathophysiology of depression. The possibility of using knowledge about the taxonomic composition and metabolic profile of the microbiota of patients with depression to select gene compositions (metagenomic signature) as biomarkers of the disease is evaluated. The use of in silico technologies (machine learning) for the diagnosis of depression based on the biomarkers of the gut microbiota is given. Alternative approaches to the treatment of depression are being considered by balancing the microbial composition through dietary modifications and the use of additives, namely probiotics, postbiotics (including vesicles) and prebiotics as psychobiotics, and fecal transplantation. The bacterium Faecalibacterium prausnitzii is under consideration as a promising new-generation probiotic and auxiliary diagnostic biomarker of depression. The analysis conducted in this review may be useful for clinical practice and pharmacology.

The Probiotic Strain Lactobacillus acidophilus CL1285 Reduces Fat Deposition and Oxidative Stress and Increases Lifespan in Caenorhabditis elegans

Caenorhabditis elegans was recently shown to be a powerful model for studying and identifying probiotics with specific functions. Lactobacillus acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2, which are three bacteria that were marketed by Bio-K+, were evaluated using the nematode C. elegans to study fat accumulation, lifespan, and resistance to oxidative stress. Although the general effects of probiotics in terms of protection against oxidative stress were highlighted, the CL1285 strain had an interesting and specific feature, namely its ability to prevent fat accumulation in nematodes; this effect was verified by both the Oil Red and Nile Red methods. This observed phenotype requires daf-16 and is affected by glucose levels. In addition, in a daf-16- and glucose-dependent manner, CL1285 extended the lifespan of C. elegans; this effect was unique to CL1285 and not found in the other L. acidophilus subtypes in this study. Our findings indicate that L. acidophilus CL1285 impacts fat/glucose metabolism in C. elegans and provides a basis to further study this probiotic, which could have potential health benefits in humans and/or in mammals.

Effectiveness of probiotic/prebiotic/synbiotic treatments on anxiety: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Anxiety can adversely affect human well-being. This meta-analysis aimed to evaluate the effects of interventions that alter the gut microbes (including probiotics, prebiotics, and synbiotics) on anxiety.

METHODS

A systematic meta-analysis of the effects of probiotics, prebiotics, and synbiotics on anxiety was conducted by searching randomized controlled trials (RCTs) in 13 databases. The primary outcomes were the pre- and post-intervention anxiety scores in the intervention and placebo groups. Anxiety scores were extracted as standard mean differences (SMDs) and pooled based on a random effects model. Subgroup analyses of anxiety scales, health status, gastrointestinal symptoms, flora strains, treatment type, probiotic dose, region, and treatment duration were also performed.

RESULTS

29 RCTs (2035 participants) were included, revealing that both probiotics and synbiotics significantly reduced anxiety scores. Additionally, anxiety scores did not significantly reduce when comparing prebiotics and placebos.

LIMITATIONS

Owing to the small combined effect size of probiotic/prebiotic/synbiotic treatments and the relatively few studies on prebiotics and synbiotics included in the analysis, the findings of probiotic/prebiotic/synbiotic treatments are preliminary.

CONCLUSIONS

Our study indicated that probiotics and synbiotics can reduce anxiety scores; however, it might be premature to conclude their clinical efficacy in alleviating anxiety due to the small effect size. There is no consensus regarding the optimal dose, treatment duration, treatment type, or probiotic strain to improve anxiety. Moreover, the mechanisms by which probiotics and synbiotics improve anxiety remain unclear. More RCTs are needed to determine the mechanisms of action and to identify appropriate markers to clarify their effects.

Hyperphagia is prominent in adult patients with short bowel syndrome: A role for the colon?

RATIONALE

Short Bowel Syndrome (SBS) is the major cause of chronic intestinal failure (IF) and requires parenteral nutrition (PN). After bowel resection, some patients develop spontaneous intestinal adaptations and hyperphagia. Since promoting oral energy intake contributes to PN weaning, this study aims to characterize hyperphagia in patients with SBS and identify its determinants.

METHODS

This observational retrospective study included adult patients with SBS who were followed at an expert PN center between 2006 and 2019, with at least 2 separate nutritional assessments. Exclusion criteria were: active neoplasia, alternative treatment for IF or appetite-affecting medication. Resting energy expenditure (REE) was calculated for each patient using the Harris-Benedict equation. Food Intake Ratio (FIR) was calculated by dividing the highest caloric oral intake by REE and hyperphagia was defined as FIR >1.5.

RESULTS

Among the 59 patients with SBS included in this study, 82.6% had a FIR >1.5, including 15.5% with a FIR >3. Protein supplied approximately 16% of total energy intake while fat and carbohydrates provided 36% and 48%, respectively. The FIR was independent of gender and whether patients received oral nutrition alone (n = 28) or combined with PN (n = 31). The FIR was also not associated with residual small bowel length, nor the proportion of preserved colon. However, it was negatively correlated with the body mass index (BMI) of these patients (r = -0.533, p < 0.001), whether they had PN support or not. Patients with either a jejuno-colonic (n = 31) or a jejuno-ileal anastomosis (n = 9), had a significantly higher FIR compared to those with an end-jejunostomy (n = 18) (p < 0.05). However, no difference was found in the proportion of calories provided by protein, fat and carbohydrate between the 3 patients groups divided according to the SBS anatomical type.

CONCLUSION

A large majority of patients with SBS exhibited a hyperphagia regardless of PN dependence or bowel length, which was inversely correlated with BMI. The presence of the colon in continuity, thus in contact with the nutritional flow, seems to favor a higher oral intake which is beneficial for the nutritional autonomy of patients. This raises the question of a role of colonic microbiota and hormones in this behavior. Finally, this study also revealed an unexpected discrepancy between recommended energy intakes from protein, fat and carbohydrate and the actual intake of patients with SBS.

Endocrine, genetic, and microbiome nexus of obesity and potential role of postbiotics: a narrative review

Obesity is a public health crisis, presenting a huge burden on health care and the economic system in both developed and developing countries. According to the WHO's latest report on obesity, 39% of adults of age 18 and above are obese, with an increase of 18% compared to the last few decades. Metabolic energy imbalance due to contemporary lifestyle, changes in gut microbiota, hormonal imbalance, inherent genetics, and epigenetics is a major contributory factor to this crisis. Multiple studies have shown that probiotics and their metabolites (postbiotics) supplementation have an effect on obesity-related effects in vitro, in vivo, and in human clinical investigations. Postbiotics such as the SCFAs suppress obesity by regulating metabolic hormones such as GLP-1, and PPY thus reducing feed intake and suppressing appetite. Furthermore, muramyl di-peptides, bacteriocins, and LPS have been tested against obesity and yielded promising results in both human and mice studies. These insights provide an overview of targetable pharmacological sites and explore new opportunities for the safer use of postbiotics against obesity in the future.

