The study to investigate the potential benefits of probiotics in yogurt, a patient-oriented, double-blind, cluster-randomised, placebo-controlled, clinical trial

The effect of oral probiotics on glycemic control of women with gestational diabetes mellitus-a multicenter, randomized, double-blind, placebo-controlled trial

BACKGROUND

Gestational diabetes mellitus should be treated adequately to avoid maternal hyperglycemia-related complications. Previously, probiotic supplements were suggested to improve fasting blood glucose in women with gestational diabetes mellitus. However, a major limitation of previous studies was that preprandial and especially postprandial glucose values, which are important predictors of pregnancy outcomes, were not studied.

OBJECTIVE

This study aimed to examine the effect of a mixture of probiotic strains on maternal glycemic parameters, particularly preprandial and postprandial glucose values and pregnancy outcomes among women with gestational diabetes mellitus.

STUDY DESIGN

A multicenter prospective randomized, double-blind, placebo-controlled trial was conducted. Women newly diagnosed with gestational diabetes mellitus were randomly allocated into a research group, receiving 2 capsules of oral probiotic formula containing Bifidobacterium bifidum, B lactis, Lactobacillus acidophilus, L paracasei, L rhamnosus, and Streptococcus thermophilus (>6 × 109/capsule), and a control group, receiving a placebo (2 capsules/day) until delivery. Glycemic control was evaluated by daily glucose charts. After 2 weeks, pharmacotherapy was started in case of poor glycemic control. The primary outcomes were the rate of women requiring medications for glycemic control and mean daily glucose charts after 2 weeks of treatment with the study products.

RESULTS

Forty-one and 44 women were analyzed in the treatment and placebo cohorts, respectively. Mean daily glucose during the first 2 weeks in the probiotics and placebo groups was 99.7±7.9 and 98.0±9.3 mg/dL, respectively (P=.35). The rate of women needing pharmacotherapy because of poor glycemic control after 2 weeks of treatment in the probiotics and placebo groups was 24 (59%) and 18 (41%), respectively (P=.10). Mean preprandial and postprandial glucose levels throughout the study period were similar between the groups (P>.05). There were no differences in maternal and neonatal outcomes, including birthweight and adverse effect profile between the groups.

CONCLUSION

The oral probiotic product tested in this study did not affect glycemic control of women with gestational diabetes mellitus.

Administration of Bifidobacterium animalis subsp. lactis strain BB-12® in healthy children: characterization, functional composition, and metabolism of the gut microbiome

Introduction

The consumption of probiotics may influence children's gut microbiome and metabolome, which may reflect shifts in gut microbial diversity composition and metabolism. These potential changes might have a beneficial impact on health. However, there is a lack of evidence investigating the effect of probiotics on the gut microbiome and metabolome of children. We aimed to examine the potential impact of a two (Streptococcus thermophilus and Lactobacillus delbrueckii; S2) vs. three (S2 + Bifidobacterium animalis subsp. lactis strain BB-12) strain-supplemented yogurt.

Methods

Included in this study were 59 participants, aged one to five years old, recruited to phase I of a double-blinded, randomized controlled trial. Fecal samples were collected at baseline, after the intervention, and at twenty days post-intervention discontinuation, and untargeted metabolomics and shotgun metagenomics were performed.

Results

Shotgun metagenomics and metabolomic analyses showed no global changes in either intervention group's gut microbiome alpha or beta diversity indices, except for a lower microbial diversity in the S2 + BB12 group at Day 30. The relative abundance of the two and three intervention bacteria increased in the S2 and S2 + BB12 groups, respectively, from Day 0 to Day 10. In the S2 + BB12 group, the abundance of several fecal metabolites increased at Day 10, including alanine, glycine, lysine, phenylalanine, serine, and valine. These fecal metabolite changes did not occur in the S2 group.

Discussion

In conclusion, there were were no significant differences in the global metagenomic or metabolomic profiles between healthy children receiving two (S2) vs. three (S2 + BB12) probiotic strains for 10 days. Nevertheless, we observed a significant increase (Day 0 to Day 10) in the relative abundance of the two and three probiotics administered in the S2 and S2 + BB12 groups, respectively, indicating the intervention had a measurable impact on the bacteria of interest in the gut microbiome. Future research using longer probiotic intervention durations and in children at risk for gastrointestinal disorders may elucidate if functional metabolite changes confer a protective gastrointestinal effect.

