Isolation, identification, and in vitro probiotic characterization of forty novel Bifidobacterium strains from neonatal feces in Erzurum province, Türkiye

BACKGROUND

Neonatal feces are one of the most important sources for probiotic isolation. The purpose of this study was the isolation and identification of Bifidobacterium spp. from neonatal feces and the evaluation of in vitro probiotic properties of strains including safety tests.

RESULTS

A total of 40 isolates were obtained from 14 healthy newborns' feces in Erzurum province, Türkiye. By their rep-PCR patterns and 16S rRNA gene sequences, isolates were identified as 26 Bifidobacterium breve and 14 Bifidobacterium longum. Fifteen of the isolates tolerated bile salts and showed high resistance to simulated gastric juice. Isolates exhibited varying rates of auto-aggregation and hydrophobicity. In addition, most of the isolates displayed antibacterial activity against Escherichia coli O157:H7, Staphylococcus aureus ATCC 29213, Salmonella Typhimurium RSHMB 95091, and Pseudomonas aeruginosa ATCC 9027. However, only one strain showed bile salt hydrolase activity and two strains showed the ability to produce H2O2. Bifidobacterium strains were generally sensitive to the tested antibiotics and lacked kanamycin, gentamicin, and streptomycin resistance genes, and hemolytic and DNAse activities. On the other hand, it was determined that five strains had various virulence genes including gelE, esp, efaAfs, hyl, and ace.

CONCLUSION

Results of the present study suggested that B. longum BH28, B. breve BH4 and B. breve BH5 strains have the potential as probiotic candidates for further studies. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Evidence of the Beneficial Impact of Three Probiotic-Based Food Supplements on the Composition and Metabolic Activity of the Intestinal Microbiota in Healthy Individuals: An Ex Vivo Study

Scientific evidence has increasingly supported the beneficial effects of probiotic-based food supplements on human intestinal health. This ex vivo study investigated the effects on the composition and metabolic activity of the intestinal microbiota of three probiotic-based food supplements, containing, respectively, (1) Bifidobacterium longum ES1, (2) Lactobacillus acidophilus NCFM®, and (3) a combination of L. acidophilus NCFM®, Lactobacillus paracasei Lpc-37™, Bifidobacterium lactis Bi-07™, and Bifidobacterium lactis Bl-04™. This study employed fecal samples from six healthy donors, inoculated in a Colon-on-a-plate® system. After 48 h of exposure or non-exposure to the food supplements, the effects were measured on the overall microbial fermentation (pH), changes in microbial metabolic activity through the production of short-chain and branched-chain fatty acids (SCFAs and BCFAs), ammonium, lactate, and microbial composition. The strongest effect on the fermentation process was observed for the combined formulation probiotics, characterized by the significant stimulation of butyrate production, a significant reduction in BCFAs and ammonium in all donors, and a significant stimulatory effect on bifidobacteria and lactobacilli growth. Our findings suggest that the combined formulation probiotics significantly impact the intestinal microbiome of the healthy individuals, showing changes in metabolic activity and microbial abundance as the health benefit endpoint.

Carotenoids and Their Health Benefits as Derived via Their Interactions with Gut Microbiota

Carotenoids have been related to a number of health benefits. Their dietary intake and circulating levels have been associated with a reduced incidence of obesity, diabetes, certain types of cancer, and even lower total mortality. Their potential interaction with the gut microbiota (GM) has been generally overlooked but may be of relevance, as carotenoids largely bypass absorption in the small intestine and are passed on to the colon, where they appear to be in part degraded into unknown metabolites. These may include apo-carotenoids that may have biological effects because of higher aqueous solubility and higher electrophilicity that could better target transcription factors, i.e., NF-κB, PPARγ, and RAR/RXRs. If absorbed in the colon, they could have both local and systemic effects. Certain microbes that may be supplemented were also reported to produce carotenoids in the colon. Although some bactericidal aspects of carotenoids have been shown in vitro, a few studies have also demonstrated a prebiotic-like effect, resulting in bacterial shifts with health-associated properties. Also, stimulation of IgA could play a role in this respect. Carotenoids may further contribute to mucosal and gut barrier health, such as stabilizing tight junctions. This review highlights potential gut-related health-beneficial effects of carotenoids and emphasizes the current research gaps regarding carotenoid-GM interactions.

The Role of Probiotics in Inducing and Maintaining Remission in Crohn's Disease and Ulcerative Colitis: A Systematic Review of the Literature

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the gastrointestinal tract affecting millions of patients worldwide. The gut microbiome partly determines the pathogenesis of both diseases. Even though probiotics have been widely used as a potential treatment, their efficacy in inducing and maintaining remission is still controversial. Our study aims to review the present-day literature about the possible role of probiotics in treating inflammatory bowel diseases in adults. This research was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. We included studies concerning adult patients who compared probiotics with placebo or non-probiotic intervention. We identified thirty-three studies, including 2713 patients from fourteen countries. The role of probiotics in Crohn's disease was examined in eleven studies. Only four studies presented statistically significant results in the remission of disease, primarily when used for three to six months. On the other hand, in twenty-one out of twenty-five studies, probiotics proved effective in achieving or maintaining remission in ulcerative colitis. Supplementation with Bifidobacterium sp. or a combination of probiotics is the most effective intervention, especially when compared with a placebo. There is strong evidence supporting the usage of probiotic supplementation in patients with ulcerative colitis, yet more research is needed to justify their efficacy in Crohn's disease.

