Contemporary meta-analysis of short-term probiotic consumption on gastrointestinal transit

Photothermally Active Quantum Dots in Cancer Imaging and Therapeutics: Nanotheranostics Perspective

Cancer is becoming a global threat, as the cancerous cells manipulate themselves frequently, resulting in mutants and more abnormalities. Early-stage and real-time detection of cancer biomarkers can provide insight into designing cost-effective diagnostic and therapeutic modalities. Nanoparticle and quantum dot (QD)-based approaches have been recognized as clinically relevant methods to detect disease biomarkers at the molecular level. Over decades, as an emergent noninvasive approach, photothermal therapy has evolved to eradicate cancer. Moreover, various structures, viz., nanoparticles, clusters, quantum dots, etc., have been tested as bioimaging and photothermal agents to identify tumor cells selectively. Among them, QDs have been recognized as versatile probes. They have attracted enormous attention for imaging and therapeutic applications due to their unique colloidal stability, optical and physicochemical properties, biocompatibility, easy surface conjugation, scalable production, etc. However, a few critical concerns of QDs, viz., precise engineering for molecular imaging and sensing, selective interaction with the biological system, and their associated toxicity, restrict their potential intervention in curing cancer and are yet to be explored. According to the U.S. Food and Drug Administration (FDA), there is no specific regulation for the approval of nanomedicines. Therefore, these nanomedicines undergo the traditional drug, biological, and device approval process. However, the market survey of QDs is increasing, and their prospects in translational nanomedicine are very promising. From this perspective, we discuss the importance of QDs for imaging, sensing, and therapeutic usage pertinent to cancer, especially in its early stages. Moreover, we also discuss the rapidly growing translational view of QDs. The long-term safety studies and cellular interaction of these QDs could enhance their visibility and bring photothermally active QDs to the clinical stage and concurrently to FDA approval.

The Efficacy of Probiotics Supplementation on the Quality of Life of Patients with Gastrointestinal Disease: A Systematic Review of Clinical Studies

Patients with gastrointestinal (GI) disorders might benefit from probiotic supplementation to resolve their bowel symptoms and enhance their quality of life (QoL). This systematic review aimed to evaluate the effects of oral probiotic supplementation on improving QoL. Relevant studies were systematically searched in online databases, including PubMed, Scopus, Embase, ProQuest, and Google Scholar up to September 2022 using relevant keywords. Studies that were conducted on GI patients and presented QoL outcomes were included. The Revised Cochrane Risk of Bias 2 tool and the Risk Of Bias In Non-randomized Studies of Intervention tool were used to assess the risk of bias. Of the 4,555 results found in the systematic search of databases, only 36 studies were eligible for evaluation. According to this systematic review, 24 studies reported improvements, whereas 12 studies reported no improvements on QoL in GI patients supplemented with probiotics. We found that probiotics may improve the QoL of patients with GI diseases and related metabolic complications. Therefore, probiotics can be a useful supportive treatment strategy in these patients.

Efficacy in bowel movement and change of gut microbiota on adult functional constipation patients treated with probiotics-containing products: a systematic review and meta-analysis

OBJECTIVES

This study aimed to pool the efficacy in bowel movement and explore the change of gut microbiota on adult functional constipated patients after probiotics-containing products treatment.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Cochrane Library for published studies and ClinicalTrials.gov for 'grey' researches were independently investigated for randomised controlled trials up to November 2022.

ELIGIBILITY CRITERIA, DATA EXTRACTION AND SYNTHESIS

The intervention was probiotics-containing product, either probiotics or synbiotics, while the control was placebo. The risk of bias was conducted. The efficacy in bowel movement was indicated by stool frequency, stool consistency and Patient Assessment of Constipation Symptom (PAC-SYM), while the change of gut microbiota was reviewed through α diversity, β diversity, change/difference in relative abundance and so on. The subgroup analysis, sensitivity analysis and random-effect meta-regression were conducted to explore the heterogeneity. The Grading of Recommendations Assessment Development and Evaluation was conducted to grade the quality of evidence.

RESULTS

17 studies, comprising 1256 participants, were included with perfect agreements between two researchers (kappa statistic=0.797). Compared with placebo, probiotics-containing products significantly increased the stool frequency (weighted mean difference, WMD 0.93, 95% CI 0.47 to 1.40, p=0.000, I²=84.5%, 'low'), improved the stool consistency (WMD 0.38, 95% CI 0.05 to 0.70, p=0.023, I²=81.6%, 'very low') and reduced the PAC-SYM (WMD -0.28, 95% CI: -0.45 to -0.11, p=0.001, I²=55.7%, 'very low'). In subgroup analysis, synbiotics was superior to probiotics to increase stool frequency. Probiotics-containing products might not affect α or β diversity, but would increase the relative abundance of specific strain.

CONCLUSIONS

Probiotics-containing products, significantly increased stool frequency, improved stool consistency, and alleviated functional constipation symptoms. They increased the relative abundance of specific strain. More high-quality head-to-head randomised controlled trials are needed.

Probiotics and synbiotics in chronic constipation in adults: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND & AIMS

Probiotics and synbiotics have been increasingly investigated for the management of chronic constipation. We aimed to investigate the effect of probiotics and synbiotics on stool output, gut transit time, symptoms and quality of life in adults with chronic constipation via a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

Studies were identified using electronic databases, backward citation and hand-searching abstracts. The search date was 10 July 2022. RCTs reporting administration of probiotics or synbiotics in adults with chronic constipation were included. Risk of bias (RoB) was assessed with the Cochrane RoB 2.0 tool. Meta-analysis was conducted separately for probiotics and synbiotics. Results were synthesized using risk ratios (RRs), mean differences or standardized mean differences (SMDs) and 95% confidence intervals (CIs) using a random-effects model.

