Lacticaseibacillus paracasei NK112 mitigates Escherichia coli-induced depression and cognitive impairment in mice by regulating IL-6 expression and gut microbiota

The gut microbiota communicates with the brain through microbiota-gut-brain (MGB) and hypothalamus-pituitary-adrenal (HPA) axes and other pathways. Excessive expression of interleukin (IL)-6 is closely associated with the occurrence of the psychiatric disorders depression and dementia. Therefore, to understand whether IL-6 expression-suppressing probiotics could alleviate psychiatric disorders, we isolated IL-6 expression-inhibiting Lacticaseibacillus paracasei (formerly Lactobacillus paracasei) NK112 from the human faecal bacteria strain collection (Neurobiota Research Center, Seoul, Korea) and examined its therapeutic effect for the depression and cognitive impairment in mice. C57 BL/6J mice with depression and cognitive impairment were prepared by exposure to Escherichia coli K1. Oral gavage of NK112 significantly alleviated K1-induced anxious, depressive, and memory-impaired behaviours in the elevated plus maze, tail-suspension and Y-maze tasks, IL-1β, IL-6, and tumour necrosis factor (TNF)-α expression, and nuclear factor kappa beta (NF-κB) activation in the hippocampus, while K1-suppressed brain-derived neurotrophic factor (BDNF) expression increased. Treatment with NK112 also improved K1-induced myeloperoxidase activity, IL-6 and TNF-α expression, and NF-κB activation in the colon and reduced K1-induced Proteobacteria population in the gut microbiota. Heat-killed NK112 and its lysate supernatant, and precipitate fractions also improved anxiety/depression, cognitive impairment, and colitis in mice. In conclusion, NK112, even if heat-killed or lysed, alleviated K1 stress-induced colitis, anxiety/depression, and cognitive impairment by suppressing IL-6, TNF-α, and BDNF expression through the regulation of gut microbiota and NF-κB activation.

Resilience of Faecal Microbiota in Stabled Thoroughbred Horses Following Abrupt Dietary Transition between Freshly Cut Pasture and Three Forage-Based Diets

The management of competition horses in New Zealand often involves rotations of short periods of stall confinement and concentrate feeding, with periods of time at pasture. Under these systems, horses may undergo abrupt dietary changes, with the incorporation of grains or concentrate feeds to the diet to meet performance needs, or sudden changes in the type of forage fed in response to a lack of fresh or conserved forage. Abrupt changes in dietary management are a risk factor for gastrointestinal (GI) disturbances, potentially due to the negative effects observed on the population of GI microbiota. In the present study, the faecal microbiota of horses was investigated to determine how quickly the bacterial communities; (1) responded to dietary change, and (2) stabilised following abrupt dietary transition. Six Thoroughbred mares were stabled for six weeks, consuming freshly cut pasture (weeks 1, 3 and 5), before being abruptly transitioned to conserved forage-based diets, both offered ad libitum. Intestinal markers were administered to measure digesta transit time immediately before each diet change. The conserved forage-based diets were fed according to a 3 × 3 Latin square design (weeks 2, 4 and 6), and comprised a chopped ensiled forage fed exclusively (Diet FE) or with whole oats (Diet FE + O), and perennial ryegrass hay fed with whole oats (Diet H + O). Faecal samples were collected at regular intervals from each horse following the diet changes. High throughput 16S rRNA gene sequencing was used to evaluate the faecal microbiota. There were significant differences in alpha diversity across diets (p < 0.001), and a significant effect of diet on the beta diversity (ANOSIM, p = 0.001), with clustering of samples observed by diet group. There were differences in the bacterial phyla across diets (p < 0.003), with the highest relative abundances observed for Firmicutes (62–64%) in the two diets containing chopped ensiled forage, Bacteroidetes (32–38%) in the pasture diets, and Spirochaetes (17%) in the diet containing hay. Major changes in relative abundances of faecal bacteria appeared to correspond with the cumulative percentage of intestinal markers retrieved in the faeces as the increasing amounts of digesta from each new diet transited the animals. A stable faecal microbiota profile was observed in the samples from 96 h after abrupt transition to the treatment diets containing ensiled chopped forage. The present study confirmed that the diversity and community structure of the faecal bacteria in horses is diet-specific and resilient following dietary transition and emphasised the need to have modern horse feeding management that reflects the ecological niche, particularly by incorporating large proportions of forage into equine diets.