In Vitro Selection of Lactobacillus and Bifidobacterium Probiotic Strains for the Management of Oral Pathobiont Infections Associated to Systemic Diseases

The human oral pathobionts Aggregatibacter actinomycetemcomitans, Streptococcus mitis and Streptococcus mutans, in dysbiosis-promoting conditions, lead to oral infections, which also represent a threat to human systemic health. This scenario may be worsened by antibiotic misuse, which favours multi-drug resistance, making the research on pathogen containment strategies more than crucial. Therefore, we aimed to in vitro select the most promising probiotic strains against oral pathogen growth, viability, biofilm formation, and co-aggregation capacity, employing both the viable probiotics and their cell-free supernatants (CFSs). Interestingly, we also assessed probiotic efficacy against the three-pathogen co-culture, mimicking an environment similar to that in vivo. Overall, the results showed that Lactobacillus CFSs performed better than the Bifidobacterium, highlighting Limosilactobacillus reuteri LRE11, Lacticaseibacillus rhamnosus LR04, Lacticaseibacillus casei LC04, and Limosilactobacillus fermentum LF26 as the most effective strains, opening the chance to deeper investigation of their action and CFS composition. Altogether, the methodologies presented in this study can be used for probiotic efficacy screenings, in order to better focus the research on a viable probiotic, or on its postbiotics, suitable in case of infections.

Immunomodulatory Effects of Bifidobacterium spp. and Use of Bifidobacterium breve and Bifidobacterium longum on Acute Diarrhea in Children

The intake of probiotic lactic acid bacteria not only promotes digestion through the microbiome regulated host intestinal metabolism but also improves diseases such as irritable bowel syndrome and inflammatory bowel disease, and suppresses pathogenic harmful bacteria. This investigation aimed to evaluate the immunomodulatory effects in intestinal epithelial cells and to study the clinical efficacy of the selected the Bifidobacterium breve and Bifidobacterium longum groups. The physiological and biochemical properties were characterized, and immunomodulatory activity was measured against pathogenic bacteria. In order to find out the mechanism of inflammatory action of the eight viable and sonicated Bifidobacterium spp., we tried to confirm the changes in the pro-inflammatory cytokines (TNF-α, interleukin (IL)-6, IL-12) and anti-inflammatory cytokine (IL-10), and chemokines, (monocyte chemoattractant protein-1, IL-8) and inflammatory enzymatic mediator (nitric oxide) against Enterococcus faecalis ATCC 29212 infection in Caco-2 cells and RAW 264.7 cells. The clinical efficacy of the selected B. breve and B. longum group was studied as a probiotic adjuvant for acute diarrhea in children by oral administration. The results showed significant immunomodulatory effects on the expression levels of TNF-α, IL-6, IL-12, MCP-1, IL-8 and NO, in sonicated Bifidobacterium extracts and viable bifidobacteria. Moreover, each of the Bifidobacterium strains was found to react more specifically to different cytokines. However, treatment with sonicated Bifidobacterium extracts showed a more significant effect compared to treatment with the viable bacteria. We suggest that probiotics functions should be subdivided according to individual characteristics, and that personalized probiotics should be designed to address individual applications.

Effect of Fructooligosaccharides Supplementation on the Gut Microbiota in Human: A Systematic Review and Meta-Analysis

Background: Numerous studies have investigated the effects of the supplementation of fructooligosaccharides (FOS) on the number of bacteria in the gut that are good for health, but the results have been inconsistent. Additionally, due to its high fermentability, supplementation of FOS may be associated with adverse gastrointestinal symptoms such as bloating and flatulence. Therefore, we assessed the effects of FOS interventions on the composition of gut microbiota and gastrointestinal symptoms in a systematic review and meta-analysis. Design: All randomized controlled trials published before 10 July 2022 that investigated the effects of FOS supplementation on the human gut microbiota composition and gastrointestinal symptoms and met the selection criteria were included in this study. Using fixed or random-effects models, the means and standard deviations of the differences between the two groups before and after the intervention were combined into weighted mean differences using 95% confidence intervals (CIs). Results: Eight studies containing 213 FOS supplements and 175 controls remained in this meta-analysis. Bifidobacterium spp. counts significantly increased during FOS ingestion (0.579, 95% CI: 0.444−0.714) in comparison with that of the control group. Subgroup analysis showed greater variation in Bifidobacterium spp. in adults (0.861, 95% CI: 0.614−1.108) than in infants (0.458, 95% CI: 0.297−0.619). The increase in Bifidobacterium spp. counts were greater in the group with an intervention duration greater than 4 weeks (0.841, 95% CI: 0.436−1.247) than an intervention time less than or equal to four weeks (0.532, 95% CI: 0.370−0.694), and in the group with intervention doses > 5 g (1.116, 95% CI: 0.685−1.546) the counts were higher than those with doses ≤ 5 g (0.521, 95% CI: 0.379−0.663). No differences in effect were found between FOS intervention and comparators in regard to the abundance of other prespecified bacteria or adverse gastrointestinal symptoms. Conclusions: This is the first meta-analysis to explore the effect of FOS on gut microbiota and to evaluate the adverse effects of FOS intake on the gastrointestinal tract. FOS supplementation could increase the number of colonic Bifidobacterium spp. while higher dose (7.5−15 g/d) and longer duration (>4 weeks) showed more distinct effects and was well tolerated.

Consortium of Indigenous Fecal Bacteria in the Treatment of Metabolic Syndrome

The features of gut microbiota in metabolic syndrome (MS) and ways to correct it using autoprobiotics, based on indigenous bacteria obtained from fecal samples of the host, remain unexplored. The aim of the study was to investigate the effectiveness of an indigenous consortium (IC) of fecal bacteria in treatment of patients with MS. The study was carried out on 36 patients with MS, manifested with abdominal obesity, eating disorders, dyslipidemia, and hypertension. The control group was formed by 20 healthy volunteers. Samples of IC and gut microbiota content were examined by qPCR and metagenome (16S rRNA) analysis before and after therapy. The decrease in anthropometric parameters of obesity, liver enzyme level correction, reduction in C reactive protein and triglyceride concentrations were revealed after IC usage. The decrease in genera Bifidobacterium, Enterobacter, Paraprevotella, and Prevotella, as well as an increase in Bacteroides fragilis and Oscillospira spp. populations were shown after consumption of IC. A negative correlation between the quantity of B. fragilis and the anthropometric parameters of obesity (r = -0.48) and C reactive protein level (r = -0.36) in serum was established. Thus, IC can be considered as a potential functional personified product for the therapy of MS.

