Modulation of Lactobacillus casei in ileal and fecal samples from healthy volunteers after consumption of a fermented milk containing Lactobacillus casei DN-114 001Rif

Tunable control of B. infantis abundance and gut metabolites by co-administration of human milk oligosaccharides

Precision engineering of the gut microbiome holds promise as an effective therapeutic approach for diseases associated with a disruption in this microbial community. Engrafting a live biotherapeutic product (LBP) in a predictable, controllable manner is key to the consistent success of this approach and has remained a challenge for most LBPs under development. We recently demonstrated high-level engraftment of Bifidobacterium longum subsp. infantis (B. infantis) in adults when co-dosed with a specific prebiotic, human milk oligosaccharides (HMO). Here, we present a cellular kinetic-pharmacodynamic approach, analogous to pharmacokinetic-pharmacodynamic-based analyses of small molecule- and biologic-based drugs, to establish how HMO controls expansion, abundance, and metabolic output of B. infantis in a human microbiota-based model in gnotobiotic mice. Our data demonstrate that the HMO dose controls steady-state abundance of B. infantis in the microbiome, and that B. infantis together with HMO impacts gut metabolite levels in a targeted, HMO-dependent manner. We also found that HMO creates a privileged niche for B. infantis expansion across a 5-log range of bacterial inocula. These results demonstrate remarkable control of both B. infantis levels and the microbiome community metabolic outputs using this synbiotic approach, and pave the way for precision engineering of desirable microbes and metabolites to treat a range of diseases.

Precision modulation of dysbiotic adult microbiomes with a human-milk-derived synbiotic reshapes gut microbial composition and metabolites

Manipulation of the gut microbiome using live biotherapeutic products shows promise for clinical applications but remains challenging to achieve. Here, we induced dysbiosis in 56 healthy volunteers using antibiotics to test a synbiotic comprising the infant gut microbe, Bifidobacterium longum subspecies infantis (B. infantis), and human milk oligosaccharides (HMOs). B. infantis engrafted in 76% of subjects in an HMO-dependent manner, reaching a relative abundance of up to 81%. Changes in microbiome composition and gut metabolites reflect altered recovery of engrafted subjects compared with controls. Engraftment associates with increases in lactate-consuming Veillonella, faster acetate recovery, and changes in indolelactate and p-cresol sulfate, metabolites that impact host inflammatory status. Furthermore, Veillonella co-cultured in vitro and in vivo with B. infantis and HMO converts lactate produced by B. infantis to propionate, an important mediator of host physiology. These results suggest that the synbiotic reproducibly and predictably modulates recovery of a dysbiotic microbiome.

A six-month prospective, randomised, double-blinded, placebo-controlled, crossover, dietary trial design to investigate the potential of psychobiotics on seizure semiology and comorbidities in canine epilepsy: study protocol

BACKGROUND

Epilepsy is the most common chronic neurological disease in dogs. More than two-thirds of these patients suffer from associated behavioural comorbidities. The latter could have their origin in partially overlapping pathomechanisms, with the intestinal microbiome as a potential key link between them. The current arsenal of drugs for epilepsy management remains limited. Most canine patients continue to have seizures despite treatment and the occurrence of comorbidities is not sufficiently addressed, limiting quality of life of affected dogs and owners. Therefore, novel additional epilepsy management options are urgently needed. The microbiome-gut-brain axis may serve as a new target for the development of innovative multimodal therapeutic approaches to overcome current shortcomings in epilepsy management.

METHODS

A six-month prospective, randomised, double-blinded, placebo-controlled, crossover, dietary trial was designed to investigate the potential of the psychobiotic Bifidobacterium longum on behavioural comorbidities in canine epilepsy. Seizure semiology will be evaluated as a secondary outcome measure. Thirty-four privately owned dogs are planned to be included in the ongoing study meeting the following inclusion criteria: Dogs displaying increased anxiety/fear behaviour since the start of the idiopathic epilepsy. Tier II confidence level of the International Veterinary Epilepsy Task Force for the diagnosis of idiopathic epilepsy, with a maximum seizure interval of 3 month and a minimum of three generalised seizures within that period and chronically treated with at least one antiseizure drug without improvement in seizure frequency Each dog will receive the allocated supplement (probiotic vs. placebo) alongside its normal diet for a 3-month period. After a three-week wash out period, the second phase starts by administering the respective other supplement for another 3 months.

