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

BACKGROUND: Probiotics have shown promise in alleviating symptoms of diarrhea-predominant irritable bowel syndrome (IBS-D); however, the certainty of evidence is low. Well-powered randomized controlled dose-ranging trials are warranted on promising single-strain candidates. AIM: To investigate the clinical efficacy of Lactiplantibacillus plantarum (L. plantarum) Lpla33 (DSM34428) in adults with IBS-D. METHODS: This is a randomized, double-blind, placebo-controlled, multi-center, and dose-ranging study. Three hundred and seven adults, 18-70 years of age, with IBS-D, according to Rome IV criteria, were allocated (1:1:1) to receive placebo or L. plantarum Lpla33 at 1 × 109 (1B) or 1 × 1010 (10B) colony-forming units/d over an 8-wk intervention period. The primary outcome was the change in IBS severity scoring system (IBS-SSS) total score after 8 wk, while secondary and exploratory outcomes included abdominal pain severity, IBS related quality of life, stool and microbial profile, and perceived stress. RESULTS: IBS-SSS was significantly reduced, after 8 wk, in participants receiving L. plantarum 1B (-128.45 ± 83.30; P < 0.001) and L. plantarum 10B (-156.77 ± 99.06; P < 0.001), compared to placebo (-58.82 ± 74.75). Further, a dose-ranging effect was observed, with a greater absolute reduction in the L. plantarum 10B group (P < 0.05). A reduction in sub-scores related to abdominal pain, abdominal distension, bowel habits, and quality of life was observed in both L. plantarum groups compared to placebo (P < 0.001). Further, 62.5% and 88.4% of participants administered L. plantarum 1B and 10B, respectively, were classified as stool consistency responders based on a reduction in diarrheal stool form, as compared to 26.3% in the placebo group (P < 0.001). In contrast, no significant shifts were observed in microbial diversity. CONCLUSION: L. plantarum Lpla33 (DSM34428) is well tolerated and improves IBS symptom severity with a dose-ranging effect and a corresponding normalization of bowel habits in adults with IBS-D.

Emerging issues in probiotic safety: 2023 perspectives.

Probiotics are used for both generally healthy consumers and in clinical settings. However, theoretical and proven adverse events from probiotic consumption exist. New probiotic strains and products, as well as expanding use of probiotics into vulnerable populations, warrants concise, and actionable recommendations on how to work toward their safe and effective use. The International Scientific Association for Probiotics and Prebiotics convened a meeting to discuss and produce evidence-based recommendations on potential acute and long-term risks, risks to vulnerable populations, the importance for probiotic product quality to match the needs of vulnerable populations, and the need for adverse event reporting related to probiotic use. The importance of whole genome sequencing, which enables determination of virulence, toxin, and antibiotic resistance genes, as well as clear assignment of species and strain identity, is emphasized. We present recommendations to guide the scientific and medical community on judging probiotic safety.

What is the context? Probiotics, available to healthy consumers as both dietary supplements and foods, are also used by some patient populations. The goal of this paper is to determine if any new factors have emerged that would impact current views about probiotic safety for both these populations.What is new? The authors conclude that established practices are sensibly addressing factors important to the safety of traditional probiotics used by the general population. They also make recommendations regarding emerging safety considerations. Probiotics targeted for patient populations should undergo stringent testing to meet quality standards appropriate for that population, preferably verified by an independent third party. The safety of probiotics derived from species without a history of safe use must be considered on a case-by-case basis. Research is needed to address some gaps, for example which best animal models to use for safety assessment of live microbes, the possibility of antibiotic resistance gene transfer via transformation, and potential impact of probiotic-induced changes in microbiomes, interactions with drugs, and probiotic colonization.What is the impact? Probiotics of sufficient quality for patient populations are being developed and should be used accordingly. Long-term safety assessments for probiotics should be consistent with, and not more stringent than, current regulatory requirements for biologic drugs, including fecal microbial transplants. Rigor in collecting and reporting data on adverse events is needed. The authors confirm the need for understanding the entire genetic makeup of a probiotic as a cornerstone for assessing its safety.

