Interactions between host genetics and gut microbiome in diabetes and metabolic syndrome

Lactobacillus probiotic cell-free supernatants and vitamin D influence interleukin-6 production and mitigate oral periodontopathogens-induced cytotoxicity in FaDu cells

Oral eubiosis is of utmost importance for local and systemic health. Consolidated habits, as excessive alcohol consumption, smoke, inappropriate oral hygiene, and western diet, exert detrimental effects on oral microbiota composition and function. This leads to caries, gingivitis, and periodontitis, also increasing the risk of preterm births, inflammation, and cancer. Thus, effective tools to contain pathobiont overgrowth and virulence and restore oral eubiosis are needed. Therefore, the effects of Limosilactobacillus reuteri LRE11, Lacticaseibacillus rhamnosus LR04, Lacticaseibacillus casei LC04, and their co-culture cell-free supernatants (CFSs), produced in both conventional MRS medium and a novel animal derivative-free medium named TIL, along with vitamin D, were assessed on the viability and interleukin (IL)-6 production of oral epithelial FaDu cells infected with Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis. The CFS proteomic, short chain fatty acid, and lactic acid contents were also investigated. Interestingly, probiotic CFSs and vitamin D differentially reduced the infected cell IL-6 production and counteracted the infection-induced cytotoxicity. Taken together, these results suggest that probiotics and vitamin D can reverse pathogen-induced cell damage. Since probiotic CFS effect is both strain and growth medium composition dependent, further experiments are required to deepen the probiotic and vitamin D synergic activity in this context.

Protective Effects of Polygonatum sibiricum Polysaccharides Against Type 2 Diabetic Mice Induced by High-Fat Diet and Low-Dose Streptozotocin

Polysaccharides possessing hypoglycemic effects have shown promising results in treating diabetes. Polygonatum sibiricum polysaccharide (PSP) is one of the most active ingredients in the Chinese medicine P. sibiricum Redoute with many biological activities. However, its efficacy in alleviating type 2 diabetes mellitus (T2DM) remains unexplored. Our aim is to evaluate the protective effect of PSP against T2DM by measuring body weight and serum biochemical indicators, examining the histopathological images of pancreatic and liver tissues, detecting fecal short-chain fatty acid (SCFA) content, and analyzing the intestinal flora diversity and the microbiota structure in T2DM mice. The findings indicated that PSP treatment in T2DM mice could obviously decrease the fasting blood glucose and fasting insulin levels, ameliorate glucose tolerance, insulin resistance, lipid, and inflammatory factor levels, attenuate pancreatic and liver damage, and increase the fecal SCFA content. In addition, PSP could modulate the composition of gut microbiota in T2DM mice, resulting in the relative abundance of Firmicutes decreasing and that of Bacteroidetes increasing, along with the abundance of beneficial flora significantly increasing, especially SCFA-producing bacteria. The findings indicate that PSP administration protected against diabetes by controlling disordered glucolipid metabolism and modulating the gut microbiota, which provides a valuable strategy for the utilization of PSP to treat T2DM.

A systematic review on gut microbiota in type 2 diabetes mellitus

Aims/hypothesis

The gut microbiota play crucial roles in the digestion and degradation of nutrients, synthesis of biological agents, development of the immune system, and maintenance of gastrointestinal integrity. Gut dysbiosis is thought to be associated with type 2 diabetes mellitus (T2DM), one of the world's fastest growing diseases. The aim of this systematic review is to identify differences in the composition and diversity of the gut microbiota in individuals with T2DM.

Methods

A systematic search was conducted to identify studies reporting on the difference in gut microbiota composition between individuals with T2DM and healthy controls. Relevant studies were evaluated, and their characteristics and results were extracted using a standardized data extraction form. The studies were assessed for risk of bias and their findings were reported narratively.

Results

58 observational studies published between 2010 and 2024 were included. Beta diversity was commonly reported to be different between individuals with T2DM and healthy individuals. Genera Lactobacillus, Escherichia-Shigella, Enterococcus, Subdoligranulum and Fusobacteria were found to be positively associated; while Akkermansia, Bifidobacterium, Bacteroides, Roseburia, Faecalibacteirum and Prevotella were found to be negatively associated with T2DM.

