Live/dead state is not the factor influencing adhesion ability of Bifidobacterium animalis KLDS2.0603

Alteration of the gut microbiome in patients with heart failure: A systematic review and meta-analysis

Recent research has revealed that alterations of the gut microbiome (GM) play a comprehensive role in the pathophysiology of HF. However, findings in this field remain controversial. In this study, we focus on differences in GM diversity and abundance between HF patients and non-HF people, based on previous 16 S ribosomal RNA (16rRNA) gene sequencing. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search of PubMed, Web of Science, Embase, Cochrane Library, and Ovid databases using the keyword "Heart failure" and "Gastrointestinal Microbiome". A significant decrease in alpha diversity was observed in the HF patients (Chao1, I2 = 87.5 %, p < 0.001; Shannon index, I2 = 62.8 %, p = 0.021). At the phylum level, the HF group exhibited higher abundances of Proteobacteria (I2 = 92.0 %, p = 0.004) and Actinobacteria (I2 = 82.5 %, p = 0.010), while Bacteroidetes (I2 = 45.1 %, p = 0.017) and F/B ratio (I2 = 0.0 %, p＜0.001) were lower. The Firmicutes showed a decreasing trend but did not reach statistical significance (I2 = 82.3 %, p = 0.127). At the genus level, the relative abundances of Streptococcus, Bacteroides, Alistipes, Bifidobacterium, Escherichia-Shigella, Enterococcus and Klebsiella were increased in the HF group, whereas Ruminococcus, Faecalibacterium, Dorea and Megamona exhibited decreased relative abundances. Dialister, Blautia and Prevotella showed decreasing trends but without statistical significance. This observational meta-analysis suggests that GM changes are associated with HF, manifesting as alterations in GM abundance, disruptions in the production of short-chain fatty acids (SCFAs) bacteria, and an increase in trimethylamine N-oxide (TMAO) producing bacteria.

The Effects of Cellular Membrane Damage on the Long-Term Storage and Adhesion of Probiotic Bacteria in Caco-2 Cell Line

Adhesion is one of the main factors responsible for the probiotic properties of bacteria in the human gut. Membrane proteins affected by cellular damage are one of the key aspects determining adhesion. Fluid-bed-dried preparations containing probiotic bacteria were analyzed in terms of their stability (temperature of glass transition) and shelf life in different conditions (modified atmosphere, refrigeration). Imaging flow cytometry was utilized to determine four subpopulations of cells based on their physiological and morphological properties. Lastly, adhesion was measured in bacteria cultured in optimal conditions and treated with heat shock. The results show that the subpopulations with no or low levels of cell membrane damage exhibit the ability to adhere to Caco-2 cells. The temperature of protein denaturation in bacteria was recorded as being between 65 °C and 70 °C. The highest glass transition temperature (Tg) value for hydroxypropyl methylcellulose (used as a coating substance) was measured at 152.6 °C. Drying and coating can be utilized as a sufficient treatment, allowing a long shelf-life (up to 12 months). It is, however, worth noting that technological processing, especially with high temperatures, may decrease the probiotic value of the preparation by damaging the bacterial cells.

The Role of the PFNA Operon of Bifidobacteria in the Recognition of Host's Immune Signals: Prospects for the Use of the FN3 Protein in the Treatment of COVID-19

Bifidobacteria are some of the major agents that shaped the immune system of many members of the animal kingdom during their evolution. Over recent years, the question of concrete mechanisms underlying the immunomodulatory properties of bifidobacteria has been addressed in both animal and human studies. A possible candidate for this role has been discovered recently. The PFNA cluster, consisting of five core genes, pkb2, fn3, aaa-atp, duf58, tgm, has been found in all gut-dwelling autochthonous bifidobacterial species of humans. The sensory region of the species-specific serine-threonine protein kinase (PKB2), the transmembrane region of the microbial transglutaminase (TGM), and the type-III fibronectin domain-containing protein (FN3) encoded by the I gene imply that the PFNA cluster might be implicated in the interaction between bacteria and the host immune system. Moreover, the FN3 protein encoded by one of the genes making up the PFNA cluster, contains domains and motifs of cytokine receptors capable of selectively binding TNF-α. The PFNA cluster could play an important role for sensing signals of the immune system. Among the practical implications of this finding is the creation of anti-inflammatory drugs aimed at alleviating cytokine storms, one of the dire consequences resulting from SARS-CoV-2 infection.