Impact of a probiotic chewable tablet on stool habits and microbial profile in children with functional constipation: A randomized controlled clinical trial.

Constipation is a common and typically multifactorial childhood complaint, and the clinical management of childhood functional constipation (FC) is challenging. A randomized, single-blind, placebo-controlled, multi-center clinical trial was conducted in 92 children (47 from Beijing, China and 45 from Shanghai, China) aged 4-12 with FC according to Rome III criteria. Children were assigned to receive a probiotic chewable tablet (5 × 109 CFU/day, n = 47), consisting of Lactobacillus acidophilus DDS-1® and Bifidobacterium animalis subsp. lactis UABla-12™ or placebo (n = 45), twice daily for 4 weeks, followed by a week follow-up period. Results suggested that the probiotic group showed a faster and more pronounced normalization of stool frequency over the intervention period (3.15 vs. 1.83) when compared to placebo group (2.51 vs. 1.87). Meanwhile, the percentage of subjects with hard defecation decreased from 43 to 14% in the probiotic group, while the percentage of subjects with normal defecation increased from 56 to 80% in the probiotic group, further confirming the normalization of stools habits. This randomized controlled trial demonstrated the potential of a probiotic chewable tablet containing L. acidophilus DDS-1® and B. Lactis UABla-12™ as a daily probiotic dosage form for children with FC.

Effects of a 10-Strain Oral Probiotic on Parameters of Vaginal Health and Microbial Community: A Pilot Clinical Study.

OBJECTIVE: To investigate the clinical effects of a 10-strain probiotic on parameters of vaginal health in a pilot, open label study in women with intermediate Nugent score (NS) or vaginal pH >4.5. METHODOLOGY: A total of 43 healthy premenopausal women, ages 18 to 50 years, with NS of 4-6 or vaginal pH >4.5 were enrolled. Participants consumed a probiotic formulation (Feminine Support™), containing 8 lactobacilli and 2 bifidobacteria strains, with a daily dose of 2.5×1010 CFU for 28 (subgroup 1) or 42 (subgroup 2) days. Investigational visits occurred at day 0, 14, 28 and 42 with assessment of vaginal pH, NS and vaginal microbiota, via next-generation sequencing. RESULTS: A total of 36 participants were included in the analysis set, with 24 and 12 participants included in subgroups 1 and 2, respectively. In the analysis set, there was a significant reduction in vaginal pH, from baseline, at day 28 (mean change=-0.19, P = 0.047). Participants in subgroup 1 achieved a significant reduction in vaginal pH from baseline, at day 28 (mean change=-0.23, P = 0.029) and day 42 (mean change=-0.29, P = 0.008), while participants in subgroup 2 achieved a significant and quantitatively greater reduction in vaginal pH from baseline to day 42 (mean change=-0.64, P = 0.008). No significant changes in NS were reported, due in part to highly diverse baseline levels. Vaginal microbial abundance exhibited a majority lactobacilli abundance at baseline, which was maintained over the study period. Vaginal pH was inversely associated with lactobacilli abundance throughout the study (P < 0.005). The product was well tolerated with high compliance. Two participants reported adverse events with suspected causality, which were mild and resolved during the study. CONCLUSION: This 10-strain probiotic formulation was well tolerated and helped reduce vaginal pH in women with intermediate NS or elevated vaginal pH. The study product warrants a randomized controlled trial to further assess efficacy.

Corrigendum: Probiotics, Anticipation Stress, and the Acute Immune Response to Night Shift.

[This corrects the article DOI: 10.3389/fimmu.2020.599547.].

Real-Time PCR Assays for the Specific Identification of Probiotic Strains Lactobacillus gasseri BNR17 and Lactobacillus reuteri LRC (NCIMB 30242).