Conclusions

This systematic review demonstrates a strong association between T2DM and gut dysbiosis, as evidenced by differential microbial abundances and altered diversity indices. Among these taxa, Escherichia-Shigella is consistently associated with T2DM, whereas Faecalibacterium prausnitzii appears to offer a protective effect against T2DM. However, the heterogeneity and observational nature of these studies preclude the establishment of causative relationships. Future research should incorporate age, diet and medication-matched controls, and include functional analysis of these gut microbes.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023459937.

Exploration of gut microbial diversity of pheasants through pyrosequencing of 16S rRNA gene

Despite the diversity of microbiota in birds is similar to that of other animals, there is a lack of research on the gut microbial diversity of nondomesticated bird species. This study aims to address this gap in knowledge by analyzing the bacterial communities present in the gut of two important game bird species, the Ring-necked pheasant (Phasianus colchicus) and the Green pheasant (Phasianus versicolor) to understand the gut microbial diversity of these species. The gut microbiome of 10 individual pheasants from two different species was studied using pooled fecal samples. We used 16S rRNA gene sequencing on the Ion S5 XL System next-generation sequencing with Mothur and SILVA Database for taxonomic division. An average of 141 different operational taxonomic units were detected in the gut microbiome. Analysis of microbial classification revealed the presence of 191 genera belonging to 12 different phyla in both pheasants. Alpha diversity indices revealed that P. colchicus exhibited most prevalence firmicutes with bacillus species microbial community than P. versicolor. Alpha diversity indices indicated that P. colchicus had a more diverse community and P. versicolor had a greater diversity of evolutionary lineages, while both species had similar levels of species richness and sample inclusiveness. These findings may have implications for the health and well-being of pheasants, serving as a reference for their bacterial diversity. Additionally, they provide a baseline for future research and conservation efforts aimed at improving the health and well-being of these and possibly other avian species.

Metabolic Syndrome and Biotherapeutic Activity of Dairy (Cow and Buffalo) Milk Proteins and Peptides: Fast Food-Induced Obesity Perspective-A Narrative Review

Metabolic syndrome (MS) is defined by the outcome of interconnected metabolic factors that directly increase the prevalence of obesity and other metabolic diseases. Currently, obesity is considered one of the most relevant topics of discussion because an epidemic heave of the incidence of obesity in both developing and underdeveloped countries has been reached. According to the World Obesity Atlas 2023 report, 38% of the world population are presently either obese or overweight. One of the causes of obesity is an imbalance of energy intake and energy expenditure, where nutritional imbalance due to consumption of high-calorie fast foods play a pivotal role. The dynamic interactions among different risk factors of obesity are highly complex; however, the underpinnings of hyperglycemia and dyslipidemia for obesity incidence are recognized. Fast foods, primarily composed of soluble carbohydrates, non-nutritive artificial sweeteners, saturated fats, and complexes of macronutrients (protein-carbohydrate, starch-lipid, starch-lipid-protein) provide high metabolic calories. Several experimental studies have pointed out that dairy proteins and peptides may modulate the activities of risk factors of obesity. To justify the results precisely, peptides from dairy milk proteins were synthesized under in vitro conditions and their contributions to biomarkers of obesity were assessed. Comprehensive information about the impact of proteins and peptides from dairy milks on fast food-induced obesity is presented in this narrative review article.

Role of circular RNAs and gut microbiome in gastrointestinal cancers and therapeutic targets

Gastrointestinal cancers are a huge worldwide health concern, which includes a wide variety of digestive tract cancers. Circular RNAs (circRNAs), a kind of non-coding RNA (ncRNAs), are a family of single-stranded, covalently closed RNAs that have become recognized as crucial gene expression regulators, having an impact on several cellular functions in cancer biology. The gut microbiome, which consists of several different bacteria, actively contributes to the regulation of host immunity, inflammation, and metabolism. CircRNAs and the gut microbiome interact significantly to greatly affect the growth of GI cancer. Several studies focus on the complex functions of circRNAs and the gut microbiota in GI cancers, including esophageal cancer, colorectal cancer, gastric cancer, hepatocellular cancer, and pancreatic cancer. It also emphasizes how changed circRNA expression profiles and gut microbiota affect pathways connected to malignancy as well as how circRNAs affect hallmarks of gastrointestinal cancers. Furthermore, circRNAs and gut microbiota have been recommended as biological markers for therapeutic targets as well as diagnostic and prognostic purposes. Targeting circRNAs and the gut microbiota for the treatment of gastrointestinal cancers is also being continued to study. Despite significant initiatives, the connection between circRNAs and the gut microbiota and the emergence of gastrointestinal cancers remains poorly understood. In this study, we will go over the most recent studies to emphasize the key roles of circRNAs and gut microbiota in gastrointestinal cancer progression and therapeutic options. In order to create effective therapies and plan for the future gastrointestinal therapy, it is important to comprehend the functions and mechanisms of circRNAs and the gut microbiota.