DISCUSSION

The current study considers modern high-quality standards for epilepsy medication trials. Common biasing effects should be limited to a possible minimum (regression-to-the mean effect, placebo effect, observer effect), ensuring a high validity and accuracy of the acquired results, thus enabling a representative nature of the efficacy of Bifidobacterium longum as add-on supplement for dogs suffering from epilepsy and its comorbidities. This publication should provide a description of the study procedure and data acquisition methods, including prognosed statistical analysis.

Improved gut microbiome recovery following drug therapy is linked to abundance and replication of probiotic strains

Probiotics have been used for decades to alleviate the negative side-effects of oral antibiotics, but our mechanistic understanding on how they work is so far incomplete. Here, we performed a metagenomic analysis of the fecal microbiota in participants who underwent a 14-d Helicobacter pylori eradication therapy with or without consumption of a multi-strain probiotic intervention (L. paracasei CNCM I-1518, L. paracasei CNCM I-3689, L. rhamnosus CNCM I-3690, and four yogurt strains) in a randomized, double-blinded, controlled clinical trial. Using a strain-level analysis for detection and metagenomic determination of replication rate, ingested strains were detected and replicated transiently in fecal samples and in the gut during and following antibiotic administration. Consumption of the fermented milk product led to a significant, although modest, improvement in the recovery of microbiota composition. Stratification of participants into two groups based on the degree to which their microbiome recovered showed i) a higher fecal abundance of the probiotic L. paracasei and L. rhamnosus strains and ii) an elevated replication rate of one strain (L. paracasei CNCMI-1518) in the recovery group. Collectively, our findings show a small but measurable benefit of a fermented milk product on microbiome recovery after antibiotics, which was linked to the detection and replication of specific probiotic strains. Such functional insight can form the basis for the development of probiotic-based intervention aimed to protect gut microbiome from drug treatments.

Dosing a synbiotic of human milk oligosaccharides and B. infantis leads to reversible engraftment in healthy adult microbiomes without antibiotics

Predictable and sustainable engraftment of live biotherapeutic products into the human gut microbiome is being explored as a promising way to modulate the human gut microbiome. We utilize a synbiotic approach pairing the infant gut microbe Bifidobacterium longum subspecies infantis (B. infantis) and human milk oligosaccharides (HMO). B. infantis, which is typically absent in adults, engrafts into healthy adult microbiomes in an HMO-dependent manner at a relative abundance of up to 25% of the bacterial population without antibiotic pretreatment or adverse effects. Corresponding changes in metabolites are detected. Germ-free mice transplanted with dysbiotic human microbiomes also successfully engraft with B. infantis in an HMO-dependent manner, and the synbiotic augments butyrate levels both in this in vivo model and in in vitro cocultures of the synbiotic with specific Firmicutes species. Finally, the synbiotic inhibits the growth of enteropathogens in vitro. Our findings point to a potential safe mechanism for ameliorating dysbioses characteristic of numerous human diseases.

Colonization Ability and Impact on Human Gut Microbiota of Foodborne Microbes From Traditional or Probiotic-Added Fermented Foods: A Systematic Review

A large subset of fermented foods act as vehicles of live environmental microbes, which often contribute food quality assets to the overall diet, such as health-associated microbial metabolites. Foodborne microorganisms also carry the potential to interact with the human gut microbiome via the food chain. However, scientific results describing the microbial flow connecting such different microbiomes as well as their impact on human health, are still fragmented. The aim of this systematic review is to provide a knowledge-base about the scientific literature addressing the connection between foodborne and gut microbiomes, as well as to identify gaps where more research is needed to clarify and map gut microorganisms originating from fermented foods, either traditional or added with probiotics, their possible impact on human gut microbiota composition and to which extent foodborne microbes might be able to colonize the gut environment. An additional aim was also to highlight experimental approaches and study designs which could be better standardized to improve comparative analysis of published datasets. Overall, the results presented in this systematic review suggest that a complex interplay between food and gut microbiota is indeed occurring, although the possible mechanisms for this interaction, as well as how it can impact human health, still remain a puzzling picture. Further research employing standardized and trans-disciplinary approaches aimed at understanding how fermented foods can be tailored to positively influence human gut microbiota and, in turn, host health, are therefore of pivotal importance.