The influence of probiotics on gastrointestinal tract infections among children attending childcare: A systematic review and meta-analysis

Current literature related to the impact of probiotics on the incidence of gastrointestinal tract infections (GITIs) has shown mixed results and no systematic review available with pooled analysis exists. Thus, the aim of this systematic review was to provide contemporary evidence regarding the overall and strain-specific influence of probiotics in preventing GITIs among infants and children attending childcare centres. The review shortlisted 18 RCTs after screening through the initial search results of 779 articles. However, only 15 trials were deemed eligible, addressing at least one outcome in the pooled analysis. It is concluded that the supplementation of probiotics (overall effect) may reduce the risk of GITI episode by 26%, with Lacticaseibacillus paracasei, Limosilactobacillus reuteri and Lacticaseibacillus rhamnosus GG being specifically potent probiotic strains in reducing GITI episode, duration of infection and absence from childcare respectively. There is insufficient evidence to determine the effect of Bifidobacterium animalis subsp. lactis BB-12 based on the findings of the trials included in this review.

The relationship between dairy products intake and breast cancer incidence: a meta-analysis of observational studies

Background

The effect of dairy products intake on breast cancer (BC) is highly controversial. This study aims to investigate the relationship between dairy intake and BC incidence.

Methods

A search was carried out in PubMed, EBSCO, Web of Science, and Cochrane Library databases before January 2021. The primary objective was the risk of BC and intake of dairy products were exposure variables.

Results

The meta-analysis comprised 36 articles with 1,019,232 participants. Total dairy products have a protective effect on female population (hazard ratio (HR) =0.95, 95% confidence interval (CI) =0.91–0.99, p = 0.019), especially for estrogen receptor-positive (ER+) (HR = 0.79, p = 0.002) and progesterone receptor-positive (PR+) BC (HR = 0.75, p = 0.027). For ER+/PR+ BC, there is a trend of protection, but it has not reached statistical significance (HR = 0.92, p = 0.075). Fermented dairy products can reduce BC risk in postmenopausal population (HR = 0.96, 95%CI = 0.93–0.99, p = 0.021), but have no protective effect on premenopausal population (HR = 0.98, 95%CI = 0.94–1.03, p = 0.52). Non-fermented dairy products have no significant effect on BC occurrence (p > 0.05). High-fat dairy products are harmful to women, without statistical difference (HR = 1.06, 95%CI = 1.00–1.13, p = 0.066). On the contrary, low-fat dairy products can protect the premenopausal population (HR = 0.94, 95%CI = 0.89–1.00, p = 0.048).

Conclusion

The intake of dairy products can overall reduce BC risk in the female population, but different dairy products have varying effects on different BC subtypes and menopausal status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08854-w.

Bifidobacterium animalis subsp. lactis BB-12 Protects against Antibiotic-Induced Functional and Compositional Changes in Human Fecal Microbiome

The administration of broad-spectrum antibiotics is often associated with antibiotic-associated diarrhea (AAD), and impacts gastrointestinal tract homeostasis, as evidenced by the following: (a) an overall reduction in both the numbers and diversity of the gut microbiota, and (b) decreased short-chain fatty acid (SCFA) production. Evidence in humans that probiotics may enhance the recovery of microbiota populations after antibiotic treatment is equivocal, and few studies have addressed if probiotics improve the recovery of microbial metabolic function. Our aim was to determine if Bifidobacterium animalis subsp. lactis BB-12 (BB-12)-containing yogurt could protect against antibiotic-induced fecal SCFA and microbiota composition disruptions. We conducted a randomized, allocation-concealed, controlled trial of amoxicillin/clavulanate administration (days 1-7), in conjunction with either BB-12-containing or control yogurt (days 1-14). We measured the fecal levels of SCFAs and bacterial composition at baseline and days 7, 14, 21, and 30. Forty-two participants were randomly assigned to the BB-12 group, and 20 participants to the control group. Antibiotic treatment suppressed the fecal acetate levels in both the control and probiotic groups. Following the cessation of antibiotics, the fecal acetate levels in the probiotic group increased over the remainder of the study and returned to the baseline levels on day 30 (-1.6% baseline), whereas, in the control group, the acetate levels remained suppressed. Further, antibiotic treatment reduced the Shannon diversity of the gut microbiota, for all the study participants at day 7. The magnitude of this change was larger and more sustained in the control group compared to the probiotic group, which is consistent with the hypothesis that BB-12 enhanced microbiota recovery. There were no significant baseline clinical differences between the two groups. Concurrent administration of amoxicillin/clavulanate and BB-12 yogurt, to healthy subjects, was associated with a significantly smaller decrease in the fecal SCFA levels and a more stable taxonomic profile of the microbiota over time than the control group.