Brown adipose tissue: can it keep us slim? A discussion of the evidence for and against the existence of diet-induced thermogenesis in mice and men

The issue under discussion here is whether a decrease in the degree of UCP1 activity (and brown adipose tissue activity in general) could be a cause of obesity in humans. This possibility principally requires the existence of the phenomenon of diet-induced thermogenesis. Obesity could be a consequence of a reduced functionality of diet-induced thermogenesis. Experiments in mice indicate that diet-induced thermogenesis exists and is dependent on the presence of UCP1 and thus of brown adipose tissue activity. Accordingly, many (but not all) experiments indicate that in the absence of UCP1, mice become obese. Whether similar mechanisms exist in humans is still unknown. A series of studies have indicated a correlation between obesity and low brown adipose tissue activity, but it may be so that the obesity itself may influence the estimates of brown adipose tissue activity (generally glucose uptake), partly explaining the relationship. Estimates of brown adipose tissue catabolizing activity would seem to indicate that it may possess a capacity sufficient to help maintain body weight, and obesity would thus be aggravated in its absence. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Multi-omics approach to socioeconomic disparity in metabolic syndrome reveals roles of diet and microbiome

The epidemy of metabolic syndrome (MetS) is typically preceded by adoption of a "risky" lifestyle (e.g., dietary habit) among populations. Evidence shows that those with low socioeconomic status (SES) are at an increased risk for MetS. To investigate this, we recruited 123 obese subjects (body mass index [BMI] ≥ 30) from Chicago. Multi-omic data were collected to interrogate fecal microbiota, systemic markers of inflammation and immune activation, plasma metabolites, and plasma glycans. Intestinal permeability was measured using the sugar permeability testing. Our results suggest a heterogenous metabolic dysregulation among obese populations who are at risk of MetS. Systemic inflammation, linked to poor diet, intestinal microbiome dysbiosis, and gut barrier dysfunction may explain the development of MetS in these individuals. Our analysis revealed 37 key features associated with increased numbers of MetS features. These features were used to construct a composite metabolic-inflammatory (MI) score that was able to predict progression of MetS among at-risk individuals. The MI score was correlated with several markers of poor diet quality as well as lower levels of gut microbial diversity and abnormalities in several species of bacteria. This study reveals novel targets to reduce the burden of MetS and suggests access to healthy food options as a practical intervention.

Microbes are potential key players in the evolution of life histories and aging in Caenorhabditis elegans

Microbes can have profound effects on host fitness and health and the appearance of late-onset diseases. Host-microbe interactions thus represent a major environmental context for healthy aging of the host and might also mediate trade-offs between life-history traits in the evolution of host senescence. Here, we have used the nematode Caenorhabditis elegans to study how host-microbe interactions may modulate the evolution of life histories and aging. We first characterized the effects of two non-pathogenic and one pathogenic Escherichia coli strains, together with the pathogenic Serratia marcescens DB11 strain, on population growth rates and survival of C. elegans from five different genetic backgrounds. We then focused on an outbred C. elegans population, to understand if microbe-specific effects on the reproductive schedule and in traits such as developmental rate and survival were also expressed in the presence of males and standing genetic variation, which could be relevant for the evolution of C. elegans and other nematode species in nature. Our results show that host-microbe interactions have a substantial host-genotype-dependent impact on the reproductive aging and survival of the nematode host. Although both pathogenic bacteria reduced host survival in comparison with benign strains, they differed in how they affected other host traits. Host fertility and population growth rate were affected by S. marcescens DB11 only during early adulthood, whereas this occurred at later ages with the pathogenic E. coli IAI1. In both cases, these effects were largely dependent on the host genotypes. Given such microbe-specific genotypic differences in host life history, we predict that the evolution of reproductive schedules and senescence might be critically contingent on host-microbe interactions in nature.