A critical evaluation of the factors affecting the survival and persistence of beneficial bacteria in healthy adults

The efficacy of a probiotic depends on its ability to survive and persist in the digestive tract. Regulatory agencies around the world recommend minimum dosages in order for a product to be termed a probiotic. However, the effect of dosage on the survival of the bacteria in the gut - the primary objective of probiotic administration - has not been critically evaluated. We performed a systematic literature review to assess the available data on the survival rate, during gastrointestinal transit, of probiotic bacteria that were orally administered to healthy adults. We also evaluated the persistence of the administered strain(s) after discontinuation of treatment and the potential role played by the food matrix in which probiotics have been administered. From a regulatory perspective, the profile of the target population is key to establishing the efficacy of probiotics. Therefore, we focussed on subjects without disease conditions. We evaluated 17 studies of single strains and 13 studies of multi-strain products, which reported survival and persistence outcomes. Persistence in the gut and recovery from stool were strain dependent. When the administered dose was higher than 10¹⁰ cfu/day, the probiotic could be recovered from stool regardless of the strain used. Treatment duration did not affect faecal recovery. Thus, dosage recommendations for probiotics by regulatory agencies are lower than that required for a strain to survive, persist and be efficacious in the gut.

Using naso- and oro-intestinal catheters in physiological research for intestinal delivery and sampling in vivo: practical and technical aspects to be considered

Intestinal catheters have been used for decades in human nutrition, physiology, pharmacokinetics, and gut microbiome research, facilitating the delivery of compounds directly into the intestinal lumen or the aspiration of intestinal fluids in human subjects. Such research provides insights about (local) dynamic metabolic and other intestinal luminal processes, but working with catheters might pose challenges to biomedical researchers and clinicians. Here, we provide an overview of practical and technical aspects of applying naso- and oro-intestinal catheters for delivery of compounds and sampling luminal fluids from the jejunum, ileum, and colon in vivo. The recent literature was extensively reviewed, and combined with experiences and insights we gained through our own clinical trials. We included 60 studies that involved a total of 720 healthy subjects and 42 patients. Most of the studies investigated multiple intestinal regions (24 studies), followed by studies investigating only the jejunum (21 studies), ileum (13 studies), or colon (2 studies). The ileum and colon used to be relatively inaccessible regions in vivo. Custom-made state-of-the-art catheters are available with numerous options for the design, such as multiple lumina, side holes, and inflatable balloons for catheter progression or isolation of intestinal segments. These allow for multiple controlled sampling and compound delivery options in different intestinal regions. Intestinal catheters were often used for delivery (23 studies), sampling (10 studies), or both (27 studies). Sampling speed decreased with increasing distance from the sampling syringe to the specific intestinal segment (i.e., speed highest in duodenum, lowest in ileum/colon). No serious adverse events were reported in the literature, and a dropout rate of around 10% was found for these types of studies. This review is highly relevant for researchers who are active in various research areas and want to expand their research with the use of intestinal catheters in humans in vivo.