Improving the Gut Microbiota with Probiotics and Faecal Microbiota Transplantation

Probiotics are “live strains of strictly selected microorganisms which, when administered in adequate amounts, confer a health benefit on the host”. After birth, our intestine is colonized by microbes like Escherichia coli, Clostridium spp., Streptococcus spp., Lactobacillus spp., Bacteroides spp., and Bifidobacterium spp. Our intestine is an extremely complex living system that participates in the protection of host through a strong defence against external aggregations. The microbial ecosystem of the intestine includes many native species of Bacteroides and Firmicutes that permanently colonize the gastrointestinal tract. The composition of flora changes over time depending upon diet and medical emergencies which leads to the diseased condition. Probiotics exert their mode of action by altering the local environment of the gut by competing with the pathogens, bacteriocins production, H2O2 production etc. Obesity is one of the major health problems and is considered as the most prevalent form of inappropriate nutrition. Probiotics like Lactobacillus Sp., Bifidobacterium Sp., Streptococcus Sp. are successfully used in the treatment of obesity proved in clinical trials. Faecal microbiota transplant (FMT), also known as a stool transplant, is the process of transplantation of Faecal bacteria from a healthy donor into a recipient’s gut to restore normal flora in the recipient. The therapeutic principle on which FMT works is microbes and their functions and metabolites produced by them which are used to treat a variety of diseases. The present review focuses on the role of gastrointestinal microbiome, probiotic selection criteria, their applications and FMT to treat diseases.

Assessing the Microbial Quality of Commercial Aquaculture Probiotics by Next Generation Sequencing Revealed Faecal Bacteria and Bacteria of Public Health Significance

There is an increasing trend in the application of probiotics in aquaculture as an environment friendly alternative to antibiotics for the control and treatment of diseases. The microbiome of commercial aquaculture probiotics were evaluated using NGS to understand the microbial species composition vis-à-vis the label on the probiotic product. Bacteria belonging to 12 bacterial species stated on the labels of five probiotics were absent. The sequence reads of the microorganisms declared on the label ranged from 0.28-79 % for the probiotics tested while the rest were contaminants. The number of contaminant bacteria varied from 2 to 15 for the tested products. All products were found to have at least one bacterial species that were potentially pathogenic or of fecal origin. To our knowledge this is the first study that utilized the potential of NGS to assess the microbial quality of commercial aquaculture probiotics providing novel insights in understanding the microbial composition of probiotic products which are otherwise difficult to identify. It is proposed that probiotic products shall be approved for use in aquaculture after determining the performance efficiency by in vivo trails in farms, analysis of bacterial composition and concentration which shall be displayed on product labels.

Increase of SARS-CoV-2 RNA load in faecal samples prompts for rethinking of SARS-CoV-2 biology and COVID-19 epidemiology

Background Scientific evidence for the involvement of human microbiota in the development of COVID-19 disease has been reported recently. SARS-CoV-2 RNA presence in human faecal samples and SARS-CoV-2 activity in faeces from COVID-19 patients have been observed. Methods Starting from these observations, an experimental design was developed to cultivate in vitro faecal microbiota from infected individuals, to monitor the presence of SARS-CoV-2, and to collect data on the relationship between faecal bacteria and the virus. Results Our results indicate that SARS-CoV-2 replicates in vitro in bacterial growth medium, that the viral replication follows bacterial growth and it is influenced by the administration of specific antibiotics. SARS-CoV-2-related peptides have been detected in 30-day bacterial cultures and characterised. Discussion Our observations are compatible with a ‘bacteriophage-like’ behaviour of SARS-CoV-2, which, to our knowledge has not been observed or described before. These results are unexpected and hint towards a novel hypothesis on the biology of SARS-CoV-2 and on the COVID-19 epidemiology. The discovery of possible new modes of action of SARS-CoV-2 has far-reaching implications for the prevention and the treatment of the disease.

Physicochemical interaction with faecal bacteria in characterisation of beach water quality, Gulf of Guinea, Ghana

Human activities such as industrial and agricultural waste discharges directly in the coastal areas increasingly contribute to pollution in coastal waters of Western Africa. The study employed physicochemical and faecal analysis to understand water pollution along the coast of Ghana. The physicochemical parameter such as temperature, salinity, electrical conductivity, pH, dissolved oxygen concentration, dissolved oxygen saturation, total dissolved solids, and redox potential) were measured in situ while water samples were collected determination of total suspended solids, nutrients, chlorophyll-a, and faecal bacteria. The abundance of total coliforms (4061.6 ± 4159.14 CFU/100 ml water), Escherichia coli, and Enterococcus spp. varied significantly (p < 0.05) among the beaches. The high amount of faecal bacteria suggest microbial contamination, possible ecosystem, and health risks to water resource users. This baseline study provides evidence of coastal water contamination to improve beach water quality standards to ensure safe environmental health.

Increase of SARS-CoV-2 RNA load in faecal samples prompts for rethinking of SARS-CoV-2 biology and COVID-19 epidemiology

Background Scientific evidence for the involvement of human microbiota in the development of COVID-19 disease has been reported recently. SARS-CoV-2 RNA presence in human faecal samples and SARS-CoV-2 activity in faeces from COVID-19 patients have been observed. Methods Starting from these observations, an experimental design was developed to cultivate in vitro faecal microbiota from infected individuals, to monitor the presence of SARS-CoV-2, and to collect data on the relationship between faecal bacteria and the virus. Results Our results indicate that SARS-CoV-2 replicates in vitro in bacterial growth medium, that the viral replication follows bacterial growth and it is influenced by the administration of specific antibiotics. SARS-CoV-2-related peptides have been detected in 30-day bacterial cultures and characterised. Discussion Our observations are compatible with a ‘bacteriophage-like’ behaviour of SARS-CoV-2, which, to our knowledge has not been observed or described before. These results are unexpected and hint towards a novel hypothesis on the biology of SARS-CoV-2 and on the COVID-19 epidemiology. The discovery of possible new modes of action of SARS-CoV-2 has far-reaching implications for the prevention and the treatment of the disease.

Plant debris are hotbeds for pathogenic bacteria on recreational sandy beaches

On recreational sandy beaches, there are guidelines for the management of bacterial pollution in coastal waters regarding untreated sewage, urban wastewater, and industrial wastewater. However, terrestrial plant debris on coastal beaches can be abundant especially after floods and whilst it has rarely been considered a concern, the bacterial population associated with this type of pollution from the viewpoint of public health has not been adequately assessed. In this study, microbes associated with plant debris drifting onto Kizaki Beach in Japan were monitored for 8 months throughout the rainy season, summer, typhoon season, and winter. Here we show that faecal-indicator bacteria in the plant debris and sand under the debris were significantly higher than the number of faecal bacteria in the sand after a 2015 typhoon. When we focused on specific pathogenic bacteria, Brevundimonas vesicularis and Pseudomonas alcaligenes were commonly detected only in the plant debris and sand under the debris during the survey period. The prompt removal of plant debris would therefore help create safer beaches.

Increase of SARS-CoV-2 RNA load in faecal samples prompts for rethinking of SARS-CoV-2 biology and COVID-19 epidemiology

Background Scientific evidence for the involvement of human microbiota in the development of COVID-19 disease has been reported recently. SARS-CoV-2 RNA presence in human faecal samples and SARS-CoV-2 activity in faeces from COVID-19 patients have been observed. Methods Starting from these observations, an experimental design was developed to cultivate in vitro faecal microbiota from infected individuals, to monitor the presence of SARS-CoV-2, and to collect data on the relationship between faecal bacteria and the virus. Results Our results indicate that SARS-CoV-2 replicates in vitro in bacterial growth medium, that the viral replication follows bacterial growth and it is influenced by the administration of specific antibiotics. SARS-CoV-2-related peptides have been detected in 30-day bacterial cultures and characterised. Discussion Our observations are compatible with a ‘bacteriophage-like’ behaviour of SARS-CoV-2, which, to our knowledge has not been observed or described before. These results are unexpected and hint towards a novel hypothesis on the biology of SARS-CoV-2 and on the COVID-19 epidemiology. The discovery of possible new modes of action of SARS-CoV-2 has far-reaching implications for the prevention and the treatment of the disease.