The evidence to support health claims for probiotics

Flavonoids, Phenolic Acids, and Tannin Quantities and Their Antioxidant Activity in Fermented Fireweed Leaves Grown in Different Systems

The increasing demand for organic and biodynamically cultivated fireweeds worldwide has led to a paucity of studies on the effects of solid-phase fermentation and various growth techniques on the quantities of biologically active substances and their antioxidant activity. This experiment was carried out in 2023 at the organic farm in the Jonava district (Safarkos village, Lithuania). The aim of this work was to investigate polyphenols (flavonoids and phenolic acids) and antioxidant activity in fireweed (Chamerion angustifolium (L.) Holub) leaves fermented for 24 and 48 h in solid-phase fermentation and natural, organic, and biodynamic cultivation. Fireweeds have high quantities of polyphenols and strong antioxidant activity. The method employed for determining antioxidant activity was spectrophotometric, for measuring polyphenols, high-performance liquid chromatography (HPLC). Principal component analysis (PCA) was used to determine the relationships between the average content of total polyphenols and antioxidant activity in fermented fireweed leaves grown in different systems. This study's findings demonstrated that the leaves of fireweed cultivated organically had the greatest concentration of total flavonoids, total phenolic acids, and total polyphenols. Comparing the fermentation process effect, the amount of predominant phenolic acids-chlorogenic, p-coumaric, and ellagic acids-as well as the content of oenothein B, during the fermentation process significantly decreased, but the concentration of quercetin-3-O-glucoside after a short time of the fermentation process significantly increased. According to the obtained results, it would be possible to create various health-giving and nature-friendly products from fireweeds.

Characterization of a Lactobacillus gasseri strain as a probiotic for female vaginitis

Vaginitis, a prevalent gynecological condition in women, is mainly caused by an imbalance in the vaginal micro-ecology. The two most common types of vaginitis are vaginal bacteriosis and vulvovaginal candidiasis, triggered by the virulent Gardnerella vaginalis and Candida albicans, respectively. In this study, a strain capable of inhibiting G. vaginalis and C. albicans was screened from vaginal secretions and identified as Lactobacillus gasseri based on 16S rRNA sequences. The strain, named L. gasseri VHProbi E09, could inhibit the growth of G. vaginalis and C. albicans under co-culture conditions by 99.07% ± 0.26% and 99.95% ± 0.01%, respectively. In addition, it could significantly inhibit the adhesion of these pathogens to vaginal epithelial cells. The strain further showed the ability to inhibit the enteropathogenic bacteria Escherichia coli and Salmonella enteritidis, to tolerate artificial gastric and intestinal fluids and to adhere to intestinal Caco-2 cells. These results suggest that L. gasseri VHProbi E09 holds promise for clinical trials and animal studies whether administered orally or directly into the vagina. Whole-genome analysis also revealed a genome consisting of 1752 genes for L. gasseri VHProbi E09, with subsequent analyses identifying seven genes related to adhesion and three genes related to bacteriocins. These adhesion- and bacteriocin-related genes provide a theoretical basis for understanding the mechanism of bacterial inhibition of the strain. The research conducted in this study suggests that L. gasseri VHProbi E09 may be considered as a potential probiotic, and further research can delve deeper into its efficacy as an agent which can restore a healthy vaginal ecosystem.

Inhibition and Mechanism of Protein Nonenzymatic Glycation by Lactobacillus fermentum

Lactobacillus fermentum (L. fermentum) was first evaluated as a potential advanced glycation end-product (AGE) formation inhibitor by establishing a bovine serum albumin (BSA) + glucose (glu) glycation model in the present study. The results showed that the highest inhibition rates of pentosidine and total fluorescent AGEs by L. fermentum were approximately 51.67% and 77.22%, respectively, which were higher than that of aminoguanidine (AG). Mechanistic analysis showed that L. fermentum could capture methylglyoxal and glyoxal, inhibit carbonyl and sulfhydryl oxidation, reduce the binding of glucose and amino groups, increase total phenolic content and antioxidant activity, and release intracellular substances to scavenge free radicals; these abilities were the basis of the antiglycation mechanism of L. fermentum. In addition, L. fermentum significantly prevented conformational changes in proteins during glycation, reduced protein cross-linking by 35.67%, and protected the intrinsic fluorophore. Therefore, the inhibition of L. fermentum on glycation mainly occurs through antioxidation, the capture of dicarbonyl compounds, and the protection of the BSA structure. These findings collectively suggest that Lactobacillus is an inhibitor of protein glycation and AGE formation and has the potential for nutraceutical applications.