Effects of a Fermented Dairy Drink Containing Lacticaseibacillus paracasei subsp. paracasei CNCM I-1518 (Lactobacillus casei CNCM I-1518) and the Standard Yogurt Cultures on the Incidence, Duration, and Severity of Common Infectious Diseases: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

There is considerable interest in the role of probiotics in immune function. The objective of this systematic review and meta-analysis was to assess the effects of the consumption of a fermented dairy drink containing Lacticaseibacillus paracasei subsp. paracasei CNCM I-1518 (the previous taxonomic nomenclature was Lactobacillus casei CNCM I-1518, prior to the nomenclature change in April 2020) and the standard yogurt cultures (hereinafter referred to collectively as “FDD”) on common infectious diseases (CIDs) in generally healthy children and adults. Nine literature databases were searched, and nine randomized controlled trials from eight publications were eligible for inclusion. Combined effect sizes were determined for three metrics of CID incidence, two metrics of CID duration, and one metric of CID severity. Compared to the control, the consumption of the FDD resulted in (1) a significant reduction in the odds of experiencing ≥1 CID (odds ratio (OR) (with a 95% confidence interval (CI)): 0.81 (0.66, 0.98); p = 0.029); (2) a significant reduction in mean CIDs per subject (−0.09 (−0.15, −0.04); p = 0.001); and (3) a trend towards reduced risk in cumulative CIDs (relative risk (RR): 0.91 (0.82, 1.01); p = 0.082). The consumption of the FDD had no significant effect on CID duration or severity. Based on the studies conducted thus far, these results suggest that the FDD may reduce CID incidence in the general population.

In vitro Study of Lactobacillus paracasei CNCM I-1518 in Healthy and Clostridioides difficile Colonized Elderly Gut Microbiota

Consumption of probiotic bacteria can result in a transient colonization of the human gut and thereby in potential interactions with the commensal microbiota. In this study, we used novel PolyFermS continuous fermentation models to investigate interactions of the candidate probiotic strain Lactobacillus paracasei CNCM I-1518 (L. paracasei) with colonic microbiota from healthy elderly subjects using 16S rRNA gene amplicon sequencing and metatranscriptomics, or with microbiota in vitro-colonized with Clostridioides difficile (C. difficile NCTC 13307 and C. difficile DSM 1296)—an enteropathogen prevalent in the elderly population. Small changes in microbiota composition were detected upon daily addition of L. paracasei, including increased abundances of closely related genera Lactobacillus and Enterococcus, and of the butyrate producer Faecalibacterium. Microbiota gene expression was also modulated by L. paracasei with distinct response of the Faecalibacterium transcriptome and an increase in carbohydrate utilization. However, no inhibitory effect of L. paracasei was observed on C. difficile colonization in the intestinal models under the tested conditions. Our data suggest that, in the in vitro experimental conditions tested and independent of the host, L. paracasei has modulatory effects on both the composition and function of elderly gut microbiota without affecting C. difficile growth and toxin production.

Effects of synbiotics on ileal microbiota

Background & objectives:

Despite advancements in molecular-based methods, the composition of the human ileal microbiota and the effects of synbiotics/probiotics on its microbes remain poorly understood. The aim of this study was to determine the composition of the mucus microbiota in the human ileum and to assess the effects of oral administration of synbiotics on the microbiota.

Methods:

As part of a clinical trial for synbiotics treatment and surgical infection, ileal mucus was sampled when resection of the ileocecal portion was required. The microbiota composition was examined using 16S rRNA-targeted real-time-quantitative polymerase chain reaction.

Results:

A total of 33 samples from the synbiotics group and 39 from the control group were analyzed. Total numbers of bacteria in the ileum were 10^8.5 cells/g in the synbiotics group and 10^8.4 cells/g in the control group, in which obligate anaerobes were dominant over facultative anaerobes. The level of Enterobacteriaceae was significantly lower in the synbiotics group than in the control group. The administered probiotics species Lactobacillus casei strain Shirota and Bifidobacterium breve strain Yakult were detected in 42 and 76 per cent of the synbiotics group, respectively. No significant correlations were observed between tumour stage/size and the various microbes present, except for a negative correlation between tumour size and Bifidobacterium.

Interpretation & conclusions:

The present analysis of a substantial number of samples from surgically resected intestines showed an abundance of obligate anaerobes as a characteristic feature of the ileal mucus microbiota. Our results also indicated that the synbiotics intervention induced a prominent reduction in Enterobacteriaceae in the ileal microbiota.