Exploring the Role of IL-17A in Oral Dysbiosis-Associated Periodontitis and Its Correlation with Systemic Inflammatory Disease

Oral microbiota play a pivotal role in maintaining homeostasis, safeguarding the oral cavity, and preventing the onset of disease. Oral dysbiosis has the potential to trigger pro-inflammatory effects and immune dysregulation, which can have a negative impact on systemic health. It is regarded as a key etiological factor for periodontitis. The emergence and persistence of oral dysbiosis have been demonstrated to mediate inflammatory pathology locally and at distant sites. The heightened inflammation observed in oral dysbiosis is dependent upon the secretion of interleukin-17A (IL-17A) by various innate and adaptive immune cells. IL-17A has been found to play a significant role in host defense mechanisms by inducing antibacterial peptides, recruiting neutrophils, and promoting local inflammation via cytokines and chemokines. This review seeks to present the current knowledge on oral dysbiosis and its prevention, as well as the underlying role of IL-17A in periodontitis induced by oral dysbiosis and its impact on systemic inflammatory disease.

Comparison of the gut microbiota and untargeted gut tissue metabolome of Chinese mitten crabs (Eriocheir sinensis) with different shell colors

Introduction

The Chinese mitten crab (Eriocheir sinensis) is a highly valued freshwater crustacean in China. While the natural shell color of E. sinensis is greenish brown (GH), we found a variety with a brownish-orange shell color (RH). Although RH is more expensive, it exhibits a lower molting frequency and growth rate compared with GH, which significantly reduces its yield and hinders large-scale farming. The growth and development of animals are closely related to their gut microbiota and gut tissue metabolic profiles.

Methods

In this study, we compared the gut microbiome communities and metabolic profiles of juvenile RH and GH crabs using 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC-MS), respectively.

Results

Our findings indicated that the intestinal microbial composition and metabolic characteristics of E. sinensis differed significantly between RH and GH. At the operational taxonomic unit (OTU) level, the α-diversity of the gut microbiota did not differ significantly between RH and GH, while the β-diversity of the RH gut microbiota was higher than that of the GH gut microbiota. At the species level, the richness of unclassified_c_Alphaproteobacteria was significantly higher in the GH group, while the RH group had a significantly higher richness of three low-abundance species, Flavobacteria bacterium BAL38, Paraburkholderia ferrariae, and uncultured_bacterium_g__Legionella. In the current study, 598 gut tissue metabolites were identified, and 159 metabolites were significantly different between GH and RH. The metabolite profile of RH was characteristic of a low level of most amino acids and lipid metabolites and a high level of several pigments compared with that of GH. These metabolites were enriched in 102 KEGG pathways. Four pathways, including (1) Central carbon metabolism in cancer, (2) protein digestion and absorption, (3) alanine, aspartate and glutamate metabolism, and (4) aminoacyl-tRNA biosynthesis, were significantly enriched. The correlation analysis between metabolites and microbiotas indicated that most key differential metabolites were positively correlated with the abundance of Shewanella_sp_MR-7.

Discussion

This research provided a greater understanding of the physiological conditions of E. sinensis varieties with different shell colors by comparing the gut microbiota and gut tissue metabolome.

Reduced intestinal lipid absorption improves glucose metabolism in aged G2-Terc knockout mice

BACKGROUND

Biological aging is an important factor leading to the development of pathologies associated with metabolic dysregulation, including type 2 diabetes, cancer, cardiovascular and neurodegenerative diseases. Telomere length, a central feature of aging, has additionally been identified as inversely associated with glucose tolerance and the development of type 2 diabetes. However, the effects of shortened telomeres on body weight and metabolism remain incompletely understood. Here, we studied the metabolic consequences of moderate telomere shortening using second generation loss of telomerase activity in mice.

RESULTS

Aged male and female G2 Terc-/- mice and controls were characterized with respect to body weight and composition, glucose homeostasis, insulin sensitivity and metabolic activity. This was complemented with molecular and histological analysis of adipose tissue, liver and the intestine as well as microbiota analysis. We show that moderate telomere shortening leads to improved insulin sensitivity and glucose tolerance in aged male and female G2 Terc-/- mice. This is accompanied by reduced fat and lean mass in both sexes. Mechanistically, the metabolic improvement results from reduced dietary lipid uptake in the intestine, characterized by reduced gene expression of fatty acid transporters in enterocytes of the small intestine. Furthermore, G2-Terc-/- mice showed significant alterations in the composition of gut microbiota, potentially contributing to the improved glucose metabolism.