Studies of the Variability of Biologically Active Compounds and Antioxidant Activity in Organically, Biodynamically, and Naturally Grown and Fermented Fireweed (Chamerion angustifolium (L.) Holub) Leaves

With the growing global demand for organically and biodynamically grown fireweeds, little research is being conducted on them, and little is known about how the different growing systems and the process of solid-phase fermentation changes biologically active substances and antioxidant activity. Our experiment was conducted in 2022 in Jonava district, Safarkos village, Giedres Nacevicienes organic farm (No. SER-T-19-00910, Lithuania, 55°00'22″ N 24°12'22″ E). This study aimed to investigate the influence of various growing systems (natural, organic, and biodynamic) and technological parameters (different duration: 24, 48 and 72 h) of aerobic solid-phase fermentation on the change of flavonoids, phenolic acids, tannins, carotenoids, chlorophylls, and antioxidant activity. High-performance liquid chromatography (HPLC) for polyphenols, carotenoids, and chlorophylls as well as the spectrophotometric method for antioxidant activity determinations were used. The results of the study showed that different growing systems (natural, organic, and biodynamic) and solid-phase fermentation had a significant effect on the quantitative composition of biologically active substances in the leaves of the fireweeds. According to these data, it would be possible to recommend fermented fireweed leaves grown organically as a source of polyphenols (especially: phenolic acids and flavonoids), leaves grown biodynamically as a source of carotenoids (exceptionally: lutein and beta-carotene) and chlorophyll, and leaves grown naturally for better antioxidant activity.

The Impact of Solid-Phase Fermentation on Flavonoids, Phenolic Acids, Tannins and Antioxidant Activity in Chamerion angustifolium (L.) Holub (Fireweed) Leaves

At present, the consumption of medical plants and functional foods is growing across the whole world. Fireweed (Chamerion angustifolium (L.) Holub), an important medicinal plant that has various pharmacological effects (antioxidant, anti-inflammatory, anticancer and others), can improve the state of health and well-being and reduce the risk of various diseases. The aim of this work was to investigate polyphenols (flavonoids, phenolic acids and tannins) and antioxidant activity in fireweed leaves fermented for 24, 48 and 72 h in solid-phase fermentation under aerobic and anaerobic conditions. High-performance liquid chromatography (HPLC) for polyphenols and the spectrophotometric method based on quenching of stable colored radical (ABTS•+) for antioxidant activity determinations were used. The results showed that the highest amounts of total polyphenols, total flavonoids and tannin oenothein B in the dried matter were found after 72 h and the highest total phenolic acids after 48 h of anaerobic solid-phase fermentation. The highest antioxidant activity was found after 72 h of solid-phase fermentation under aerobic conditions.

Capabilities of bio-binding, antioxidant and intestinal environmental repair jointly determine the ability of lactic acid bacteria to mitigate perfluorooctane sulfonate toxicity

Perfluorooctane sulfonate (PFOS) is a novel environmental contaminant that can be enriched in humans through the food chain, causing liver diseases, neurotoxicity and metabolic disorders. Lactic acid bacteria (LAB) are safe food-grade microorganisms that exhibit high antioxidant activity and bio-binding capacity towards toxins. Here, strains of LAB with different PFOS binding capacities and antioxidant activities were selected and analyzed for their ability in mitigating the toxic effects of PFOS. The results showed that the PFOS binding capacity and antioxidant activity of LAB largely influenced their ability in alleviating the toxic effects of PFOS. Notably, the individual LAB strains with low PFOS binding capacities and antioxidant activities also attenuated the toxic effects of PFOS, which was shown to up-regulate the contents of short-chain fatty acids (SCFAs) in the cecum and of tight junction proteins in the intestines of mice. Therefore, the mitigation pathway of PFOS-induced toxic damage by LAB is not limited to bio-binding and antioxidant. Repairing the gut environment damaged by PFOS is also essential for LAB to alleviate the toxic damage due to PFOS and may be partly independent of the bio-binding and antioxidant. Therefore, LAB as an alternative pathway for alleviating PFOS toxicity is suggested.

Rotaviruses: From Pathogenesis to Disease Control-A Critical Review

Since their first recognition in human cases about four decades ago, rotaviruses have remained the leading cause of acute severe dehydrating diarrhea among infants and young children worldwide. The WHO prequalification of oral rotavirus vaccines (ORV) a decade ago and its introduction in many countries have yielded a significant decline in the global burden of the disease, although not without challenges to achieving global effectiveness. Poised by the unending malady of rotavirus diarrhea and the attributable death cases in developing countries, we provide detailed insights into rotavirus biology, exposure pathways, cellular receptors and pathogenesis, host immune response, epidemiology, and vaccination. Additionally, recent developments on the various host, viral and environmental associated factors impacting ORV performance in low-and middle-income countries (LMIC) are reviewed and their significance assessed. In addition, we review the advances in nonvaccine strategies (probiotics, candidate anti-rotaviral drugs, breastfeeding) to disease prevention and management.

Probiotics: controversial issues

Recent studies have strongly confirmed the health benefits of a variety of probiotic microorganisms. However, some issues regarding the use of probiotics currently remain unresolved or ambiguous. This article highlights some controversial issues of probiotic use in clinical practice such as regulatory status of probiotics, co-administration of probiotics and antibiotics, potential impact of probiotics on antimicrobial resistance emergence and spread, dosing and duration of probiotic use, contraindications and some other debatable topics.

Quality, physicochemical, and textural properties of dairy products containing fruits and vegetables: A review

Due to the high utilization rate of dairy products, enrichment of these products will successfully decrease or prevent diseases related with nutrition deficiencies. Fruits and vegetables in different forms (i.e., fresh, juices, powder, puree, and extract) are excellent sources for the enrichment of dairy products because of their desired taste, color, aroma, fibers, and vitamins content. So, this manuscript reviews the effect of some fruits and vegetables on the rheological behavior, physicochemical attributes, color parameters, sensorial and quality properties of dairy products including cheeses, ice creams, and yogurts. The physicochemical, color, texture, and sensorial properties of dairy products were affected with addition of fruits or vegetables. Also, the addition of these products contributes to the higher content of vitamins, natural colorants, minerals, polyphenols, crude fiber, and carotenoids. In addition, some fruits and vegetables are considered as potential dairy products stabilizing agent due to their desirable functional properties, such as water binding and holding, gelling and thickening ability. In summary, enrichment of cheeses, ice creams, and yogurts with fruits and vegetables increase the market share of these products due to the high demand for goods for an improved diet, rich in compounds with antioxidant activity and biological properties.

Next Generation Probiotics for Neutralizing Obesogenic Effects: Taxa Culturing Searching Strategies

The combination of diet, lifestyle, and the exposure to food obesogens categorized into "microbiota disrupting chemicals" (MDC) could determine obesogenic-related dysbiosis and modify the microbiota diversity that impacts on individual health-disease balances, inducing altered pathogenesis phenotypes. Specific, complementary, and combined treatments are needed to face these altered microbial patterns and the specific misbalances triggered. In this sense, searching for next-generation beneficial microbes or next-generation probiotics (NGP) by microbiota culturing, and focusing on their demonstrated, extensive scope and well-defined functions could contribute to counteracting and repairing the effects of obesogens. Therefore, this review presents a perspective through compiling information and key strategies for directed searching and culturing of NGP that could be administered for obesity and endocrine-related dysbiosis by (i) observing the differential abundance of specific microbiota taxa in obesity-related patients and analyzing their functional roles, (ii) developing microbiota-directed strategies for culturing these taxa groups, and (iii) applying the successful compiled criteria from recent NGP clinical studies. New isolated or cultivable microorganisms from healthy gut microbiota specifically related to obesogens' neutralization effects might be used as an NGP single strain or in consortia, both presenting functions and the ability to palliate metabolic-related disorders. Identification of holistic approaches for searching and using potential NGP, key aspects, the bias, gaps, and proposals of solutions are also considered in this review.

Polyphenols, Antioxidant Activity and Volatile Compounds in Fermented Leaves of Medicinal Plant Rosebay Willowherb (Chamerion angustifolium (L.) Holub)

At present, the consumption of medical plants and functional foods is growing in the whole world. Rosebay willowherb (Chamerionangustifolium (L.) Holub) is an important medicinal plant that has various pharmacological effects (antioxidant, anti-inflammatory, anticancer, and others), can improve the state of health and well-being, and reduce the risk of various diseases. The aim of this work was to investigate volatile compounds, polyphenols, and antioxidant activity in rosebay willowherb leaves fermented for 24 and 48 h in solid state fermentation under aerobic and anaerobic conditions. High-performance liquid chromatography (HPLC) for polyphenols and the spectrophotometric method for antioxidant activity determinations were used. To recognize and identify the leaves’ fragrances, electronic nose (Alpha M.O.S) measurement technology was used. The results showed that the highest amounts of total polyphenols in dried matter were after 48 h aerobic solid state fermentation (SSF). Antioxidant activity was higher under 48 h SSF compared to the control. The most abundant flavoring compound groups were esters, terpenes, and aldehydes. In unfermented leaves, (z)-3-hexen-1-ol, acetate, hexyl acetate, and trans-hex-2-enyl acetate prevailed, characterized by fragrances of greenery, flowers, and fruits. The undesired esters group compounds, ethyl butyrate and butyl acetate, with pungent odor, were detected after 48 h anaerobic SSF.

The effect of Lactobacillus fermentum DALI02 in reducing the oxidative stress and inflammatory response induced by high-fat diet of rats

A long-term high-fat diet (HFD) leads to significant oxidative stress in the body and induces inflammation. A preliminary evidence suggests a potential therapeutic utility of probiotics for this condition. To evaluate the potential effect of Lactobacillus fermentum DALI02 on the oxidative stress and inflammatory damage induced by HFD, we used a hyperlipidemic rat as a model fed with HFD. Results revealed that HFD induced a significant oxidative stress and inflammation. However, results reveal that L. fermentum DALI02, manifested a significant decrease in levels of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and resistin, while the catalase (CAT), total antioxidant capability (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and adiponectin (ADPN) levels significantly increased. And it was dose-dependent that the effect of high dose groups with high viable count was particularly notable. The results suggest that L. fermentum DALI02 could alleviate oxidative stress and inflammation as it appeared to reduce lipid peroxidation and improved the lipid metabolism in vivo.

A long-term high-fat diet (HFD) leads to significant oxidative stress in the body and induces inflammation.

Effect of Different Durations of Solid-Phase Fermentation for Fireweed (Chamerion angustifolium (L.) Holub) Leaves on the Content of Polyphenols and Antioxidant Activity In Vitro

Fireweed has recently been recognized as a plant with high antioxidant potential and phenolic content. Its leaves can be fermented to prepare an infusion with ideal antioxidant activity. The aim of this study was to investigate and to determine the influence of solid-phase fermentation of different durations on the variation of polyphenols in the leaves of fireweed. Laboratory experiments were conducted in 2017-2018. The leaves of fireweed, naturally growing, were fermented for different periods of time: not fermented (control) and fermented for 24 and 48 h. The evaluation of polyphenols and antioxidant activity in leaves was performed using high- performance liquid chromatography (HPLC). Additionally, principal component analysis was used to characterize differences in bioactive compounds between fireweed samples fermented at different durations. Solid-phase fermented leaves were characterized by higher contents of oenothein B, quercetin and benzoic acid but had lower contents of quercetin-3-O-rutinoside, luteolin and chlorogenic and gallic acids. Antioxidant activity in short- (24 h) and long-term (48 h) fermentation (compared to control) gave the highest level of regression in 2017, but in 2018 the effect was observed only with short-term fermentation and control. In conclusion, solid-phase fermentation can be used to modulate biologically active compounds in fireweed leaves.

Probiotics and Maternal Mental Health: A Randomised Controlled Trial among Pregnant Women with Obesity

Poor maternal mental health has been associated with a myriad of pregnancy and child health complications. Obesity in pregnancy is known to increase one’s risk of experiencing poor maternal mental health and associated physical and mental health complications. Probiotics may represent a novel approach to intervene in poor mental health and obesity. We conducted this pre-specified secondary analysis of the Healthy Mums and Babies (HUMBA) randomised controlled trial to investigate whether probiotics would improve maternal mental health outcomes up to 36 weeks of pregnancy. Two-hundred-and-thirty pregnant women with obesity (BMI ≥ 30.0 kg/m²) were recruited and randomised to receive probiotic (Lactobacillus rhamnosus GG and Bifidobacterium lactis BB12, minimum 6.5 × 10⁹ CFU) or placebo capsules. Depression, anxiety, and functional health and well-being were assessed at baseline (12⁰−17⁶ weeks’ gestation) and 36 weeks of pregnancy. Depression scores remained stable and did not differ between the probiotic (M = 7.18, SD = 3.80) and placebo groups (M = 6.76, SD = 4.65) at 36 weeks (p-values > 0.05). Anxiety and physical well-being scores worsened over time irrespective of group allocation, and mental well-being scores did not differ between the two groups at 36 weeks. Probiotics did not improve mental health outcomes in this multi-ethnic cohort of pregnant women with obesity.

Effect of Lactobacillus gasseri PA3 on gut microbiota in an in vitro colonic simulation

It has been reported that Lactobacillus gasseri PA3 has an ability to absorb exogenous purines in the intestine to reduce a risk of gout and hyperuricemia. However, influences of this strain on gut microbiota and their metabolisms remain unclear. Herein, we aimed to investigate the effect of L. gasseri PA3 on microbiota composition and metabolisms. L. gasseri PA3 was isolated from yogurt and supplemented into a single-stage colonic fermentation in a culture volume of 30 ml and subjected to in vitro colonic simulation for 8 days. Microbiota composition was determined with 16S rRNA (V3 + V4) sequencing, and their metabolisms were predicted by PICRUSt. Short-chain fatty acids were measured by GC-MS. We found that L. gasseri PA3 reduced the diversity of microbiota, increased the relative abundances of Lactobacillus (73.5%) and Escherichia (36.5%), and decreased Bacterioides and Phascolarctobacterium. Total amount of short-chain fatty acids was found to decline. Fundamental metabolisms, especially nucleotide, was significantly higher after intervention with L. gasseri PA3, but the purine metabolism was lower, which means that PA3 might reduce uric acid concentrations by weakening purine metabolism. Our results indicated that L. gasseri PA3 can survive and play a role in the ascending colon environment. Therefore, the evaluation of the effect of L. gasseri PA3 on intestinal microbes and their metabolisms has great guiding significance for the development of treatment to prevent gout.