The impact of aerobic exercise training on cognitive function and gut microbiota in methamphetamine-dependent individuals in the community

OBJECTIVE

This study aimed to investigate the impact and mechanism of gut microbiota on the enhancement of cognitive function in methamphetamine (MA)-dependent individuals during aerobic exercise training.

METHODS

A total of sixty-four MA-dependent individuals were randomly assigned to either an aerobic exercise training group (DK, n = 32) or a conventional rehabilitation group (CK, n = 32). After an eight-week intervention, the participants' working memory and inhibition ability were assessed using the Stroop paradigm and Go/NoGo paradigm, respectively. Gut microbiota composition was analyzed using high-throughput sequencing.

RESULTS

1) Eight weeks of aerobic exercise training significantly improved the working memory and inhibition ability of MA-dependent individuals (P < 0.05). 2) Following the intervention, the DK group exhibited significantly higher levels of Lactobacillus, Lactococcus lactis, Prevotellaceae, and Ruminococcaceae compared to the CK group. Conversely, the DK group demonstrated significantly lower levels of Desulfovibrio and Akkermansia compared to the CK group. Furthermore, the DK group showed significantly increased metabolic pathways associated with d-Glutaralate and d-Galactate Degradation, as well as the Alanine, aspartate, and glutamate metabolism pathway, compared to the control group. 3) Cognitive function related to MA addiction positively correlated with Bifidobacterium, Dialister, and Adlercreutzia, while negatively correlated with Enterobacteria, Bacillus cereus, Catabacter, and Akkermansia.

CONCLUSION

Aerobic exercise training enhances working memory and inhibition ability in MA-dependent individuals, thereby mitigating the detrimental effects of MA addiction on cognitive function. Additionally, analysis of gut microbiota suggests that the modulation of gut microbiota and associated metabolic pathways play a role in regulating the improvement of cognitive function in MA-dependent individuals through exercise.

Microbes, oxytocin and stress: Converging players regulating eating behavior

Oxytocin is a peptide-hormone extensively studied for its multifaceted biological functions and has recently gained attention for its role in eating behavior, through its action as an anorexigenic neuropeptide. Moreover, the gut microbiota is involved in oxytocinergic signaling through the brain-gut axis, specifically in the regulation of social behavior. The gut microbiota is also implicated in appetite regulation and is postulated to play a role in central regulation of hedonic eating. In this review, we provide an overview on oxytocin and its individual links with the microbiome, the homeostatic and non-homeostatic regulation of eating behavior as well as social behavior and stress.

The brain-gut-microbiota axis in the treatment of neurologic and psychiatric disorders

The human gut microbiota is a complex ecosystem made of trillions of microorganisms. The composition can be affected by diet, metabolism, age, geography, stress, seasons, temperature, sleep, and medications. The increasing evidence about the existence of a close and bi-directional correlation between the gut microbiota and the brain indicates that intestinal imbalance may play a vital role in the development, function, and disorders of the central nervous system. The mechanisms of interaction between the gut-microbiota on neuronal activity are widely discussed. Several potential pathways are involved with the brain-gut-microbiota axis, including the vagus nerve, endocrine, immune, and biochemical pathways. Gut dysbiosis has been linked to neurological disorders in different ways that involve activation of the hypothalamic-pituitary-adrenal axis, imbalance in neurotransmitter release, systemic inflammation, and increase in the permeability of the intestinal and the blood-brain barrier. Mental and neurological diseases have become more prevalent during the coronavirus disease 2019pandemic and are an essential issue in public health globally. Understanding the importance of diagnosing, preventing, and treating dysbiosis is critical because gut microbial imbalance is a significant risk factor for these disorders. This review summarizes evidence demonstrating the influence of gut dysbiosis on mental and neurological disorders.

Shared biological mechanisms of depression and obesity: focus on adipokines and lipokines

Depression and obesity are both common disorders currently affecting public health, frequently occurring simultaneously within individuals, and the relationship between these disorders is bidirectional. The association between obesity and depression is highly co-morbid and tends to significantly exacerbate metabolic and related depressive symptoms. However, the neural mechanism under the mutual control of obesity and depression is largely inscrutable. This review focuses particularly on alterations in systems that may mechanistically explain the in vivo homeostatic regulation of the obesity and depression link, such as immune-inflammatory activation, gut microbiota, neuroplasticity, HPA axis dysregulation as well as neuroendocrine regulators of energy metabolism including adipocytokines and lipokines. In addition, the review summarizes potential and future treatments for obesity and depression and raises several questions that need to be answered in future research. This review will provide a comprehensive description and localization of the biological connection between obesity and depression to better understand the co-morbidity of obesity and depression.

Effects of probiotic supplementation with weight reducing intervention on anthropometric measures, body composition, eating behavior, and related hormone levels in patients with food addiction and weight regain after bariatric surgery: a study protocol for a randomized clinical trial

BACKGROUND

One of the unfortunate events after bariatric surgery is the weight regain, which occurs in some patients. Food addiction is an eating disorder related to the brain-intestinal axis and can be effective in weight regain after bariatric surgery. In addition, the gut microbiome plays a vital role in eating behaviors, including food addiction. So, this study will aim to evaluate the effects of probiotic supplementation with a weight-reducing diet and cognitive behavioral therapy on anthropometric measures, body composition, eating behavior, and related hormone levels, leptin, oxytocin, and serotonin, in patients with food addiction and weight regain after bariatric surgery.

METHODS

We will carry out a triple-blinded randomized clinical trial for 12 weeks to evaluate the effect of probiotic supplementation with a weight-reducing diet and cognitive behavioral therapy on anthropometric measures, body composition, eating behavior, and related hormone levels including leptin, oxytocin, and serotonin, in patients with food addiction and weight regain after bariatric surgery.

DISCUSSION

Based on the available evidence, probiotic supplementation by modifying the intestinal microbiome can improve food addiction and subsequent weight loss.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT20220406054437N1 Registered on 2022-06-01.

Chronic consumption of a blend of inulin and arabinoxylan reduces energy intake in an ad libitum meal but does not influence perceptions of appetite and satiety: a randomised control-controlled crossover trial

PURPOSE

Prebiotic foods can be used to increase production of short-chain fatty acids (SCFA) in the gut. Of the SCFA, propionate is credited with the strongest anorectic activity. In previous work, a 50/50 blend of inulin and arabinoxylan was produced (I + AX) that significantly increased propionate production in an in vitro gut model. This study sought to establish whether chronic consumption of a prebiotic blend of I + AX decreases appetite and energy intake and increases intestinal propionate production in human participants.

METHODS

MIXSAT (clinicaltrials.gov id: NCT02846454, August 2016) was a double-blind randomised acute-within-chronic crossover feeding trial in healthy adult men (n = 20). Treatments were 8 g per day I + AX for 21 days or weight-matched maltodextrin control. The primary outcome measure was perceived satiety and appetite during an acute study visit. Secondary outcomes were energy intake in an ad libitum meal, faecal SCFA concentration, and faecal microbiota composition.