CONCLUSIONS

Our study shows that moderate telomere shortening reduces intestinal lipid absorption, resulting in reduced adiposity and improved glucose metabolism in aged mice. These findings will guide future murine and human aging studies and provide important insights into the age associated development of type 2 diabetes and metabolic syndrome.

Housing temperature plays a critical role in determining gut microbiome composition in research mice: Implications for experimental reproducibility

Preclinical mouse models are widely used for studying mechanisms of disease and responses to therapeutics, however there is concern about the lack of experimental reproducibility and failure to predict translational success. The gut microbiome has emerged as a regulator of metabolism and immunological processes in health and disease. The gut microbiome of mice differs by supplier and this affects experimental outcomes. We have previously reported that the mandated, mildly cool housing temperature for research mice (22°-26 °C) induces chronic adrenergic stress which suppresses anti-tumor immunity and promotes tumor growth compared to thermoneutral housing (30 °C). Therefore, we wondered how housing temperature affects the microbiome. Here, we demonstrate that the gut microbiome of BALB/c mice is easily modulated by a few degrees difference in temperature. Our results reveal significant differences between the gut microbiome of mice housed at 22°-23 °C vs. 30 °C. Although the genera vary, we consistently observed an enrichment of members of the family Lachnospiraceae when mice are housed at 22°-23 °C. These findings demonstrate that adrenergic stress and need for increased energy harvest to support thermogenesis, in addition to other factors such as diet, modulates the gut microbiome and this could be one mechanism by which housing temperature affects experimental outcomes. Additionally, tumor growth in mice housed at 30 °C also increases the proportion of Lachnospiraceae. The idea that stress can alter the gut microbiome and cause differences in experimental outcomes is applicable to mouse studies in general and is a variable that has significant potential to affect experimental reproducibility.

The roles of dietary lipids and lipidomics in gut-brain axis in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM), one of the main types of Noncommunicable diseases (NCDs), is a systemic inflammatory disease characterized by dysfunctional pancreatic β-cells and/or peripheral insulin resistance, resulting in impaired glucose and lipid metabolism. Genetic, metabolic, multiple lifestyle, and sociodemographic factors are known as related to high T2DM risk. Dietary lipids and lipid metabolism are significant metabolic modulators in T2DM and T2DM-related complications. Besides, accumulated evidence suggests that altered gut microbiota which plays an important role in the metabolic health of the host contributes significantly to T2DM involving impaired or improved glucose and lipid metabolism. At this point, dietary lipids may affect host physiology and health via interaction with the gut microbiota. Besides, increasing evidence in the literature suggests that lipidomics as novel parameters detected with holistic analytical techniques have important roles in the pathogenesis and progression of T2DM, through various mechanisms of action including gut-brain axis modulation. A better understanding of the roles of some nutrients and lipidomics in T2DM through gut microbiota interactions will help develop new strategies for the prevention and treatment of T2DM. However, this issue has not yet been entirely discussed in the literature. The present review provides up-to-date knowledge on the roles of dietary lipids and lipidomics in gut-brain axis in T2DM and some nutritional strategies in T2DM considering lipids- lipidomics and gut microbiota interactions are given.

Combined metabolomics and gut microbiome to investigate the effects and mechanisms of Yuquan Pill on type 2 diabetes in rats

Yuquan Pill (YQP) is a traditional Chinese medicine (TCM) for the treatment of type 2 diabetes (T2DM) in China for many years, and has a beneficial clinical effect. In this study, the antidiabetic mechanism of YQP was investigated for the first time from the perspective of metabolomics and intestinal microbiota. After 28 days of high-fat feeding, rats were injected intraperitoneally with streptozotocin (STZ, 35 mg/kg) followed by a single oral administration of YQP 2.16 g/kg and metformin 200 mg/kg for 5 weeks. The results showed that YQP was effectively improved insulin resistance and alleviated hyperglycemia and hyperlipidemia associated with T2DM. YQP was found to regulate metabolism and gut microbiota in T2DM rats using untargeted metabolomics and gut microbiota integration. Forty-one metabolites and five metabolic pathways were identified, including Ascorbate and aldarate metabolism, Nicotinate and nicotinamide metabolism, Galactose metabolism, Pentose phosphate pathway and Tyrosine metabolism. YQP can regulate T2DM-induced dysbacteriosis by modulating the abundance of Firmicutes, Bacteroidetes, Ruminococcus, Lactobacillus. The restorative effects of YQP in rats with T2DM have been confirmed and provide a scientific basis for the clinical treatment of diabetic patients.