RESULTS

Thirty RCTs investigating probiotics and four RCTs investigating synbiotics were included. Overall, 369/647 (57%) responded to probiotic treatment and 252/567 (44%) to control (RR 1.28, 95% CI 1.07, 1.52, p = 0.007). Probiotics increased stool frequency (SMD 0.71, 95% CI 0.37, 1.04, p < 0.00001), with Bifidobacterium lactis having a significant effect, but not mixtures of probiotics, Bacillus coagulans Unique IS2 or Lactobacillus casei Shirota. Probiotics did not impact stool consistency (SMD 0.26, 95% CI -0.03, 0.54, p = 0.08). Probiotics improved integrative symptom scores compared to control (SMD -0.46, 95% CI -0.89, -0.04). Synbiotics did not impact stool output or integrative symptom scores compared to control.

CONCLUSIONS

Certain probiotics may improve response to treatment, stool frequency and integrative constipation symptoms, providing cautious optimism for their use as a dietary management option. There is currently insufficient evidence to recommend synbiotics in the management of chronic constipation. Caution is needed when interpreting these results due to high heterogeneity and risk of bias amongst the studies.

Bacillus clausii for Gastrointestinal Disorders: A Narrative Literature Review

The gut microbiota is intrinsically linked to human health; disturbances in microbial homeostasis are implicated in both intestinal and extraintestinal disorders. Probiotics are "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host," and many commercial preparations comprising a diverse range of species are available. While probiotics have been much researched, better understanding of the probiotic effects and applications of species such as Bacillus clausii is warranted. In this narrative literature review, we review the characteristics and mechanisms of action supporting B. clausii as a probiotic and discuss the evidence from clinical studies evaluating B. clausii probiotics for the management of a variety of gastrointestinal disorders and symptoms in children and adults. Finally, we highlight the challenges of future research and the need for more robust and diverse clinical evidence to guide physicians in the clinical application of probiotics for gastrointestinal disorders and other conditions.

The effect of probiotics on functional constipation in adults: A randomized, double-blind controlled trial

BACKGROUND

Two formulations were developed in the form of an oral sachet containing probiotics, and their efficacy and safety were evaluated in adults with functional constipation.

METHODS

One formulation with Lactobacillus acidophilus, Bifidobacterium bifidum and Lactobacillus rhamnosus (3 billion Colony Forming Units - CFU); and another with Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus rhamnosus, Lactobacillus paracasei, Bifidobacterium longum, Bifidobacterium lactis, Lactobacillus casei, Bifidobacterium animallis (8 billion CFU). The participants were randomized in a 3-arm parallel study and one oral sachet was auto-administered once a day for 30 days.

RESULTS

Primary outcomes were improvement in increasing the frequency of weekly bowel movements and improvement in stool quality. Secondary outcomes were number of adverse events. In the first week one observed an increase in stool frequency and in the quality of stools, showing an improvement in constipation. No statistically significant differences were observed between the three treatment groups in relation to these outcomes (P ≥ .05). Only one adverse event was observed in a patient of group 2, related to abdominal pain.

CONCLUSION

The two probiotic cocktails were effective in improving the symptoms of functional constipation, by increasing both the weekly frequency of evacuation and stool quality, and were deemed safe. Clinicaltrials.gov number: NCT04437147.

Effects of Lactobacillus plantarum P9 Probiotics on Defecation and Quality of Life of Individuals with Chronic Constipation: Protocol for a Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Background

Although probiotics have been shown to improve constipation-related symptoms, a clear consensus on the use of probiotics as a constipation-relieving agent has not been reached, which is attributed to the limited available evidence and inconsistent protocols used in existing studies.

Method

A randomized, double-blind, placebo-controlled clinical trial is designed to study the efficiency and possible mechanism of action of probiotics for chronic constipation, in which 200 eligible volunteers with chronic constipation will be randomly assigned to a probiotic group (oral Lactobacillus plantarum P9 probiotic powder, 100 billion colony-forming units (CFUs)/day) or a placebo group. Volunteers, treatment distributors, data collectors, and data analysts will be blinded. The primary outcome is the weekly mean frequency of complete spontaneous bowel movements (CSBMs), and secondary outcomes include weekly mean frequency of CSBMs ≥3, weekly mean frequency of spontaneous bowel movements (SBMs), weekly mean stool appearance score, weekly mean difficulty of passing stool score, weekly percentage of volunteers who use auxiliary measures to assist with defecation (WPUAMA), quality-of-life (QOL) score, emotional status score, gut microbiome, and faecal metabolome. Each outcome measure will be assessed at the time points of preadministration (day 0), administration (day 14 and/or 28), and postadministration (day 42) to identify inter- and intragroup differences. Adverse events will be recorded to evaluate the safety of L. plantarum P9. Discussion. The protocol will provide methodological guidance for other similar studies, avoiding methodological bias and ultimately facilitating the formulation of consensus on the use of probiotics as a constipation-relieving agent. In addition, the results are more comprehensive than those of existing studies and may objectively and scientifically reflect the effectiveness of L. plantarum P9 on constipation. If the expected study findings are obtained, L. plantarum P9, taken as a probiotic, may become a complementary choice for chronically constipated patients. This trial is registered with Chinese Clinical Trial Registry (ChiCTR) (no. ChiCTR2000038396) registered on November 22, 2020, https://www.chictr.org.cn/showproj.aspx?proj=54024.

Microbiota in health and diseases

The role of microbiota in health and diseases is being highlighted by numerous studies since its discovery. Depending on the localized regions, microbiota can be classified into gut, oral, respiratory, and skin microbiota. The microbial communities are in symbiosis with the host, contributing to homeostasis and regulating immune function. However, microbiota dysbiosis can lead to dysregulation of bodily functions and diseases including cardiovascular diseases (CVDs), cancers, respiratory diseases, etc. In this review, we discuss the current knowledge of how microbiota links to host health or pathogenesis. We first summarize the research of microbiota in healthy conditions, including the gut-brain axis, colonization resistance and immune modulation. Then, we highlight the pathogenesis of microbiota dysbiosis in disease development and progression, primarily associated with dysregulation of community composition, modulation of host immune response, and induction of chronic inflammation. Finally, we introduce the clinical approaches that utilize microbiota for disease treatment, such as microbiota modulation and fecal microbial transplantation.