The potential role of Bifidobacterium spp. as a preventive and therapeutic agent in controlling inflammation via affecting inflammatory signalling pathways

Inflammatory bowel disease (IBD) is a chronic inflammatory disease with relapses and periods of remission. Forasmuch as, dysregulation of the immune system is one of the triggers of IBD, taking probiotics as one of the immunomodulators in the gut, could help to control inflammation and IBD via influencing signalling pathways. Here, we aimed to investigate the efficacy of five selected Bifidobacterium strains in modulating JAK/STAT and NF-kB inflammatory signalling pathways via using the in vitro assay. A quantitative real-time polymerase chain reaction assay was used to analyse the expression of JAK/STAT and inflammatory genes followed by potential probiotic treatments before, after and simultaneously with the inflammation induction (sonicated pathogen). The production of IL-6 and IL-1β after probiotic treatment was evaluated. Probiotic treatment resulted in the downregulation of TIRAP, IRAK4, NEMO and RIP genes in the NF-kB pathway, as well as JAK genes compared to sonicate-treated cells. The expression of STAT genes was different after our selected Bifidobacterium strains treatment. The production of IL-6 and IL-1β decreased after probiotic treatment. These strains of Bifidobacterium spp. showed anti-inflammatory effects on HT-29 cells via modulation of JAK/STAT and NF-kB signalling pathways. The use of Bifidobacterium spp. could be considered as a suitable preventive and complementary treatment for patients with inflammatory bowel disease.

Assessing synergistic effect of Jerusalem Artichoke juice and antioxidant compounds on enhanced viability and persistence of Bifidobacterium species, palatability, and shelf life

Commercial vegetable and fruit juices with probiotics are new functional type of beverages; however, limitations including persistence and impact of probiotic bacteria on palatability and shelf life may prevent their industrial development. This study evaluated the effect of antioxidant compounds (ascorbic acid, astaxanthin, and ginseng) on viability and persistence of Bifidobacterium spp. in Jerusalem Artichoke (JA) juice; and determine the impact of these antioxidants on the sensory (color, texture, flavor, acidity) properties, free reducing sugar (inulin and fructose), and shelf life in the fortified JA juice. Overall, the JA juice fortified with ascorbic acid showed a significant impact on the rate of persistence of two targeted bifidobacterial strains from 1 to 28 days at 5°C. Both strains produced slight acidity in ascorbic acid fortified JA juice as compared to other tested samples. Similarly, the JA juice fortified with ascorbic acid showed a significantly high increase in the total number of bifidobacterial cells of both species, enhanced palatability, and shelf life as compared to astaxanthin and ginseng extract. The quadratic model indicated a strong association between ascorbic acid, ginseng extract, and astaxanthin with a bifidobacterial cell concentration in the fortified JA juices. The Box–Behnken design was considered a feasible analysis for describing fortified JA juice and the rate of viability and persistence of bifidobacteria during 28 days of storage at 5°C in all trials. In conclusion, JA juice fortified with ascorbic acid showed a significant impact on improving the cell viability and persistence of probiotic bacteria, enhanced palatability, and shelf life as compared to other compounds tested.

Bifidobacterium spp. as functional foods: A review of current status, challenges, and strategies

Members of Bifidobacterium are among the first microbes to colonize the human intestine naturally, their abundance and diversity in the colon are closely related to host health. Recently, the gut microbiota has been gradually proven to be crucial mediators of various metabolic processes between the external environment and the host. Therefore, the health-promoting benefits of Bifidobacterium spp. and their applications in food have gradually been widely concerned. The main purpose of this review is to comprehensively introduce general features, colonization methods, and safety of Bifidobacterium spp. in the human gut, highlighting its health benefits and industrial applications. On this basis, the existing limitations and scope for future research are also discussed. Bifidobacteria have beneficial effects on the host's digestive system, immune system, and nervous system. However, the first prerequisite for functioning is to have enough live bacteria before consumption and successfully colonize the colon after ingestion. At present, strain breeding, optimization (e.g., selecting acid and bile resistant strains, adaptive evolution, high cell density culture), and external protection technology (e.g., microencapsulation and protectants) are the main strategies to address these challenges in food application.

Native and Engineered Probiotics: Promising Agents against Related Systemic and Intestinal Diseases

Intestinal homeostasis is a dynamic balance involving the interaction between the host intestinal mucosa, immune barrier, intestinal microecology, nutrients, and metabolites. Once homeostasis is out of balance, it will increase the risk of intestinal diseases and is also closely associated with some systemic diseases. Probiotics (Escherichia coli Nissle 1917, Akkermansia muciniphila, Clostridium butyricum, lactic acid bacteria and Bifidobacterium spp.), maintaining the gut homeostasis through direct interaction with the intestine, can also exist as a specific agent to prevent, alleviate, or cure intestinal-related diseases. With genetic engineering technology advancing, probiotics can also show targeted therapeutic properties. The aims of this review are to summarize the roles of potential native and engineered probiotics in oncology, inflammatory bowel disease, and obesity, discussing the therapeutic applications of these probiotics.

Preparation of rice fermented food using root of Asparagus racemosus as herbal starter and assessment of its nutrient profile

The popularity of traditional fermented food products is based on their healthiness. The addition of a starter brings consistent, desirable, and predictable food changes with improved nutritive, functional, and sensory qualities. The addition of a mixture of plant residues as a starter or source of microbes is an age-old practice to prepare traditional fermented food and beverages, and most of the reported data on traditional foods were based on the analysis of the final product. The contribution of an individual starter component (plant residue) is not experimentally substantiated for any traditional fermented food, but this data are very essential for the formulation of an effective starter. In this study, Asparagus racemosus, which used as a common ingredient of starter for preparation of rice fermented food in the Indian sub-continent, was used as a starter for the preparation of rice fermented food under laboratory scale, and its microbial and nutrient profile was evaluated. The fermented product was a good source of lactic acid bacteria, Bifidobacterium sp., yeast, etc. The food product was acidic and enriched with lactic acid and acetic acid with titratable acidity of 0.65%. The content of protein, fat, minerals, and vitamins (water-soluble) was considerably improved. Most notably, oligosaccharide (G3-matotriose), unsaturated fatty acids (ω3, ω6, ω7, and ω9), and a pool of essential and non-essential amino acids were enriched in the newly formulated food. Thus, the herbal starter-based rice fermented food would provide important macro- and micronutrients. They could also deliver large numbers of active microorganisms for the sustainability of health. Therefore, the selected plant part conferred its suitability as an effective starter for the preparation of healthier rice-based food products.

Graphic abstract

Investigation of Antibacterial Activity and Probiotic Properties of Strains Belonging to Lactobacillus and Bifidobacterium Genera for Their Potential Application in Functional Food and Feed Products

For novel food/feed product formulation, the selection of the right culture with probiotic properties is essential. The purpose of this research was to evaluate antibacterial activity and probiotic features of Lactobacillus and Bifidobacterium spp. for its potential application in functional food/feed products as supplement. The evaluation of antibacterial activities was carried out by agar diffusion assay and broth inhibition assay methods against twelve pathogenic strains belonging to Staphylococcus aureus, Escherichia coli, Staphylococcus chromogenes, and Staphylococcus hyicus species. Metabolites produced by Lactobacillus paracasei subsp. paracasei DSM 20020, L. paracasei subsp. paracasei DSM 4905, and L. gasseri DSM 20077 inhibited the growth of all tested pathogens. The strains were characterized in vitro for their probiotic characteristics such as resistance to low pH and bile salts, antibiotic sensitivity by gradient diffusion using MIC Test Strips, autoaggregation and coaggregation assay with E. coli DSM 27503, and antioxidant activity by 1-diphenyl-2-picrylhydrazyl (DPPH) and 2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assays. The results demonstrated that tested probiotic properties varied among the strains. Lactobacillus spp. tolerated pH 3 for 4 h, while 8 of 14 strains survived 4 h in pH 2. Most of tested strains were able to tolerate 0.3% bile salts for 4 h. All tested strains were sensitive to ampicillin. No gelatinase and hemolytic activities were detected. These results suggest Lactobacillus acidophilus DSM 20079, Bifidobacterium pseudolongum DSM 20099, and Bifidobacterium animalis DSM 20105 as probiotic candidates for the development of functional food/feed.

Emulsifier and Xylanase Can Modulate the Gut Microbiota Activity of Broiler Chickens

Simple Summary

Modern broiler nutrition, due to widely accepted goals of sustainable production, is concerned with the improvement of nutrient utilization. To achieve this, in our study, we used feed additives that improve the value of feed components. Due to the significant amounts of non-starch polysaccharides (which are not digested under broiler intestinal tract conditions and negatively affect broilers performance) in popular feed components like wheat, enzymes are needed. Furthermore, the use of emulsifiers to improve fat digestion is necessary, as young birds do not secrete sufficient enzyme and bile salts. Previous studies have shown that an additional increase in carbohydrate digestibility can be obtained by using an emulsifier containing xylanase in the feed. Presumably, the increase in carbohydrate digestibility occurred after adding the emulsifier. In our study, we aimed to investigate the effect of xylanase, emulsifier, and a combination of both in wheat diets with high level of tallow on the gastrointestinal tract microbiota activity of 480 one-day-old male ROSS 308 broiler chickens. The simultaneous usage of both additives in wheat-based diets with beef tallow reduces the ileum microbiota activity and enhances cecum microbiota activity. Presumably, the addition of both additives results in a cumulative effect on the gut microbiota activity.

Abstract

In this study, we aimed to investigate the effect of xylanase (XYL), emulsifier (EMU), and a combination of both (XYL + EMU) in wheat diet with a high level of tallow on gastrointestinal tract microbiota activity, excretion of sialic acids, and selected gut segments morphology of 480 one-day-old male ROSS 308 broiler chickens. The activities of bacterial enzymes in the ileal digesta were lower in experimental groups compared to the control (CON) group. Enzyme activity in the cecum was significantly higher than in the ileum. The additives did not affect the excretion of sialic acid. The number of duodenum goblet cells on the villi decreased in all of the experimental groups (p < 0.05). The simultaneous use of XYL + EMU deepened the ileum crypts (p < 0.05). The total short-chain fatty acid (SCFA) concentration in the cecal digesta was higher in experimental groups. The abundance of Bifidobacterium, Lactobacillus, and Escherichia coli did not change among experimental groups. The relative abundance of Clostridium was significantly (p < 0.05) lower in groups with emulsifier addition. In conclusion, the simultaneous usage of EMU and XYL in wheat-based diets with beef tallow reduces the ileum microbiota activity and enhances cecum microbiota activity. Presumably, the addition of both additives results in a cumulative effect on the gut microbiota activity.

Human milk oligosaccharide supplementation in irritable bowel syndrome patients: A parallel, randomized, double-blind, placebo-controlled study

OBJECTIVES

Human milk oligosaccharides safely and beneficially impact bifidobacteria abundance in healthy adults, while their effects in patients with irritable bowel syndrome (IBS) are unknown. Hence, we aimed to determine the dose of 4:1 mix of 2'-O-fucosyllactose and Lacto-N-neotetraose (2'FL/LNnT) that increases fecal bifidobacteria abundance without aggravating overall gastrointestinal symptoms in IBS patients in a randomized, double-blind, controlled study. Additionally, the impact of 2'FL/LNnT on the fecal bacterial profile was assessed.

METHODS

Irritable bowel syndrome patients diagnosed according to the Rome IV criteria received placebo (glucose), or 5 g or 10 g 2'FL/LNnT for 4 weeks followed by a four-week follow-up period. Gastrointestinal Symptom Rating Scale-IBS was used to assess gastrointestinal symptom severity; fecal microbiota composition was evaluated by GA-map™ Dysbiosis Test.

RESULTS

Of the included 60 patients, two (one placebo and one 10 g) discontinued prematurely. Fecal bifidobacteria abundance was increased at week 4, but not at week 8, in the 10 g group compared to the other groups. Severity of overall or individual gastrointestinal symptoms did not differ between the groups at week 4 or 8, and no symptom deterioration was seen in any of the groups. The 10 g dose influenced overall fecal microbiota composition, and responders-defined as bifidobacteria increase ≥50%-could be discriminated from non-responders based on fecal microbiota modulation.

CONCLUSIONS

The 10 g dose of 2'FL/LNnT induced an increase in the beneficial Bifidobacterium spp. without aggravating gastrointestinal symptoms in patients with IBS. This approach may be worthwhile to modulate gut microbiota of IBS patients toward a healthier profile.

Effect of probiotics on the maintenance of intestinal homeostasis after chemotherapy: systematic review and meta-analysis of pre-clinical studies

Gastrointestinal mucositis (GIM) is an inflammation caused by antitumor therapy, especially after chemotherapy and radiotherapy. Currently in the clinical practice, only palliative measures are taken to treat GIM, representing the main clinical limitation in the management of this condition. Several studies have highlighted the potential benefits of probiotics for the management of GIM, but the actual role of these microorganisms in the maintenance of intestinal homeostasis remains elusive. In this context, here we aimed to realise a systematic review with meta-analysis to evaluate the effect of probiotics on experimental GIM. The meta-analysis showed that probiotics significantly suppressed the body weight loss related to GIM in rodents (95% confidence interval (CI): -2.67 to -0.70; I²=98%, P<0.00). Subgroup analysis showed that pre-treatment (≥7 days before chemotherapy) (95% CI: -8.84 to -0.17; I²=98%, P<0.04) with a high dose of probiotics (≥ 10⁹ cfu/day) (95% CI: -2.58 to -0.28; I²=98%, P<0.00) comprising two or more microorganism species (95% CI: -6.49 to -0.28; I²=96%, P=0.03) remedied GIM more effectively. It was also revealed that fungi (specifically Saccharomyces boullardii) are more effective in remedying GIM than bacteria (P=0.03 vs P<0.00), and the mouse models are more receptive than rats to the enteroprotective effects of probiotics (95% CI: -4.76, -0.69; I²=97%, P=0.01). Qualitative analyses highlighted that probiotics suppress GIM through several mechanisms; they reduce the intestinal permeability, suppress the pro-inflammatory cytokine production while stimulating production and secretion of anti-inflammatory cytokines, inhibit the signalling pathways coupled to inflammation and apoptosis, accelerate the proliferation of enterocytes, reduce the levels of reactive oxygen species, and help maintain the protective mucus layer. In conclusion, this review highlights the therapeutic benefits of probiotics in experimental GIM.

A randomized double-blind placebo-controlled trial of probiotics in post-surgical colorectal cancer

Background

Our study aimed to determine the effect of probiotic consumption containing six viable microorganisms of 30 × 10¹⁰ cfu Lactobacillus and Bifidobacteria strains for six months on clinical outcomes and inflammatory cytokines (TNF-α, IFN-γ, IL-6, IL-10, IL-12, IL-17A, IL-17C and IL-22) in patients with colorectal cancer.

Methods

Fifty-two patients with colorectal cancer were randomized at four weeks after surgery to receive either a placebo (n = 25) or 30 billion colony-forming unit (CFU) of a mixture of six viable strains including 107 mg of Lactobacillus acidophilus BCMC® 12,130, Lactobacillus lactis BCMC® 12,451, Lactobacillus casei subsp BCMC® 12,313, Bifidobacterium longum BCMC® 02120, Bifidobacterium bifidum BCMC® 02290 and Bifidobacterium infantis BCMC® 02129 (n = 27). Patients were instructed to take the product orally twice daily for six months. Infection status, diarrhea or hospital admission were recorded throughout the study. Blood was taken pre- and post-intervention to measure TNF-α, IFN-γ, IL-6, IL-10, IL-12, IL-17A, IL-17C and IL-22 using ELISA multiplex kit.

Results

The majority of cases (~ 70%) were in Duke’s C colorectal cancer for both groups. No surgical infection occurred and no antibiotics were required. Chemotherapy induced diarrhea was observed in both groups. Significant reduction in the level of pro-inflammatory cytokine, TNF-α, IL-6, IL-10, IL-12, IL-17A, IL-17C and IL-22 were observed in CRC patients who received probiotics as compared to pre-treatment level (P < 0.05). However, there was no significant difference in the IFN-γ in both groups.

Conclusions

We have shown that probiotics containing six viable microorganisms of Lactobacillus and Bifidobacteria strains are safe to be consumed at four weeks after surgery in colorectal cancer patients and have reduced pro-inflammatory cytokines (except for IFN-gamma). Probiotic may modify intestinal microenvironment resulting in a decline in pro-inflammatory cytokines.

Trial registration

NCT03782428; retrospectively registered on 20th December 2018.

Gut microbiota disorders cause type 2 diabetes mellitus and homeostatic disturbances in gut-related metabolism in Japanese subjects

Few studies have investigated the host-microbe metabolic axis in people with type 2 diabetes mellitus (T2DM). This study aimed to determine and compare the nutrient intakes and metabolic markers and to elucidate the relationships among these factors in Japanese T2DM patients and control individuals. Fifty-nine Japanese T2DM patients and 59 matched healthy control individuals participated in this study. We examined the differences regarding the participants’ dietary habits, microbiota, and fecal short-chain fatty acids, and analyzed the relationships between the gut microbiota and blood metabolic markers in the T2DM patients and the control subjects. The T2DM patients consumed more carbohydrates, and had lower fecal propionate and butyrate concentrations, larger fecal populations of Bifidobacterium spp. and bacteria of the order Lactobacillales, and smaller fecal Bacteroides spp. populations than the control individuals. In the T2DM patients, the level of Bifidobacterium spp. correlated negatively with the carbohydrate intake and the level of bacteria of the order Lactobacillales correlated negatively with the protein intake. T2DM patients have gut dysbiosis that may contribute to disease onset and influence its prognosis. Furthermore, homeostatic disturbances in the gut-related metabolism may underlie the pathogenesis of T2DM.

A Preliminary Report on the Use of the Design of Experiments for the Production of a Synbiotic Yogurt Supplemented With Gluten FriendlyTM Flour and Bifidobacterium infantis

The main goal of this paper was to design a synbiotic yogurt containing Bifidobacterium infantis and Gluten Friendly FlourTM; the proposed approach relies upon milk fermentation through the classical starter of yogurt (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus) to avoid a strong production of acetic acid by bifidobacterial and inoculum of B. infantis after the fermentation. The research was divided in 3 steps. The aim of the first step was the optimization of fermentation kinetic by L. delbureckii and S. thermophilus, by combining the amount of flour (either Gluten Friendly Flour-GF- or Control Flour-CF) in milk, temperature and inoculum level; the factors were combined through a mixture design. As a result of this step, the best combination was pointed out: flour at 2.5 g/l; L. delbrueckii subsp. bulgaricus at 6 log cfu/ml; temperature at 37-40°C. The goal of the second step was to study the effect of flour (2.5 g/l) on the viability of B. infantis. GF prolonged the viability of the probiotic for 14 days. In the last step, a synbiotic yogurt, supplemented with GF and fermented with L. delbureckii and S. thermophilus, and then inoculated with B. infantis, was produced. The product was stored at 8 and 15°C. A positive effect of GF was found at 15°C, with B. infantis at 7.0 log cfu/g in GF sample and 5.5.5.7 log cfu/g in CF sample.

Dietary Polysaccharide from Enteromorpha Clathrata Modulates Gut Microbiota and Promotes the Growth of Akkermansia muciniphila, Bifidobacterium spp. and Lactobacillus spp

Recently, accumulating evidence has suggested that Enteromorpha clathrata polysaccharide (ECP) could contribute to the treatment of diseases. However, as a promising candidate for marine drug development, although ECP has been extensively studied, less consideration has been given to exploring its effect on gut microbiota. In this light, given the critical role of gut microbiota in health and disease, we investigated here the effect of ECP on gut microbiota using 16S rRNA high-throughput sequencing. As revealed by bioinformatic analyses, ECP considerably changed the structure of the gut microbiota and significantly promoted the growth of probiotic bacteria in C57BL/6J mice. However, interestingly, ECP exerted different effects on male and female microbiota. In females, ECP increased the abundances of Bifidobacterium spp. and Akkermansia muciniphila, a next-generation probiotic bacterium, whereas in males, ECP increased the population of Lactobacillus spp. Moreover, by shaping a more balanced structure of the microbiota, ECP remarkably reduced the antigen load from the gut in females. Altogether, our study demonstrates for the first time a prebiotic effect of ECP on gut microbiota and forms the basis for the development of ECP as a novel gut microbiota modulator for health promotion and disease management.

Bifidobacteria and its rice fermented products on diet induced obese mice: analysis of physical status, serum profile and gene expressions

Obesity is highly correlated with the dysbiosis of intestinal microbiota, and bifidobacteria are one of the soft targets of this metabolic syndrome. The aim of this study is to evaluate the efficacy of Bifidobacterium sp. MKK4 and rice-based fermented foods on physical, haematological, gut microbiota and lypogenic-lypolytic marker genes in diet-induced obese mice. Adult male mice (21±0.7 g) were randomly divided into four groups (n=10) according to the type of diet: normal diet (ND), high fat diet (HFD), HFD supplemented with Bifidobacterium sp. MKK4 and HFD supplemented with MKK4 associated rice-fermented food. 8 weeks of bacterial therapy in the obese mice resulted in significant reduction of body and organ weights, improved serum levels of glucose, triglyceride and cholesterol, the histological structure of the liver (steatosis), and re-establishment of gut Lactobacillus, Bifidobacterium and Bacteroides species. The bacterial therapy led to up-regulation of lipolytic transcription factors, such as peroxisome proliferator-activated receptor (PPAR)-α, PPAR-δ, and their regulated gene products in fatty acid metabolism and glucose uptake, such as acyl-CoA oxidase, carnitine palmitoyl-transferase-1, uncoupling protein-3 and glucose transporter-4. Concomitantly, both adipocytogenesis and fatty acid synthesis were arrested as reflected by the down-regulation of sterol regulatory element binding protein-1c, acetyl-CoA carboxylase, fatty acid synthase and tumour necrosis factor alpha genes. The effectiveness of the fermented product was more profound than the single bacterium. These data provide experimental support with regard to the use of Bifidobacterium sp. MKK4 as a natural therapeutic agent to control obesity.

Bifidobacterium callitrichidarum sp. nov. from the faeces of the emperor tamarin (Saguinus imperator)

Three Gram-stain-positive, non-spore-forming, microaerophilic and fructose-6-phosphate phosphoketolase positive strains were isolated from a faecal sample of an adult subject of the emperor tamarin (Saguinus imperator). Given that the isolates revealed identical BOX PCR profiles, strain TRI 5^T was selected as a representative and characterized further. Comparative analysis of 16S rRNA gene sequence similarity revealed that strain TRI 5^T was closely related to Bifidobacterium saguini DSM 23967^T (96.4 %) and to Bifidobacterium longum subsp. longum ATCC 15708 (96.2 %). Multilocus sequence analyses of five housekeeping genes showed the close phylogenetic relatedness of this strain to Bifidobacterium breve DSM 20213^T (hsp60 94.1 %), Bifidobacterium saguini DSM 23967^T (clpC 91 %), Bifidobacterium avesanii DSM 100685^T (dnaG 80.3 %), Bifidobacterium longumsubsp. infantis ATCC 15697^T (dnaJ 85.3 %) and Bifidobacterium longumsubsp. longum ATCC 15708 (rpoB 93 %), respectively. The peptidoglycan type was A3β, with an interpeptide bridge comprising l-Orn (Lys) - l-Ser - l-Ala - l-Thr - l-Ala. The DNA G+C content of strain TRI 5^T was 60.9 mol%. Based on the data provided, strain TRI 5^T represents a novel species of the genus Bifidobacterium for which the name Bifidobacteriumcallitrichidarum sp. nov. is proposed. The type strain is TRI 5^T (=DSM 103152^T=JCM 31790^T).

Ratio of Klebsiella/Bifidobacterium in early life correlates with later development of paediatric allergy

Several studies have reported that intestinal microbial colonisation patterns differ between non-allergic and allergic infants. However, the microbial signature underlying the pathogenesis of allergies remains unclear. We aim to gain insight into the development of the intestinal microbiota of healthy infants and infants who develop allergy in early life, and identify potential microbiota biomarkers of later allergic disease. Using a case-control design in a Chinese sub-cohort of a Singaporean birth cohort (GUSTO), we utilised 16S rRNA gene sequencing to assess intestinal microbial composition and diversity of 21 allergic and 18 healthy infants at 3 weeks, 3 months and 6 months of age, and correlated the microbiota with allergy at ages 18 and 36 months. Pronounced differences in intestinal microbiota composition between allergic and healthy infants were observed at 3 months of age. The intestine of healthy infants was colonised with higher abundance of commensal Bifidobacterium. Conversely, Klebsiella, an opportunistic pathogen, was significantly enriched in the allergic infants. Interestingly, infants with a high Klebsiella/Bifidobacterium (K/B) ratio (above the population median K/B ratio) at age 3 months had an odds ratio of developing allergy by 3 years of age of 9.00 (95% confidence interval 1.46-55.50) compared to those with low K/B ratio. This study demonstrated a relationship between the ratio of genera Klebsiella and Bifidobacterium during early infancy and development of paediatric allergy in childhood. Our study postulates that an elevated K/B ratio in early infancy could be a potential indicator of an increased risk of allergy development. This line of research might enable future intervention strategies in early life to prevent or treat allergy. Our study provides new insights into microbial signatures associated with childhood allergy, in particular, suggests that an elevated K/B ratio could be a potential early-life microbiota biomarker of allergic disease.

Different physiological properties of human-residential and non-human-residential bifidobacteria in human health

Bifidobacteria have increasingly been shown to exert positive health benefits to humans, which are clearly reflected by their application in various commercialised dairy products and supplements. Bifidobacteria naturally inhabit a range of ecological niches and display substantial differences in their ecological adaptation among species. In general, bifidobacteria could be categorised into two major groups; bifidobacterial species of human origins as human-residential bifidobacteria (HRB) while other species which are the natural inhabitants of animals or environment as non-HRB. Current research has focused on the differential physiological features of HRB and non-HRB, such as metabolic capabilities, whilst comparative and functional genomic investigations have revealed the genetic attributes of bifidobacteria that may explain their colonisation affinities in human gut. It is becoming more apparent that distinct residential origins of bifidobacteria are likely contributed to their comparable adaptive health attributes on human host. Notably, debate still remains about the nature of bifidobacteria for use as human probiotics. Clinical evaluations involving supplementation of bifidobacteria of different origins point out the superiority of HRB in human host. Evidence also suggests that HRB especially infant-type HRB may exert better health-promoting effects and therefore serve as a better probiotic candidate for infant use. In this review, we aim to provide an overview of the genotypic and physiological differences of bifidobacteria associated with different residential origins and to shed light on the practical considerations for selection of bifidobacteria as probiotics in order to establish a healthy gut microbial community in humans.