Effects from supplementary feeding of bamboo powder in perinatal period on farrowing process, serum biochemical indexes, and fecal microbes of sows and offspring piglets

Introduction

This study was conducted to explore the effects of supplementary feeding of bamboo powder on the physical parameters of sows during the perinatal period of 7 days ± in parturition, including farrow duration, serum biochemical indexes, fecal physicochemical indexes, and microbial flora.

Methods

Thirty pregnant sows were randomly divided into three groups: the control group was fed a basal diet, TRE1 group and TRE2 group were fed a basal diet supplemented with 30 g d^-1 and 60 g d^-1 bamboo powder, respectively. Multiple parameters of sows and offspring piglets were determined.

Results

The contents of serum total cholesterol and triglyceride of sows in TRE2 group were significantly lower than those in the control group. The contents of serum malondialdehyde of sows in TRE2 and TRE1 groups were significantly lower than that in control group. The water content of sow feces in TRE2 group was significantly higher than that in control group, and the pH values of sows in TRE2 and TRE1 groups were significantly higher than that in control group. The richness index (Chao) of sow fecal bacterial community in TRE2 group was significantly lower than that of the control group, and the Ace and Sobs indexes tended to be lower than those of the control group. At the phylum level, the relative abundance of Actinobacteriota in the feces of sows in TRE2 group was significantly lower than that of the control group, while that of Fusobacteriota in the feces of suckling piglets in TRE2 group tended to be lower than that of the control group. At the genus level, among the Top10 dominant bacteria, the relative abundance of Tissierella in the feces of sows in TRE2 group was significantly lower than that of the control group while that of Fusobacterium in the feces of suckling piglets in TRE2 group tended to be lower than that of the control group. The relative abundance of Clostridium_sensu_stricto_1, Terrisporobacter, Turicibacter, and Tissierella in the feces of sows in TRE2 group was significantly lower than that of TRE1 group (p < 0.05), while Lactobacillus tended to be higher than that of TRE1 group (p < 0.10).

Discussion

The results suggested that supplementary feeding 60 g d^-1 bamboo powder could increase the water content in the feces of sows, reduce the oxidative damage, and tend to reduce the relative abundance of opportunistic pathogenic Fusobacterium for suckling piglets, while it reduced the fecal microbial diversity of sows.

α-D-1,3-glucan from Radix Puerariae thomsonii improves NAFLD by regulating the intestinal flora and metabolites

Radix Puerariae thomsonii, the root of the botanical family Fabaceae species Pueraria montana var. thomsonii (Benth.) MR Almeida, can be used as food or medicine. Polysaccharides are important active constituents of this root. A low molecular weight polysaccharide, RPP-2 having α-D-1,3-glucan as the main chain, was isolated and purified. RPP-2 could promote the growth of probiotics in-vitro. Therefore, the effects of RPP-2 on a high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) C57/BL6J mouse models were investigated. RPP-2 could reduce HFD-induced liver injury by reducing inflammation, glucose metabolism, and steatosis, thereby improving NAFLD. RPP-2 regulated the abundances of intestinal floral genera Flintibacter, Butyricicoccus, and Oscillibacter, and their metabolites Lipopolysaccharide (LPS), bile acids, and short-chain fatty acids (SCFAs), thereby improving inflammation, lipid metabolism, and energy metabolism signaling pathways. These results confirmed that RPP-2 play a prebiotic role by regulating intestinal flora and microbial metabolites, playing a multi-pathway and multi-target role in improving NAFLD.

Diet-induced gut dysbiosis and inflammation: Key drivers of obesity-driven NASH

Sucrose, the primary circulating sugar in plants, contains equal amounts of fructose and glucose. The latter is the predominant circulating sugar in animals and thus the primary fuel source for various tissue and cell types in the body. Chronic excessive energy intake has, however, emerged as a major driver of obesity and associated pathologies including nonalcoholic fatty liver diseases (NAFLD) and the more severe nonalcoholic steatohepatitis (NASH). