Influence of a probiotic mixture on antibiotic induced microbiota disturbances

Evaluation of penicillin-resistance and probiotic traits in Lactobacillus plantarum during laboratory evolution

The aim of this study was to obtain the Lactobacillus plantarum ATCC14917 with high-level resistance to penicillin and evaluate their probiotic traits using laboratory evolution assay and whole-genome sequencing. In penicillin environment, the minimum inhibitory concentration (MIC) of L. plantarum to penicillin increased from 1 μg/mL to 16 μg/mL and remained stable after the removal of antibiotic pressure, suggesting that the resistance acquisition to penicillin was an irreversible process. Subsequently, change of probiotic characteristics was further evaluated, and the results showed that the acid tolerance, bile tolerance and adhesion ability were significantly declined in the highly resistant strains. Whole-genome sequencing indicated that genes encoding hypothetical protein, LPXTG-motif cell wall anchor domain protein and acetyltransferase were detected in highly resistant L. plantarum, and these genes were still present after the following subculture in the absence of penicillin, suggesting that these three mutants might be the main reason for the development of penicillin resistance. The homology-based analysis of surrounding DNA regions of mutant genes was further performed and indicated that no resistant genes were located on mobile elements in evolved L. plantarum strains, signifying that the spread of antibiotic resistance genes in the gut would not occur for these mutant genes. This study provided a basis for the combined use of highly resistant L. plantarum and penicillin in the treatment of pathogen induced gut diseases.

Human Gut Microbiota in Heart Failure: Trying to Unmask an Emerging Organ

There is a bidirectional relationship between the heart and the gut. The gut microbiota, the community of gut micro-organisms themselves, is an excellent gut-homeostasis keeper since it controls the growth of potentially harmful bacteria and protects the microbiota environment. There is evidence suggesting that a diet rich in fatty acids can be metabolized and converted by gut microbiota and hepatic enzymes to trimethyl-amine N-oxide (TMAO), a product that is associated with atherogenesis, platelet dysfunction, thrombotic events, coronary artery disease, stroke, heart failure (HF), and, ultimately, death. HF, by inducing gut ischemia, congestion, and, consequently, gut barrier dysfunction, promotes the intestinal leaking of micro-organisms and their products, facilitating their entrance into circulation and thus stimulating a low-grade inflammation associated with an immune response. Drugs used for HF may alter the gut microbiota, and, conversely, gut microbiota may modify the pharmacokinetic properties of the drugs. The modification of lifestyle based mainly on exercise and a Mediterranean diet, along with the use of pre- or probiotics, may be beneficial for the gut microbiota environment. The potential role of gut microbiota in HF development and progression is the subject of this review.

Probiotic supplementation during antibiotic treatment is unjustified in maintaining the gut microbiome diversity: a systematic review and meta-analysis

BACKGROUND

Probiotics are often used to prevent antibiotic-induced low-diversity dysbiosis, however their effect is not yet sufficiently summarized in this regard. We aimed to investigate the effects of concurrent probiotic supplementation on gut microbiome composition during antibiotic therapy.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials reporting the differences in gut microbiome diversity between patients on antibiotic therapy with and without concomitant probiotic supplementation. The systematic search was performed in three databases (MEDLINE (via PubMed), Embase, and Cochrane Central Register of Controlled Trials (CENTRAL)) without filters on 15 October 2021. A random-effects model was used to estimate pooled mean differences (MD) with 95% confidence intervals (CI). This review was registered on PROSPERO (CRD42021282983).

RESULTS

Of 11,769 identified articles, 15 were eligible in the systematic review and 5 in the meta-analyses. Quantitative data synthesis for Shannon (MD = 0.23, 95% CI: [(-)0.06-0.51]), Chao1 (MD = 11.59 [(-)18.42-41.60]) and observed OTUs (operational taxonomic unit) (MD = 17.15 [(-)9.43-43.73]) diversity indices revealed no significant difference between probiotic supplemented and control groups. Lacking data prevented meta-analyzing other diversity indices; however, most of the included studies reported no difference in the other reported α- and ß-diversity indices between the groups. Changes in the taxonomic composition varied across the eligible studies but tended to be similar in both groups. However, they showed a potential tendency to restore baseline levels in both groups after 3-8 weeks. This is the first meta-analysis and the most comprehensive review of the topic to date using high quality methods. The limited number of studies and low sample sizes are the main limitations of our study. Moreover, there was high variability across the studies regarding the indication of antibiotic therapy and the type, dose, and duration of antimicrobials and probiotics.