A randomised, double-blind, placebo-controlled trial of Bifidobacterium bifidum CCFM16 for manipulation of the gut microbiota and relief from chronic constipation

A variety of opinions exist on the potential of probiotics to provide relief from chronic constipation with much focus being placed on their mechanism of action and causes of heterogeneity in the results of different studies. We aimed to determine the efficacy and safety of ingesting Bifidobacterium bifidum (B. bifidum) CCFM16 for 28 days to relieve constipation and to understand the mechanism of action. Using Rome IV criterion, 53 and 50 participants diagnosed with chronic constipation were included in the probiotic group and placebo group, respectively. Spontaneous bowel movements (SBMs) per week, stool consistency (Bristol Stool Form Scale [BSFS]), the proportion of SBM responders, patient assessment of constipation symptoms (PAC-SYM), and quality of life (PAC-QoL) were evaluated. The gut microbiota, short-chain fatty acids (SCFAs) and other indicators were also assessed. B. bifidum CCFM16 treatment improved the stool consistency and increased the proportion of SBM responders, but the differences in PAC-SYM and PAC-QoL were statistically insignificant between the groups. Analysis of the SCFAs and microbiome revealed that CCFM16 significantly increased the acetic acid and butyric acid concentrations and enhanced the Firmicutes/Bacteroidetes ratio. Levels of Clostridia were particularly increased and were associated with the increase in butyric acid. In addition, we found the other side of Clostridia; several taxa in the order Clostridiales were observed to prevent CCFM16 from proper functioning in the pre-treatment microbiome. In conclusion, CCFM16 can potentially and efficaciously relieve chronic constipation in Chinese adults by regulating the gut microbiota and SCFA metabolism. The two sides of Clostridia illustrate its importance in microbial therapy for constipation.

One Giant Leap from Mouse to Man: The Microbiota-Gut-Brain Axis in Mood Disorders and Translational Challenges Moving towards Human Clinical Trials

The microbiota–gut–brain axis is a bidirectional communication pathway that enables the gut microbiota to communicate with the brain through direct and indirect signaling pathways to influence brain physiology, function, and even behavior. Research has shown that probiotics can improve several aspects of health by changing the environment within the gut, and several lines of evidence now indicate a beneficial effect of probiotics on mental and brain health. Such evidence has prompted the arrival of a new term to the world of biotics research: psychobiotics, defined as any exogenous influence whose effect on mental health is bacterially mediated. Several taxonomic changes in the gut microbiota have been reported in neurodevelopmental disorders, mood disorders such as anxiety and depression, and neurodegenerative disorders such as Alzheimer’s disease. While clinical evidence supporting the role of the gut microbiota in mental and brain health, and indeed demonstrating the beneficial effects of probiotics is rapidly accumulating, most of the evidence to date has emerged from preclinical studies employing different animal models. The purpose of this review is to focus on the role of probiotics and the microbiota–gut–brain axis in relation to mood disorders and to review the current translational challenges from preclinical to clinical research.

Gut microbiota: A new target for T2DM prevention and treatment

Type 2 diabetes mellitus (T2DM), one of the fastest growing metabolic diseases, has been characterized by metabolic disorders including hyperglycemia, hyperlipidemia and insulin resistance (IR). In recent years, T2DM has become the fastest growing metabolic disease in the world. Studies have indicated that patients with T2DM are often associated with intestinal flora disorders and dysfunction involving multiple organs. Metabolites of the intestinal flora, such as bile acids (BAs), short-chain fatty acids (SCFAs) and amino acids (AAs)may influence to some extent the decreased insulin sensitivity associated with T2DM dysfunction and regulate metabolic as well as immune homeostasis. In this paper, we review the changes in the gut flora in T2DM and the mechanisms by which the gut microbiota modulates metabolites affecting T2DM, which may provide a basis for the early identification of T2DM-susceptible individuals and guide targeted interventions. Finally, we also highlight gut microecological therapeutic strategies focused on shaping the gut flora to inform the improvement of T2DM progression.

Effects of Bifidobacterium animalis subspecies lactis supplementation on gastrointestinal symptoms: systematic review with meta-analysis

CONTEXT

The effects of probiotics on gastrointestinal (GI) symptoms have been increasingly investigated, particularly that of Bifidobacterium animalis. Clinical trials so far have shown differing evidence regarding these effects in healthy adults.

OBJECTIVE

To synthesize the published evidence on the effects of B. animalis subspecies lactis on GI symptoms (GIS) in healthy adults.

DATA SOURCE

A search of the Medline, Embase, Lilacs, Scopus, Web of Science, ProQuest, and Google Scholar databases was conducted for reports on randomized controlled trials published up to October 2021.

DATA EXTRACTION

Population characteristics and data on colonic transit time (CTT), stool consistency, defecation frequency, abdominal pain, bloating, flatulence, volunteer compliance, and adverse events were extracted. A random-effects model was used to estimate the effect of probiotic treatment on these variables.

DATA SYNTHESIS

In total, 1551 studies were identified, of which 14 were included in the qualitative synthesis and 13 in the meta-analysis. Overall, probiotic supplementation increased defecation frequency (standardized mean difference [SMD], 0.26; 95%CI, 0.13-0.39). Subgroup analysis revealed a decrease in CTT (SMD, -0.34; 95%CI, -0.62 to -0.07) in short-term treatment (≤14 d) and an improvement in stool consistency (SMD, 0.76; 95%CI, 0.44-1.08) in individuals without GIS. No improvement in abdominal pain and bloating was found.

CONCLUSIONS

B. animalis subspecies lactis supplementation may increase defecation frequency and, in short-term treatment, may reduce CTT in healthy adults and improve stool consistency in individuals without GIS. More high-quality randomized controlled trials are needed to develop a clinical protocol for the use of this strain to improve these symptoms.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020154060.