RESULTS

Perceived satiety and appetite were not affected by the intervention. I + AX was associated with a reduction in energy intake in an ad libitum meal, increased faecal SCFA concentration, and an increase in cell counts of Bifidobacteria, Lactobacilli, and other microbial genera associated with health.

IMPLICATIONS

Chronic consumption of this blend of prebiotics decreased energy intake in a single sitting. Further studies are needed to confirm mechanism of action and to determine whether this might be useful in weight control.

The Role of Probiotics and Their Metabolites in the Treatment of Depression

Depression is a common and complex mental and emotional disorder that causes disability, morbidity, and quite often mortality around the world. Depression is closely related to several physical and metabolic conditions causing metabolic depression. Studies have indicated that there is a relationship between the intestinal microbiota and the brain, known as the gut–brain axis. While this microbiota–gut–brain connection is disturbed, dysfunctions of the brain, immune system, endocrine system, and gastrointestinal tract occur. Numerous studies show that intestinal dysbiosis characterized by abnormal microbiota and dysfunction of the microbiota–gut–brain axis could be a direct cause of mental and emotional disorders. Traditional treatment of depression includes psychotherapy and pharmacotherapy, and it mainly targets the brain. However, restoration of the intestinal microbiota and functions of the gut–brain axis via using probiotics, their metabolites, prebiotics, and healthy diet may alleviate depressive symptoms. Administration of probiotics labeled as psychobiotics and their metabolites as metabiotics, especially as an adjuvant to antidepressants, improves mental disorders. It is a new approach to the prevention, management, and treatment of mental and emotional illnesses, particularly major depressive disorder and metabolic depression. For the effectiveness of antidepressant therapy, psychobiotics should be administered at a dose higher than 1 billion CFU/day for at least 8 weeks.

Paraprobiotic Lacticaseibacillus rhamnosus Protects Intestinal Damage in an Experimental Murine Model of Mucositis

Intestinal mucositis (IM) is a common side effect resulting from cancer treatment. However, the management so far has not been very effective. In the last years, the role of the gut microbiota in the development and severity of mucositis has been studied. Therefore, the use of probiotics and paraprobiotics could have a potential therapeutic effect on IM. The aim of our study was to investigate the impact of the administration of Lacticaseibacillus rhamnosus (L. rhamnosus) CGMCC1.3724 and the paraprobiotic on IM in mice. For 13 days, male Balb/c mice were divided into six groups: control (CTL) and mucositis (MUC)/0.1 mL of saline; CTL LrV and MUC LrV/0.1 mL of 10⁸ CFU of viable Lr; CTL LrI and MUC LrI/0.1 mL of 10⁸ CFU of inactivated Lr. On the 10th day, mice from the MUC, MUC LrV, and MUC LrI groups received an intraperitoneal injection (300 mg/kg) of 5-fluorouracil to induce mucositis. The results showed that the administration of the chemotherapeutic agent increased the weight loss and intestinal permeability of the animals in the MUC and MUC LrV groups. However, administration of paraprobiotic reduced weight loss and maintained PI at physiological levels. The paraprobiotic also preserved the villi and intestinal crypts, reduced the inflammatory infiltrate, and increased the mucus secretion, Muc2 gene expression, and Treg cells frequency.

Effects of Probiotics on Intermediate Cardiovascular Outcomes in Patients with Overweight or Obesity: A Systematic Review and Meta-Analysis

Background: Clinical trials evaluating the effect of probiotics on cardiovascular intermediate outcomes have been scarce in recent years. We systematically evaluated the efficacy of probiotics on intermediate cardiovascular outcomes in patients with overweight or obesity. Methods: We searched for randomized controlled trials (RCTs) in four databases (until August 2021) that evaluated the effects of probiotics versus controls on intermediate cardiovascular outcomes. The outcomes were body mass index (BMI), weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), glucose, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels. Inverse variance random effects meta-analyses were used. The effects were reported as mean difference (MD), with their 95% confidence intervals (95% CI). The quality of evidence (QoE) was assessed with GRADE (grading of recommendations, assessment, development and evaluations) methodology. Results: A total of 25 RCTs were included (n = 2170), with a range of follow-up from two to six months. Probiotics likely reduced BMI (MD −0.27 kg/m2, 95%CI: −0.35 to −0.19; 17 RCTs; I2 = 26%, QoE: moderate), as well as likely reduced weight (MD −0.61 kg, 95%CI: −0.89 to −0.34; 15 RCTs; I2 = 0%, QoE: moderate), and may have slightly reduce LDL (MD −4.08 mg/dL; 95%CI: −6.99 to −1.17; 9 RCTs; I2 = 87%, QoE: low) in comparison to the controls. However, probiotics had no effect on SBP (MD −0.40 mmHg; 95%CI: −5.04 to 4.25; 7 RCTs; I2 = 100%, QoE: very low), DBP (MD −1.73 mmHg; 95%CI: −5.29 to 1.82; 5 RCTs; I2 = 98%, QoE: very low), glucose (MD −0.07 mg/dL; 95%CI −0.89 to 0.75; I2 = 96%, QoE: very low), HDL (MD −1.83 mg/dL; 95%CI: −4.14 to 2.47; 14 RCTs; I2 = 98%, QoE: very low), or triglycerides (MD −3.29 mg/dL, 95%CI −17.03 to 10.45; 14 RCTs, I2 = 95%, QoE: very low) compared to control arms, and the evidence was very uncertain. Conclusions: In obese or overweight patients, BMI, weight, and LDL were lower in patients who received probiotics compared to those who received controls. Other lipids, glucose, and blood pressure were not affected by the probiotics.

Fermented dairy foods consumption and depressive symptoms: A meta-analysis of cohort studies

BACKGROUND

The gut-brain axis has been potentially proposed as a link between the intake of fermented dairy foods and depression. We carried out this meta-analysis on published cohort studies to estimate the overall depression risk of fermented dairy foods intake.

METHODS

We searched the CNKI (China National Knowledge Infrastructure) and PubMed databases for all articles within a range of published years from 2010 to 2022 on the association between fermented dairy foods intake and depression.

RESULTS

Finally, 8 studies met the inclusion criteria for this study, with 83,533 participants. Overall, there was statistical evidence of significantly decreased depression risk was found to be associated with fermented dairy foods intake (OR = 0.89, 95% CI = 0.81-0.98). In subgroup analysis, cheese and yogurt consumptions were significantly associated with decreased depression risk (OR = 0.91, 95% CI = 0.84-0.98 for cheese and OR = 0. 84, 95% CI = 0.72-0.99 for yogurt). However, we failed to find superabundant intake of fermented dairy foods intake decreased the risk of depression.

CONCLUSION

Our meta-analysis indicated that fermented dairy foods intake may have potential beneficial effect on depression via the gut-brain axis.

Effects of probiotic fermented milk on management of obesity studied in high-fat-diet induced obese rat model

The current study aimed to explore the hypothesis that probiotic bacteria are significantly involved in the control of obesity using Wistar rats as the test group by feeding high fat diets (HFD) induced obesity. A total of four groups of rats were considered viz., normal pellet diet fed (NC), HFD fed (DC), HFD fed rats treated with probiotic fermented milk with soy protein isolate (SPI) and whey protein concentrate (WPC) (T1), HFD fed rats treated with probiotic fermented milk without WPC and SPI (T2). Body weight, abdominal fat weight, liver weight, serum Alanine aminotransferase level, and alkaline phosphatase level significantly (p < 0.05) decreased after giving daily probiotic milk product supplementation with @ 2 ml per day for continuous 4 weeks. Whereas, C-reactive protein and Aspartate aminotransferase levels were not altered to a significant extent. The histology of the liver from the disease model group showed large lipid vacuoles deposited in the parenchyma cells. Product T2 confirmed fewer micro vesicular fatty changes and the appearance of T2 was better than T1. Overall, the in vivo study results indicated that the probiotic fermented milk exerted a better anti-obesity effect.

Graphical Abstract

Fecal microbiota transplantation in a rodent model of short bowel syndrome: A therapeutic approach?

Extensive intestinal resection leads to Short Bowel Syndrome (SBS), the main cause of chronic intestinal failure. Colon preservation is crucial for spontaneous adaptation, to improve absorption and reduce parenteral nutrition dependence. Fecal microbiota transplantation (FMT), a promising approach in pathologies with dysbiosis as the one observed in SBS patients, was assessed in SBS rats with jejuno-colonic anastomosis. The evolution of weight and food intake, the lenght of intestinal villi and crypts and the composition of fecal microbiota of Sham and SBS rats, transplanted or not with high fat diet rat microbiota, were analyzed. All SBS rats lost weight, increased their food intake and exhibited jejunal and colonic hyperplasia. Microbiota composition of SBS rats, transplanted or not, was largely enriched with Lactobacillaceae, and α- and β-diversity were significantly different from Sham. The FMT altered microbiota composition and α- and β-diversity in Sham but not SBS rats. FMT from high fat diet rats was successfully engrafted in Sham, but failed to take hold in SBS rats, probably because of the specific luminal environment in colon of SBS subjects favoring aero-tolerant over anaerobic bacteria. Finally, the level of food intake in SBS rats was positively correlated with their Lactobacillaceae abundance. Microbiota transfer must be optimized and adapted to this specific SBS environment.

Evidence for Constitutive Microbiota-Dependent Short-Term Control of Food Intake in Mice: Is There a Link with Inflammation, Oxidative Stress, Endotoxemia, and GLP-1?

Aims: Although prebiotics, probiotics, and fecal transplantation can alter the sensation of hunger and/or feeding behavior, the role of the constitutive gut microbiota in the short-term regulation of food intake during normal physiology is still unclear. Results: An antibiotic-induced microbiota depletion study was designed to compare feeding behavior in conventional and microbiota-depleted mice. Tissues were sampled to characterize the time profile of microbiota-derived signals in mice during consumption of either standard or high-fat food for 1 h. Pharmacological and genetic tools were used to evaluate the contribution of postprandial endotoxemia and inflammatory responses in the short-term regulation of food intake. We observed constitutive microbial and macronutrient-dependent control of food intake at the time scale of a meal; that is, within 1 h of food introduction. Specifically, microbiota depletion increased food intake, and the microbiota-derived anorectic effect became significant during the consumption of high-fat but not standard food. This anorectic effect correlated with a specific postprandial microbial metabolic signature, and did not require postprandial endotoxemia or an NOD-, LRR-, and Pyrin domain-containing protein 3-inflammasome-mediated inflammatory response. Innovation and Conclusion: These findings show that the gut microbiota controls host appetite at the time scale of a meal under normal physiology. Interestingly, a microbiota-derived anorectic effect develops specifically with a high-fat meal, indicating that gut microbiota activity is involved in the satietogenic properties of foods. Antioxid. Redox Signal. 37, 349-369.

The significance and potential of functional food ingredients for control appetite and food intake

Dramatically rising global levels of obesity have raised consumers’ commercial and public health interest in foods that may help control appetite and weight. The satiety cascade consists of sensory, cognitive, physical, and hormonal events following food intake, preventing overeating, and the desire to eat for a long time. Functional foods can be one of the most influential factors in reducing appetite as long as effective ingredients, such as fiber and protein, are used to design these products. Also, functional foods should be designed to reduce appetite at different levels of oral processing, stomach, small intestine, and large intestine by various mechanisms. Therefore, the satiety power of functional foods depends on the type of ingredients and their amount. Because each compound has a different mechanism of action, it is recommended to use different compounds to influence satiety in functional foods.

Neurohormonal Changes in the Gut–Brain Axis and Underlying Neuroendocrine Mechanisms following Bariatric Surgery

Obesity is a complex, multifactorial disease that is a major public health issue worldwide. Currently approved anti-obesity medications and lifestyle interventions lack the efficacy and durability needed to combat obesity, especially in individuals with more severe forms or coexisting metabolic disorders, such as poorly controlled type 2 diabetes. Bariatric surgery is considered an effective therapeutic modality with sustained weight loss and metabolic benefits. Numerous genetic and environmental factors have been associated with the pathogenesis of obesity, while cumulative evidence has highlighted the gut–brain axis as a complex bidirectional communication axis that plays a crucial role in energy homeostasis. This has led to increased research on the roles of neuroendocrine signaling pathways and various gastrointestinal peptides as key mediators of the beneficial effects following weight-loss surgery. The accumulate evidence suggests that the development of gut-peptide-based agents can mimic the effects of bariatric surgery and thus is a highly promising treatment strategy that could be explored in future research. This article aims to elucidate the potential underlying neuroendocrine mechanisms of the gut–brain axis and comprehensively review the observed changes of gut hormones associated with bariatric surgery. Moreover, the emerging role of post-bariatric gut microbiota modulation is briefly discussed.

Effectiveness of a polyphenolic extract (Lippia citriodora and Hibiscus sabdariffa) on appetite regulation in overweight and obese grade I population: an 8-week randomized, double-blind, cross-over, placebo-controlled trial

INTRODUCTION

Polyphenols have shown capacity to improve appetite sensation, leading to enhanced control of body weight. However, despite being related with hunger-related hormones, metabolic and mechanism are not well known.

METHODS

The effectiveness of a nutraceutical composed of extract to Lippia citriodora and Hibiscus sabdarrifa (Lc-Hs) for controlling satiety and hunger was analyzed in a cross-over, placebo-controlled (Pla) clinical intervention. The study was divided in two 60-day periods separated by 30-day length wash-out period. At the end of each period, overweight and obese subjects (n = 33; age = 33.76 ± 12.23; BMI = 28.20 kg/m2 ± 2.47; fat mass 30.65 ± 8.39%; both sexes were proposed to eat an ad-libitum meal. Meanwhile, appetite sensation was determined by visual analog scales at different times. Moreover, blood extraction was performed to determine biochemical parameters (lipid and glucidic profile and safety parameters) and to evaluate hunger-related hormones (insulin, leptin, ghrelin, adiponectin, GLP-1 and peptide YY).

RESULTS

A decrease in appetite sensation was observed in Lc-Hs treatment, showing higher satiety quotient (Pla = 3.36 ± 2.33%mm/kcal; Lc-Hs = 5.53 ± 2.91%mm/kcal; p < 0.0001). Area under the curve was higher in Pla compared to Lc-Hs during the test, from baseline to minute 240 (240 (Pla 9136.65 ± 2261.46% x min-1; Lc-Hs 8279.73 ± 2745.71% x min-1; p < 0.014). Energy consumption was lower for subjects treated with Lc-Hs (774.44 ± 247.77 kcal) compared to those treated with Pla (849.52 ± 246.54 kcal) (p < 0.004). Leptin values varied from baseline (Pla 12.36 ± 1.98 ng/mL; Lc-Hs 13.13 ± 1.99 ng/mL) to the end of the study (Pla 12.60 ± 2.02 ng/mL; Lc-Hs 12.06 ± 2.05 ng/mL; p < 0.047). GLP-1 values varied (p < 0.001) in Lc-Hs treatment from baseline (4.34 ± 0.49 ng/mL) to the end of the study (3.23 ± 0.52 ng/mL).

CONCLUSION

The supplementation with the Lc-Hs extract decreases appetite sensation in overweight and obese population, reducing calorie intake after an ad-libitum meal. Due to variation on hunger-related hormones and the relationship between satiety feeling, it would be interesting to develop future research focused on the variation of the hormones themselves.

Effect of Probiotics on Psychiatric Symptoms and Central Nervous System Functions in Human Health and Disease: A Systematic Review and Meta-Analysis

Background: The gut microbiota impacts on central nervous system (CNS) function via the microbiota–gut–brain axis. Thus, therapeutics targeting the gut microbiota such as probiotics have the potential for improving mental health. This meta-analysis synthesizes the evidence regarding the impacts of probiotics on psychological well-being, psychiatric symptoms and CNS functioning. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were applied for executing this review using the databases PubMed, Web of Science and Cochrane Library. The data were summarized at qualitative and quantitative level. Results: Fifty-four randomized placebo-controlled studies were included, of which 30 were eligible for meta-analysis. If investigated, the probiotics mostly exerted effects on CNS function. Most probiotics did not affect mood, stress, anxiety, depression and psychiatric distress when compared to placebo at the qualitative level. At quantitative level, depression and psychiatric distress improved slightly in the probiotic condition (depression: mean difference −0.37 (95% CI: −0.55, −0.20); p ≤ 0.0001; psychiatric distress: mean difference −0.33 (95% CI: −0.53, −0.13); p = 0.001). Conclusions: To date it is unclear to which extent and in which specific areas next generation probiotics selected and developed for their ability to improve psychiatric condition and potentially other CNS functions are promising.

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

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

Depression and obesity among females, are sex specificities considered?

This study aimed to systematically review the relationship of obesity-depression in the female sex. We carried out a systematic search (PubMed, MEDLINE, Embase) to quantify the articles (controlled trials and randomized controlled trials) regarding obesity and depression on a female population or a mixed sample. Successively, we established whether the sex specificities were studied by the authors and if they reported on collecting data regarding factors that may contribute to the evolution of obesity and depression and that could be responsible for the greater susceptibility of females to those conditions. After applying the inclusion and exclusion criteria, we found a total of 20 articles with a female sample and 54 articles with a mixed sample. More than half of all articles (51.35%, n = 38) evaluated the relationship between depression and obesity, but only 20 (27.03%) evaluated this relationship among females; still, 80% of those (n = 16) presented supporting results. However, few articles considered confounding factors related to female hormones (12.16%, n = 9) and none of the articles focused on factors responsible for the binomial obesity-depression in the female sex. The resulting articles also supported that depression (and related impairments) influencing obesity (and related impairments) is a two-way road. This systematic review supports the concurrency of obesity-depression in females but also shows how sex specificities are ultimately under-investigated. Female sex specificity is not being actively considered when studying the binomial obesity-depression, even within a female sample. Future studies should focus on trying to understand how the female sex and normal hormonal variations influence these conditions.

Microbiome First Approaches to Rescue Public Health and Reduce Human Suffering

The is a sequential article to an initial review suggesting that Microbiome First medical approaches to human health and wellness could both aid the fight against noncommunicable diseases and conditions (NCDs) and help to usher in sustainable healthcare. This current review article specifically focuses on public health programs and initiatives and what has been termed by medical journals as a catastrophic record of recent failures. Included in the review is a discussion of the four priority behavioral modifications (food choices, cessation of two drugs of abuse, and exercise) advocated by the World Health Organization as the way to stop the ongoing NCD epidemic. The lack of public health focus on the majority of cells and genes in the human superorganism, the microbiome, is highlighted as is the "regulatory gap" failure to protect humans, particularly the young, from a series of mass population toxic exposures (e.g., asbestos, trichloroethylene, dioxin, polychlorinated biphenyls, triclosan, bisphenol A and other plasticizers, polyfluorinated compounds, herbicides, food emulsifiers, high fructose corn syrup, certain nanoparticles, endocrine disruptors, and obesogens). The combination of early life toxicity for the microbiome and connected human physiological systems (e.g., immune, neurological), plus a lack of attention to the importance of microbial rebiosis has facilitated rather than suppressed, the NCD epidemic. This review article concludes with a call to place the microbiome first and foremost in public health initiatives as a way to both rescue public health effectiveness and reduce the human suffering connected to comorbid NCDs.

The effect of interventions targeting gut microbiota on depressive symptoms: a systematic review and meta-analysis

BACKGROUND

Despite their popularity, the efficacy of interventions targeting gut microbiota to improve depressive symptoms is unknown. Our objective is to summarize the effect of microbiome-targeting interventions on depressive symptoms.

METHODS

We conducted a systematic review and meta-analysis. We searched MEDLINE, Embase, PsycINFO, Database of Abstracts of Reviews of Effects, Cochrane Database of Systematic Reviews and the Cochrane Controlled Register of Trials from inception to Mar. 5, 2021. We included studies that evaluated probiotic, prebiotic, synbiotic, paraprobiotic or fecal microbiota transplant interventions in an adult population (age ≥ 18 yr) with an inactive or placebo comparator (defined by the absence of active intervention). Studies must have measured depressive symptoms with a validated scale, and used a randomized controlled trial study design. We conducted a random effects meta-analysis of change scores, using standardized mean difference as the measure of effect.

RESULTS

Sixty-two studies formed the final data set, with 50 included in the meta-analysis. Probiotic, prebiotic, and synbiotic interventions on depressive symptoms showed statistically significant benefits. In the single studies evaluating each of fecal microbiota transplant and paraprobiotic interventions, neither showed a statistically significant benefit.

INTERPRETATION

Despite promising findings of benefit of probiotic, prebiotic and synbiotic interventions for depressive symptoms in study populations, there is not yet strong enough evidence to favour inclusion of these interventions in treatment guidelines for depression. Critical questions about species administered, dosage and timing relative to other antidepressant medications remain to be answered.

STUDY REGISTRATION

PROSPERO no. 143178.

Effect of Bifidobacterium on olanzapine-induced body weight and appetite changes in patients with psychosis

RATIONALE

Gut microbiota plays an important role in host metabolism. Antipsychotic drugs can result in metabolic abnormalities. Probiotics may ameliorate the antipsychotic drug-induced metabolic abnormalities by regulating gut microbiota.

OBJECTIVE

To determine whether Bifidobacterium intervention can ameliorate olanzapine-induced weight increase.

METHODS

Enrolled patients were assigned to either the olanzapine or olanzapine plus Bifidobacterium group. The following were assessed: body weight, body mass index (BMI), appetite, latency to increased appetite, and baseline weight increase of more than 7%. All assessments were conducted at baseline and at 4, 8, and 12 weeks of treatment.

RESULTS

We enrolled 70 patients with schizophrenia or schizophrenic affective disorder, and 67 completed the study. Treatment for 4 weeks led to between-group differences in weight change (2.4 vs. 1.1 kg, p < 0.05) and BMI (0.9 vs. 0.4, p < 0.05). However, this difference disappeared at 8 and 12 weeks of treatment (both p > 0.05). The two groups did not differ in appetite increase at any time point (p > 0.05). The mean time from olanzapine initiation to appetite increase was also not significantly different between the two groups (t = 1.243, p = 0.220).

CONCLUSIONS

Probiotics may mitigate olanzapine-induced weight gain in the early stage of treatment and delay olanzapine-induced appetite increase.

From gut microbiota to host appetite: gut microbiota-derived metabolites as key regulators

Feelings of hunger and satiety are the key determinants for maintaining the life of humans and animals. Disturbed appetite control may disrupt the metabolic health of the host and cause various metabolic disorders. A variety of factors have been implicated in appetite control, including gut microbiota, which develop the intricate interactions to manipulate the metabolic requirements and hedonic feelings. Gut microbial metabolites and components act as appetite-related signaling molecules to regulate appetite-related hormone secretion and the immune system, or act directly on hypothalamic neurons. Herein, we summarize the effects of gut microbiota on host appetite and consider the potential molecular mechanisms. Furthermore, we propose that the manipulation of gut microbiota represents a clinical therapeutic potential for lessening the development and consequence of appetite-related disorders. Video abstract.

Gutted! Unraveling the Role of the Microbiome in Major Depressive Disorder

Microorganisms can be found in virtually any environment. In humans, the largest collection of microorganisms is found in the gut ecosystem. The adult gut microbiome consists of more genes than its human host and typically spans more than 60 genera from across the taxonomic tree. In addition, the gut contains the largest number of neurons in the body, after the brain. In recent years, it has become clear that the gut microbiome is in communication with the brain, through the gut-brain axis. A growing body of literature shows that the gut microbiome plays a shaping role in a variety of psychiatric disorders, including major depressive disorder (MDD). In this review, the interplay between the microbiome and MDD is discussed in three facets. First, we discuss factors that affect the onset/development of MDD that also greatly impinge on the composition of the gut microbiota-especially diet and stressful life events. We then examine the interplay between the microbiota and MDD. We examine evidence suggesting that the microbiota is altered in MDD, and we discuss why the microbiota should be considered during MDD treatment. Finally, we look toward the future and examine how the microbiota might become a therapeutic target for MDD. This review is intended to introduce those familiar with the neurological and psychiatric aspects of MDD to the microbiome and its potential role in the disorder. Although research is in its very early days, with much yet to be the understood, the microbiome is offering new avenues for developing potentially novel strategies for managing MDD.

The Influence of Gut Microbiota on the Cardiovascular System Under Conditions of Obesity and Chronic Stress

PURPOSE OF REVIEW

Based on the available data, it can be assumed that microbiota is an integral part of the human body. The most heavily colonized area of the human body is the gut, with bacterial accumulation ranging from 101-103 cells/g in the upper intestine to 1011-1012 cells/g in the colon. However, colonization of the gut is not the same throughout, as it was shown that there are differences between the composition of the microbiota in the intestine lumen and in the proximity of the mucus layer.

RECENT FINDINGS

Gut microbiota gradient can be differentially regulated by factors such as obesity and chronic stress. In particular, a high fat diet influences the gut microbial composition. It was also found that chronic stress may cause the development of obesity and thus change the organization of the intestinal barrier. Recent research has shown the significant effect of intestinal microflora on cardiovascular function. Enhanced absorption of bacterial fragments, such as lipopolysaccharide (LPS), promotes the onset of "metabolic endotoxemia," which could activate toll-like receptors, which mediates an inflammatory response and in severe cases could cause cardiovascular diseases. It is presumed that the intestinal microbiota, and especially its metabolites (LPS and trimethylamine N-oxide (TMAO)), may play an important role in the pathogenesis of arterial hypertension, atherosclerosis, and heart failure. This review focuses on how gut microbiota can change the morphological and functional activity of the cardiovascular system in the course of obesity and in conditions of chronic stress.

The Putative Antidepressant Mechanisms of Probiotic Bacteria: Relevant Genes and Proteins

Probiotic bacteria are widely accepted as therapeutic agents against inflammatory bowel diseases for their immunostimulating effects. In the last decade, more evidence has emerged supporting the positive effects of probiotics on the course of neurodegenerative and psychiatric diseases. This brief review summarizes the data from clinical studies of probiotics possessing antidepressant properties and focuses on the potential genes and proteins underlying these mechanisms. Data from small-sample placebo-controlled pilot studies indicate that certain strains of bacteria can significantly reduce the symptoms of depression, especially in depressed patients. Despite the disparity between studies attempting to pinpoint the bacterial putative genes and proteins accounting for these mechanisms, they ultimately show that bacteria are a potential source of metabiotics—microbial metabolites or structural components. Since the constituents of cells—namely, secreted proteins, peptides and cell wall components—are most likely to be entangled in the gut–brain axis, they can serve as starting point in the search for probiotics with concrete properties.