Probiotics for respiratory tract infections in children attending day care centers-a systematic review

Probiotics have been suggested to have a preventive effect on respiratory tract infections (RTIs), but limited evidence exist on strain-specific effects. The main aim of this systematic review and meta-analysis was to evaluate strain-specific probiotic effects on RTIs in children attending day care. We included 15 RCTs with 5121 children in day care settings (aged 3 months to 7 years), but due to high diversity in reported outcomes, different number of RCTs were available for evaluated outcomes. Twelve RCTs (n = 4527) reported results which could be compared in at least one outcome of the meta-analysis. Compared to placebo, Lactobacillus rhamnosus GG (LGG) significantly reduced duration of RTIs (three RCTs, n = 1295, mean difference - 0.78 days, 95% confidence interval (CI) - 1.46; - 0.09), whereas no effect was found on other evaluated outcomes. Based on the results from two studies (n = 343), Bifidobacterium animalis subsp. lactis BB-12 showed no effect on duration of RTIs or on absence from day care. Meta-analyses on other strains or their combination were not possible due to limited data and different outcome measures.Conclusion: LGG is modestly effective in decreasing the duration of RTIs. More RCTs investigating specific probiotic strains or their combinations in prevention of RTIs are needed. What is known: • Previously published systematic reviews have suggested that probiotics may have a preventive effect on respiratory infections, but limited data exist on strain specific effects. What is new: • This systematic review showed that use of Lactobacillus rhamnosus GG modestly reduces the duration of respiratory tract infections.

Guidance on the use of probiotics in clinical practice in children with selected clinical conditions and in specific vulnerable groups

AIM

The use of probiotics has been covered by many guidelines, position papers and evidence-based recommendations, but few have referred to specific patient groups or clinical indications. This review summarises recommendations and scientifically credited guidelines on the use of probiotics for children with selected clinical conditions and provides practice points.

METHODS

An expert panel was convened by the European Paediatric Association in June 2017 to define the relevant clinical questions for using probiotics in paediatric health care and review and summarise the guidelines, recommendations, position papers and high-quality evidence.

RESULTS

The panel found that specific probiotic strains were effective in preventing antibiotic-associated and nosocomial diarrhoea, treating acute gastroenteritis and treating infantile colic in breastfed infants. However, special caution is indicated for premature infants, immunocompromised and critically ill patients and those with central venous catheters, cardiac valvular disease and short-gut syndrome. This review discusses the safety of using probiotics in selected groups of paediatric patients and the quality of the available products providing practice points based on proved findings.

CONCLUSION

Efficacy of probiotics is strain specific. Their benefits are currently scientifically proven for their use in selected clinical conditions in children and not recommended for certain patient groups.

Probiotics in Children: What Is the Evidence?

The number of papers discussing probiotics increases tremendously that limits the possibility for primary care physicians and clinicians to stay updated. Therefore, the aim of this paper will be to summarize available evidence of probiotic use in well-defined clinical indications of importance for pediatricians. Based on currently available evidence certain probiotic strains (Lactobacillus rhamnosus GG [LGG] and Saccharomyces boulardii) have proven effect in the treatment of acute gastroenteritis and prevention of antibiotic associated diarrhea. Furthermore, LGG was proven to be effective in prevention of nosocomial diarrhea and respiratory tract infection in day care centers. In conclusion, not all probiotic strains have same efficacy for all clinical indications, therefore, only strains with proven efficacy and safety should be recommended.

Mismatch between Probiotic Benefits in Trials versus Food Products

Probiotic food products contain a variety of different bacterial strains and may offer different health effects. The objective was to document the prevalence and dosage of probiotic strains in the Canadian food supply and to review the literature investigating these strains in order to understand what health benefits these products may offer. The Food Label Information Program was used to identify probiotic-containing products in the food supply. PubMed, Web of Science, and Embase were searched for randomized controlled trials that tested the health effects of these strains in humans. There were six probiotic strains/strain combinations identified in the food supply. Thirty-one studies investigated these strains and found that they are associated with decreased diarrhea and constipation, improved digestive symptoms, glycemic control, antioxidant status, blood lipids, oral health, and infant breastfeeding outcomes, as well as enhanced immunity and support for Helicobacter pylori eradication. There were a limited number of studies investigating these strains. Many studies were funded by the food industry and tested dosages that were up to twenty-five times the dosage found in most food products. Probiotic food products could have health benefits not currently reported on their labels. However, many dosages are too low to provide the benefits demonstrated in clinical trials. Further research is needed to enable more effective use of these functional foods.

Usual Consumption of Specific Dairy Foods Is Associated with Breast Cancer in the Roswell Park Cancer Institute Data Bank and BioRepository

Background: Dairy foods are complex mixtures which include nutrients and non-nutrient substances that could potentially influence cancer etiology, including breast cancer. Objective: The purpose of this study was to examine associations between the types and quantity of dairy foods consumed and the risk of breast cancer among women participating in the Roswell Park Cancer Institute Data Bank and BioRepository (DBBR) between 2003 and 2014. Methods: Archived clinical and questionnaire data were obtained from the DBBR from 1941 women diagnosed with breast cancer between December 2003 and October 2014, and 1237 control participants. Intakes of dairy foods were queried with a self-administered food-frequency questionnaire and grouped into monthly intakes of total dairy, milk, yogurt, low-fat cheese, other cheese, and sweet dairy. ORs and 95% CIs were estimated with unconditional logistic regression adjusting for age, race, body mass index, menopausal status, energy intake, type of milk usually consumed, cigarette smoking status, and family history of breast cancer. Results: Total dairy intakes were associated with a non-significant 15% reduction in breast cancer risk (P = 0.11). Higher intakes of yogurt were associated with reduced risk of breast cancer (OR: 0.61; 95% CI: 0.46, 0.82) and higher intakes of American, cheddar, and cream cheeses were associated with a marginally significant increased risk (OR: 1.53; 95% CI: 0.99, 2.34; P = 0.05). Associations with dairy foods were mixed when stratified by estrogen receptor (ER) status, and in general reflected those of overall breast cancer. However, we observed positive associations between milk intake and risk of ER- breast cancer (OR: 1.58; 95% CI: 1.05, 2.37) and inverse associations between sweet dairy and ER+ breast cancer (OR: 0.52; 95% CI: 0.29, 0.95). Conclusions: Specific dairy foods may contribute to breast cancer risk in women, although the risk varies by source of dairy. Future studies are warranted to confirm the protective potential of yogurt in this type of cancer.

The Association between Dairy Intake and Breast Cancer in Western and Asian Populations: A Systematic Review and Meta-Analysis

Purpose

To date, studies investigating the association between dairy consumption and breast cancer in women have produced conflicting results. As diet is an important, modifiable factor affecting cancer development, the aim of this study was to examine the association between dairy consumption and breast cancer risk.

Methods

PubMed, Embase, and Cochrane Library databases were searched with a priority for prospective cohort studies. Case-control studies were also considered in case of the absence of a cohort study.

Results

We analyzed 22 prospective cohort studies (1,566,940 participants) and five case-control studies (33,372 participants). High and modest dairy consumption (>600 and 400-600 g/day, respectively) significantly reduced the risk of breast cancer compared with low dairy consumption (<400 g/day; risk ratio [RR], 0.90, 95% confidence interval [CI], 0.83-0.98, and RR, 0.94, 95% CI, 0.91-0.98, respectively). A significant linear relationship between dairy consumption and breast cancer risk was found on dose-response analysis. Subgroup analysis found that yogurt (RR, 0.91; 95% CI, 0.83-0.99) and low-fat dairy (RR, 0.85; 95% CI, 0.75-0.96) reduced the risk of breast cancer, while other dairy product types did not. A reduced risk was observed for people in the United States (RR, 0.91; 95% CI, 0.83-0.99) and in those followed for ≥10 years (RR, 0.90; 95% CI, 0.81-0.99). Additionally, the highest level of dairy consumption among Asians was associated with a reduced risk of breast cancer (odds ratio, 0.74; 95% CI, 0.62-0.88).

Conclusion

Dairy consumption was inversely associated with the risk of developing breast cancer and this effect was dependent on the dose, dairy-type, and time.

Randomized, double-blind, placebo-controlled study of synbiotic yogurt effect on the health of children

OBJECTIVE

To assess the effects of daily consumption of a synbiotic yogurt drink on the health, growth, and quality of life of healthy children 12-48 months of age in out-of-home child care.