Improvement in Lactose Tolerance in Hypolactasic Subjects Consuming Ice Creams with High or Low Concentrations of Bifidobacterium bifidum 900791

Although Bifidobacterium bifidum expresses lactase activity, no clinical trials have determined its impact on lactose-intolerant subjects. This study evaluated whether acute and chronic ingestion of ice creams containing B. bifidum 900791 at high (10⁷ CFU/g) or low (10⁵ CFU/g) concentrations improved lactose tolerance in hypolactasic subjects. Fifty subjects were selected based on a positive lactose (20 g) hydrogen breath test (HBT0) and the presence of digestive symptoms. The recruited subjects were required to perform breath tests after the acute ingestion of: (1) ice cream containing 20 g of lactose without a probiotic (HBT1); (2) the same ice cream, accompanied by a lactase tablet (HBT2); (3) the same ice cream containing the low or high dose of probiotic (HBT3-LD and HBT3-HD); and (4) after the chronic consumption of the ice cream without (placebo) or with the low concentration of probiotic for 1 month (HBT4). Significant decreases in H₂ excretion during HBT2 and HBT3-HD as well as digestive symptoms during HBT2, HBT3-HD and HBT3-LD were observed compared to HBT0 and HBT1, while the orocecal transit time increased. Chronic consumption of the probiotic ice cream did not enhance lactose tolerance compared to the placebo. These results suggest that the acute ingestion of ice cream containing high or low concentrations of B. bifidum 900791 improves lactose tolerance in hypolactasic subjects.

Chronic constipation in adults: Contemporary perspectives and clinical challenges. 2: Conservative, behavioural, medical and surgical treatment

BACKGROUND

Chronic constipation is a prevalent disorder that affects quality of life of patients and consumes resources in healthcare systems worldwide. In clinical practice, it is still considered a challenge as clinicians frequently are unsure as to which treatments to use and when. Over a decade ago, a Neurogastroenterology and Motility journal supplement devoted to the investigation and management of constipation was published (Neurogastroenterol Motil 2009;21(Suppl 2):1). In October 2018, the 3rd London Masterclass, entitled "Contemporary management of constipation" was held. The faculty members of this symposium were invited to write two reviews to present a collective synthesis of talks presented and discussions held during this meeting. The first review addresses epidemiology, diagnosis, clinical associations, pathophysiology, and investigation.

PURPOSE

The present is the second of these reviews, providing contemporary perspectives and clinical challenges regarding behavioral, conservative, medical, and surgical treatments for patients presenting with constipation. It includes a management algorithm to guide clinical practice.

The effect of probiotics on functional constipation in adults: Double-blind, randomized, placebo-controlled study

BACKGROUND

: Evacuation disorders are common in industrialized countries, affecting an average of 15% to 20% of the healthy adult population. Probiotic therapy can reduce functional constipation and increase both the number of weekly bowel movements and quality of stools. Based on the hypothesis that a combination of more strains may provide better results for constipation and facilitate adherence to treatment, this study will evaluate the efficacy and safety of a combination of different strains of Lactobacillus sp. and Bifidobacterium sp. in functional constipation.

METHODS

: A single-centre trial of adults aged 20 to 80 years with intestinal constipation will be conducted at a Gastroenterology Clinic in Sorocaba, State of São Paulo, Brazil. Participants will be allocated into 3 groups receiving: 1. mixture of 3 probiotics: [Lactobacillus acidophilus, Bifidobacterium bifidum, and Lactobacillus rhamnosus (3 × 10⁹ CFU)]; 2. mixture of 8 probiotics [Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus rhamnosus, Lactobacillus paracasei, Bifidobacterium longum, Bifidobacterium lactis, Lactobacillus defensis, Bifidobacterium animallis (8 × 10⁹ CFU)]; or 3. placebo, for 4 weeks. The outcomes of interest will be change in frequency of weekly bowel movements, change in stool quality according to the 4–6 Bristol scale, number of volunteer withdrawal, number of adverse events and number of serious adverse effect.

DISCUSSION:

The probiotic products are expected to induce beneficial changes in the intestinal microbiota, thereby increasing intestinal frequency to over 3 times a week and improving stool quality. The results can guide patients and healthcare practitioners and help in decision-making in the treatment of functional constipation.

TRIAL REGISTRATION AND REGISTRY NAME:

ClinicalTrials.gov Identifier: NCT04437147: The Effect of Probiotics on Functional Constipation in Adults: Study protocol for Double blind, Randomized, Placebo controlled Study

PROTOCOL VERSION:

Version 01 August 30, 2020.

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

Background

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

Methods

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

Results

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

Conclusion

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

Effect of multispecies probiotic on gut microbiota composition in individuals with intestinal constipation: A double-blind, placebo-controlled randomized trial

OBJECTIVE

The aim of this study was to evaluate the effect of a multispecies probiotic on gut microbiota composition and constipation symptoms.

METHODS

A randomized, double-blind, placebo-controlled clinical trial was conducted with 35 individuals with constipation for 30 days. The individuals were randomized into two groups: the control capsule (CC) and the probiotic capsule (PC) groups. Constipation symptoms were evaluated by the ROME IV criteria and by evacuation diaries. Fecal microbiota was analyzed by 16 S rRNA gene sequencing.

RESULTS

The majority of participants were women (85.7%). There was a significant reduction in the percent of participants who had incomplete defecation (P = 0.034), blockage sensation (P = 0.025), and rarely present liquid stools without the aid of laxatives (P = 0.046) only within the PC group (but no significant difference between groups). There was a significant increase in the relative abundance percentage of Blautia faecis and Ruminococcus torques in the CC group (P = 0.003 and P = 0.011, respectively), although there was no significant change in the PC group (P = 0.794 and P = 0.958, respectively), with a significant difference between groups (P = 0.029 and P 0.013, respectively), suggesting that probiotic treatment prevented the increase of percent relative abundance of these two species.

CONCLUSION

These results suggest that multispecies probiotics in capsule form may modulate gut microbiota by reducing the bacteria that are commonly increased in patients with constipation, contributing to the balance of microbiota and, consequently, to the well-being of the individual. Future studies with larger numbers of patients are required.

Nutraceuticals as modulators of gut microbiota: Role in therapy

As our knowledge of the various roles of the gut microbiota in the maintenance of homeostasis grows and as we learn how a disrupted microbiota may contribute to disease, therapeutic strategies that target our microbial fellow-travellers become ever more attractive. Most appealing are those interventions that seek to modify or supplement our diet through the addition of nutraceuticals. We now know that our diet, whether in the short or long term, is a major modifier of microbiota composition and function. Of the various nutraceuticals, two categories, prebiotics and probiotics, have received the greatest attention in basic research and product development. While our understanding of the impacts of prebiotics and probiotics on the indigenous microbiota and host biology have been described in great detail in vitro and in animal models, the clinical literature leaves much to be desired. While many claims have been made, few are supported by high quality clinical trials. LINKED ARTICLES: This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc.

Efficacy of probiotics on cognition, and biomarkers of inflammation and oxidative stress in adults with Alzheimer's disease or mild cognitive impairment - a meta-analysis of randomized controlled trials

Probiotics are live microbes that confer health benefits to the host. Preliminary animal evidence supports the potential role of probiotics in ameliorating cognitive health, however, findings from clinical trials in Alzheimer’s disease (AD) or mild cognitive impairment (MCI) subjects are controversial. Thus, a meta-analysis is needed to clarify the efficacy of probiotics on cognition in AD or MCI patients. EMBASE, PubMed, Web of Science and Cochrane library were systematically searched and manually screened for relevant published randomized controlled trials (RCTs). Among the 890 citations identified, 5 studies involving 297 subjects met eligibility. There was a significant improvement in cognition (SMD = 0.37; 95% CI, 0.14, 0.61; P = 0.002; I² = 24%), while a significant reduction in malondialdehyde (SMD = −0.60; 95% CI, −0.91, −0.28; P = 0.000; I² = 0.0%) and high-sensitivity C-reactive protein (SMD = −0.57; 95% CI, −0.95, −0.20; P = 0.003; I² = 0.0%) post-intervention levels between the probiotics and control group. This meta-analysis indicated that probiotics improved cognitive performance in AD or MCI patients, possibly through decreasing levels of inflammatory and oxidative biomarkers. However, current evidence is insufficient, and more reliable evidence from large-scale, long-period, RCT is needed.

Recent advances in modulating the microbiome

We are in the midst of “the microbiome revolution”—not a day goes by without some new revelation on the potential role of the gut microbiome in some disease or disorder. From an ever-increasing recognition of the many roles of the gut microbiome in health and disease comes the expectation that its modulation could treat or prevent these very same diseases. A variety of interventions could, at least in theory, be employed to alter the composition or functional capacity of the microbiome, ranging from diet to fecal microbiota transplantation (FMT). For some, such as antibiotics, prebiotics, and probiotics, an extensive, albeit far from consistent, literature already exists; for others, such as other dietary supplements and FMT, high-quality clinical studies are still relatively few in number. Not surprisingly, researchers have turned to the microbiome itself as a source for new entities that could be used therapeutically to manipulate the microbiome; for example, some probiotic strains currently in use were sourced from the gastrointestinal tract of healthy humans. From all of the extant studies of interventions targeted at the gut microbiome, a number of important themes have emerged. First, with relatively few exceptions, we are still a long way from a precise definition of the role of the gut microbiome in many of the diseases where a disturbed microbiome has been described—association does not prove causation. Second, while animal models can provide fascinating insights into microbiota–host interactions, they rarely recapitulate the complete human phenotype. Third, studies of several interventions have been difficult to interpret because of variations in study population, test product, and outcome measures, not to mention limitations in study design. The goal of microbiome modulation is a laudable one, but we need to define our targets, refine our interventions, and agree on outcomes.

Meta-analysis of randomized controlled trials of the effects of probiotics on functional constipation in adults

BACKGROUND & AIMS

Clinical trials have reported controversial results regarding the effectiveness of probiotics in alleviating functional constipation in adults. We reviewed relevant randomized controlled trials to elucidate the effectiveness of probiotics on constipation symptoms in adults with functional constipation.

METHODS

We searched Medline, the Cochrane Library, Web of Science, and Google Scholar for relevant articles published up to April 2019. The primary outcomes of interest were stool frequency, gut transit time (GTT), stool consistency, and bloating. Two authors independently performed the study selection, risk-of-bias assessment, and data extraction. The outcome data were extracted from each included study and synthesized using weighted mean differences (WMDs) or standardized mean differences (SMDs). Pooled data synthesis was performed using a random-effects model.

RESULTS

In total, 2327 relevant studies were identified, 15 of which were found to be eligible randomized controlled trials and were included in the meta-analysis. Pooling of the extracted data demonstrated that probiotic consumption significantly reduced the whole GTT by 13.75 h [95% confidence interval (CI): -21.93 to -5.56 h] and increased the stool frequency by 0.98 (95% CI: 0.36 to 1.60) bowel movements per week. This increase was significant with the consumption of multispecies probiotics [at least two bacteria; WMD: 1.22 (95% CI: 0.50 to 1.94) bowel movements per week] but not with the consumption of Bifidobacterium lactis [WMD: 1.34 (95% CI: -0.27 to 2.94) bowel movements per week] or B. longum [WMD: -0.02 (95% CI: -0.56 to 0.53) bowel movements per week] alone. Multispecies probiotics (WMD: 1.37; 95% CI: 0.72 to 2.01), but not single-species probiotics (WMD: 1.18; 95% CI: -0.59 to 2.96), improved stool consistency (WMD: 1.30; 95% CI: 0.22 to 2.38). Similarly, multispecies probiotics (at least two bacteria; WMD: -0.49; 95% CI: -0.85 to -0.13), but not single-species probiotics (WMD: -0.24; 95% CI: -0.55 to 0.07), significantly decreased bloating. Performance bias were high, whereas detection bias was unclear because of inadequate reporting.

CONCLUSION

Consumption of probiotics, in particular, multispecies probiotics, may substantially reduce the GTT, increase the stool frequency, and improve the stool consistency. Thus, probiotics can be regarded as safe and natural agents for alleviation of functional constipation in adults.

Effects of Probiotic Use on Quality of Life and Physical Activity in Constipated Female University Students: A Randomized, Double-Blind Placebo-Controlled Study

Objectives: To evaluate the effect of a probiotic supplement containing two genera and five species of bacteria versus placebo on the quality of life (QoL) in female university students with intestinal constipation (IC). Design: A randomized, double-blind placebo-controlled study was conducted on female university students in a single study center. Settings/Location: Two phases of interventions were carried out, the pilot and main study. All participants were female students of Federal University of Mato Grosso, Brazil. Subjects: Female students whose ages ranged from 20 to 40 years and self-reported to be suffering from IC based on a questionnaire containing Rome III criteria were included. Interventions: Interventions occurred during a period of 30 days in the pilot phase (n = 32) and 15 days in the main study phase (n = 63). The subjects were numbered and randomly divided into experimental probiotic and placebo control groups. Therefore, neither the participants nor the researchers were aware of the allocations of the treatment groups. Outcome measures: The sociodemographic, Rome III, Patient Assessment of Constipation Quality of Life (PAC-QoL) and International Physical Activity questionnaires, and anthropometric measures were utilized. The relative risk (RR) treatment effect, absolute risk reduction (ARR), RR reduction, number needed to treat (NNT), and odds ratio were calculated. Results: Improvement in the QoL (ARR = 14% and p < 0.01) and satisfaction (ARR = 44% and p < 0.01) according to the PAC-QoL questionnaire was observed in the experimental group compared with the control group. For probiotic supplementation, an NNT = 7 was obtained. This implies that for every seven constipated women treated, a worsening in the QoL is prevented in one. An NNT = 1 was obtained concerning satisfaction in the same group of women with respect to the treatment. No clinically significant observations related to the safety of the product were reported. The authors did not detect the effect of exercise intensity on the QoL of participants. Conclusion: The probiotic supplementation had a positive impact on the QoL of constipated female university students.

Targeted Release of Probiotics from Enteric Microparticulated Formulations

The development of advanced probiotic delivery systems, which preserve bacteria from degradation of the gastrointestinal tract and achieve a targeted release mediated by pH-independent swelling, is of great interest to improve the efficient delivery of probiotic bacteria to the target tissue. Gram-positive and Gram-negative bacteria models (Lactobacillus acidophilus (Moro) Hansen and Mocquot (ATCC® 4356™) and Escherichia coli S17, respectively) have been successfully encapsulated for the first time in pH-independent microparticulate polymethacrylates (i.e., Eudraguard biotic) used for the targeted delivery of nutraceuticals to the colon. These bacteria have also been encapsulated within the mucoadhesive polymethacrylate Eudragit RS 100 widely used as targeted release formulation for active pharmaceutical ingredients. The enteric microparticles remained unaltered under simulated gastric conditions and released the contained viable microbial cargo under simulated intestinal conditions. Buoyancies of 90.2% and 57.3% for Eudragit and Eudraguard microparticles, respectively, and long-term stability (5 months) for the encapsulated microorganisms were found. Cytotoxicity of the microparticles formulated with both polymers was evaluated (0.5-20 mg/mL) on Caco-2 cells, showing high cytocompatibility. These results underline the suitability of the synthesized materials for the successful delivery of probiotic formulations to the target organ, highlighting for the first time the potential use of Eudraguard biotic as an effective enteric coating for the targeted delivery of probiotics.

The effect of a probiotic blend on gastrointestinal symptoms in constipated patients: a double blind, randomised, placebo controlled 2-week trial

Selected strains of lactobacilli and bifidobacteria are known to ameliorate constipation-related symptoms and have previously shown efficacy on digestive health. In this clinical trial, the safety and effectiveness of a probiotic blend containing lactobacilli and bifidobacteria were evaluated in adults with self-reported bloating and functional constipation. Constipation was diagnosed by the Rome III criteria. A total of 156 adults were randomised into this double-blind and placebo-controlled trial. Participants consumed the combination of Lactobacillus acidophilus NCFM (10¹⁰ cfu), Lactobacillus paracasei Lpc-37 (2.5×10⁹ cfu), Bifidobacterium animalis subsp. lactis strains Bl-04 (2.5×10⁹ cfu), Bi-07 (2.5×10⁹ cfu) and HN019 (10¹⁰ cfu) (n=78), or placebo (microcrystalline cellulose) (n=78) for two weeks. After treatment the following were measured: primary outcome of bloating and secondary outcomes of colonic transit time, bowel movement frequency, stool consistency, other gastrointestinal symptoms (flatulence, abdominal pain, and burbling), constipation-related questionnaires (PAC-SYM and PAC-QoL) and product satisfaction. Faecal recovery of consumed strains was determined. The enrolled population was defined as constipated, however, the initial bloating severity was lower than in previous similar studies. No clinically significant observations related to the safety of the product were reported. Product efficacy was not shown in the primary analysis for bloating nor for the secondary efficacy analyses. The placebo functioned similarly as the probiotic product. In post-hoc analysis, a statistically significant decrease in flatulence in favour of the probiotic group was observed; day 7 (intention-to-treat (ITT): P=0.0313; per-protocol (PP): 0.0253) and on day 14 (ITT: P=0.0116; PP: P=0.0102) as measured by area under the curve (AUC) analysis. The mean AUC of all symptoms decreased in favour of the probiotic group, indicating less digestive discomfort. The study was registered at the ISRCTN registry (ISRCTN41607808).

Probiotics and constipation: mechanisms of action, evidence for effectiveness and utilisation by patients and healthcare professionals

The aim of this narrative review is to assess and present evidence on the mechanisms of action of probiotics in constipation, their effectiveness and their utilisation by patients and healthcare professionals. Chronic constipation is a common bothersome disorder that has a considerable impact on patients' quality of life. Probiotics have been increasingly investigated for their effectiveness in various disorders, including chronic constipation. Probiotics may affect gut motility and constipation through their impact on the gut microbiota and fermentation, the central and enteric nervous system and the immune system. However, evidence for the effectiveness of probiotics in the management of constipation remains varied, with some strains demonstrating improvements, while others show no effect. Despite the uncertainty in evidence and the fact that the majority of healthcare professionals do not recommend probiotics for constipation, an increased prevalence of probiotic use by people with constipation has been shown. Therefore, there is a need for public health strategies to inform the public about where strong evidence of probiotic effectiveness exist, and where evidence is still weak. Education of healthcare professionals on the increased utilisation of probiotics for constipation by the public and on current evidence for the effectiveness of specific strains is also required.

Randomised clinical trial: Bifidobacterium lactis NCC2818 probiotic vs placebo, and impact on gut transit time, symptoms, and gut microbiology in chronic constipation

BACKGROUND

Constipation is a prevalent gastrointestinal disorder. Patient dissatisfaction with prescribed medications is common, and there is need for alternative management strategies. Evidence shows that Bifidobacterium species may be beneficial in constipation.

AIM

To investigate changes in physiological and clinical measures of gut function in patients with chronic constipation following the consumption of Bifidobacterium lactis NCC2818, compared to placebo.

METHODS

Participants were randomised to a 4-week supplementation with B. lactis NCC2818 (1.5 x 10¹⁰ CFU/d) or placebo. Gut transit time was measured using a radio-opaque marker, while symptoms and quality of life were assessed using validated questionnaires. Gut microbiota composition was assessed using quantitative polymerase chain reaction. Analysis of covariance was used for normally distributed variables, and Mann-Whitney test for non-normally distributed variables.

RESULTS

Seventy-five participants were randomised. There was no significant difference between the probiotic and placebo groups in gut transit time change from baseline to week 2 (-11.7 hours, SD 33.0 hours vs -12.9 hours, SD 33.6 hours; P = 0.863) or to week 4 (-20.4 hours, SD 32.5 h vs -8.7 hours, SD 33.8 hours; P = 0.103). There were also no improvements in stool output, symptoms, or quality of life. No differences were found in Bifidobacterium concentrations between the probiotic and placebo groups at week 4 (9.5 log₁₀ /g dry faeces, SD 0.3 vs 9.4 log₁₀ /g, SD 1.0; P = 0.509).

CONCLUSIONS

Bifidobacterium lactis NCC2818 was not effective in the management of mild chronic constipation. This study highlights the importance of further studies and their publication to better understand the strain-specific effects of probiotics.

Microbiota transplantation: concept, methodology and strategy for its modernization

Fecal microbiota transplantation (FMT) has become a research focus of biomedicine and clinical medicine in recent years. The clinical response from FMT for different diseases provided evidence for microbiota-host interactions associated with various disorders, including Clostridium difficile infection, inflammatory bowel disease, diabetes mellitus, cancer, liver cirrhosis, gut-brain disease and others. To discuss the experiences of using microbes to treat human diseases from ancient China to current era should be important in moving standardized FMT forward and achieving a better future. Here, we review the changing concept of microbiota transplantation from FMT to selective microbiota transplantation, methodology development of FMT and step-up FMT strategy based on literature and state experts' perspectives.

Microbiota transplantation: concept, methodology and strategy for its modernization

Fecal microbiota transplantation (FMT) has become a research focus of biomedicine and clinical medicine in recent years. The clinical response from FMT for different diseases provided evidence for microbiota-host interactions associated with various disorders, including Clostridium difficile infection, inflammatory bowel disease, diabetes mellitus, cancer, liver cirrhosis, gut-brain disease and others. To discuss the experiences of using microbes to treat human diseases from ancient China to current era should be important in moving standardized FMT forward and achieving a better future. Here, we review the changing concept of microbiota transplantation from FMT to selective microbiota transplantation, methodology development of FMT and step-up FMT strategy based on literature and state experts' perspectives.

Effects of 28-day Bifidobacterium animalis subsp. lactis HN019 supplementation on colonic transit time and gastrointestinal symptoms in adults with functional constipation: A double-blind, randomized, placebo-controlled, and dose-ranging trial

Bifidobacterium animalis subsp. lactis HN019 (HN019) ameliorates chronic idiopathic constipation. Our aim was to determine the efficacy and safety of 28-day supplementation with 1 × 109 or 1 × 1010 CFU of HN019/day for constipation. A total of 228 adults who were diagnosed with functional constipation according to the Rome III criteria were randomized in a double-blind and placebo-controlled trial. Colonic transit time (CTT), the primary outcome, and secondary outcomes that were measured using inventories-patient assessment of constipation symptoms (PAC-SYM) and quality of life (PAC-QoL), bowel function index (BFI), bowel movement frequency (BMF), stool consistency, degree of straining, bowel emptying, bloating, and pain severity-were assessed. Ancillary parameters and harms were also evaluated. There were no statistically significant differences in the primary or secondary outcomes between interventions. A post hoc analysis of 65 participants with fewer than 3 bowel movements per week (BMF ≤ 3/week) showed a physiologically relevant increase in weekly BMF in the high- (+2.0) and low-dose (+1.7) HN019 groups-by RMANOVA, the HN019 groups with BMF ≤ 3/week, pooled together, had a higher BMF versus placebo (P value = 0.01). Thus, improving low stool frequency could be a target of future interventions with HN019. High-dose HN019 also decreased the degree of straining at Day 28 versus placebo in those with BMF ≤ 3/week (P value = 0.02). Three unlikely related AEs-2 with low-dose HN019 and 1 with placebo-were followed until full recovery. In conclusion, although there were no differences in the primary analysis, HN019 is well tolerated and improves BMF in adults with low stool frequency.

Effects of probiotic-containing products on stool frequency and intestinal transit in constipated adults: systematic review and meta-analysis of randomized controlled trials

Background:

Probiotics are commonly recommended for the alleviation of constipation symptoms. The aim of this research was to determine the effects of probiotic-containing products on stool frequency and intestinal transit time (ITT) in constipated adults and to determine the factors that influence the efficacy of these products.

Methods:

We conducted a systematic review of randomized controlled trials that measured weekly stool frequency or ITT in constipated adults receiving probiotic-containing supplements. A random effects meta-analysis was performed; stool frequency was summarized by the mean difference statistic and ITT was summarized by the standardized mean difference (SMD) statistic. Meta-regression and diagnostic model performance testing were used to identify publication bias and sources of heterogeneity.

Results:

A total of 21 studies (23 comparisons) comprising 2656 subjects were included. All studies utilized probiotics containing Lactobacillus or Bifidobacterium species. Probiotic-containing products resulted in a mean increase in weekly stool frequency of 0.83 (95% confidence interval [CI] 0.53-1.14, P<0.001). There was high heterogeneity among the studies (I²=85%, P<0.001) and evidence of significant publication bias (Egger’s P-value <0.01). After adjustment for publication bias, the mean difference in weekly stool frequency was reduced from 0.83 to 0.30. The effects on stool frequency were greater in studies where functional constipation was diagnosed using Rome III (P<0.01), or Rome II or III criteria (P<0.05), compared to non-Rome diagnosis techniques. Probiotic-containing products were also efficacious in reducing ITT (SMD=0.65, 95%CI 0.33-0.97, P<0.001). There was high heterogeneity among studies (I²=66%, P<0.01), but no evidence of publication bias (Egger’s P-value=0.52). A larger total sample size was associated with greater efficacy as regards ITT (P=0.03). The probiotic species, the number of probiotic strains and the daily probiotic dosage had no influence on the outcomes.

Conclusion:

Supplementation with products containing Lactobacillus or Bifidobacterium species increases stool frequency and reduces ITT in constipated adults. However, since significant heterogeneity in outcomes was detected among the studies analyzed, the results should be interpreted with caution.

A review of dose-responses of probiotics in human studies

The probiotic definition requires the administration of an 'adequate amount' in order to obtain a health benefit. What that amount should be is not indicated. Here, an overview is given of studies that investigated the dose-response relation of probiotics in human interventions. Studies were divided in; meta-analyses, meta-analyses on specific probiotic strains, and studies testing two or more doses of a probiotic (combination) in the same study. Meta-analyses on the effect of probiotics on antibiotic associated diarrhoea (AAD) suggest a dose-response effect; for Clostridium difficile-associated diarrhoea on the other hand no dose-response was observed. For other end-points; such as necrotising enterocolitis, prevention of atopic dermatitis and slow intestinal transit, no dose-response relation was identified in meta-analyses. For prophylaxis in colorectal cancer and relief of irritable bowel syndrome, no dose-response relation was determined. However, for blood pressure, a meta-analysis observed that higher doses (greater than 10¹¹ cfu) were more effective than lower doses. Meta-analyses of specific strains suggest a break-point for effectiveness of Lactobacillus rhamnosus GG in the treatment of acute gastroenteritis in children; no dose-response was observed for two other probiotics assessed. Studies comparing two or more doses indicate that faecal recovery and risk reduction of AAD follow a positive dose-response relationship. Other end-points such as immune markers, general health, and bowel function did not exhibit clear dose-response relations. For AAD, the findings are very compelling; both meta-analyses and dedicated dose-response studies observe a positive correlation between dose and AAD risk. These findings do not allow for extrapolation, but suggest that studying higher doses for this end-point would be worthwhile. The lack of a clear dose-response for other end-points, does not mean it does not exist; present data does just not allow drawing any conclusions.

Effects of Prebiotics and Synbiotics on Functional Constipation

The objective was to determine the effects of prebiotics and synbiotics on adults with functional constipation (FC). Medline, Embase and the Cochrane Library were searched for literature published up to February 2015. We selected randomized controlled trials (RCTs) that reported administration of prebiotics or synbiotics to adults with FC. The end points included stool frequency, stool consistency and other symptoms related to constipation. Mean differences (MD) or standard mean differences (SMD) were used for continuous outcomes and risk ratios for discontinuous outcomes using a random-effects model. The Cochrane Risk of Bias Tool was used to determine the quality of the trials. Funnel plots and Egger's test were used to analyze for publication bias. We included 5 RCTs involving 199 patients who were administered prebiotics and 8 RCTs involving 825 patients who were administered synbiotics. Prebiotics increased weekly stool frequency (MD: 1.01bowel movements/week, 95% CI: 0.04-1.99) and improved stool consistency (SMD: -0.59, 95% CI: -1.16 to -0.02). Subgroup analysis showed specific effects for galacto-oligosaccharides on stool frequency, consistency, ease of defecation and abdominal pain. Synbiotics significantly improved stool frequency (MD: 1.15bowel movements/week, 95% CI: 0.58-1.71), consistency (SMD: 0.63, 95% CI: 0.33-0.92) and reduced whole-gut transit time (MD: 13.52, 95% CI: -26.56 to -0.49) in patients with FC. Subgroup analysis showed specific effects for fructo-oligosaccharides and probiotic combinations on stool frequency, consistency, straining defecation and bloating. Galacto-oligosaccharides and synbiotics made up of fructo-oligosaccharides with probiotic combinations may improve stool frequency, consistency and some other symptoms related to constipation.