The broad spectrum of health benefits attributed to probiotics has contributed to a rapid increase in the value of the probiotic market. Probiotic health benefits can be strain specific. Thus, strain-level identification of probiotic strains is of paramount importance to ensure probiotic efficacy. Both Lactobacillus gasseri BNR17 and Lactobacillus reuteri LRC (NCIMB 30242) strains have clinically proven health benefits; however, no assays were developed to enable strain-level identification of either of these strains. The objective of this study is to develop strain-specific PCR-based methods for Lactobacillus gasseri BNR17 and Lactobacillus reuteri LRC strains, and to validate these assays according to the guidelines for validating qualitative real-time PCR assays. Using RAST (Rapid Annotation using Subsystem Technology), unique sequence regions were identified in the genome sequences of both strains. Probe-based assays were designed and validated for specificity, sensitivity, efficiency, repeatability, and reproducibility. Both assays were specific to target strain with 100% true positive and 0% false positive rates. Reaction efficiency for both assays was in the range of 90 to 108% with R square values > 0.99. Repeatability and reproducibility were evaluated using five samples at three DNA concentrations each and relative standard deviation was < 4% for repeatability and < 8% for reproducibility. Both of the assays developed and validated in this study for the specific identification of Lactobacillus gasseri BNR17 and Lactobacillus reuteri LRC strains are specific, sensitive, and precise. These assays can be applied to evaluate and ensure compliance in probiotic products.

Lactobacillus acidophilus DDS-1 and Bifidobacterium lactis UABla-12 Improve Abdominal Pain Severity and Symptomology in Irritable Bowel Syndrome: Randomized Controlled Trial.

This randomized, double-blind, placebo-controlled, multi-center study investigated the clinical efficacy of two probiotic strains on abdominal pain severity and symptomology in irritable bowel syndrome (IBS). Three hundred and thirty adults, aged 18 to 70 years, with IBS according to Rome IV criteria were allocated (1:1:1) to receive placebo, Lactobacillus acidophilus DDS-1 (1 × 1010 CFU/day) or Bifidobacterium animalis subsp. lactis UABla-12 (1 × 1010 CFU/day) over six weeks. The primary outcome was the change in Abdominal Pain Severity - Numeric Rating Scale (APS-NRS). Over the intervention period, APS-NRS was significantly improved in both probiotic groups vs. placebo in absolute terms (DDS-1: -2.59 ± 2.07, p = 0.001; UABla-12: -1.56 ± 1.83, p = 0.001) and in percentage of significant responders (DDS-1: 52.3%, p < 0.001); UABla-12 (28.2%, p = 0.031). Significant amelioration vs. placebo was observed in IBS Symptom Severity Scale (IBS-SSS) scores for L. acidophilus DDS-1 (-133.4 ± 95.19, p < 0.001) and B. lactis UABla-12 (-104.5 ± 96.08, p < 0.001) groups, including sub-scores related to abdominal pain, abdominal distension, bowel habits and quality of life. Additionally, a significant normalization was observed in stool consistency in both probiotic groups over time and as compared to placebo. In conclusion, L. acidophilus DDS-1 and B. lactis UABla-12 improved abdominal pain and symptom severity scores with a corresponding normalization of bowel habits in adults with IBS.

Probiotics, Anticipation Stress, and the Acute Immune Response to Night Shift.

Introduction: Sleep disturbance and sleep disruption are associated with chronic, low grade inflammation and may underpin a range of chronic diseases in night shift workers. Through modulation of the intestinal microbiota, probiotic supplements may moderate the effects of sleep disruption on the immune system. The aim of this study was to examine 14 days of daily probiotic supplementation on the acute response of acute phase proteins and immune markers to sleep disruption associated with night shift work (Australia and New Zealand Clinical Trials Registry: 12617001552370). Methods: Individuals (mean age 41 ± 11 yrs; 74% female) performing routine night shift were randomly assigned to a probiotic group (1 × 1010 colony forming units (CFU) Lactobacillus acidophilus DDS-1 or 1 × 1010 CFU Bifidobacterium animalis subsp. lactis UABla-12) or placebo (n= 29 per group). Participants undertook a 14-day supplementation period that coincided with a period of no night shifts followed by two consecutive night shifts. Blood samples were collected prior to the start of supplementation (V1), prior to commencing the first night shift (V2), after the first night shift (V3) and after the second night shift (V4). Serum was assessed for markers of stress (cortisol), acute phase response (C reactive protein (CRP), erythrocyte sedimentation rate, pentraxin), adhesion markers (serum E-selectin, mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1), and serum cytokines (interleukin (IL)-1ra, IL-1ß, IL-6, tumor necrosis factor (TNF)-α, IL-10). Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI) and a Fitbit activity tracker. Results: The groups were well balanced on key markers and the probiotic strains were well tolerated. The 14-day supplementation period that coincided with typical night-day sleep-wake cycles leading up to night shift (V1 to V2) was associated with significant changes in the placebo group in the concentration of serum cortisol (p = 0.01), pentraxin (p = 0.001), MAdCAM-1 (p = 0.001), and IL-1ra (p=0.03). In contrast, probiotic supplementation moderated changes in these serum markers from V1 to V2. No significant interaction effects (time by group) were observed for the serum markers prior to and after night shift work following probiotic supplementation due to the substantial changes in the serum markers that occurred during the normal sleep period from V1 to V2. Conclusions: Probiotics may moderate the effects of anticipatory stress on the immune system in the lead up to night shift.

Impact of a probiotic product on bowel habits and microbial profile in participants with functional constipation: A randomized controlled trial.

OBJECTIVE: To investigate the clinical efficacy of a multi-strain probiotic product on bowel habits and microbial profile in participants with functional constipation. METHODS: This was a randomized, double-blind, placebo-controlled and parallel-arm study. Altogether 94 otherwise healthy adults aged 18 to 65 years with symptoms of functional constipation were randomized as part of the intention-to-treat population. The participants received a placebo or the probiotic product (1.5 × 1010 CFU/day), consisting of Lactobacillus acidophilus DDS-1, Bifidobacterium animalis subsp. lactis UABla-12, Bifidobacterium longum UABl-14 and Bifidobacterium bifidum UABb-10 over 4 weeks. Outcomes included the patient assessment of constipation-symptom (PAC-SYM) questionnaire, stool frequency and consistency, and microbial profile. RESULTS: There were no significant between-group differences in the PAC-SYM score, despite significant within-group differences (P < 0.001) over the study period. The probiotic group showed a faster normalization of stool frequency and consistency, with most participants achieving a normalized profile after 1 week. Fecal samples of the probiotic group exhibited higher relative abundance of Ruminococcaceae (P = 0.0047), including the Ruminococcus genus, and lower relative abundance of Erysipelotrichaceae (P = 0.0172) at end-point compared with baseline. Placebo group samples showed similar abundance profiles over the study, with the exception of Clostridiaceae, which was lower at the study end-point (P = 0.0033). Among treated participants, all four probiotic strains were significantly more abundant after the intervention. CONCLUSIONS: No significant differences were observed in symptomology, with both groups showing a more than 20% improvement. However, the probiotic helped modulate bowel function earlier than the placebo, with a corresponding shift to a more fibrolytic microbiota.

Probiotic use in at-risk populations.

OBJECTIVE: To inform health care providers about quality standards for manufacture of probiotic products being recommended for at-risk patient populations. SUMMARY: Probiotics are used in a variety of clinical settings, sometimes in at-risk populations for therapeutic endpoints. Although probiotics might not be approved as drugs, they are sometimes used for the prevention or treatment of disease. In the United States, and many regions of the world, probiotic products are marketed as dietary supplements (not drugs) and are therefore subject to different manufacturing and quality control standards than approved drugs are. Health care providers need to be assured that probiotic products used in at-risk populations are safe for this use. Pharmacists should require certificates of analysis, which document quality standards, from manufacturers of products stocked in hospital formularies or other pharmacies dispensing to at-risk people. Although responsible manufacturers use stringent quality standards on their processes and finished products, using a third party to verify compliance with manufacturing and accuracy of product labeling adds assurance to end users that the product is of high quality. CONCLUSION: It is in patients' best interest to use probiotics in the prevention and treatment of conditions when the evidence is convincing. To protect high-risk patients, probiotic products should meet stringent microbiological standards. Product testing results should be available for review before recommending probiotic products to at-risk individuals. For products used in at-risk populations, manufacturers should provide this information or participate in a third-party verification program that certifies compliance.

Determining the safety of microbial cultures for consumption by humans and animals.

Fermented foods and feeds have been consumed for millennia, and microorganisms isolated from traditional fermentations have been used as probiotics. There is interest in developing new microbial cultures for these uses, but to date safety evaluation procedures have only been discussed in general terms. We propose a comprehensive approach for determining the safety of microbial cultures that lack an established history of safe use for their intended new applications. Three scenarios are considered: (1) substantially increased exposure to a culture that has an established record of safety in a more limited application; (2) a new strain without a history of safe use that was isolated from a food or feed that has a history of safe use; and (3) a new strain isolated from a non-food or non-feed source. Our safety evaluation process is based on scientific procedures and is in the form of a decision tree composed of 13 questions. Our decision tree for determining the safety of microbial cultures for consumption by humans or animals is modeled on previous decision trees that are used worldwide to evaluate the safety of microbial enzymes for use in human food or animal feed.

Dose-response effect of Bifidobacterium lactis HN019 on whole gut transit time and functional gastrointestinal symptoms in adults.

OBJECTIVE: To assess the impact of Bifidobacterium lactis HN019 supplementation on whole gut transit time (WGTT) and frequency of functional gastrointestinal (GI) symptoms in adults. MATERIAL AND METHODS: We randomized 100 subjects (mean age: 44 years; 64% female) with functional GI symptoms to consume a proprietary probiotic strain, B. lactis HN019 (Fonterra Research Centre, Palmerston North, New Zealand), at daily doses of 17.2 billion colony forming units (CFU) (high dose; n = 33), 1.8 billion CFU (low dose; n = 33), or placebo (n = 34) for 14 days. The primary endpoint of WGTT was assessed by X-ray on days 0 and 14 and was preceded by consumption of radiopaque markers once a day for 6 days. The secondary endpoint of functional GI symptom frequency was recorded with a subject-reported numeric (1-100) scale before and after supplementation. RESULTS: Decreases in mean WGTT over the 14-day study period were statistically significant in the high dose group (49 ± 30 to 21 ± 32 h, p < 0.001) and the low dose group (60 ± 33 to 41 ± 39 h, p = 0.01), but not in the placebo group (43 ± 31 to 44 ± 33 h). Time to excretion of all ingested markers was significantly shorter in the treatment groups versus placebo. Of the nine functional GI symptoms investigated, eight significantly decreased in frequency in the high dose group and seven decreased with low dose, while two decreased in the placebo group. No adverse events were reported in any group. CONCLUSIONS: Daily B. lactis HN019 supplementation is well tolerated, decreases WGTT in a dose-dependent manner, and reduces the frequency of functional GI symptoms in adults.

Probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07 versus placebo for the symptoms of bloating in patients with functional bowel disorders: a double-blind study.