STUDY DESIGN

Healthy children attending child care centers were enrolled in a prospective, double-blind, placebo-controlled clinical trial. The intervention was a yogurt drink containing Streptococcus thermophilus, Lactobacillus bulgaricus, and Bifidobacterium animalis subspecies lactis (BB-12) (5 × 10(9) cfu/100 mL serving), and 1 g of inulin (synbiotic group) vs a similar nonsynbiotic-containing acidified milk drink (placebo group) once daily for 16 weeks. The end points were days of diarrhea, fever, vomiting, symptoms of upper respiratory tract infection, use of antibiotics, physician visits, child care absenteeism, parental work absenteeism, and quality of life (PedsQL 4.0; Mapi Research Trust, Lyon, France).

RESULTS

Compared with placebo (n = 73), children receiving synbiotic (n = 76) had significantly fewer days of reported fever (1.85 vs 1.95, P < .05), significant improvement in social functioning (P < .035; pre-to-end intervention), and school functioning (P < .045; pre-to-mid intervention). More days with ≥ 3 loose/watery stools were reported in the synbiotic group (P < .05).

CONCLUSIONS

Daily supplementation of children's diet with yogurt containing probiotic bacteria BB-12 and inulin significantly reduced days of fever and improved social and school functioning. The increased frequency of bowel movements may be explained by an accelerating effect of BB-12 and inulin on intestinal transit. Further research on the possible benefits of synbiotics on children's health is advised.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00653705.

Probiotics for the prevention of pediatric upper respiratory tract infections: a systematic review

BACKGROUND

Acute upper respiratory tract infections (URTIs) contribute substantially to pediatric morbidity and mortality worldwide. Prevention of these infections in childhood is a very important public health challenge. Previous systematic reviews, including both adult and childhood populations, have reported that probiotics seem promising, but with modest evidence. This study aimed to focus on prophylactic probiotic use in the prevention of URTIs in childhood.

METHODS

Relevant trials on two databases were identified in a systematic review, from inception to June 2014. Study selection, data extraction and quality assessment were carried out by two reviewers. In this review, the effects of probiotics, particularly the Lactobacillus and Bifidobacterium strains, on the incidence and symptom scores of URTI in otherwise healthy children were evaluated for the first time. This review comprises 14 randomized controlled trials (RCTs) applied to a pediatric population with high-quality methodology.

RESULTS

This systematic review suggests that probiotics in immunocompetent children have a modest effect both in diminishing the incidence of URTIs and the severity of the infection symptoms.

CONCLUSIONS

At least one beneficial effect of prophylactic probiotic was observed in the majority of RCTs. Even a minimal reduction of 5 - 10% in the incidence of URTIs would have an important clinical and economic mpact on societies. Furthermore, the long-term administration of probiotics appeared to have a good safety profile in childhood and none of the studies reported any serious adverse events related to the probiotic strain.

Evaluation of the immune benefits of two probiotic strains Bifidobacterium animalis ssp. lactis, BB-12® and Lactobacillus paracasei ssp. paracasei, L. casei 431® in an influenza vaccination model: a randomised, double-blind, placebo-controlled study

The present study investigated the ability of Bifidobacterium animalis ssp. lactis (BB-12®) and Lactobacillus paracasei ssp. paracasei (L. casei 431®) to modulate the immune system using a vaccination model in healthy subjects. A randomised, double-blind, placebo-controlled, parallel-group study was conducted in 211 subjects (56 % females, mean age 33·2 (sd 13·1) years). Subjects consumed a minimum of 10⁹ colony-forming units of BB-12® (capsule) or L. casei 431® (dairy drink) or a matching placebo once daily for 6 weeks. After 2 weeks, a seasonal influenza vaccination was given. Plasma and saliva samples were collected at baseline and after 6 weeks for the analysis of antibodies, cytokines and innate immune parameters. Changes from baseline in vaccine-specific plasma IgG, IgG1 and IgG3 were significantly greater in both probiotic groups v. the corresponding placebo group (L. casei 431®, P = 0·01 for IgG; P < 0·001 for remaining comparisons). The number of subjects obtaining a substantial increase in specific IgG (defined as ≥ 2-fold above baseline) was significantly greater in both probiotic groups v. placebo (BB-12®, P < 0·001 for IgG, IgG1 and IgG3; L. casei 431®, P < 0·001 for IgG1 and IgG3). Significantly greater mean fold increases for vaccine-specific secretory IgA in saliva were observed in both probiotic groups v. placebo (BB-12®, P = 0·017; L. casei 431®, P = 0·035). Similar results were observed for total antibody concentrations. No differences were found for plasma cytokines or innate immune parameters. Data herein show that supplementation with BB-12® or L. casei 431® may be an effective means to improve immune function by augmenting systemic and mucosal immune responses to challenge.