In vitro characterisation of the fermentation profile and prebiotic capacity of gold-fleshed kiwifruit

A new Actinidia chinensis gold-fleshed kiwifruit cultivar 'Zesy002' was tested to investigate whether it could positively modulate the composition of the human colonic microbiota. Digested Zesy002 kiwifruit was added to in vitro pH-controlled anaerobic batch fermenters that were inoculated with representative human faecal microbiota. Alterations to the gut microbial ecology were determined by 16S rRNA gene sequencing and metabolic end products were measured using gas chromatography and liquid chromatography - mass spectrometry. Results indicated a substantial shift in the composition of bacteria within the gut models caused by kiwifruit supplementation. Zesy002 supplemented microbiota had a significantly higher abundance of Bacteroides spp., Parabacteroides spp. and Bifidobacterium spp. after 48 h of fermentation compared with the start of the fermentation. Organic acids from kiwifruit were able to endure simulated gastrointestinal digestion and were detectable in the first 10 h of fermentation. The fermentable carbohydrates were converted to beneficial organic acids with a particular predilection for propionate production, corresponding with the rise in Bacteroides spp. and Parabacteroides spp. These results support the claim that Zesy002 kiwifruit non-digestible fractions can effect favourable changes to the human colonic microbial community and primary metabolites, and demonstrate a hitherto unknown effect of Zesy002 on colonic microbiota under in vitro conditions.

Histo-FISH protocol to detect bacterial compositions and biofilms formation in vivo

The study of biofilm function in vivo in various niches of the gastrointestinal tract (GIT) is rather limited. It is more frequently used in in vitro approaches, as an alternative to the studies focused on formation mechanisms and function of biofilms, which do not represent the actual in vivo complexity of microbial structures. Additionally, in vitro tests can sometimes lead to unreliable results. The goal of this study was to develop a simple approach to detect bacterial populations, particularly Lactobacillus and Bifidobacterium in biofilms, in vivo by the fluorescent in situ hybridisation (FISH) method. We standardised a new Histo-FISH method based on specific fluorochrome labelling probes which are able to detect Lactobacillus spp. and Bifidobacterium spp. within biofilms on the mucosal surface of the GIT embedded in paraffin in histological slices. This method is also suitable for visualisation of bacterial populations in the GIT internal content. Depending on the labelling probes, the Histo-FISH method has the potential to detect other probiotic strains or pathogenic bacteria. This original approach permits us to analyse bacterial colonisation processes as well as biofilm formation in stomach and caecum of BALB/c and germ-free mice.

Aciduric microbial taxa including Scardovia wiggsiae and Bifidobacterium spp. in caries and caries free subjects

Actinobacteria came into focus of being potential caries-associated pathogens and could, together with the established Streptococcus mutans and lactobacilli thus function as caries indicator species. Here we analyzed the role and diagnostic predictive value of the acidogenic-aciduric species Scardovia wiggsiae and Bifidobacterium dentium together with S. mutans, lactobacilli and bifidobacteria in biofilm of non-cavitated (n = 20) and cavitated (n = 6) caries lesions versus controls (n = 30). For the genus Bifidobacterium and for B. dentium new sets of primers were designed. Based on real-time quantitative PCR and confirmed by DNA sequencing we found a higher prevalence (61.5%) of S. wiggsiae in caries lesions than in controls (40%). However, among the controls we found three individuals with both the highest absolute and relative S. wiggsiae numbers. Testing for S. mutans revealed the same prevalence as S. wiggsiae in caries lesions (61.5%) but in controls its prevalence was only 10%. B. dentium was never found in healthy plaque but in 30.8% of clinical cases, with the highest numbers in cavitated lesions. The Bifidobacterium-genus specific PCR had less discriminative power as more control samples were positive. We calculated the relative abundances and applied receiver operating characteristic analyses. The top results of specificity (93% and 87%) and sensitivity (100% and 88%) were found when the constraint set was "Lactobacillus relative abundance ≥0.02%" and "two aciduric species with a relative abundance of each ≥0.007%". Combinatory measurement of several aciduric taxa may be useful to reveal caries activity or even to predict caries progression.

Isolation and identification of cultivable Bifidobacterium spp. from the faeces of 5 baby common marmosets (Callithrix jacchus L.)

Ninety-two bifidobacterial strains were obtained from the faeces of 5 baby common marmosets, three known species Bifidobacterium aesculapii, Bifidobacterium callithricos and Bifidobacterium reuteri and 4 novel putative bifidobacterial species were retrieved. The occurrence of bifidobacteria in non-human primate babies is described for the first time.

1-Kestose consumption during pregnancy and lactation increases the levels of IgA in the milk of lactating mice

To examine the effect of dietary supplementation with 1-kestose on the IgA levels in milk, BALB/c mice were fed diets with or without 5% 1-kestose during pregnancy and lactation. The total and specific IgA levels in the milk were measured at 7 and 14 days after delivery. A two-way ANOVA with repeated measures resulted in a significant effect of 1-kestose-supplementation on total IgA concentrations (p < 0.05) and the level of anti-Bacteroides IgA (p < 0.05). A significant positive correlation was found between the mean count of Bacteroides spp. in maternal feces and the total IgA concentration in maternal milk (r = 0.55, p < 0.05), suggesting a potential link between the gut and mammary gland immune system. In conclusion, this study demonstrated the effects of dietary prebiotics on milk IgA production.

Using a simplex centroid to study the effects of pH, temperature and lactulose on the viability of Bifidobacterium animalis subsp. lactis in a model system

This paper reports on the effects of lactulose (0-10 g/l) on Bifidobacterium animalis subsp. lactis, along with the influence of pH (4.5-8.5) and temperature (15-45 °C); the three factors were combined through a simplex centroid. The experiments were performed in a laboratory medium and the data of cells counts were modeled through the Weibull equation for the evaluation of the first reduction time, the shape parameter and the death time. These fitting parameters were used as input values to build a desirability profile and a second-order model through the DoE approach (Design of Experiments). The medium containing glucose was used as control. The prebiotic enhanced the viability of the microbial target, by prolonging the first reduction time and inducing a shoulder phase in the death kinetic; moreover, in some combinations the statistical analysis highlighted a kind of interaction with the pH.