Comparison of microbial diversity in rumen and small intestine of Xinong Saanen dairy goats using 16S rRNA gene high-throughput sequencing

Context Gastrointestinal microorganisms play an important role in ruminant digestion and metabolism, immune regulation and disease prevention and control. Different parts of the digestive tract have different functions and microbial community structures. Aims This study aims to explore the microbial diversity in the rumen and the small intestine of Xinong Saanen dairy goats. Methods Rumen fluid and jejunum fluid from three Xinong Saanen dairy bucks with the average slaughter weight of 33.93 ± 0.68 kg were collected and analysed for microbial diversity, by using 16S rRNA gene high-throughput sequencing. Key results In total, 1118 operational taxonomic units (OTUs) were identified, with 1020 OTUs and 649 OTUs being clustered to rumen and jejunum samples respectively. Alpha-diversity indices were significantly (P < 0.05) different between rumen and jejunum, as indicated by the fact that the rumen microbial community diversity, richness and uniformity/evenness were higher than those of jejunum. At the phylum level, the dominant phyla in the rumen were Bacteroidetes (66.7%) and Firmicutes (25.1%), accounting for 91.8% of the rumen microorganisms. The dominant phylum in the jejunum was Firmicutes, accounting for 73.0% of the jejunum microorganisms. At the genus level, the dominant bacteria in the rumen were Prevotella_1, norank_f_Bacteroidales_BS11_gut_group, Rikenellaceae_RC9_gut_group, Christensenellaceae_R-7_group and Family_XIII_AD3011_group, whereas the dominant bacteria in the jejunum were Omboutsia, Aeriscardovia, Intestinibacter, unclassified_f_Peptostreptococcaceae and unclassified_f_Bifidobacteriaceae. Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that the major functions of microorganisms in the rumen and jejunum were carbohydrate metabolism, amino acid metabolism, nucleotide metabolism, membrane transport and translation. Interestingly, fructose and mannose metabolism and peptidoglycan biosynthesis were abundant in the rumen, while homologous recombination and nucleotide excision repair were abundant in the jejunum. Conclusions Our study clarified the differences in microbial diversity and community structure between the rumen and the jejunum in Xinong Saanen dairy goats. Prevotella was the most predominant genus in the rumen, compared with Romboutsia, Bifidobacterium as well as Peptostreptococcaceae genera, which were the predominant genera in the jejunum. Implications In combination with the functional prediction of microorganisms and the metabolic characteristics of different parts of the digestive tract in ruminants, our findings provided information for further exploring the relationship among genes, species and functions of microorganisms and their hosts’ nutritional and physiological functions.

Adhesion mechanisms of Bifidobacterium animalis subsp. lactis JCM 10602 to dietary fiber

Adherence of probiotics to dietary fibers present in the intestinal tract may affect adhesion to intestinal epithelial cells. The properties of the adhesion of bifidobacteria to mucin or epithelial cells have been well studied; however, adhesion of bifidobacteria to dietary fiber has not been investigated. The adhesion ratio of six Bifidobacterium strains to cellulose and chitin was examined; among the strains, Bifidobacterium animalis subsp. lactis JCM 10602 showed high adherence to both cellulose and chitin, and two strains showed high adherence to only chitin. The ratios of adhesion of B. animalis to cellulose and chitin were positively and negatively correlated with ionic strength, respectively. These data suggest that hydrophobic and electrostatic interactions are involved in the adhesion to cellulose and chitin, respectively. The adhesion ratios of the cells in the late logarithmic phase to cellulose and chitin decreased by approximately 40% and 70% of the cells in the early logarithmic phase, respectively. Furthermore, the adhesion ratio to cellulose decreased with increasing bile concentration regardless of the culture phase of the cells. On the other hand, the adhesion ratio to chitin of cells in the early logarithmic phase decreased with increasing bile concentration; however, that of cells in the late logarithmic phase increased slightly, suggesting that adhesins differ depending on the culture phase. Our results indicated the importance of considering adhesion to both dietary fibers and the intestinal mucosa when using bifidobacteria as probiotics.

Antimicrobial and Immunomodulatory Effects of Bifidobacterium Strains: A Review

Bifidobacterium strains can provide several health benefits, such as antimicrobial and immunomodulatory effects. Some strains inhibit growth or cell adhesion of pathogenic bacteria, including multidrug-resistant bacteria, and their antibacterial activity can be intensified when combined with certain antibiotics. In addition, some strains of bifidobacteria reduce viral infectivity, leading to less epithelial damage of intestinal tissue, lowering the virus shedding titer, and controlling the release of antiviral substances. Furthermore, bifidobacteria can modulate the immune system by increasing immunoglobulins, and inducing or reducing pro- or antiinflammatory cytokines, respectively. In particular, these anti-inflammatory effects are helpful in the treatment of patients who are already suffering from infection or inflammatory diseases. This review summarizes the antimicrobial effects and mechanisms, and immunomodulatory effects of Bifidobacterium strains, suggesting the potential of bifidobacteria as an alternative or complementary treatment option.

Potential Immunomodulatory Activity of a Selected Strain Bifidobacterium bifidum H3-R2 as Evidenced in vitro and in Immunosuppressed Mice

The microbiota is directly involved in the development and modulation of the intestinal immune system. In particular, members of the genus Bifidobacterium play a primary role in immune regulation. In the present study, Bifidobacterium bifidum H3-R2 was screened from 15 bifidobacterium strains by in vitro experiment, showing a positive tolerance to digestive tract conditions, adhesion ability to intestinal epithelial cells and a regulatory effect on immune cell activity. Immunostimulatory activity of B. bifidum H3-R2 was also elucidated in vivo in cytoxan (CTX)-treated mice. The results showed that the administration of B. bifidum H3-R2 ameliorated the CTX-induced bodyweight loss and imbalanced expression of inflammatory cytokines, enhanced the production of secretory immunoglobulin A (SIgA), and promoted splenic lymphocyte proliferation, natural killer (NK) cell activity and phagocytosis of macrophages in immunosuppressed mice. In addition, B. bifidum H3-R2 restored injured intestinal mucosal, and increased the villus length and crypt depth in CTX-treated mice. The results could be helpful for understanding the functions of B. bifidum H3-R2, supporting its potential as a novel probiotic for immunoregulation.

Using probiotics for type 2 diabetes mellitus intervention: Advances, questions, and potential

Type 2 diabetes mellitus (T2DM) has become one of the most prevalent diseases on earth and several treatments have been developed. However, the current intervention approaches have not been as effective as expected. One promising supplementary strategy is the use of probiotics through direct or indirect approaches. Probiotics are microbial food cultures conferring health-promoting properties. In this review, we summarized the current theories and mechanisms of T2DM intervention using probiotics and hypothesize that probiotics intervene T2DM during its onsetting, developing, and complicating. For the first time, we comprehensively analyzed T2DM intervention in animal models using both wide-type probiotics in different forms and using recombinant probiotics. Then, probiotic intervention in T2DM patients was reviewed and the main results were compared with that obtained from animal studies. Finally yet importantly, remaining questions that are important such as in which form and in which state, as well as the future potential of probiotic intervention in T2DM were discussed from a perspective of food microbiologists. In conclusion, probiotic intervention in T2DM is promising but there are still many important issues unsolved yet. Critical review of the advances, questions, and potential of probiotic intervention in T2DM promotes the development of this approach for further application in humans.

Effects of prebiotics on immunologic indicators and intestinal microbiota structure in perioperative colorectal cancer patients

OBJECTIVE

The aim of the present study was to investigate the effects of prebiotics (containing fructooligosaccharides, xylooligosaccharides, polydextrose, and resistant dextrin) intake on immune function and intestinal microbiota structure in perioperative patients with colorectal cancer (CRC).

METHODS

A randomized, double-blind, no-treatment parallel control clinical trial involving 140 perioperative patients (90 men and 50 women, aged 40-75 y) with CRC was performed. Patients were randomly divided into two groups: an intervention group (prebiotic group, n = 70) that received prebiotic supplementation of 30 g/d for 7 d, and a control group (non-prebiotic group, n = 70) that received no prebiotic supplementation. The nutritional and immunologic indices were evaluated for both groups before and after operation and analyzed against baseline values. Moreover, fecal samples were collected from 40 patients randomly chosen from the two groups to study intestinal microbiota, which was analyzed by sequencing the V3-V4 region of 16S ribosomal DNA using the Illumina (San Diego, CA) MiSeq (PE 2 × 300 bp) platform.

RESULTS

Oral intake of prebiotics produced significant effects on immunologic indices in both the preoperative and postoperative periods, but the patterns of effects were different. In the preoperative period, prebiotics increased serum levels of immunoglobulin G (IgG; P = 0.02), IgM (P = 0.00), and transferrin (P = 0.027; all P < 0.05). In the postoperative period, enhanced levels of IgG (P = 0.003), IgA (P = 0.007), suppressor/cytotoxic T cells (CD3⁺CD8⁺; P = 0.043), and total B lymphocytes (CD19⁺; P = 0.012) were identified in the prebiotic group (all P < 0.05). The differences in the intestinal microbiota at the phylum level were not statistically significant between the intervention and control groups (P > 0.05). At the genus level, prebiotics increased the abundance of Bifidobacterium (P = 0.017) and Enterococcus (P = 0.02; both P < 0.05) but decreased the abundance of Bacteroides (P = 0.04) in the preoperative period (all P < 0.05). In the postoperative period, the abundance of Bacteroides (P = 0.04) was decreased, but the abundance of Enterococcus (P = 0.00), Bacillus (P = 0.01), Lactococcus (P = 0.00), and Streptococcus (P = 0.037) increased in the non-prebiotic group (all P < 0.05); however, no significant change was identified in the abundance of Enterococcus (P = 0.56), Lactococcus (P = 0.07), and Streptococcus (P = 0.56) as a result of prebiotic intervention in this period (all P > 0.05). The abundance of Escherichia-Shigella was increased after prebiotic intake in the postoperative period (P = 0.014, P < 0.05). There was a notable trend of decline in the abundance of intestinal microbiota from preoperative to postoperative in the non-prebiotic group.

CONCLUSIONS

Prebiotic intake is recommended to improve serum immunologic indicators in patients with CRC 7 d before operation. Prebiotics improved the abundance of four commensal microbiota containing opportunistic pathogens in patients with CRC. Surgical stress decreased the abundance of most intestinal microbiota in the intestinal tract but increased the abundance of some opportunistic pathogens and commensal microbiota. Bacteroides is a relevant bacterial species for further research on the mechanism of prebiotics.

Probiotic properties of Enterococcus strains isolated from traditional naturally fermented cream in China

The purpose of this study was to evaluate the probiotic properties of Enterococcus strains isolated from traditional naturally fermented cream in China. Four Enterococcus isolates showed high cholesterol removal ability in media were identified as Enterococcus durans (KLDS 6.0930 and 6.0933) and Enterococcus faecalis (KLDS 6.0934 and 6.0935) by 16S rRNA and pheS gene sequences, respectively, and selected for further evaluation. In order to assess the probiotic potential and safety of these strains, the property of four Enterococcus strains were examined, including acid and bile tolerance, adherence to Caco-2 cells and antibiotics susceptibility. All four strains showed potential cholesterol assimilation, de-conjugation of bile salts and/or cholesterol degradation to remove cholesterol in vitro. In addition, the potential effect of E. durans KLDS 6.0930 on serum cholesterol levels was evaluated in Sprague-Dawley rats. After 4 weeks administration, compared with rats fed a high-cholesterol diet without lactic acid bacteria supplementation, there was a significant (P < 0.05) decrease in the total cholesterol and low-density lipoprotein cholesterol levels in the serum of rats treated with KLDS 6.0930. Furthermore, total bile acid level in the feces was significantly (P < 0.05) increased after KLDS 6.0930 administration. These observations suggested that the strain E. durans KLDS 6.0930 may be used in the future as a good candidate for lowering human serum cholesterol levels.

Identification of surface-associated proteins of Bifidobacterium animalis ssp. lactis KLDS 2.0603 by enzymatic shaving

Bifidobacteria are commensal microorganisms of the human and animal intestinal tract, and their surface proteins can mediate bacterial communication and chemical sensing in the environment, as well as facilitate interactions between bacteria and the host. However, a systematic study of the outer surface-associated proteome of bifidobacteria has not been undertaken. In the present study, the proteins located on the surface of Bifidobacterium animalis ssp. lactis KLDS 2.0603 were systematically identified by a nongel proteomic approach, which consisted of the shaving of the bacterial surface with trypsin and an analysis of the released peptides by liquid chromatography-tandem mass spectrometry. A total of 105 surface-associated proteins were found, of which 15 proteins could potentially be involved in adhesion and interactions between bifidobacteria and the host. The proteins related to adhesion and interaction between bacteria and the host include pilus structure proteins (Fim A, Fim B), 10 moonlighting proteins, an NLP/P60 family protein, an immunogenic secreted protein, and a putative sugar-binding secreted protein. The results provide the basis for future studies on the molecular mechanisms of the interactions between bifidobacteria and the host.