Effect of Lactobacillus gasseri BNR17 on irritable bowel syndrome: a randomized, double-blind, placebo-controlled, dose-finding trial

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.

Outcome-Specific Efficacy of Different Probiotic Strains and Mixtures in Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis

Irritable bowel syndrome (IBS) is a common gastrointestinal disease. The efficacy of different probiotics in treating IBS remains controversial. This network meta-analysis aimed to compare and rank the outcome-specific efficacy of different probiotic strains or combinations in adults with IBS. We searched the literature up to June 2023. Randomized controlled trials (RCTs) that evaluated the efficacy of probiotics in IBS were included. A frequentist framework was used to perform this study. In total, 9253 participants from 81 RCTs were included in the study. Four probiotic strains and five mixtures were significantly superior to placebo in improving IBS Symptom Severity Scale, among which Lactobacillus acidophilus DDS-1 ranked first (surface under the cumulative ranking, SUCRA, 92.9%). A mixture containing five probiotics (SUCRA, 100%) ranked first in improving the IBS-Quality of life. Bacillus coagulans MTCC 5856 (SUCRA, 96.9%) and Bacillus coagulans Unique IS2 (SUCRA, 92.6%) were among the most effective probiotics for improving abdominal pain. Three probiotic strains and two mixtures were effective in alleviating abdominal bloating. Four probiotic strains and a mixture were significantly superior to placebo in reducing the bowel movement frequency in diarrhea-predominant IBS (IBS-D). Bacillus coagulans MTCC 5856 (SUCRA, 99.6%) and Saccharomyces cerevisiae CNCM I-3856 (SUCRA, 89.7%) were among the most effective probiotics for improving the Bristol stool form scale of IBS-D. Only some probiotics are effective for particular outcomes in IBS patients. This study provided the first ranking of outcome-specific efficacy of different probiotic strains and combinations in IBS. Further studies are needed to confirm these results.

Efficacy and dose response of Lactiplantibacillus plantarum in diarrhea-predominant irritable bowel syndrome

BACKGROUND

Probiotics have shown promise in alleviating symptoms of diarrhea-predominant irritable bowel syndrome (IBS-D); however, the certainty of evidence is low. Well-powered randomized controlled dose-ranging trials are warranted on promising single-strain candidates.

AIM

To investigate the clinical efficacy of Lactiplantibacillus plantarum (L. plantarum) Lpla33 (DSM34428) in adults with IBS-D.

METHODS

This is a randomized, double-blind, placebo-controlled, multi-center, and dose-ranging study. Three hundred and seven adults, 18-70 years of age, with IBS-D, according to Rome IV criteria, were allocated (1:1:1) to receive placebo or L. plantarum Lpla33 at 1 × 109 (1B) or 1 × 1010 (10B) colony-forming units/d over an 8-wk intervention period. The primary outcome was the change in IBS severity scoring system (IBS-SSS) total score after 8 wk, while secondary and exploratory outcomes included abdominal pain severity, IBS related quality of life, stool and microbial profile, and perceived stress.

RESULTS

IBS-SSS was significantly reduced, after 8 wk, in participants receiving L. plantarum 1B (-128.45 ± 83.30; P < 0.001) and L. plantarum 10B (-156.77 ± 99.06; P < 0.001), compared to placebo (-58.82 ± 74.75). Further, a dose-ranging effect was observed, with a greater absolute reduction in the L. plantarum 10B group (P < 0.05). A reduction in sub-scores related to abdominal pain, abdominal distension, bowel habits, and quality of life was observed in both L. plantarum groups compared to placebo (P < 0.001). Further, 62.5% and 88.4% of participants administered L. plantarum 1B and 10B, respectively, were classified as stool consistency responders based on a reduction in diarrheal stool form, as compared to 26.3% in the placebo group (P < 0.001). In contrast, no significant shifts were observed in microbial diversity.

CONCLUSION

L. plantarum Lpla33 (DSM34428) is well tolerated and improves IBS symptom severity with a dose-ranging effect and a corresponding normalization of bowel habits in adults with IBS-D.

Effects of Glutamine, Curcumin and Fish Bioactive Peptides Alone or in Combination on Intestinal Permeability in a Chronic-Restraint Stress Model

Irritable bowel syndrome (IBS), a multifactorial intestinal disorder, is often associated with a disruption in intestinal permeability as well as an increased expression of pro-inflammatory markers. The aim of this study was to first test the impact of treatment with glutamine (Gln), a food supplement containing natural curcumin extracts and polyunsaturated n-3 fatty acids (Cur); bioactive peptides from a fish protein hydrolysate (Ga); and a probiotic mixture containing Bacillus coagulans, Lactobacillus acidophilus, Lactobacillus gasseri and Lactobacillus helveticus. These compounds were tested alone on a stress-based IBS model, the chronic-restraint stress model (CRS). The combination of Gln, Cur and Ga (GCG) was also tested. Eight-week-old C57Bl/6 male mice were exposed to restraint stress for two hours every day for four days and received different compounds every day one week before and during the CRS procedure. Plasma corticosterone levels were measured as a marker of stress, and colonic permeability was evaluated ex vivo in Ussing chambers. Changes in the gene expression of tight junction proteins (occludin, claudin-1 and ZO 1) and inflammatory cytokines (IL1β, TNFα, CXCL1 and IL10) were assessed using RT-qPCR. The CRS model led to an increase in plasma corticosterone and an increase in colonic permeability compared with unstressed animals. No change in plasma corticosterone concentrations was observed in response to CRS with the different treatments (Gln, Cur, Ga or GCG). Stressed animals treated with Gln, Cur and Ga alone and in combination showed a decrease in colonic permeability when compared to the CRS group, while the probiotic mixture resulted in an opposite response. The Ga treatment induced an increase in the expression of the anti-inflammatory cytokine IL-10, and the GCG treatment was able to decrease the expression of CXCL1, suggesting the synergistic effect of the combined mixture. In conclusion, this study demonstrated that a combined administration of glutamine, a food supplement containing curcumin and polyunsaturated n-3 fatty acids, and bioactive peptides from a fish hydrolysate was able to reduce colonic hyperpermeability and reduce the inflammatory marker CXCL1 in a stress-based model of IBS and could be of interest to patients suffering from IBS.

Dachengqi Decoction alleviates intestinal inflammation in ovalbumin-induced asthma by reducing group 2 innate lymphoid cells in a microbiota-dependent manner

Background and aim

Dachengqi Decoction (DCQD) as a classic traditional Chinese medicine has been reported to be effective in treating asthma, but its mechanism remains unknown. This study aimed to reveal the mechanisms of DCQD on the intestinal complications of asthma mediated by group 2 innate lymphoid cells (ILC2) and intestinal microbiota.

Experimental procedure

Ovalbumin (OVA) was used to construct asthmatic murine models. IgE, cytokines (e.g., IL-4, IL-5), fecal water content, colonic length, histopathologic appearance, and gut microbiota were evaluated in asthmatic mice treated with DCQD. Finally, we administered DCQD to antibiotic-treated asthmatic mice to measure the ILC2 in the small intestine and colon.

Results and conclusion

DCQD decreased pulmonary IgE, IL-4, and IL-5 levels in asthmatic mice. The fecal water content, the colonic length weight loss, and the epithelial damage of jejunum, ileum, and colon of asthmatic mice were ameliorated by DCQD. Meanwhile, DCQD greatly improved intestinal dysbiosis by enriching Allobaculum, Romboutsia and Turicibacter in the whole intestine, and Lactobacillus gasseri only in the colon. However, DCQD caused less abundant Faecalibaculum and Lactobacillus vaginalis in the small intestine of asthmatic mice. A higher ILC2 proportion in different gut segments of asthmatic mice was reversed by DCQD. Finally, significant correlations appeared between DCQD-mediated specific bacteria and cytokines (e.g., IL-4, IL-5) or ILC2. These findings indicate that DCQD alleviated the concurrent intestinal inflammation in OVA-induced asthma by decreasing the excessive accumulation of intestinal ILC2 in a microbiota-dependent manner across different gut locations.

Lactobacillus gasseri LA806 Supplementation in Patients with Irritable Bowel Syndrome: A Multicenter Study

The potential benefits of Lactobacillus gasseri LA806 in IBS were previously identified in a comprehensive preclinical research program. The purpose of this multicenter study was to explore in real-life conditions changes in IBS symptoms and quality of life in patients receiving a 4-week supplementation with L. gasseri LA806. Altogether 119 patients meeting Rome IV criteria for IBS were included, of whom 118 received the supplement. The majority of patients (71.8% (95% CI 63.6−79.9%)) manifested a ≥30% decrease in abdominal pain at 4 weeks, the mean abdominal pain score diminishing by 54.2% (from 5.3 ± 2.2 to 2.2 ± 2.4, p < 0.0001). A statistically significant decrease in abdominal pain was seen as early as the first week. A decrease of ≥30% in both abdominal pain score and global IBS symptom score was attained in 61.5% of patients (95% CI 51.7−71.2%). The mean IBS-SSS score fell by 152 ± 112 points (p = 0.001), with symptoms being attenuated in 85% of patients (CGI-I). Supplementation led to a 10-fold decrease in the number of patients reporting severe IBS symptoms. The concomitant intake of antidiarrheals, antispasmodics and analgesics decreased and quality of life scores significantly improved. These preliminary results warrant confirmation by a randomized, placebo-controlled study that this study will allow a better design.

Progress in application of probiotics, prebiotics, and synbiotics in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common functional bowel disorder characterized by recurrent abdominal pain accompanied by changes in defecation frequency and/or stool characteristics. The global incidence of IBS is increasing year by year. Intestinal symptoms caused by IBS (such as constipation, diarrhea, abdominal pain, and abdominal distension) and accompanying changes in general nervous system function can significantly reduce patients' quality of life and work efficiency, and lead to high medical costs. Therefore, finding safe, effective, and economical treatments has become a hot research topic in recent years. Studies have shown that the intestinal flora of patients with IBS is different from that of healthy subjects, and regulating the intestinal flora can treat IBS. The purpose of this review is to summarize the application and recent progress of probiotics, prebiotics, and synbiotics in the treatment of IBS by regulating the intestinal flora.

Anti-Melanogenic and Antioxidant Effects of Cell-Free Supernatant from Lactobacillus gasseri BNR17

In recent years, there has been considerable interest in the use of cell-free supernatant of probiotics culture for nutritional and functional applications. In this study, we investigated the effect of the cell-free supernatant from Lactobacillus gasseri BNR17 (CFS) on anti-melanogenesis and reducing oxidative stress in B16-F10 murine melanoma cells and HaCaT human keratinocytes. Treatment with CFS significantly inhibited the production of extracellular and intracellular melanin without cytotoxicity during melanogenesis induced by the α-MSH in B16-F10 cells. The CFS dramatically reduced tyrosinase activity and the melanogenesis-related gene expression. Further, it showed antioxidative effects in a dose-dependent manner in DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assays and significantly increased the mRNA levels of HO-1 and CAT in HaCaT cells. Furthermore, the CFS increased HO-1 and anti-oxidative-related gene expression during H2O2-induced oxidative stress in HaCaT cells. Together, this study suggests that the CFS reduces hyperpigmentation and inhibits oxidative stress, and thus can be used as a potential skincare product in the future.

Probiotics, Prebiotics, and Synbiotics in the Irritable Bowel Syndrome Treatment: A Review

Irritable bowel syndrome is not a life-threatening disease, yet it significantly affects the quality of life and contributes to economic loss. It is estimated that even up to 45% of the world's population can suffer from the disease. The first attempts to diagnose irritable bowel syndrome were made at the end of the 19th century; however, establishing appropriate diagnostic criteria and treatment methods is still ongoing. To date, little is known about the etiology of irritable bowel syndrome; however, growing attention is drawn to the intestinal microbiota as a factor in the disease development. For this reason, researchers have conducted many studies on therapies that modulate the microbiota, among which probiotics, prebiotics, and synbiotics are widely studied. To date, most studies have examined probiotics; however, there are also several studies demonstrating the efficacy of prebiotics and synbiotics. The aim of this review was to summarize findings on the usefulness of probiotics, prebiotics, and synbiotics in the treatment of irritable bowel syndrome.

Therapeutic, Prophylactic, and Functional Use of Probiotics: A Current Perspective

Probiotics are considered as the twenty-first century panpharmacon due to their competent remedial power to cure from gastrointestinal dysbiosis, systematic metabolic diseases, and genetic impairments up to complicated neurodegenerative disorders. They paved the way for an innovative managing of various severe diseases through palatable food products. The probiotics' role as a "bio-therapy" increased their significance in food and medicine due to many competitive advantages over traditional treatment therapies. Their prophylactic and therapeutic potential has been assessed through hundreds of preclinical and clinical studies. In addition, the food industry employs probiotics as functional and nutraceutical ingredients to enhance the added value of food product in terms of increased health benefits. However, regardless of promising health-boosting effects, the probiotics' efficacy still needs an in-depth understanding of systematic mechanisms and factors supporting the healthy actions.

Probiotic Properties and Antioxidant Activities of Pediococcus pentosaceus SC28 and Levilactobacillus brevis KU15151 in Fermented Black Gamju

Black gamju is Korean traditional beverage fermented with molds. The aim of this study was to assess the probiotic properties and antioxidant activities of novel Pediococcus pentosaceus SC28 and Levilactobacillus brevis KU15151 to develop black gamju with bioactive properties for health. Tolerance against artificial gastric juice and bile salts, adhesion ability on HT-29 cells of strains, and antibiotics susceptibility were evaluated as probiotics, and various enzyme productions were detected. The 2,2-diphenyl-1-picrylhydrazyl assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate, and β-carotene bleaching assay were used for antioxidant activity of samples. The tolerance of both strains to artificial gastric juice and bile salts (Oxgall) was more than 90%. Additionally, both strains did not produce β-glucuronidase and were resistant to gentamicin, kanamycin, streptomycin, and ciprofloxacin. After fermentation of black gamju with each strain, the number of viable lactic acid bacteria increased to 8.25-8.95 log colony forming unit/mL, but the pH value of fermented samples decreased more (to pH 3.33-3.41) than that of control (pH 4.37). L. brevis KU15151 showed higher adhesion activity to HT-29 cells and antioxidant effects than P. pentosaceus SC28 in three antioxidant assays.

Efficacy and Safety of Probiotics in Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis

Background

Irritable bowel syndrome is a functional gastrointestinal disease. Evidence has suggested that probiotics may benefit IBS symptoms. However, clinical trials remain conflicting.

Aims

To implement a systematic review and meta-analysis of clinical trials regarding the efficacy and safety of probiotics for IBS patients.

Methods

We searched for relevant trials in Medline(1966 to Jan 2019), Embase(1974 to Jan 2019), the Cochrane Central Register of Controlled Trials(up to Jan 2019), the ClinicalTrials.gov trials register(up to Jan 2019), and Chinese Biomedical Literature Database(1978 to Jan 2019). Risk ratio (RR) and a 95% confidence interval (CI) were calculated for dichotomous outcomes. Standardized mean difference (SMD) and 95% CI were calculated for continuous outcomes.

Results

A total of 59 studies, including 6,761 patients, were obtained. The RR of the improvement or response with probiotics versus placebo was 1.52 (95% CI 1.32-1.76), with significant heterogeneity (I² = 71%, P < 0.001). The SMD of Probiotics in improving global IBS symptoms vs. Placebo was -1.8(95% CI -0.30 to -0.06), with significant heterogeneity (I² = 65%, P < 0.001). It was impossible to draw a determinate conclusion. However, there were differences in subgroup analyses of probiotics type, dose, treatment duration, and geographic position. Probiotics seem to be safe by the analysis of adverse events(RR = 1.07; 95% CI 0.92-1.24; I² = 0, P = 0.83).

Conclusion

Probiotics are effective and safe for IBS patients. Single probiotics with a higher dose (daily dose of probiotics ≥10¹⁰) and shorter duration (< 8 weeks) seem to be a better choice, but it still needs more trials to prove it.

Effect of Cell Concentration on the Persistence in the Human Intestine of Four Probiotic Strains Administered through a Multispecies Formulation

Studies devoted to evaluating the outcome of different doses of probiotics are very limited, especially for multistrain formulations. In this context, we performed an intervention study that aimed to compare the effect of the administration of two doses (7 billion and 70 billion bacterial cells) of a multistrain probiotic formulation on the persistence of the four probiotic strains that were present in the product in the fecal samples collected from healthy subjects. The overall persistence of the probiotic strains was significantly higher for the 70 billion formulation than for the 7 billion formulation. Furthermore, probiotic strains were detected earlier and for longer for the 70 billion formulation compared to those for the 7 billion formulation. All probiotic strains were recovered alive from the 70 billion preparation, whereas recovery was not possible in a few fecal samples upon administration of the 7 billion preparation. In addition, the overall number of viable probiotic cells recovered on day 14 (i.e., the last day of consumption) was significantly higher for the 70 billion formulation than that for the 7 billion formulation. Finally, we found that the viability of the probiotic cells was stable over the course of the trial independent of volunteers' handling, demonstrating good manufacturing of the product. In conclusion, this study demonstrated that strains belonging to different taxa may coexist in the human gastrointestinal tract upon ingestion of a multispecies probiotic formulation. Moreover, this study suggests that higher doses of bacterial cells in probiotic formulations may permit a higher, earlier, and longer recovery of the probiotics in the feces of healthy adults.