BACKGROUND: Recent data suggest a role for the intestinal microbiota in the pathogenesis of functional bowel disorders (FBDs). Probiotic studies in FBDs generated inconsistent results suggesting a strain-specific and product-specific effect. AIM: To investigate the clinical efficacy of Lactobacillus acidophilus NCFM (L-NCFM) and Bifidobacterium lactis Bi-07 (B-LBi07) in nonconstipation FBDs. METHODS: A double-blind, placebo-control clinical trial of the probiotic bacterias L-NCFM and B-LBi07 twice a day (2×10(11) CFU/d) versus placebo over 8 weeks. Primary endpoints were global relief of gastrointestinal symptoms and satisfaction with treatment. Secondary endpoints were change in symptoms severity, well-being, and quality of life. Microbiological effect was assessed by quantitative real time polymerase chain reaction on fecal samples. RESULTS: Sixty patients (probiotic, n=31; placebo, n=29), 72% females, 84% whites, mean age 37 years. Abdominal bloating improved in the probiotics compared with the placebo group at 4 weeks (4.10 vs 6.17, P=0.009; change in bloating severity P=0.02) and 8 weeks (4.26 vs 5.84, P=0.06; change in bloating severity P<0.01). Analyses on the irritable bowel syndrome subgroup (n=33) showed similar results. CONCLUSIONS: L-NCFM and B-LBi07 twice a day improve symptoms of bloating in patients with FBDs. These data supports the role of intestinal bacteria in the pathophysiology of FBD and the role for probiotic bacteria in the management of these disorders.

Probiotic effects on cold and influenza-like symptom incidence and duration in children.

OBJECTIVE: Probiotic consumption effects on cold and influenza-like symptom incidence and duration were evaluated in healthy children during the winter season. METHODS: In this double-blind, placebo-controlled study, 326 eligible children (3-5 years of age) were assigned randomly to receive placebo (N = 104), Lactobacillus acidophilus NCFM (N = 110), or L acidophilus NCFM in combination with Bifidobacterium animalis subsp lactis Bi-07 (N = 112). Children were treated twice daily for 6 months. RESULTS: Relative to the placebo group, single and combination probiotics reduced fever incidence by 53.0% (P = .0085) and 72.7% (P = .0009), coughing incidence by 41.4% (P = .027) and 62.1% (P = .005), and rhinorrhea incidence by 28.2% (P = .68) and 58.8% (P = .03), respectively. Fever, coughing, and rhinorrhea duration was decreased significantly, relative to placebo, by 32% (single strain; P = .0023) and 48% (strain combination; P < .001). Antibiotic use incidence was reduced, relative to placebo, by 68.4% (single strain; P = .0002) and 84.2% (strain combination; P < .0001). Subjects receiving probiotic products had significant reductions in days absent from group child care, by 31.8% (single strain; P = .002) and 27.7% (strain combination; P < .001), compared with subjects receiving placebo treatment. CONCLUSION: Daily dietary probiotic supplementation for 6 months was a safe effective way to reduce fever, rhinorrhea, and cough incidence and duration and antibiotic prescription incidence, as well as the number of missed school days attributable to illness, for children 3 to 5 years of age.

Probiotics to minimize the disruption of faecal microbiota in healthy subjects undergoing antibiotic therapy.

A novel combination of culturing and DNA-based terminal restriction fragment length polymorphism (TRFLP) analysis was used to investigate the effect of probiotics on antibiotic-induced gut microbiota alterations to determine if a probiotic preparation containing bifidobacteria and lactobacilli, taken during and after antibiotic therapy, can minimize antibiotic disturbance of faecal microbiota. Healthy subjects administered amoxicillin/clavulanate were randomized and concomitantly received a placebo or probiotic mixture. The primary end point was similarity of faecal microbiota as determined by culturing and TRFLP from subjects taking probiotics compared to those taking a placebo measured by comparing data from baseline to post-treatment for each subject. TRFLP analysis revealed a high subject to subject variation in the baseline faecal microbiota. The most common antibiotic-induced disturbance was a relative increase in Clostridium, Eubacterium, Bacteroides and Enterobacteraceae. The mean similarity to the baseline increased over time in both treatment groups, although the probiotic group was less disturbed according to both TRFLP and culture data. The culture method revealed that post-antibiotic faecal microbiota in probiotic-consuming subjects were more similar to the baseline microbiota than the control group (P=0.046). Changes in Enterobactereaceae (P=0.006) and Bifidobacterium (P=0.030) counts were significantly different between the groups. Analysis of TRFLP data reinforced the trend between groups but was not statistically significant (P=0.066). This study indicates this mixture of probiotics promotes a more rapid return to pre-antibiotic baseline faecal bacterial microbiota.

