Safety and Effect of a Low- and High-Dose Multi-Strain Probiotic Supplement on Microbiota in a General Adult Population: A Randomized, Double-Blind, Placebo-Controlled Study.

Few studies have focused on dose-response analyses of multi-strain probiotics in the general adult population. This study aimed at comparing how a low- and high-dose of a multi-strain probiotic supplement (containing Lactobacillus helveticus R0052, Lactobacillus rhamnosus R0011, Lactobacillus casei R0215, Pediococcus acidilactici R1001, Bifidobacterium breve R0070, Bifidobacterium longum ssp. longum BB536, Lactobacillus plantarum R1012, Lactococcus lactis ssp. lactis R1058) affected microbiota composition, transit persistence and safety in adults. After a 7-d baseline, participants were randomized to receive capsules containing 5 or 25 billion CFU, or placebo daily for 28 days, followed by a 7-d washout. Digestive health and general wellness were assessed. Fecal microbiota composition was analyzed using 16S rRNA gene amplicon sequencing and strain persistence, by qPCR. Participants' gastrointestinal and general wellbeing were unaffected. No adverse events were associated with either dose. Supplemented strains contributed to the Lactobacillus and Bifidobacterium genera detected in stool, with 0.40 ± 0.11% and 0.51 ± 0.26%, respectively, in the high-dose group. Strain-specific qPCR assays revealed variable levels of post-intervention persistence between strains. Sequencing and composition analyses using the 16S V4 region revealed a decrease in Holdemania and increase in Bacteroidales. The formulation was well tolerated in this sample of the general adult population, even at the higher dose. The strains appear to have influenced microbiota composition minimally, as expected in the absence of dysbiosis, and consistently with the dose administered. Overall, the results provide a rationale to study the effects this formulation on microbiota composition in individuals exhibiting dysbiosis associated with metabolic disorders or obesity.

In older women, a high-protein diet including animal-sourced foods did not impact serum levels and urinary excretion of trimethylamine-N-oxide.

Diets including red meat and other animal-sourced foods may increase proteolytic fermentation and microbial-generated trimethylamine (TMA) and, subsequently, trimethylamine-N-oxide (TMAO), a metabolite associated with increased risk of cardiovascular disease and dementia. It was hypothesized that compared to usual dietary intake, a maintenance-energy high-protein diet (HPD) would increase products of proteolytic fermentation, whereas adjunctive prebiotic, probiotic, and synbiotic supplementation may mitigate these effects. An exploratory aim was to determine the association of the relative abundance of the TMA-generating taxon, Emergencia timonensis, with serum and urinary TMAO. At 5 time points (usual dietary intake, HPD diet, HPD + prebiotic, HPD + probiotic, and HPD + synbiotic), urinary (24-hour) and serum metabolites and fecal microbiota profile of healthy older women (n = 20) were measured by liquid chromatography-tandem mass spectrometry and 16S rRNA gene amplicon sequencing analyses, respectively. The HPD induced increases in serum levels of l-carnitine, indoxyl sulfate, and phenylacetylglutamine but not TMAO or p-cresyl sulfate. Urinary excretion of l-carnitine, indoxyl sulfate, phenylacetylglutamine, and TMA increased with the HPD but not TMAO or p-cresyl sulfate. Most participants had undetectable levels of E.timonensis at baseline and only 50% during the HPD interventions, suggesting other taxa are responsible for the microbial generation of TMA in these individuals. An HPD diet with or without a prebiotic, probiotic, or synbiotic elicited an increase in products of proteolytic fermentation. The urinary l-carnitine response suggests that the additional dietary l-carnitine provided was primarily bioavailable, providing little substrate for microbial conversion to TMA and subsequent TMAO formation.

Microbiota Stability and Gastrointestinal Tolerance in Response to a High-Protein Diet with and without a Prebiotic, Probiotic, and Synbiotic: A Randomized, Double-Blind, Placebo-Controlled Trial in Older Women.

BACKGROUND: Higher protein intakes may help reduce sarcopenia and facilitate recovery from illness and injury in older adults. However, high-protein diets (HPDs) including animal-sourced foods may negatively perturb the microbiota, and provision of probiotics and prebiotics may mitigate these effects. OBJECTIVE: The aim of this study was to examine the effects of HPD, with and without a probiotic and/or prebiotic, on gut microbiota and wellness in older women. DESIGN: We conducted an 18-week, double-blind, placebo-controlled, crossover study. PARTICIPANTS/SETTING: Participants were healthy, older women (mean age±standard deviation=73.7±5.6 years; n=26) recruited from Florida. INTERVENTION: Participants received a weight-maintenance HPD for 2-week periods and the following, in random order: HPD alone (1.5 to 2.2 g/kg/day protein); HPD plus multistrain probiotic formulation (1.54×109Bifidobacterium bifidum HA-132, 4.62×109Bifidobacterium breve HA-129, 4.62×109Bifidobacterium longum HA-135, 4.62×109Lactobacillus acidophilus HA-122, and 4.62×109Lactobacillus plantarum HA-119), HPD plus prebiotic (5.6 g inulin), and HPD plus synbiotic (probiotic plus inulin), separated by 2-week washouts. Stools were collected per period for quantitative polymerase chain reaction (strain recovery) and 16S ribosomal RNA gene amplicon sequencing analyses (microbiota profile). Measures of gastrointestinal and general wellness were assessed. MAIN OUTCOME MEASURES: Microbiota composition and probiotic strain recovery were measured. STATISTICAL ANALYSES: Microbiota composition was analyzed by Wilcoxon signed-rank test and t test. Secondary outcomes were analyzing using generalized linear mixed models. RESULTS: The microbiota profile demonstrated relative stability with the HPD; representation of Lactobacillus, Lactococcus, and Streptococcus were enhanced, whereas butyrate producers, Roseburia and Anaerostipes, were suppressed. Lactococcus was suppressed with synbiotic vs other HPD periods. Recovery was confirmed for all probiotic strains. Indicators of wellness were unchanged, with the exception of a minimal increase in gastrointestinal distress with inulin. Fat-free mass increased from baseline to study end. CONCLUSIONS: An HPD adhering to the recommended acceptable macronutrient distribution ranges maintains wellness in healthy older women and exerts minor perturbations to the microbiome profile, a group that may benefit from a higher protein intake. ClinicalTrials.gov ID: NCT #02445560.

The effects of Bifidobacterium animalis ssp. lactis B94 on gastrointestinal wellness in adults with Prader-Willi syndrome: study protocol for a randomized controlled trial.

BACKGROUND: Constipation is a frequent problem in adults with Prader-Willi syndrome. Certain probiotics have been shown to improve transit and gastrointestinal symptoms of adults with functional constipation. The aim of this study is to determine the effect of daily consumption of Bifidobacterium animalis ssp. lactis B94 (B. lactis B94) on stool frequency, stool form, and gastrointestinal symptoms in adults with Prader-Willi syndrome. METHODS: Adults with Prader-Willi syndrome (18-75 years old, n = 36) will be recruited and enrolled in a 20-week, randomized, double-blind, placebo-controlled, crossover study. Study subjects will be randomized to B. lactis B94 or placebo each for a 4-week period, preceded by a 4-week baseline and followed by 4-week washouts. Subjects will complete daily records of stool frequency and stool form (a proxy of transit time). Dietary intake data also will be collected. Stools, one in each period, will be collected for exploratory microbiota analyses. DISCUSSION: To our knowledge, this is the first randomized controlled trial evaluating the effectiveness of B. lactis in adults with Prader-Willi syndrome. The results of this study will provide evidence of efficacy for future clinical trials in patient populations with constipation. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03277157 ). Registered on 08 September 2017.