Modulation of Gut Microbiota and Immune System by Probiotics, Pre-biotics, and Post-biotics

Probiotic of Lactiplantibacillus plantarum NWAFU-BIO-BS29 Isolated from Chinese Traditional Fermented Milk and Its Potential Therapeutic Applications Based on Gut Microbiota Regulation

Lactic acid bacteria are one of the bioresources that can promote the host's health and have potential therapeutic applications. This study aimed to evaluate the probiotic properties of novel Lactiplantibacillus plantarum NWAFU-BISO-BS29 isolated in vitro from traditional Chinese fermented milk, assess its safety, and study its interaction with the gut microbiota using a BALB/c mouse model. The findings reveal that this strain had a high tolerance to gastric acidity (64.4%) and bile salts (19.83-87.92%) with remarkable auto-aggregation and co-aggregation abilities (33.01-83.96%), respectively. Furthermore, it lowered the cholesterol levels in dead cells (44.02%) and live cells (34.95%) and produced short-chain fatty acids (SCFAs). Likewise, it showed good antioxidant properties and strong antipathogen activity against Escherichia coli and Staphylococcus aureus with inhibition zones at 21 and 25 mm, respectively. The safety assessment results indicate that all of the virulence factor genes were not detected in the whole DNA; additionally, no hemolysis or resistance to antibiotics commonly used in food and feed was observed. Interestingly, the 16S rRNA gene sequencing of the mouse gut microbiota showed a marked alteration in the microbial composition of the administrated group, with a noticeable increase in Firmicutes, Patescibacteria, Campylobacterota, Deferribacterota, Proteobacteria, and Cyanobacteria at the phylum level. The modulation of gut microbial diversity significantly improved the production of SCFCs due to the abundance of lactobacillus genera, which was consistent with the functional gene predictive analysis and is believed to have health-promoting properties. Based on these results, our novel strain is considered a safe and good probiotic and could hold high potential to be used as a starter culture or to safely supplement functional foods as a probiotic and may provide new insights into therapeutic interventions.

Anti-Helicobacter pylori activity of potential probiotic Lactiplantibacillus pentosus SLC13

BACKGROUND

Here, we aimed to evaluate and compare the anti-Helicobacter pylori activity of potential probiotic Lactiplantibacillus pentosus SLC13 to Lactobacillus gasseri BCRC 14619 T and Lacticaseibacillus rhamnosus LGG. Phenotypic assays including growth curve, cell adhesion, and cellular cytotoxicity were performed to characterize SLC13. Anti-H. pylori activity of lactobacilli was determined by the disk diffusion method and co-culture assay. Exopolysaccharide (EPS) was extracted from lactobacilli to test its immune modulation activity, and IL-8 expression in AGS and GES-1 was determined by RT-qPCR.

RESULTS

All three lactobacilli strains were tolerant to the simulated gastrointestinal conditions. SLC13 showed the highest adhesion ability to AGS and GES-1 cells, compared to LGG and BCRC 14619 T. The coculture assays of SLC13, LGG, and BCRC 14619 T with cells for 4 h showed no significant cytotoxic effects on cells. All tested strains exhibited an inhibitory effect against H. pylori J99. The cell-free supernatant (CFS) of three strains showed activity to inhibit H. pylori urease activity in a dose-dependent manner and the CFS of SLC13 had the highest urease inhibitory activity, compared to LGG and BCRC 14619 T. Only the treatment of AGS cells with SLC13 EPS significantly decreased the IL-8 expression induced by H. pylori infection as compared to cells treated with LGG and BCRC 14619 T EPS.

CONCLUSIONS

SLC13 possesses potent antimicrobial activity against H. pylori growth, infection, and H. pylori-induced inflammation. These results suggest that SLC13 and its derivatives have the potential as alternative agents against H. pylori infection and alleviate inflammatory response.

Bifidobacterium longum subsp. infantis CECT 7210 Reduces Inflammatory Cytokine Secretion in Caco-2 Cells Cultured in the Presence of Escherichia coli CECT 515

Previous works have described the activity of Bifidobacterium longum subsp. infantis CECT 7210 (also commercially named B. infantis IM-1^®) against rotavirus in mice and intestinal pathogens in piglets, as well as its diarrhea-reducing effect on healthy term infants. In the present work, we focused on the intestinal immunomodulatory effects of B. infantis IM-1^® and for this purpose we used the epithelial cell line isolated from colorectal adenocarcinoma Caco-2 and a co-culture system of human dendritic cells (DCs) from peripheral blood together with Caco-2 cells. Single Caco-2 cultures and Caco-2: DC co-cultures were incubated with B. infantis IM-1^® or its supernatant either in the presence or absence of Escherichia coli CECT 515. The B. infantis IM-1^® supernatant exerted a protective effect against the cytotoxicity caused by Escherichia coli CECT 515 on single cultures of Caco-2 cells as viability reached the values of untreated cells. B. infantis IM-1^® and its supernatant also decreased the secretion of pro-inflammatory cytokines by Caco-2 cells and the co-cultures incubated in the presence of E. coli CECT 515, with the response being more modest in the latter, which suggests that DCs modulate the activity of Caco-2 cells. Overall, the results obtained point to the immunomodulatory activity of this probiotic strain, which might underlie its previously reported beneficial effects.

Renoprotective Effect of Pediococcus acidilactici GKA4 on Cisplatin-Induced Acute Kidney Injury by Mitigating Inflammation and Oxidative Stress and Regulating the MAPK, AMPK/SIRT1/NF-κB, and PI3K/AKT Pathways

Acute kidney injury (AKI) describes a sudden loss of kidney function and is associated with a high mortality. Pediococcus acidilactici is a potent producer of bacteriocin and inhibits the growth of pathogens during fermentation and food storage; it has been used in the food industry for many years. In this study, the potential of P. acidilactici GKA4 (GKA4) to ameliorate AKI was investigated using a cisplatin-induced animal model. First, mice were given oral GKA4 for ten days and intraperitoneally injected with cisplatin on the seventh day to create an AKI mode. GKA4 attenuated renal histopathological alterations, serum biomarkers, the levels of inflammatory mediators, and lipid oxidation in cisplatin-induced nephrotoxicity. Moreover, GKA4 significantly decreased the expression of inflammation-related proteins and mitogen-activated protein kinase (MAPK) in kidney tissues. Eventually, GKA4 also increased the levels of related antioxidant enzymes and pathways. Consistently, sirtuin 1 (SIRT1) upregulated the level of autophagy-related proteins (LC3B, p62, and Beclin1). Further studies are needed to check our results and advance our knowledge of the mechanism whereby PI3K inhibition (wortmannin) reverses the effect of GKA4 on cisplatin-treated AKI. Taken together, GKA4 provides a therapeutic target with promising clinical potential after cisplatin treatment by reducing oxidative stress and inflammation via the MAPK, AMP-activated protein kinase (AMPK)/SIRT1/nuclear factor kappa B (NF-κB), and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) axes.

Intestinal Microbiota - An Unmissable Bridge to Severe Acute Pancreatitis-Associated Acute Lung Injury

Severe acute pancreatitis (SAP), one of the most serious abdominal emergencies in general surgery, is characterized by acute and rapid onset as well as high mortality, which often leads to multiple organ failure (MOF). Acute lung injury (ALI), the earliest accompanied organ dysfunction, is the most common cause of death in patients following the SAP onset. The exact pathogenesis of ALI during SAP, however, remains unclear. In recent years, advances in the microbiota-gut-lung axis have led to a better understanding of SAP-associated lung injury (PALI). In addition, the bidirectional communications between intestinal microbes and the lung are becoming more apparent. This paper aims to review the mechanisms of an imbalanced intestinal microbiota contributing to the development of PALI, which is mediated by the disruption of physical, chemical, and immune barriers in the intestine, promotes bacterial translocation, and results in the activation of abnormal immune responses in severe pancreatitis. The pathogen-associated molecular patterns (PAMPs) mediated immunol mechanisms in the occurrence of PALI via binding with pattern recognition receptors (PRRs) through the microbiota-gut-lung axis are focused in this study. Moreover, the potential therapeutic strategies for alleviating PALI by regulating the composition or the function of the intestinal microbiota are discussed in this review. The aim of this study is to provide new ideas and therapeutic tools for PALI patients.

The Impact of Escherichia coli Probiotic Strain O83:K24:H31 on the Maturation of Dendritic Cells and Immunoregulatory Functions In Vitro and In Vivo

Early postnatal events are important for the development of the neonatal immune system. Harboring the pioneering microorganisms forming the microbiota of the neonatal gastrointestinal tract is important for priming the immune system, as well as inducing appropriate tolerance to the relatively innocuous environmental antigens and compounds of normal healthy microbiota. Early postnatal supplementation of suitable, safe probiotics could accelerate this process. In the current study, the immunomodulatory capacity of the probiotic strain of Escherichia coli O83:K24:H31 (EcO83) was characterized in vitro and in vivo. We compared the capacity of EcO83 with and without hemolytic activity on selected immune characteristics in vitro as determined by flow cytometry and quantitative real-time PCR. Both strains with and without hemolytic activity exerted comparable capacity on the maturation of dendritic cells while preserving the induction of interleukin 10 (Il10) expression in dendritic cells and T cells cocultured with EcO83 primed dendritic cells. Early postnatal supplementation with EcO83 led to massive but transient colonization of the neonatal gastrointestinal tract, as detected by in vivo bioimaging. Early postnatal EcO83 administration promoted gut barrier function by increasing the expression of claudin and occludin and the expression of Il10. Early postnatal EcO83 application promotes maturation of the neonatal immune system and promotes immunoregulatory and gut barrier functions.

Clinical trials of probiotics in patients with IBS - some points to consider

Probiotic products in various formulations are widely used world-wide for a seemingly limitless range of indications--from health maintenance to the alleviation of common intestinal ailments and on to the prevention and treatment of a variety of gastrointestinal diseases and disorders. The profusion of probiotic preparations, together with a very different regulatory climate compared to that which surrounds drugs and devices, leaves the consumer and the health care professional alike bewildered. How can they tell which products truly are what they claim to be? Which probiotics should be chosen for a particular clinical situation? These questions are thrown into stark relief when one evaluates the literature on probiotics in irritable bowel syndrome. To provide some guidance the current probiotic landscape is reviewed and some achievable steps to help bring light to a murky environment are proposed. The goal is to promote verifiable quality control and generate actionable evidence from well-conducted clinical trials of probiotic products in irritable bowel syndrome.