Dietary supplementation with probiotics regulates gut microbiota structure and function in Nile tilapia exposed to aluminum

BACKGROUNDS AND AIMS

Aluminum contamination of water is becoming increasingly serious and threatens the health status of fish. Lactobacillus plantarum CCFM639 was previously shown to be a potential probiotic for alleviation aluminum toxicity in Nile tilapia. Considering the significant role of the gut microbiota on fish health, it seems appropriate to explore the relationships among aluminum exposure, probiotic supplementation, and the gut microbiota in Nile tilapia and to determine whether regulation of the gut microbiota is related to alleviation of aluminum toxicity by a probiotic in Nile tilapia.

METHODS AND RESULTS

The tilapia were assigned into four groups, control, CCFM639 only, aluminum only, and aluminum + CCFM639 groups for an experimental period of 4 weeks. The tilapia in the aluminum only group were grown in water with an aluminum ion concentration of 2.73 mg/L. The final concentration of CCFM639 in the diet was 108 CFU/g. The results show that environmental aluminum exposure reduced the numbers of L. plantarum in tilapia feces and altered the gut microbiota. As the predominant bacterial phyla in the gut, the abundances of Bacteroidetes and Proteobacteria in aluminum-exposed fish were significantly elevated and lowered, respectively. At the genus level, fish exposed to aluminum had a significantly lower abundance of Deefgea, Plesiomonas, and Pseudomonas and a greater abundance of Flavobacterium, Enterovibrio, Porphyromonadaceae uncultured, and Comamonadaceae. When tilapia were exposed to aluminum, the administration of a probiotic promoted aluminum excretion through the feces and led to a decrease in the abundance of Comamonadaceae, Enterovibrio and Porphyromonadaceae. Notably, supplementation with a probiotic only greatly decreased the abundance of Aeromonas and Pseudomonas.

CONCLUSION

Aluminum exposure altered the diversity of the gut microbiota in Nile tilapia, and probiotic supplementation allowed the recovery of some of the diversity. Therefore, regulation of gut microbiota with a probiotic is a possible mechanism for the alleviation of aluminum toxicity in Nile tilapia.

Complete Genome Sequence of Lactobacillus reuteri SKKU-OGDONS-01, Isolated from a Chicken's Small Intestine

Lactobacillus reuteri SKKU-OGDONS-01 is a potentially indigenous probiotic strain isolated from the small intestine of a 27-week-old chicken. The complete genome of L. reuteri SKKU-OGDONS-01 comprises a single circular chromosome.

Lactobacillus reuteri SKKU-OGDONS-01 is a potentially indigenous probiotic strain isolated from the small intestine of a 27-week-old chicken. The complete genome of L. reuteri SKKU-OGDONS-01 comprises a single circular chromosome. Its length is 2,259,968 bp, with a G+C content of 38.9%.

Effect of dietary prebiotics and probiotics on snakehead (Channa striata) health: Haematology and disease resistance parameters against Aeromonas hydrophila

This study examined the effect of dietary prebiotics and probiotics after 16 weeks, followed by 8 weeks of post feeding trial with the control unsupplemented diet on haematological and immune response against Aeromonas hydrophila infection in Channa striata fingerlings. Fish were raised on a 40% protein and 12% lipid feed containing three commercial prebiotics (β-glucan, GOS or galacto-oligosaccharide, MOS or mannan-oligosaccharide); and two probiotics- (Saccharomyces cerevisiae, Lactobacillus acidophilus), respectively and a control. Throughout the study, supplementation with dietary prebiotics and probiotics led to significant (P < 0.05) improvement in the red blood cells, white blood cells, packed cell volume, haemoglobin concentration and serum protein level and lysozyme activities; and these improvements were effective significantly (P < 0.05) when the fish were challenged with Aeromonas hydrophila at the dose of 2 × 10⁶. The disease resistance against A. hydrophila was higher significantly (P < 0.05) in fish fed with probiotic feed supplements (L.acidophilus was highest) compared to prebiotics and control. The study is the first to report the absence of differences in sustaining the efficacies attained after intake of β-glucan, GOS and MOS upon post-feeding with an unsupplemented feed, over a prolonged period.

Synbiotics for Improved Human Health: Recent Developments, Challenges, and Opportunities

Research on combining pro- and prebiotics as synbiotics to enhance human and animal health has accelerated in the past 10 years, including many clinical trials that have assessed a diverse range of synbiotic formulations. In this review, we summarize these studies as well as the commercial applications of synbiotics that are available. In particular, we critically assess the claimed health benefits of synbiotic applications and the ecological and therapeutic factors to consider when designing synbiotics and discuss the implications of these concepts for future research in this field.

Assessing the Risk of Probiotic Dietary Supplements in the Context of Antibiotic Resistance

Probiotic bacteria are known to harbor intrinsic and mobile genetic elements that confer resistance to a wide variety of antibiotics. Their high amounts in dietary supplements can establish a reservoir of antibiotic resistant genes in the human gut. These resistant genes can be transferred to pathogens that share the same intestinal habitat thus resulting in serious clinical ramifications. While antibiotic resistance of probiotic bacteria from food, human and animal sources have been well-documented, the resistant profiles of probiotics from dietary supplements have only been recently studied. These products are consumed with increasing regularity due to their health claims that include the improvement of intestinal health and immune response as well as prevention of acute and antibiotic-associated diarrhea and cancer; but, a comprehensive risk assessment on the spread of resistant genes to human health is lacking. Here, we highlight recent reports of antibiotic resistance of probiotic bacteria isolated from dietary supplements, and propose complementary strategies that can shed light on the risks of consuming such products in the context of a global widespread of antibiotic resistance. In concomitant with a broader screening of antibiotic resistance in probiotic supplements is the use of computational simulations, live imaging and functional genomics to harvest knowledge on the evolutionary behavior, adaptations and dynamics of probiotics studied in conditions that best represent the human gut including in the presence of antibiotics. The underlying goal is to enable the health benefits of probiotics to be exploited in a responsible manner and with minimal risk to human health.

Prebiotic Effects of Xylooligosaccharides on the Improvement of Microbiota Balance in Human Subjects

It has been indicated that probiotics can be nourished by consuming prebiotics in order to function more efficiently, allowing the bacteria to stay within a healthy balance. In this study, we investigated the effects of xylooligosaccharides- (XOS-) enriched rice porridge consumption on the ecosystem in the intestinal tract of human subjects. Twenty healthy subjects participated in this 6-week trial, in which 10 subjects received XOS-enriched rice porridge while the others received placebo rice porridge. Fecal samples were collected at the end of weeks 0, 1, 3, 4, 6, and 7 for microorganism examination. The results showed that 6-week daily ingestion of the XOS-enriched rice porridge induced significant increases in fecal bacterial counts of Lactobacillus spp. and Bifidobacterium spp., as well as decreases in Clostridium perfringens without changing the total anaerobic bacterial counts, compared to that of placebo rice porridge. However, fluctuations in the counts of coliforms were observed in both groups during the 6-week intervention. In conclusion, the intestinal microbiota balance was improved after daily consumption of 150 g of rice porridge containing XOS for 6 weeks, demonstrating the prebiotic potential of XOS incorporated into foods. This also indicates the effectiveness of XOS as a functional ingredient in relation to its role as a prebiotic compound.

Fluorescent reporter systems for tracking probiotic lactic acid bacteria and bifidobacteria

In the last two decades, there has been increasing evidence supporting the role of the intestinal microbiota in health and disease, as well as the use of probiotics to modulate its activity and composition. Probiotic bacteria selected for commercial use in foods, mostly lactic acid bacteria and bifidobacteria, must survive in sufficient numbers during the manufacturing process, storage, and passage through the gastro-intestinal tract. They have several modes of action and it is crucial to unravel the mechanisms underlying their postulated beneficial effects. To track their survival and persistence, and to analyse their interaction with the gastro-intestinal epithelia it is essential to discriminate probiotic strains from endogenous microbiota. Fluorescent reporter proteins are relevant tools that can be exploited as a non-invasive marker system for in vivo real-time imaging in complex ecosystems as well as in vitro fluorescence labelling. Oxygen is required for many of these reporter proteins to fluoresce, which is a major drawback in anoxic environments. However, some new fluorescent proteins are able to overcome the potential problems caused by oxygen limitations. The current available approaches and the benefits/disadvantages of using reporter vectors containing fluorescent proteins for labelling of bacterial probiotic species commonly used in food are addressed.

Alterations in fecal microbiota composition by probiotic supplementation in healthy adults: a systematic review of randomized controlled trials

BACKGROUND

The effects of probiotic supplementation on fecal microbiota composition in healthy adults have not been well established. We aimed to provide a systematic review of the potential evidence for an effect of probiotic supplementation on the composition of human fecal microbiota as assessed by high-throughput molecular approaches in randomized controlled trials (RCTs) of healthy adults.

METHODS

The survey of peer-reviewed papers was performed on 17 August 2015 by a literature search through PubMed, SCOPUS, and ISI Web of Science. Additional papers were identified by checking references of relevant papers. Search terms included healthy adult, probiotic, bifidobacterium, lactobacillus, gut microbiota, fecal microbiota, intestinal microbiota, intervention, and (clinical) trial. RCTs of solely probiotic supplementation and placebo in healthy adults that examined alteration in composition of overall fecal microbiota structure assessed by shotgun metagenomic sequencing, 16S ribosomal RNA sequencing, or phylogenetic microarray methods were included. Independent collection and quality assessment of studies were performed by two authors using predefined criteria including methodological quality assessment of reports of the clinical trials based on revised tools from PRISMA/Cochrane and by the Jadad score.

RESULTS

Seven RCTs investigating the effect of probiotic supplementation on fecal microbiota in healthy adults were identified and included in the present systematic review. The quality of the studies was assessed as medium to high. Still, no effects were observed on the fecal microbiota composition in terms of α-diversity, richness, or evenness in any of the included studies when compared to placebo. Only one study found that probiotic supplementation significantly modified the overall structure of the fecal bacterial community in terms of β-diversity when compared to placebo.

CONCLUSIONS

This systematic review of the pertinent literature demonstrates a lack of evidence for an impact of probiotics on fecal microbiota composition in healthy adults. Future studies would benefit from pre-specifying the primary outcome and transparently reporting the results including effect sizes, confidence intervals, and P values as well as providing a clear distinction of between-group and within-group comparisons.

Detection of antibiotic resistance in probiotics of dietary supplements

Background

Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive.

Findings

Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers.

Conclusions

This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12937-015-0084-2) contains supplementary material, which is available to authorized users.

Probiotics (Lactobacillus acidophilus and Bifidobacterium infantis) prevent NEC in VLBW infants fed breast milk but not formula [corrected]

BACKGROUND

Specific probiotics prevent necrotizing enterocolitis (NEC). A mixture of lactobacilli and bifidobacteria (Infloran) was highly effective in Asian very-low-birth-weight (VLBW) infants. We analyzed the effect of Infloran on NEC, NEC severity, and the influence of enteral feedings (breast milk vs. formula) on NEC prevention in a cohort of European VLBW infants.

METHODS

Infloran was implemented for routine use at our department. VLBW infants receiving probiotics were prospectively followed (2010-2012) and compared with historic controls (2008-2009). Data on NEC, neonatal morbidity, feeding tolerance, and descriptive parameters on NEC cases were analyzed.

RESULTS

Infloran had no statistically significant impact on NEC (controls: 24/233 (10.3%); probiotics: 16/230 (7%); P = 0.2). However, NEC was significantly reduced in infants of the probiotics group who were fed any breast milk (20/179 (11.2%) vs. 10/183 (5.5%); P = 0.027), whereas it was ineffective in infants exclusively fed formula (4/54 (7.4%) vs. 6/44 (13.6%); P = 0.345). Occurrence of severe NEC (IIIb), time until full feeds, and gastric residuals were similar.

CONCLUSION

Infloran was of lower efficacy in a European VLBW cohort and showed a reduction of NEC only in infants fed breast milk. Future studies should investigate the influence of feeding formula or breast milk on the effect of probiotics.

The domestication of the probiotic bacterium Lactobacillus acidophilus

Lactobacillus acidophilus is a Gram-positive lactic acid bacterium that has had widespread historical use in the dairy industry and more recently as a probiotic. Although L. acidophilus has been designated as safe for human consumption, increasing commercial regulation and clinical demands for probiotic validation has resulted in a need to understand its genetic diversity. By drawing on large, well-characterised collections of lactic acid bacteria, we examined L. acidophilus isolates spanning 92 years and including multiple strains in current commercial use. Analysis of the whole genome sequence data set (34 isolate genomes) demonstrated L. acidophilus was a low diversity, monophyletic species with commercial isolates essentially identical at the sequence level. Our results indicate that commercial use has domesticated L. acidophilus with genetically stable, invariant strains being consumed globally by the human population.

Randomised clinical trial: A liquid multi-strain probiotic vs. placebo in the irritable bowel syndrome--a 12 week double-blind study

BACKGROUND

The importance of interactions between the host and gut microbiota in the pathogenesis of irritable bowel syndrome (IBS) is becoming increasingly apparent. Probiotics offer a potential new treatment for IBS, but current results are conflicting, largely as a result of poorly designed trials and nonstandardisation of outcome measures.

AIM

To assess the efficacy of a liquid, multi-strain probiotic (Symprove) in IBS.

METHODS

A single-centre, randomised, double-blind, placebo-controlled trial of adult patients with symptomatic IBS. Patients received 12 weeks of treatment with the probiotic or placebo (1 mL/kg/day). The primary efficacy measure was the difference in change in the IBS symptom severity score (IBS-SSS) between probiotic vs. placebo at week 12. Secondary outcome measures included change in the IBS quality of life (IBS-QOL) score and change in the IBS-SSS symptom component scores.

RESULTS

A total of 186 patients were randomised and 152 patients completed the study. The mean change in IBS-SSS was -63.3 probiotic vs. -28.3 placebo. The mean difference in the IBS-SSS was statistically significant [-35.0 (95% CI; -62.03, -7.87); P = 0.01]. There was no significant improvement in the IBS-QOL. No serious adverse events were reported.

CONCLUSIONS

The multi-strain probiotic was associated with a statistically significant improvement in overall symptom severity in patients with IBS, and was well tolerated. These results suggest this probiotic confers benefit in IBS and deserves further investigation (ISRCTN identifier: 77512412).