Comparison of the complete genome sequences of Bifidobacterium animalis subsp. lactis DSM 10140 and Bl-04.

Bifidobacteria are important members of the human gut flora, especially in infants. Comparative genomic analysis of two Bifidobacterium animalis subsp. lactis strains revealed evolution by internal deletion of consecutive spacer-repeat units within a novel clustered regularly interspaced short palindromic repeat locus, which represented the largest differential content between the two genomes. Additionally, 47 single nucleotide polymorphisms were identified, consisting primarily of nonsynonymous mutations, indicating positive selection and/or recent divergence. A particular nonsynonymous mutation in a putative glucose transporter was linked to a negative phenotypic effect on the ability of the variant to catabolize glucose, consistent with a modification in the predicted protein transmembrane topology. Comparative genome sequence analysis of three Bifidobacterium species provided a core genome set of 1,117 orthologs complemented by a pan-genome of 2,445 genes. The genome sequences of the intestinal bacterium B. animalis subsp. lactis provide insights into rapid genome evolution and the genetic basis for adaptation to the human gut environment, notably with regard to catabolism of dietary carbohydrates, resistance to bile and acid, and interaction with the intestinal epithelium. The high degree of genome conservation observed between the two strains in terms of size, organization, and sequence is indicative of a genomically monomorphic subspecies and explains the inability to differentiate the strains by standard techniques such as pulsed-field gel electrophoresis.

Selecting lactic acid bacteria for their safety and functionality by use of a mouse colitis model.

Studies showed that specific probiotics might provide therapeutic benefits in inflammatory bowel disease. However, a rigorous screening of new probiotics is needed to study possible adverse interactions with the host, particularly when intended for administration to individuals with certain health risks. In this context, the objective of this study was to investigate the role of three lactobacilli (LAB) on intestinal inflammation and bacterial translocation using variations of the mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced acute colitis. We first compared the in vitro ability of LAB to survive gastrointestinal tract (GIT) conditions and their ability to persist in the GIT of mice following daily oral administration. As a control, we included a nonprobiotic Lactobacillus paracasei strain, previously isolated from an endocarditis patient. Feeding high doses of LAB strains to healthy and to TNBS-treated mice did not induce any detrimental effect or abnormal translocation of the bacteria. Oral administration of Lactobacillus salivarius Ls-33 had a significant preventive effect on colitis in mice, while Lactobacillus plantarum Lp-115 and Lactobacillus acidophilus NCFM did not. None of the three selected LAB strains translocated to extraintestinal organs of TNBS-treated mice. In contrast, L. paracasei exacerbated colitis under severe inflammatory conditions and translocated to extraintestinal organs. This study showed that evaluations of the safety and functionality of new probiotics are recommended. We conclude that not all lactobacilli have similar effects on intestinal inflammation and that selected probiotics such as L. salivarius Ls-33 may be considered in the prevention or treatment of intestinal inflammation.

Analysis of treatment effects on the microbial ecology of the human intestine.

A large number of studies have investigated gastrointestinal microbiota and changes in the gastrointestinal community. However, a concern in these studies is how best to assess changes in gastrointestinal community structure. This paper presents two different human trials where the fecal terminal restriction fragment length polymorphism data sets were analyzed to search for treatment effects. Principle components analysis and cluster analysis based on grouped data are compared with analysis of data by subject using distance coefficients. Comparison with baseline within an individual before grouping by treatment provided a clearer indication of treatment effects than did an evaluation of data grouped before analysis. In addition, a large within-subject sample size and multiple baseline samples are necessary to accurately analyze treatment effects.