Probiotics Pediococcus acidilactici GR-1 promotes the functional strains and remodels gut microbiota to reduce the Cr(VI) toxicity in a dual-chamber simulated intestinal system.

Numerous animal studies have demonstrated the toxicity of hexavalent chromium [Cr(VI)] and the bioremediative effects of probiotics on the composition and functions of gut microbiota. Since the precise mechanisms of Cr(VI) detoxification and its interactions with human gut microbiota were unknown, a novel dual-chamber simulated intestinal (DCSI) system was developed to maintain both the stability of the simulated system and the composition of the gut microbiota. Probiotic GR-1 was found to regulate intestinal gut microbiota, thereby reducing the toxicity of Cr(VI) within the DCSI system. The results indicate that Cr(VI) levels were reduced from 2.260 ± 0.2438 µg/g to 1.7086 ± 0.1950 µg/g in the gut microbiota cell pellet, and Cr(VI) permeability decreased from 0.5521 ± 0.1132 µg/L to 0.3681 ± 0.0178 µg/L after 48 h in simulated gut fluid. Additionally, the removal rate of 1,1-Diphenyl-2-picrylhydrazyl (DPPH), reducibility (Vitamin C), and total antioxidant capacity (T-AOC) increased by 50.83%, 31.70%, and 27.56%, respectively, following probiotic treatment. The increase in antioxidant capacity correlated with total Cr removal (P < 0.05, r from -0.80 to 0.73). 16S rRNA sequencing analysis showed that gut microbiota composition was reshaped by the addition of probiotics, which regulated the recovery of the functional gut microbiota to normal levels, rather than restoring the entire gut microbiota composition for community function. Thus, this study not only demonstrates the feasibility and stability of culturing gut microbiota but also offers a new biotechnological approach to synthesizing functional communities with functional strains for environmental risk management.

Mixed probiotics modulated gut microbiota to improve spermatogenesis in bisphenol A-exposed male mice.

Bisphenol A (BPA), an environmental endocrine disruptor (EDC), has been implicated in impairing intestinal and male reproductive dysfunction. The efficacy of gut microbiota modulation for BPA-exposed testicular dysfunction has yet to be verified through research. Therefore, this study explored the potential of mixed probiotics in restoring spermatogenesis damage through the gut-testis axis under BPA exposure. We selected two probiotics strains (Lactobacillus rhamnosus and Lactobacillus plantarum) with BPA removal properties in vitro and the BPA-exposed male mice model was established. The probiotics mixture effectively reduced BPA residue in the gut, serum, and testis in mice. Through 16 S rDNA-seq and metabolomics sequencing, we uncovered that vitamin D metabolism and bile acid levels in the gut was abolished under BPA exposure. This perturbation was linked to an increased abundance of Faecalibaculum and decreased abundance of Lachnospiraceae_NK4A136_group and Ligilactobacillus. The probiotics mixture restored this balance, enhancing intestinal barrier function and reducing oxidative stress. This improvement was accompanied by a restored balance of short-chain fatty acids (SCFAs). Remarkably, the probiotics ameliorated testicular dysfunction by repairing structures of seminiferous tubules and reversing arrested spermiogenesis. Further, the probiotics mixture enhanced testosterone-driven increases in spermatogonial stem cells and all stages of sperm cells. Testicular transcriptome profiling linked these improvements to fatty acid degradation and peroxisome pathways. These findings suggest a significant interplay between spermatogenesis and gut microbiota, demonstrating that probiotic intake could be a viable strategy for combating male subfertility issues caused by BPA exposure.

A protocol of Chinese expert consensuses for the management of health risk in the general public.

Introduction: Non-communicable diseases (NCDs) represent the leading cause of mortality and disability worldwide. Robust evidence has demonstrated that modifiable lifestyle factors such as unhealthy diet, smoking, alcohol consumption and physical inactivity are the primary causes of NCDs. Although a series of guidelines for the management of NCDs have been published in China, these guidelines mainly focus on clinical practice targeting clinicians rather than the general population, and the evidence for NCD prevention based on modifiable lifestyle factors has been disorganized. Therefore, comprehensive and evidence-based guidance for the risk management of major NCDs for the general Chinese population is urgently needed. To achieve this overarching aim, we plan to develop a series of expert consensuses covering 15 major NCDs on health risk management for the general Chinese population. The objectives of these consensuses are (1) to identify and recommend suitable risk assessment methods for the Chinese population; and (2) to make recommendations for the prevention of major NCDs by integrating the current best evidence and experts' opinions. Methods and analysis: For each expert consensus, we will establish a consensus working group comprising 40-50 members. Consensus questions will be formulated by integrating literature reviews, expert opinions, and an online survey. Systematic reviews will be considered as the primary evidence sources. We will conduct new systematic reviews if there are no eligible systematic reviews, the methodological quality is low, or the existing systematic reviews have been published for more than 3 years. We will evaluate the quality of evidence and make recommendations according to the GRADE approach. The consensuses will be reported according to the Reporting Items for Practice Guidelines in Healthcare (RIGHT).