Anxiolytic effects of a galacto-oligosaccharides prebiotic in healthy females (18-25 years) with corresponding changes in gut bacterial composition

Current research implicates pre- and probiotic supplementation as a potential tool for improving symptomology in physical and mental ailments, which makes it an attractive concept for clinicians and consumers alike. Here we focus on the transitional period of late adolescence and early adulthood during which effective interventions, such as nutritional supplementation to influence the gut microbiota, have the potential to offset health-related costs in later life. We examined multiple indices of mood and well-being in 64 healthy females in a 4-week double blind, placebo controlled galacto-oligosaccharides (GOS) prebiotic supplement intervention and obtained stool samples at baseline and follow-up for gut microbiota sequencing and analyses. We report effects of the GOS intervention on self-reported high trait anxiety, attentional bias, and bacterial abundance, suggesting that dietary supplementation with a GOS prebiotic may improve indices of pre-clinical anxiety. Gut microbiota research has captured the imagination of the scientific and lay community alike, yet we are now at a stage where this early enthusiasm will need to be met with rigorous research in humans. Our work makes an important contribution to this effort by combining a psychobiotic intervention in a human sample with comprehensive behavioural and gut microbiota measures.

Diet, Obesity, and Depression: A Systematic Review

BACKGROUND

Obesity and depression co-occur in a significant proportion of the population. Mechanisms linking the two disorders include the immune and the endocrine system, psychological and social mechanisms. The aim of this systematic review was to ascertain whether weight loss through dietary interventions has the additional effect of ameliorating depressive symptoms in obese patients.

METHODS

We systematically searched three databases (Pubmed, Medline, Embase) for longitudinal clinical trials testing a dietary intervention in people with obesity and depression or symptoms of depression.

RESULTS

Twenty-four longitudinal clinical studies met the eligibility criteria with a total of 3244 included patients. Seventeen studies examined the effects of calorie-restricted diets and eight studies examined dietary supplements (two studies examined both). Only three studies examined people with a diagnosis of both obesity and depression. The majority of studies showed that interventions using a calorie-restricted diet resulted in decreases in depression scores, with effect sizes between ≈0.2 and ≈0.6. The results were less clear for dietary supplements.

CONCLUSIONS

People with obesity and depression appear to be a specific subgroup of depressed patients in which calorie-restricted diets might constitute a promising personalized treatment approach. The reduction of depressive symptoms may be related to immunoendocrine and psychosocial mechanisms.

Probiotics, prebiotics, and synbiotics added to dairy products: Uses and applications to manage type 2 diabetes

Diabetes mellitus type 2 (T2DM) is associated with hyperglycemia, insulin resistance, and gut dysbiosis. Probiotics and prebiotics can ameliorate T2DM through different mechanisms of action, such as reducing oxidative stress, or the inhibition of pro-inflammatory markers, among others. Multiple studies in vitro and in vivo have demonstrated the reduction of hyperglycemia, depressive behaviors, obesity, oxidative stress, and insulin resistance in diabetic patients through the consumption of dairy products, such as yogurt, fermented milk, and cheese, enriched with potential probiotic strains, prebiotic ingredients, and synbiotics (understood as a combination of both). Therefore, this review aims to provide an updated overview about the impact of dairy foods with probiotics, prebiotics, or synbiotics to prevent and manage T2DM, the mechanism of action related to the host health, and the future tendencies for developing new dairy foods. Despite the addition of probiotics, prebiotics, and synbiotics to dairy products could be highly beneficial, more evidence, especially from clinical trials, is needed to develop evidence-based T2DM prevention guidelines.

Obesity and gut microbiome: review of potential role of probiotics

Obesity prevalence has increased worldwide over the years, with pandemic levels being already reached, besides to its huge economic and health impacts. The multifactorial pathogenesis of obesity partly explains the important challenge posed to health policy regarding its clinical treatment, with increasing evidences have shown that obesity and metabolic disturbances are closely linked to variations in gut microbiota (GM) function and composition. Indeed, GM play a key contribution in energy metabolism, with GM modulation being increasingly linked to changes in body weight and body mass index. In such matter, probiotics have been proposed as a promising new therapeutic strategy to treat/prevent obesity. Thus, this review aims to provide an overview on the clinical impact and effectiveness of probiotics in obese individuals.

Effects of therapeutic probiotics on modulation of microRNAs

Probiotics are beneficial bacteria that exist within the human gut, and which are also present in different food products and supplements. They have been investigated for some decades, due to their potential beneficial impact on human health. Probiotics compete with pathogenic microorganisms for adhesion sites within the gut, to antagonize them or to regulate the host immune response resulting in preventive and therapeutic effects. Therefore, dysbiosis, defined as an impairment in the gut microbiota, could play a role in various pathological conditions, such as lactose intolerance, gastrointestinal and urogenital infections, various cancers, cystic fibrosis, allergies, inflammatory bowel disease, and can also be caused by antibiotic side effects. MicroRNAs (miRNAs) are short non-coding RNAs that can regulate gene expression in a post-transcriptional manner. miRNAs are biochemical biomarkers that play an important role in almost all cellular signaling pathways in many healthy and disease states. For the first time, the present review summarizes current evidence suggesting that the beneficial properties of probiotics could be explained based on the pivotal role of miRNAs. Video Abstract.

Effect of probiotic Lactobacillus plantarum Dad-13 powder consumption on the gut microbiota and intestinal health of overweight adults

BACKGROUND

Shifting on lifestyle, diet, and physical activity contributed on increasing number of obese people around the world. Multiple factors influence the development of obesity. Some research suggested that gut microbiota (GM) plays an important role in nutrient absorption and energy regulation of individuals, thus affecting their nutritional status. Report of Indonesia Basic Health Research showed that the prevalence of obesity in every province tended to increase. Although the root cause of obesity is excessive calorie intake compared with expenditure, the differences in gut microbial ecology between healthy and obese humans may affect energy homeostasis. GM affect body weight, especially obesity. Probiotics that are consumed while alive and able to colonize in the intestine are expected to increase the population of good bacteria, especially Bifidobacteria and Lactobacilli, and suppress pathogens such as Enterobacteriaceae and Staphylococcus. The strain of L. plantarum Dad-13 has been demonstrated to survive and colonize in the gastrointestinal tract of healthy Indonesian adults who consume fermented milk containing L. plantarum Dad-13. The consumption of probiotic L. plantarum Dad-13 powder decreased E. coli and non-E. coli coliform bacteria in school-aged children in Indonesia. L. plantarum is a dominant bacterium in the average Indonesian’s GM. For this reason, this bacterium is probably a more suitable probiotic for Indonesians.

AIM

To determine the effect of the consumption of indigenous probiotic Lactobacillus plantarum Dad-13 powder in overweight adults in Yogyakarta (Indonesia).

METHODS

Sixty overweight volunteers with a body mass index (BMI) equal to or greater than 25 consume indigenous probiotic powder L. plantarum Dad-13 (2 × 10⁹ CFU/gram/sachet) for 90 d. The study was a randomized, double-blind, placebo-controlled study. The volunteers filled in a diary on a daily basis, which consisted of questions on study product intake (only during ingestion period), other food intake, number of bowel movements, fecal quality (consistency and color), any medications received, and any symptom of discomfort, such as diarrhea, constipation, vomiting, gassing, sensation of illness, etc. Fecal samples and the subjects’ diaries were collected on the morning of day 10 + 1, which was marked as the end of the baseline period and the start of the ingestion period. During the ingestion period (from day 11 to day 101), several parameters to measure and analyze the results included body weight and height (once a month), the lipid profile, GM analysis using MiSeq, short-chain fatty acid (SCFA) analysis using gas chromatography, and the measurement of fecal pH using a pH meter.