Chilled milk-based desserts as emerging probiotic and prebiotic products

Nowadays, food companies are endeavoring to differentiate their products through creative segmentation and positioning strategies based on superior functionality and quality. Some kinds of dairy desserts have shown a great market potential, as a function of consumers interested in healthier and functional products with fine taste and mouthfeel. In this context, chilled dairy desserts are emerging as attractive options for the incorporation of probiotic cultures and prebiotic ingredients, as seen in the previous launches from the food industry, as well as in the growing number of scientific studies dealing with this subject published in the last years. The main aspects involved in the development of probiotic and/or prebiotic dairy desserts for storage under refrigerated conditions are presented in this review.

Fluorescence in situ hybridization method using a peptide nucleic acid probe for identification of Lactobacillus spp. in milk samples

Lactobacillus species constitute one of the dominant and beneficial bacteria in our body and are used in developed countries as a microbial adjuvant. Identification of these probiotic bacteria is traditionally performed by culture-based techniques. However, such methods are very time-consuming and can give inaccurate results, especially when Lactobacillus is present in mixed bacterial complex communities. Our study aimed to accurately identify Lactobacillus spp. using a novel Peptide Nucleic Acid (PNA) Fluorescence In Situ Hybridization (FISH) probe. The probe (Lac663) was tested on 36 strains belonging to different Lactobacillus species and on 20 strains of other bacterial species. The sensitivity and specificity of the method were 100% (95% confidence interval (CI), 88.0 to 100.0%) and 95.0% (95% CI, 73.1 to 99.7%), respectively. Additionally, we tested the applicability of the method on milk samples added with Lactobacillus strains at probiotic range concentrations and other taxonomically related bacteria, as well as pathogenic bacteria. The Lac663 probe bound exclusively to Lactobacillus strains and the described PNA-FISH method was capable of directly quantifying Lactobacillus spp. in concentrations at which these potential probiotic bacteria are considered to have an effective benefit on human health.

Reciprocal interference between Lactobacillus spp. and Gardnerella vaginalis on initial adherence to epithelial cells

Bacterial vaginosis (BV) is the most common vaginal disorder in women of child-bearing age. It is widely accepted that the microbial switch from normal microflora to the flora commonly associated with BV is characterized by a decrease in vaginal colonization by specific Lactobacillus species together with an increase of G. vaginalis and other anaerobes. However, the order of events leading to the development of BV remains poorly characterized and it is unclear whether the decrease in lactobacilli is a cause or a consequence of the increase in the population density of anaerobes. Our goal was to characterize the interaction between two Gardnerella vaginalis strains, one of which was isolated from a healthy woman (strain 5-1) and the other from a woman diagnosed with BV (strain 101), and vaginal lactobacilli on the adherence to cervical epithelial cells. In order to simulate the transition from vaginal health to BV, the lactobacilli were cultured with the epithelial cells first, and then the G. vaginalis strain was introduced. We quantified the inhibition of G. vaginalis adherence by the lactobacilli and displacement of adherent lactobacilli by G. vaginalis. Our results confirmed that pathogenic G vaginalis 101 had a higher capacity for adhesion to the cervical epithelial cells than strain 5-1. Interestingly, strain 101 displaced L. crispatus but not L. iners whereas strain 5-1 had less of an effect and did not affect the two species differently. Furthermore, L. iners actually enhanced adhesion of strain 101 but not of strain 5-1. These results suggest that BV-causing G. vaginalis and L. iners do not interfere with one another, which may help to explain previous reports that women who are colonized with L. iners are more likely to develop BV.

Early administration of probiotic Lactobacillus acidophilus and/or prebiotic inulin attenuates pathogen-mediated intestinal inflammation and Smad 7 cell signaling

Immaturity of gut-associated immunity may contribute to pediatric mortality associated with enteric infections. A murine model to parallel infantile enteric disease was used to determine the effects of probiotic, Lactobacillus acidophilus (La), prebiotic, inulin, or both (synbiotic, syn) on pathogen-induced inflammatory responses, NF-κB, and Smad 7 signaling. Newborn mice were inoculated bi-weekly for 4 weeks with La, inulin, or syn and challenged with Citrobacter rodentium (Cr) at 5 weeks. Mouse intestinal epithelial cells (CMT93) were exposed to Cr to determine temporal alterations in NF-Kappa B and Smad 7 levels. Mice with pretreatment of La, inulin, and syn show reduced intestinal inflammation following Cr infection compared with controls, which is associated with significantly reduced bacterial colonization in La, inulin, and syn animals. Our results further show that host defense against Cr infection correlated with enhanced colonic IL-10 and transforming growth factor-β expression and inhibition of NF-κB in syn-treated mice, whereas mice pretreated with syn, La, or inulin had attenuation of Cr-induced Smad 7 expression. There was a temporal Smad 7 and NF-κB intracellular accumulation post-Cr infection and post-tumor necrosis factor stimulation in CMT93 cells. These results, therefore, suggest that probiotic, La, prebiotic inulin, or synbiotic may promote host-protective immunity and attenuate Cr-induced intestinal inflammation through mechanisms affecting NF-κB and Smad 7 signaling.