CONCLUSIONS

Our results showed that probiotic supplementation during antibiotic therapy was not found to be influential on gut microbiome diversity indices. Defining appropriate microbiome diversity indices, their standard ranges, and their clinical relevance would be crucial.

Development of a microecologic product from Lactobacillus rhamnosus based on silica

BACKGROUND

Probiotics are primarily made into microecologic products for use in the food and feed industries. The freeze-drying technique is widely used in their preparation to maintain their high level of bioactivity. This causes high costs in terms of the energy and time needed. In this study, we developed a method to produce a highly active microecologic product from Lactobacillus rhamnosus using heating and silica.

RESULTS

A microecologic product was made successfully from L. rhamnosus using the whole bacterial culture broth, without waste, and using food-grade silica (4.5 mL g^-1 ) to absorb water before drying at 37 °C for 8 h. The activity of L. rhamnosus cells was increased significantly by adding water extracts of green tea to the culture medium. The viable amount of L. rhamnosus in the obtained microecologic product was 9.80 × 10¹⁰  cfu g^-1 with a survival rate of 224.67% in simulated gastric juice for 3 h and 68.2% in simulated intestinal juice for 3 h. The microecologic product treated an intestinal infection by multi-drug-resistant Staphylococcus aureus in mice very efficiently.

CONCLUSION

The study developed an economic, eco-friendly, and efficient method for preparing highly active microecologic agents using heating and without waste. © 2022 Society of Chemical Industry.

Effect of adding probiotics to an antibiotic intervention on the human gut microbial diversity and composition: a systematic review

Introduction. Millions of antibiotic prescriptions are written annually in the USA.

Gap Statement. Probiotics reduce antibiotic-induced gastrointestinal side effects; however, the effect of probiotics on preserving gut microbial composition in response to antibiotics is not well understood.

Aim. To evaluate whether the addition of probiotics is capable of reverting the changes in alpha diversity and gut microbial composition commonly observed in adult participants receiving antibiotics.

Methodology. A search was conducted by two researchers following the PRISMA guidelines using PubMed, Science Direct, Cochrane and Embase from January to December 2021 with the following inclusion criteria: (i) randomized clinical trials assessing the effect of antibiotics, probiotics or antibiotics+probiotics; (ii) 16S rRNA; (iii) adult participants; and (iv) in English. Once data was extracted in tables, a third researcher compared, evaluated and merged the collected data. The National Institutes of Health (NIH) rating system was utilized to analyse risk of bias.

Results. A total of 29 articles (n=11 antibiotics, n=11 probiotics and n=7 antibiotics+probiotics) met the inclusion criteria. The lack of standardization of protocols to analyse the gut microbial composition and the wide range of selected antibiotics/probiotics complicated data interpretation; however, despite these discrepancies, probiotic co-administration with antibiotics seemed to prevent some, but not all, of the gut microbial diversity and composition changes induced by antibiotics, including restoration of health-related bacteria such as Faecalibacterium prausnitzii .

Conclusion. Addition of probiotics to antibiotic interventions seems to preserve alpha diversity and ameliorate the changes to gut microbial composition caused by antibiotic interventions.

Bifidobacterium animalis subsp. lactis Bi-07 supports lactose digestion in vitro and in randomized, placebo- and lactase-controlled clinical trials

BACKGROUND

Probiotics may alleviate lactose maldigestion.

OBJECTIVES

The objective was to select a probiotic with high lactase activity and compare it with lactase and placebo in clinical trials.

METHODS

Bacterial cultures were screened for lactase activity in a model of the upper gastrointestinal (GI) tract. Bifidobacterium animalis subsp. lactis Bi-07 (Bi-07) counts were adjusted in subsequent experiments to correspond to 4500 Food Chemicals Codex (FCC) units of lactase, the amount in the European Food Safety Authority (EFSA)-approved health claim. Two crossover clinical trials, Booster Alpha and Booster Omega, were performed in participants with lactose intolerance, where 2 × 1012 CFUs Bi-07, 4662 FCC lactase, or placebo was consumed simultaneously with a lactose challenge, with 1-wk washouts between challenges. The trial designs were identical except for the source of lactose. Breath hydrogen concentration (BHC) was measured to assess the effect of the investigational products on lactose digestion, for which incremental area under the curve (iAUC) was the primary outcome. Peak BHC, cumulative BHC, and GI symptoms were secondary outcomes.

RESULTS

Bi-07 was superior to placebo in reducing BHC [iAUC, parts per million (ppm) ∙ h] in both trials (Booster Alpha: geometric least square mean ratio: 0.462; 95% CI: 0.249, 0.859; P = 0.016; Booster Omega: 0.227; 95% CI: 0.095, 0.543; P = 0.001). Lactase was superior to placebo in Booster Alpha (0.190; 95% CI: 0.102, 0.365; P < 0.001) but not Booster Omega (0.493; 95% CI: 0.210, 1.156; P = 0.102). Noninferiority of Bi-07 compared with lactase was observed in Booster Omega (0.460; 95% CI: 0.193, 1.096; P = 0.079; CI upper limit < 1.25 noninferiority margin). Odds of abdominal pain (compared with placebo: 0.32, P = 0.036) and flatulence (compared with placebo: 0.25, P = 0.007) were lower with lactase in Booster Alpha. Increased odds of nausea were seen with Bi-07 (compared with placebo: 4.0, P = 0.005) in Booster Omega.

CONCLUSIONS

Bi-07 has high lactase activity, and in 2 clinical trials, it supported lactose digestion in individuals with lactose intolerance.These trials were registered at clinicaltrials.gov as NCT03659747 (Booster Alpha) and NCT03814668 (Booster Omega).

New compound probiotic beverage protects against antibiotic-associated diarrhea in mice by modulating the microbiota

Probiotics and their products are the classic way to treat and prevent gastrointestinal diseases. In this study, the authors designed new combinations and doses of probiotic beverages for antibiotic-associated diarrhea. Group S1 was different from the other groups, including Lactobacillus rhamnosus HN001, Lactobacillus acidophilus NCFM and Bifidobacterium lactis BI-07. Its inulin content was higher than those of the other groups. Mice were induced with a 16-day administration of triple antibiotics in advance for 2 weeks prior to antibiotic treatment. In the experiment, the treatment group returned to normal more quickly than the placebo group. In group S1, the relative abundance of the phylum Firmicutes and genus Lactobacillus increased, and the structure of the microbiota was the closest to normal among all groups. In conclusion, the combinations of probiotic beverages effectively caused structural recovery of the gut and fecal microbiota against antibiotic-associated diarrhea, and the S1 formula showed the best efficacy.

Antibiotic resistant bacteria: current situation and treatment options to accelerate the development of a new antimicrobial arsenal

INTRODUCTION

Antibiotic resistance is one of the biggest public health threats worldwide. Currently, antibiotic-resistant bacteria kill 700,000 people every year. These data represent the near future in which we find ourselves, a "post-antibiotic era" where the identification and development of new treatments are key. This review is focused on the current and emerging antimicrobial therapies which can solve this global threat.

AREAS COVERED

Through a literature search using databases such as Medline and Web of Science, and search engines such as Google Scholar, different antimicrobial therapies were analyzed, including pathogen-oriented therapy, phagotherapy, microbiota and antivirulent therapy. Additionally, the development pathways of new antibiotics were described, emphasizing on the potential advantages that the combination of a drug repurposing strategy with the application of mathematical prediction models could bring to solve the problem of AMRs.

EXPERT OPINION

This review offers several starting points to solve a single problem: reducing the number of AMR. The data suggest that the strategies described could provide many benefits to improve antimicrobial treatments. However, the development of new antimicrobials remains necessary. Drug repurposing, with the application of mathematical prediction models, is considered to be of interest due to its rapid and effective potential to increase the current therapeutic arsenal.

The development of live biotherapeutics against Clostridioides difficile infection towards reconstituting gut microbiota

Clostridioides difficile is the most prevalent pathogen of nosocomial diarrhea. In the United States, over 450,000 cases of C. difficile infection (CDI), responsible for more than 29,000 deaths, are reported annually in recent years. Because of the emergence of hypervirulent strains and strains less susceptible to vancomycin and fidaxomicin, new therapeutics other than antibiotics are urgently needed. The gut microbiome serves as one of the first-line defenses against C. difficile colonization. The use of antibiotics causes gut microbiota dysbiosis and shifts the status from colonization resistance to infection. Hence, novel CDI biotherapeutics capable of reconstituting normal gut microbiota have become a focus of drug development in this field.

Regulation divergences of Lactobacillus fermentum PCC and Lactobacillus paracasei 431 on penicillin-induced upper respiratory tract microbial dysbiosis in BALB/c mice

Antibiotic-induced host health imbalance during upper respiratory tract infection (URTI) treatment is an emerging issue. Studies have confirmed that Lactobacillus casei 431 and Lactobacillus fermentum PCC alleviate gut microbiome dysbiosis and improve immune response. However, their effect on the upper respiratory tract (URT) microbial structure and the correlation between the URT microbiota and immunological indicators remain unclear. To evaluate the effects of Lactobacillus strains on restoring penicillin-induced imbalance in the URT microbiome and on immune response, Lactobacillus fermentum PCC and Lactobacillus casei 431 were individually administered to penicillin-pretreated mice, and their effects were assessed. The results revealed that L. casei 431 and L. fermentum PCC could regulate the systemic immune response imbalance, but the regulation direction of L. fermentum PCC was closer to that of the control group. Moreover, the Lactobacillus strains could restore penicillin-induced URT dysbacteriosis in the microbial community structure, but no significant change in alpha diversity was observed. The key bacterial taxa modulated by L. casei 431 were Faecalibaculum, Lactococcus, and Ralstonia. L. fermentum PCC enhanced biofilms and facultatively anaerobic bacteria. Different regulation pathways were observed in the two strains, and RDA revealed that both L. casei 431 and L. fermentum PCC groups were correlated with IL-17 and IL-1α, while the L. casei 431 group was also correlated with IL-6. In conclusion, L. casei 431 and L. fermentum PCC could beneficially and differentially ameliorate penicillin-induced imbalance in the URT microbial composition structure and functional metabolic pathways and modulate immune response, reflecting strain-specific regulation.

Association Between Gastrointestinal Symptoms and Depression in a Representative Sample of Adults in the United States: Findings From National Health and Nutrition Examination Survey (2005-2016)

BACKGROUND

The microbiome's role in the etiology of depression has been a topic of many recent investigations. Findings suggest that dysbiosis, which describes a general disturbance in the gut microbiome, underlies negative gastrointestinal symptoms and is implicated in depression. We studied associations between gastrointestinal symptoms and depressive symptoms at a population level using cross-sectional data from the National Health and Nutrition Examination Survey (2005-2016, n = 36,287). We hypothesized that the odds of depressive symptoms would be significantly higher in those showing signs of gastrointestinal distress.

METHODS

We analyzed 31,191 adults participating in the National Health and Nutrition Examination Survey from 2005-2016. Outcomes included presence of mucus or liquid in bowel leakage and stomach illness in the past month, diarrhea in the past year, and number of weekly bowel movements. The survey (and thus, our analyses) does not include microbiome samples, only self-reported gastrointestinal symptoms. Depressive symptoms were measured using the Patient Health Questionnaire. Moderate, moderately severe, and severe scores were coded as a positive outcome.

RESULTS

Compared to those without depressive symptoms, those with moderate-to-severe depressive symptoms had elevated odds of bowel mucus (odds ratio = 2.78; 95% confidence interval = 1.82-4.24), bowel liquid (odds ratio = 2.16; 95% confidence interval = 1.63-2.86), stomach illness (odds ratio = 1.82; 95% confidence interval = 1.31-2.53), diarrhea (sometimes vs. never odds ratio = 1.72; 95% confidence interval = 1.30-2.29), and constipation (sometimes vs. never odds ratio = 2.76; 95% confidence interval = 2.11-3.62). Overall, those with gastrointestinal symptoms were significantly more likely to have depressive symptoms.

CONCLUSIONS

While the intricacies of the brain-gut axis are being investigated at the molecular level, these population data provide further evidence for the association between depressive symptoms and signs of dysbiosis, which may inform health care providers' patient interactions.

Short-Term Tolerability, Safety, and Gut Microbial Composition Responses to a Multi-Strain Probiotic Supplement: An Open-Label Study in Healthy Adults

BACKGROUND

Probiotics are among the most commonly used dietary supplements and evidence of their efficacy is increasing. Despite the long historical use of probiotics, some experts suggest that additional research is necessary to understand their potential risks.

OBJECTIVES

Main aims of this study were to assess short-term tolerability and safety of a new, high colony-forming unit count, multi-strain probiotic supplement. Exploratory objectives included evaluating effects on gut microbial composition.

METHODS

Ten healthy adults were enrolled in a single-arm, open-label study. Over a 10-day period, participants consumed a once daily probiotic capsule (2.1 x 1011 CFU) containing Lactobacillus acidophilus NCFM, Lactobacillus paracasei Lpc-37, Lactobacillus plantarum Lp-115, Lactobacillus rhamnosus GG, Lactobacillus rhamnosus HN001, Bifidobacterium lactis Bi-07, Bifidobacterium lactis Bl-04, and Bifidobacterium lactis HN019. The primary measure of tolerability pertained to whether or not participants completed the study. Secondary safety measures included clinical biomarkers from a routine metabolic panel and a complete blood count. Exploratory measures included stool microbiota counts.

RESULTS

All participants completed the study and there were no serious adverse events. All documented adverse events were prompted by the investigators and the most commonly reported symptoms were gastrointestinal. There was a single instance of a biomarker abnormality in one individual. Overall, decreases in total bilirubin and aspartate aminotransferase, and increases in stool levels of Lactobacillus species, Faecalibacterium prausnitzii, and Akkermansia muciniphila (P < .05) were observed over the course of the study.

CONCLUSIONS

The findings of this study suggest the multi-strain probiotic supplement was well-tolerated and most likely safe. Changes in liver function measures suggest the probiotics could potentially impact liver health. Stool microbiota changes suggest the probiotic could potentially impact gut health by affecting levels of intestinal microbiota that have been described as bioindicators of health and potential keystone species. However, additional research is necessary to follow up on the exploratory findings of this preliminary work.

Antibiotic-induced changes in the human gut microbiota for the most commonly prescribed antibiotics in primary care in the UK: a systematic review

OBJECTIVE

The gut microbiota influences many aspects of human health. We investigated the magnitude and duration of changes in gut microbiota in response to antibiotics commonly prescribed in UK primary care.

METHODS

We searched MEDLINE, EMBASE and AMED, all years up to May 2020 including all study designs, collecting and analysing data on the effect of antibiotics prescribed for respiratory and urinary tract infections. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane standard methods. Risk of bias was evaluated using the Critical Appraisal Skills Programme. Narrative synthesis was used to report the themes emerging from the data.

MAIN OUTCOME MEASURES

Primary outcomes were antibiotic-induced changes in the composition and/or diversity of the gut microbiota. Secondary outcome was the time for the microbiota to return to baseline.

RESULTS

Thirty-one articles with low or unclear risk of bias showed that antibiotics impact the gut microbiota by causing rapid and diminished levels of bacterial diversity and changes in relative abundances. After cessation of treatment, gut bacteria recover, in most individuals, to their baseline state within a few weeks. Some studies suggested longer term effects from 2 to 6 months. Considerable heterogeneity in methodology makes the studies prone to biases and other confounding factors. Doxycycline was associated with a marked short-term decrease in Bifidobacterium diversity. Clarithromycin decreased the populations of Enterobacteria, and the anaerobic bacteria Bifidobacterium sp and Lactobacillus sp in numbers and diversity for up to 5 weeks. Phenoxymethylpenicillin, nitrofurantoin and amoxicillin had very little effect on the gut microbiome.

CONCLUSIONS

Despite substantial heterogeneity of the studies and small sample sizes, there is evidence that antibiotics commonly used in primary care influence the composition of the gastrointestinal microbiota. Larger population-based studies are needed to fully understand how antibiotics modulate the microbiota, and to determine if these are associated with (longer term) health consequences.

PROSPERO REGISTRATION NUMBER

CRD42017073750.

The Role of Probiotics, Prebiotics and Synbiotics in Combating Multidrug-Resistant Organisms

The prevalence of multidrug-resistant organisms is increasing worldwide, posing a unique challenge to global health care systems. Novel approaches are needed to combat the spread of infection with these organisms. The enteric microbiome, and in particular the resistome, offers a unique target in both the prevention of infection with these organisms and the acquisition and spread within the community. We highlight a novel approach to combat multidrug-resistant organisms: the use of prebiotics, probiotics, and synbiotics to manipulate the microbiome and resistome. This review summarizes the published literature and clinical trials related to these products to date, with a focus on efficacious trials. It highlights the probable mechanism of action for each product, as well as its safety profile in selective populations. Ultimately, although further research is needed before a definitive statement can be made on the efficacy of any of these 3 interventions, the literature to date offers new hope and a new tool in the arsenal in the fight against bacterial drug resistance.

Fecal Recovery of Probiotics Administered as a Multi-Strain Formulation during Antibiotic Treatment

The present study aimed to investigate whether probiotic recovery is affected when consumed together with antibiotics. Fecal samples were collected from an earlier antibiotic associated diarrhea, randomized, placebo-controlled study with a product consisting of a combination of Lactobacillus acidophilus NCFM, Lactobacillus paracasei Lpc-37, and Bifidobacterium lactis Bi-07, B. lactis Bl-04 at equal numbers and at a total dose of 10¹⁰ CFU. Fecal samples were collected during the screening visit (T0), i.e., at the time of antibiotic prescription, and then on the last day of the antibiotic treatment (T1) as well as seven days after the subject had stopped taking the antibiotic treatment (T2) and at two weeks after completing antibiotic treatment and one week after probiotic/placebo consumption stopped (T3). Samples were analyzed for the presence of the four administered strains. The study was registered at clinicaltrials.gov as NCT01596829. Detection levels of all four strains were significantly increased from T0 to T1 and returned to baseline level from T2 to T3. There were also significantly more subjects with detectable levels of L. paracasei Lpc-37, B. lactis Bi-07, and B. lactis Bl-04 at T1 and T2 compared to T0 and T3, and compared to placebo. Each of the four strains could be detected in the feces of patients apparently unaffected by the simultaneous consumption of antibiotics.

Gut Bacterial Microbiota and its Resistome Rapidly Recover to Basal State Levels after Short-term Amoxicillin-Clavulanic Acid Treatment in Healthy Adults

Clinical effects of antimicrobials and probiotics in combination have been reported, however, little is known about their impact on gut microbiota and its resistome. In this study 16S rRNA gene amplicon, shotgun metagenomics sequencing and antibiotic resistance (ABR) microarray were used on fecal samples of 70 healthy participants, taken at four time points in probiotic (Lactobacillus rhamnosus R0011 and Lactobacillus helveticus R0052) and placebo groups to profile the gut bacterial microbiota and its resistome following administration of amoxicillin-clavulanic acid for one week. Significant shifts in microbiota family composition caused by the antimicrobial in both groups that included decreases in the proportion of Lachnospiraceae, Coriobacteriaceae and unidentified Clostridiales; and notable increases for the proportion of Enterobacteriaceae, Bacteroidaceae and Porphyromonadaceae compared to baseline levels. Resistome showed a corresponding enrichment of ABR genes compared to baseline from such classes as aminoglycosides and beta-lactams that were linked, by in silico inference, to the enrichment of the family Enterobacteriaceae. Despite perturbations caused by short-term antibiotic treatment, both gut microbiota and resistome showed prompt recovery to baseline levels one week after cessation of the antimicrobial. This rapid recovery may be explained by the hypothesis of community resilience.

Timely Use of Probiotics in Hospitalized Adults Prevents Clostridium difficile Infection: A Systematic Review With Meta-Regression Analysis

BACKGROUND & AIMS

Systematic reviews have provided evidence for the efficacy of probiotics in preventing Clostridium difficile infection (CDI), but guidelines do not recommend probiotic use for prevention of CDI. We performed an updated systematic review to help guide clinical practice.

METHODS

We searched MEDLINE, EMBASE, International Journal of Probiotics and Prebiotics, and The Cochrane Library databases for randomized controlled trials evaluating use of probiotics and CDI in hospitalized adults taking antibiotics. Two reviewers independently extracted data and assessed risk of bias and overall quality of the evidence. Primary and secondary outcomes were incidence of CDI and adverse events, respectively. Secondary analyses examined the effects of probiotic species, dose, timing, formulation, duration, and study quality.

RESULTS

We analyzed data from 19 published studies, comprising 6261 subjects. The incidence of CDI in the probiotic cohort, 1.6% (54 of 3277), was lower than of controls, 3.9% (115 of 2984) (P < .001). The pooled relative risk of CDI in probiotic users was 0.42 (95% confidence interval, 0.30-0.57; I² = 0.0%). Meta-regression analysis demonstrated that probiotics were significantly more effective if given closer to the first antibiotic dose, with a decrement in efficacy for every day of delay in starting probiotics (P = .04); probiotics given within 2 days of antibiotic initiation produced a greater reduction of risk for CDI (relative risk, 0.32; 95% confidence interval, 0.22-0.48; I² = 0%) than later administration (relative risk, 0.70; 95% confidence interval, 0.40-1.23; I² = 0%) (P = .02). There was no increased risk for adverse events among patients given probiotics. The overall quality of the evidence was high.

CONCLUSIONS

In a systematic review with meta-regression analysis, we found evidence that administration of probiotics closer to the first dose of antibiotic reduces the risk of CDI by >50% in hospitalized adults. Future research should focus on optimal probiotic dose, species, and formulation. Systematic Review Registration: PROSPERO CRD42015016395.

Changes in the Functional Potential of the Gut Microbiome Following Probiotic Supplementation during Helicobacter Pylori Treatment

BACKGROUND

Probiotic supplementation is utilized to alleviate the side effects associated with antibiotic therapy for Helicobacter pylori infection. Several studies have described the effects of administration of probiotics on the gut microbiota during antibiotic therapy. However, most of these studies have focused on specific bacteria, thereby providing limited information on the functional roles of the altered microbiota. Therefore, we examined the impact of probiotic supplementation on the structure and functional dynamics of the gut microbiota during H. pylori eradication, using whole-metagenomic sequence analysis.

METHODS

Subjects were divided into two groups: the antibiotics group, which received only antibiotics, and the probiotics group, which received antibiotics with probiotic supplementation. The structural and functional profiles of gut microbiota was analyzed using metagenomic DNA extracted from the feces during treatment by Illumina MiSeq system.

RESULTS

The overall alterations in microbiota, as revealed by whole metagenome sequencing, were similar with results from our previous 16S rRNA gene-based analysis. The proportional shift in functional gene families was greater in the antibiotics group than in the probiotics group. In particular, the proportion of genes related to selenocompound metabolism was reduced in the probiotics group, whereas genes associated with the metabolism of nucleotide sugars were increased.

CONCLUSION

The functional alterations of gut microbiota may link to the reduction in intestinal irritation and maintenance of bacterial diversity observed following probiotic supplementation with antibiotic therapy. The potential beneficial roles of altered gut microbiota following probiotic supplementation are expected a reduction in side effects such as intestinal irritation and antibiotics resistance.

The Effect of Probiotics on Gut Microbiota during the Helicobacter pylori Eradication: Randomized Controlled Trial

BACKGROUND

Helicobacter pylori causes chronic gastritis, gastroduodenal ulcers, and gastric cancer, and has been treated with two antibiotics (amoxicillin and clarithromycin) and proton-pump inhibitors (PPIs). However, antibiotic treatment alters the indigenous gut microbiota to cause side effects. Therefore, the effects of probiotic supplementation on therapy have been studied. Although several studies have covered the probiotics' effects, details about the gut microbiota changes after H. pylori eradication have not been evaluated. Therefore, we analyzed the influences of antibiotics and their combination with probiotics on the composition of the gut microbiota using high-throughput sequencing.

METHODS

Subjects were divided into two groups. The antibiotics group was treated with general therapy, and the probiotics group with general therapy and probiotic supplementation. Fecal samples were collected from all subjects during treatments, and the influences on gut microbiota were analyzed by 16S rRNA gene-pyrosequencing.

RESULTS

Three phyla, Firmicutes, Bacteroidetes, and Proteobacteria, were predominant in the gut microbiota of all subjects. After treatment, the relative abundances of Firmicutes were reduced, whereas those of Proteobacteria were increased in both groups. However, the changed proportions of the gut microbiota in the antibiotics group were higher than those in the probiotics group. In addition, the increase in the levels of antibiotic-resistant bacteria was higher in the antibiotics group than in the probiotics one.

CONCLUSION

Probiotic supplementation can reduce the antibiotic-induced alteration and imbalance of the gut microbiota composition. This effect may restrict the growth of antibiotic-resistant bacteria in the gut and improve the H. pylori eradication success rate.

Effectiveness of Lactobacillus helveticus and Lactobacillus rhamnosus for the management of antibiotic-associated diarrhoea in healthy adults: a randomised, double-blind, placebo-controlled trial

Broad-spectrum antibiotic use can disrupt the gastrointestinal microbiota resulting in diarrhoea. Probiotics may be beneficial in managing this type of diarrhoea. The aim of this 10-week randomised, double-blind, placebo-controlled, parallel study was to investigate the effect of Lactobacillus helveticus R0052 and Lactobacillus rhamnosus R0011 supplementation on antibiotic-associated diarrhoea in healthy adults. Subjects were randomised to receive 1 week of amoxicillin-clavulanic acid (875 mg/125 mg) once per day, plus a daily dose of 8×109 colony-forming units of a multi-strain probiotic (n 80) or placebo (n 80). The probiotic or placebo intervention was maintained for 1 week after completion of the antibiotic. Primary study outcomes of consistency and frequency of bowel movements were not significantly different between the probiotic and placebo groups. The secondary outcomes of diarrhoea-like defecations, Gastrointestinal Symptoms Rating Scale scores, safety parameters and adverse events were not significantly different between the probiotic intervention and the placebo. A post hoc analysis on the duration of diarrhoea-like defecations showed that probiotic intervention reduced the length of these events by 1 full day (probiotic, 2·70 (sem 0·36) d; placebo, 3·71 (sem 0·36) d; P=0·037; effect size=0·52). In conclusion, this study provides novel evidence that L. helveticus R0052 and L. rhamnosus R0011 supplementation significantly reduced the duration of diarrhoea-like defecations in healthy adults receiving antibiotics.

Probiotic approach to prevent antibiotic resistance

Probiotics are live microorganisms, mainly belonging to the genera Lactobacillus and Bifidobacterium, although also strain of other species are commercialized, that have a beneficial effect on the host. From the perspective of antibiotic use, probiotics have been observed to reduce the risk of certain infectious disease such as certain types of diarrhea and respiratory tract infection. This may be accompanied with a reduced need of antibiotics for secondary infections. Antibiotics tend to be effective against most common diseases, but increasingly resistance is being observed among pathogens. Probiotics are specifically selected to not contribute to the spread of antibiotic resistance and not carry transferable antibiotic resistance. Concomitant use of probiotics with antibiotics has been observed to reduce the incidence, duration and/or severity of antibiotic-associated diarrhea. This contributes to better adherence to the antibiotic prescription and thereby reduces the evolution of resistance. To what extent probiotics directly reduce the spread of antibiotic resistance is still much under investigation; but maintaining a balanced microbiota during antibiotic use may certainly provide opportunities for reducing the spread of resistances. Key messages Probiotics may reduce the risk for certain infectious diseases and thereby reduce the need for antibiotics. Probiotics may reduce the risk for antibiotic-associated diarrhea Probiotics do not contribute to the spread of antibiotic resistance and may even reduce it.

Safety of Bifidobacterium animalis subsp. lactis (B. lactis) strain BB-12-supplemented yogurt in healthy adults on antibiotics: a phase I safety study

Probiotics are live microorganisms that, when administered in sufficient doses, provide health benefits on the host. The United States Food and Drug Administration (FDA) requires phase I safety studies for probiotics when the intended use of the product is as a drug. The purpose of the study was to determine the safety of Bifidobacterium animalis subsp lactis (B. lactis) strain BB-12 (BB-12)-supplemented yogurt when consumed by a generally healthy group of adults who were prescribed a 10-day course of antibiotics for a respiratory infection. Secondary aims were to assess the ability of BB-12 to affect the expression of whole blood immune markers associated with cell activation and inflammatory response. A phase I, double-blinded, randomized controlled study was conducted in compliance with FDA guidelines for an Investigational New Drug (IND). Forty participants were randomly assigned to consume 4 ounces of either BB-12 -supplemented yogurt or non-supplemented control yogurt daily for 10 d. The primary outcome was to assess safety and tolerability, assessed by the number of reported adverse events. A total of 165 non-serious adverse events were reported, with no differences between the control and BB-12 groups. When compared to the control group, B lactis fecal levels were modestly higher in the BB-12-supplemented group. In a small subset of patients, changes in whole blood expression of genes associated with regulation and activation of immune cells were detected in the BB-12-supplemented group. BB-12-supplemented yogurt is safe and well tolerated when consumed by healthy adults concurrently taking antibiotics. This study will form the basis for future randomized clinical trials investigating the potential immunomodulatory effects of BB-12-supplemented yogurt in a variety of disease states.