RESULTS

The consumption of indigenous probiotic powder L. plantarum Dad-13 caused the average body weight and BMI of the probiotic group to decrease from 84.54 ± 17.64 kg to 83.14 ± 14.71 kg and 33.10 ± 6.15 kg/m² to 32.57 ± 5.01 kg/m², respectively. No significant reduction of body weight and BMI in the placebo group was observed. An analysis of the microbiota showed that the number of Bacteroidetes, specifically Prevotella, increased significantly, while that of Firmicutes significantly decreased. No significant change in lipid profile in both groups was found. Also, no significant change in SCFAs (e.g., butyrate, propionate, acetic acid) and pH level was found after the consumption of the probiotic.

CONCLUSION

No significant differences in pH before and after ingestion were observed in both the probiotic and placebo groups as well as in the lipid profile of both cholesterol and triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and the LDL/HDL ratio. In addition, no significant changes in the concentration of SCFAs (e.g., acetic acid, propionate, and butyrate) were found after con-sumption. Interestingly, a significant decrease in body weight and BMI (P < 0.05) was determined in the treatment group. An analysis of GM shows that L. plantarum Dad-13 caused the Firmicutes population to decrease and the Bacteroidetes population (especially Prevotella) to increase.

Effect of probiotic Lactobacillus plantarum Dad-13 powder consumption on the gut microbiota and intestinal health of overweight adults

BACKGROUND

Shifting on lifestyle, diet, and physical activity contributed on increasing number of obese people around the world. Multiple factors influence the development of obesity. Some research suggested that gut microbiota (GM) plays an important role in nutrient absorption and energy regulation of individuals, thus affecting their nutritional status. Report of Indonesia Basic Health Research showed that the prevalence of obesity in every province tended to increase. Although the root cause of obesity is excessive calorie intake compared with expenditure, the differences in gut microbial ecology between healthy and obese humans may affect energy homeostasis. GM affect body weight, especially obesity. Probiotics that are consumed while alive and able to colonize in the intestine are expected to increase the population of good bacteria, especially Bifidobacteria and Lactobacilli, and suppress pathogens such as Enterobacteriaceae and Staphylococcus. The strain of L. plantarum Dad-13 has been demonstrated to survive and colonize in the gastrointestinal tract of healthy Indonesian adults who consume fermented milk containing L. plantarum Dad-13. The consumption of probiotic L. plantarum Dad-13 powder decreased E. coli and non-E. coli coliform bacteria in school-aged children in Indonesia. L. plantarum is a dominant bacterium in the average Indonesian's GM. For this reason, this bacterium is probably a more suitable probiotic for Indonesians.

AIM

To determine the effect of the consumption of indigenous probiotic Lactobacillus plantarum Dad-13 powder in overweight adults in Yogyakarta (Indonesia).

METHODS

Sixty overweight volunteers with a body mass index (BMI) equal to or greater than 25 consume indigenous probiotic powder L. plantarum Dad-13 (2 × 10⁹ CFU/gram/sachet) for 90 d. The study was a randomized, double-blind, placebo-controlled study. The volunteers filled in a diary on a daily basis, which consisted of questions on study product intake (only during ingestion period), other food intake, number of bowel movements, fecal quality (consistency and color), any medications received, and any symptom of discomfort, such as diarrhea, constipation, vomiting, gassing, sensation of illness, etc. Fecal samples and the subjects' diaries were collected on the morning of day 10 + 1, which was marked as the end of the baseline period and the start of the ingestion period. During the ingestion period (from day 11 to day 101), several parameters to measure and analyze the results included body weight and height (once a month), the lipid profile, GM analysis using MiSeq, short-chain fatty acid (SCFA) analysis using gas chromatography, and the measurement of fecal pH using a pH meter.

RESULTS

The consumption of indigenous probiotic powder L. plantarum Dad-13 caused the average body weight and BMI of the probiotic group to decrease from 84.54 ± 17.64 kg to 83.14 ± 14.71 kg and 33.10 ± 6.15 kg/m² to 32.57 ± 5.01 kg/m², respectively. No significant reduction of body weight and BMI in the placebo group was observed. An analysis of the microbiota showed that the number of Bacteroidetes, specifically Prevotella, increased significantly, while that of Firmicutes significantly decreased. No significant change in lipid profile in both groups was found. Also, no significant change in SCFAs (e.g., butyrate, propionate, acetic acid) and pH level was found after the consumption of the probiotic.

CONCLUSION

No significant differences in pH before and after ingestion were observed in both the probiotic and placebo groups as well as in the lipid profile of both cholesterol and triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and the LDL/HDL ratio. In addition, no significant changes in the concentration of SCFAs (e.g., acetic acid, propionate, and butyrate) were found after con-sumption. Interestingly, a significant decrease in body weight and BMI (P < 0.05) was determined in the treatment group. An analysis of GM shows that L. plantarum Dad-13 caused the Firmicutes population to decrease and the Bacteroidetes population (especially Prevotella) to increase.

Probiotics have minimal effects on appetite-related hormones in overweight or obese individuals: A systematic review of randomized controlled trials

BACKGROUND & AIMS

Overweight and obese individuals show changes in mechanisms related to appetite due to several factors, including excess fat and gut microbiota imbalance. Probiotics have been presented as a strategy for modulating gut microbiota and regulating these mechanisms. The aim of this systematic review was to assess the effects of probiotics on appetite-related hormones in overweight or obese individuals.

METHODS

A systematic review of randomized controlled trials was performed in nine electronic databases (Pubmed, Scopus, Web of Science, Cochrane Controlled Register of Trials, ProQuest Dissertations and Theses, PsycINFO, WHO International Clinical Trials Registry Platform, ClinicalTrials.gov and Open Grey) and in a manual search of studies until March 20, 2020. The risk of bias of each study was appraised using the RoB 2.0 tool. All research stages were carefully based on PRISMA recommendations.

RESULTS

Twenty-four studies (1587 participants) were included in this systematic review. The outcomes related to appetite assessed in the included studies were: leptin, insulin, adiponectin, resistin, nesfatin-1, adropin, omentin-1, GLP-1, GLP-2 and glucagon. Compared to the control group after supplementation, four studies involving 272 participants reported statistically significant reduction in fasting insulin. On the other hand, one study involving 56 participants reported statistically significant increase in adropin and omentin-1.

CONCLUSIONS

Probiotics have minimal effects on appetite-related hormones in overweight or obese individuals. However, knowledge in this area is progressing and further studies with a low risk of bias may help to clarify the role of probiotics in appetite control.