Investigation of the oral microbiome of children associated with dental caries: A systematic study.

OBJECTIVE: The present study aims to investigate the variations in dental caries (DC) related microbiome abnormality and metabolomics shift in children. DESIGN: The patients were divided into two groups healthy control (C) and highly affected DC children based on inclusion and exclusion criteria. Saliva samples were collected and used for the taxonomic and functional characterization of oral microbiota. RESULTS: Metatranscriptomics analysis revealed the alterations and composition of oral microbiota in the C and DC groups. Relative abundance in the C group was associated with Firmicutes, Actinobacteria, and Bacteroidetes. Whereas, the microbial composition in the DC group was found to be considerably altered with increases in the abundance of the Proteobacteria (25%), Fusobacteria (15%), and Cyanobacteria (8%) while decreases in the abundance of Firmicutes (10%) and Bacteroidetes (23%). Alterations in the phylum composition were positively and negatively correlated with several metabolites of sugars (such as fructose, sorbose, ribose, allose, and mannose) and amino acids (such as arginine, lysine, tryptophan, and proline). Moreover, in comparison with the C group, the metabolic shift of the DC group was different with an increase in certain tricarboxylic acid cycle intermediates levels, and a decrease in fatty acid. Such alterations can enhance the growth of oral pathogens and contribute to DC development. CONCLUSIONS: The findings of this study suggest that an altered abundance of Actinobacillus, Fusobacterium, and Shuttleworthia can serve as biomarkers of DC in children.

Role of oral and gut microbiota in childhood obesity.

Childhood obesity not only causes damage to children's respiratory, cardiovascular, endocrine, motor, and other systems but also is a significant risk factor for metabolic diseases such as obesity in adulthood, which has become one of the serious public health problems worldwide. The etiology and pathogenesis of obesity are complex. In addition to genetic and lifestyle factors, recent studies have found that the microbes in the digestive tract play a crucial role in the occurrence and development of obesity. Among them, the gut microbiota has been confirmed to be one of the important pathogenic factors of obesity, which can mediate the occurrence and development of obesity by interfering with the balance of host energy metabolism and inducing low-grade chronic inflammation throughout the host. Targeting the gut microbiota to treat obesity through various methods such as fecal microbiota transplantation, dietary intervention, and probiotic supplementation has become a research hotspot in obesity treatment. In addition, the oral microbiota is also considered closely related to the occurrence and development of obesity due to its regulatory effect on the balance of gut microbiota. Exploring the relationship between oral and gut microbiota and childhood obesity elucidates the pathogenesis and treatment concepts of childhood obesity from a new perspective. It may provide new methods for the prevention and treatment of childhood obesity in the future.

Influence of Environmental Factors on Salivary Microbiota and Their Metabolic Pathway: Next-Generation Sequencing Approach.

The current study aimed to investigate the effect of periodontitis and long-term heavy metal (HM) exposure on the salivary microbiome. The patients were divided into four groups as Wu Wei control (WWC) group involved healthy individuals, Wu Wei periodontitis (WWP) patients having periodontitis, Jing Chang with metal pollution periodontally healthy individuals (JCP), and Kuang periodontitis (KP). The most abundant bacteria identified at the phylum level in the WWC group were Bacteroides, Firmicutes, and Fusobacteria. Firmicutes were observed in a significantly higher proportion in the KP group than in the WWC, WWP, and JCP. At the genus level, the WWC has major dominating bacterial genera (such as Leptotrichia, Neisseria, and Fusobacterium) which were similar to WWP and KP group. The significant difference (p < 0.05) was found in alpha diversity while in beta diversity, the significant (p = 0.005) results were found among the four groups. The correlation of oral microbiota revealed that HMs present in the soil (Cr, Ni, and Cu) are associated with the growth of Capnocytophaga, Selenomonas, Aggregatibacter, and Campylobacter. The bacterial functions in the KP group were higher in translation and nucleotide metabolism than in the WWP group. This demonstrated that long-term exposure to HMs can influence the salivary microbiota which can alter the functioning, and diversity of bacteria.

Tooth loss inhibits neurogenesis in the dentate gyrus of adult mice.

Tooth loss has been shown to affect learning and memory in mice and increases the risk of Alzheimer's disease. The dentate gyrus is strongly associated with cognitive function. This study hypothesized that tooth loss affects neurons in the dentate gyrus. Adult male mice were randomly assigned to either the tooth loss group or normal control group. In the tooth loss group, the left maxillary and mandibular molars were extracted. Normal control mice did not receive any intervention. Immunofluorescence staining revealed that the density and absorbance of doublecortin- and neuronal nuclear antigen-positive cells were lower in the tooth loss group than in the normal control group. These data suggest that tooth loss may inhibit neurogenesis in the dentate gyrus of adult mice.