Fermented Milk Consumption and Common Infections in Children Attending Day-Care Centers: A Randomized Trial

OBJECTIVES

This multicenter, double-blind, randomized, placebo-controlled clinical trial investigated the effect of a fermented milk product containing the Lactobacillus casei National Collection of Microorganisms and Cell Cultures (CNCM) I-1518 strain on respiratory and gastrointestinal common infectious diseases (CIDs) in children attending day-care centers in Russia.

METHODS

Children ages 3 to 6 years received 100 g of a fermented milk product (n = 300) or a control product (n = 299) twice daily for 3 months, followed by a 1-month observation period. The primary outcome was the incidence of CIDs during the product consumption period.

RESULTS

There was no significant difference in the incidence of CIDs between the groups (N = 98 with fermented milk product vs N = 93 with control product). The overall number of CIDs (and no severe cases at all) in both study groups and in all 12 centers, however, was unexpectedly low resulting in underpowering of the study. No differences were found between the groups in the duration or severity of disease, duration of sick leave from day-care centers, parental missed working days, or in quality-of-life dimensions on the PedsQL questionnaire (P > 0.05).There was, however, a significantly lower incidence of the most frequently observed CID, rhinopharyngitis, in children consuming the fermented milk product compared with those consuming the control product (N = 81 vs N = 100, relative risk 0.82, 95% confidence interval 0.69-0.96, P = 0.017) when considering the entire study period.

CONCLUSIONS

Although no other significant differences were shown between the fermented milk and control product groups in this study, lower incidence of rhinopharyngitis may indicate a beneficial effect of this fermented milk product.

Bugs and Guts: Practical Applications of Probiotics for Gastrointestinal Disorders in Children

Probiotics are foods or products that contain live microorganisms that benefit the host when administered. In this clinical review, we evaluate the literature associated with using probiotics in common pediatric gastrointestinal disorders, focusing specifically on antibiotic-associated diarrhea, acute gastroenteritis, Clostridium difficile infection (CDI), colic, inflammatory bowel disease, and functional gastrointestinal diseases. Meta-analysis of several randomized controlled trials have confirmed benefit for the administration of Lactobacillus rhamnosus GG and Saccharomyces boulardii to prevent antibiotic-associated diarrhea and to treat acute infectious diarrhea. Individual studies have also suggested benefit of probiotics to prevent acute gastroenteritis and serve as an adjunct in ulcerative colitis, pouchitis, antibiotic-associated diarrhea, CDI, functional abdominal pain, irritable bowel syndrome, and colic in breastfed babies. Although promising, larger well-designed studies need to confirm these findings. There is currently insufficient evidence to recommend probiotics for the treatment of constipation-predominant irritable bowel syndrome or Crohn's disease.

Anti-infective activities of lactobacillus strains in the human intestinal microbiota: from probiotics to gastrointestinal anti-infectious biotherapeutic agents

A vast and diverse array of microbial species displaying great phylogenic, genomic, and metabolic diversity have colonized the gastrointestinal tract. Resident microbes play a beneficial role by regulating the intestinal immune system, stimulating the maturation of host tissues, and playing a variety of roles in nutrition and in host resistance to gastric and enteric bacterial pathogens. The mechanisms by which the resident microbial species combat gastrointestinal pathogens are complex and include competitive metabolic interactions and the production of antimicrobial molecules. The human intestinal microbiota is a source from which Lactobacillus probiotic strains have often been isolated. Only six probiotic Lactobacillus strains isolated from human intestinal microbiota, i.e., L. rhamnosus GG, L. casei Shirota YIT9029, L. casei DN-114 001, L. johnsonii NCC 533, L. acidophilus LB, and L. reuteri DSM 17938, have been well characterized with regard to their potential antimicrobial effects against the major gastric and enteric bacterial pathogens and rotavirus. In this review, we describe the current knowledge concerning the experimental antibacterial activities, including antibiotic-like and cell-regulating activities, and therapeutic effects demonstrated in well-conducted, placebo-controlled, randomized clinical trials of these probiotic Lactobacillus strains. What is known about the antimicrobial activities supported by the molecules secreted by such probiotic Lactobacillus strains suggests that they constitute a promising new source for the development of innovative anti-infectious agents that act luminally and intracellularly in the gastrointestinal tract.

Use of probiotics to correct dysbiosis of normal microbiota following disease or disruptive events: a systematic review

OBJECTIVE

To assess the evidence for the claim probiotics can correct dysbiosis of the normal microbiota resulting from disease or disruptive events.

SETTING

Systematic review of published clinical trials of patients receiving a probiotic intervention for the prevention or treatment of various diseases.

DATA SOURCES

Sources searched (1985-2013): PubMed, EMBASE, Cochrane Database of Systematic Reviews, CINAHL, AMED and ISI Web of Science. Three on-line clinical trial registries were searched: Cochrane Central Register of Controlled trials, MetaRegister of Controlled Trials and National Institutes of Health.

REVIEW METHODS

Included studies were randomised clinical trials of probiotic interventions having microbiological assays. Studies were evaluated following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for specific probiotic strains. A standard data extraction form was used to collect the raw data.

OUTCOME MEASURES

The primary outcome is the degree of microbiota correction by specific probiotic strains. Secondary outcome was the association between the degree of dysbiosis correction and clinical efficacy.

RESULTS

The review of the literature found three distinct study designs: model A (restoration) assayed patients enrolled with a healthy, undisturbed microbiota and then assayed postdisruptive event and probiotic therapy; model B (alteration) assayed patients with pre-existing disrupted microbiota and then postprobiotic therapy; model C (no dysbiosis) assayed volunteers with no disruptive event prebiotic and postprobiotic. From a total of 63 trials, 83% of the probiotic products using model A restored the microbiota, 56% using model B improved the microbiota and only 21% using model C had any effect on microbiota. Clinical efficacy was more commonly associated with strains capable of restoration of the normal microbiota.

CONCLUSIONS

The ability to assess the degree of dysbiosis improvement is dependent on the enrolled population and the timing of microbiological assays. The functional claim for correcting dysbiosis is poorly supported for most probiotic strains and requires further research.

TRIAL REGISTRATION NUMBER

PROSPERO (CRD42014007224).

Effects of genetic, processing, or product formulation changes on efficacy and safety of probiotics

Commercial probiotic strains for food or supplement use can be altered in different ways for a variety of purposes. Production conditions for the strain or final product may be changed to address probiotic yield, functionality, or stability. Final food products may be modified to improve flavor and other sensory properties, provide new product formats, or respond to market opportunities. Such changes can alter the expression of physiological traits owing to the live nature of probiotics. In addition, genetic approaches may be used to improve strain attributes. This review explores whether genetic or phenotypic changes, by accident or design, might affect the efficacy or safety of commercial probiotics. We highlight key issues important to determining the need to re-confirm efficacy or safety after strain improvement, process optimization, or product formulation changes. Research pinpointing the mechanisms of action for probiotic function and the development of assays to measure them are greatly needed to better understand if such changes have a substantive impact on probiotic efficacy.

Robustness of gut microbiota of healthy adults in response to probiotic intervention revealed by high-throughput pyrosequencing

Probiotics are live microorganisms that potentially confer beneficial outcomes to host by modulating gut microbiota in the intestine. The aim of this study was to comprehensively investigate effects of probiotics on human intestinal microbiota using 454 pyrosequencing of bacterial 16S ribosomal RNA genes with an improved quantitative accuracy for evaluation of the bacterial composition. We obtained 158 faecal samples from 18 healthy adult Japanese who were subjected to intervention with 6 commercially available probiotics containing either Bifidobacterium or Lactobacillus strains. We then analysed and compared bacterial composition of the faecal samples collected before, during, and after probiotic intervention by Operational taxonomic units (OTUs) and UniFrac distances. The results showed no significant changes in the overall structure of gut microbiota in the samples with and without probiotic administration regardless of groups and types of the probiotics used. We noticed that 32 OTUs (2.7% of all analysed OTUs) assigned to the indigenous species showed a significant increase or decrease of ≥10-fold or a quantity difference in >150 reads on probiotic administration. Such OTUs were found to be individual specific and tend to be unevenly distributed in the subjects. These data, thus, suggest robustness of the gut microbiota composition in healthy adults on probiotic administration.

Use of a fermented dairy probiotic drink containing Lactobacillus casei (DN-114 001) to decrease the rate of illness in kids: the DRINK study. A patient-oriented, double-blind, cluster-randomized, placebo-controlled, clinical trial

BACKGROUND

To evaluate whether a fermented dairy drink containing the probiotic strain Lactobacillus casei DN-114 001 could reduce the incidence of common infectious diseases (CIDs) and the change of behavior because of illness in children.

SUBJECTS/METHODS

We conducted a double-blinded, randomized, placebo-controlled allocation concealment clinical trial in the Washington, DC metropolitan area. Participants were 638 children 3-6 years old in daycare/schools. The intervention was a fermented dairy drink containing a specific probiotic strain or matching placebo with no live cultures for 90 consecutive days. Two primary outcomes were assessed: incidence of CIDs and change of behavior because of illness (both assessed by parental report).

RESULTS

The rate of change of behavior because of illness was similar among active and control groups. However, the incidence rate for CIDs in the active group (0.0782) is 19% lower than that of the control group (0.0986) (incidence rate ratio=0.81, 95% CI: 0.65, 099) P=0.046.

CONCLUSIONS

Daily intake of a fermented dairy drink containing the probiotic strain L. casei DN-114 001 showed some promise in reducing overall incidence of illness, but was primarily driven by gastrointestinal infections and there were no differences in change of behavior.

Guidance for substantiating the evidence for beneficial effects of probiotics: current status and recommendations for future research

Probiotic bacteria are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. There is a growing interest in probiotics within the scientific community, with consumers, and in the food industry. The interactions between the gut and intestinal microbiota and between resident and transient microbiota define a new arena in physiology, an understanding of which would shed light on the "cross-talk" between humans and microbes. The different beneficial effects of specific probiotic strains may be translated into different health claims. However, there is a need for comprehensive and harmonized guidelines on the assessment of the characteristics and efficacy of probiotics and of foods containing them. An international expert group of ILSI has evaluated the published evidence of the functionality of different probiotics in 4 areas of (human) application: 1) metabolism, 2) chronic intestinal inflammatory and functional disorders, 3) infections, and 4) allergy. Based on the existing evidence, concrete examples of demonstration of benefits and gaps are listed, and guidelines and recommendations are defined that should help design the next generation of probiotic studies.

Consumption of a fermented dairy product containing the probiotic Lactobacillus casei DN-114001 reduces the duration of respiratory infections in the elderly in a randomised controlled trial

Common infectious diseases (CID) of the airways and the gastrointestinal tract are still a considerable cause of morbidity and mortality in elderly. The present study examined the beneficial effect of a dairy product containing the probiotic strain Lactobacillus casei DN-114 001 (fermented product) on the resistance of free-living elderly to CID. The study was multicentric, double blind and controlled, involving 1072 volunteers (median age = 76.0 years) randomised for consumption of either 200 g/d of fermented (n 537) or control (non-fermented) dairy product (n 535) for 3 months, followed by an additional 1 month's follow-up. The results showed that, when considering all CID, the fermented product significantly reduced the average duration per episode of CID (6.5 v. 8 d in control group; P = 0.008) and the cumulative duration of CID (7 v. 8 d in control group; P = 0.009). Reduction in both episode and cumulative durations was also significant for all upper respiratory tract infections (URTI; P < 0.001) and for rhinopharyngitis (P < 0.001). This was accompanied with an increase of L. casei species in stools throughout the fermented product consumption (2-3.8 x 107 equivalents of colony-forming unit/g of stools, P < 0.001). The cumulative number of CID (primary outcome) was not different between groups nor was the CID severity, fever, pathogens' occurrence, medication, immune blood parameters and quality of life. The fermented product was safe and well tolerated. In conclusion, consumption of a fermented dairy product containing the probiotic strain L. casei DN-114 001 in elderly was associated with a decreased duration of CID in comparison with the control group, especially for URTI such as rhinopharyngitis.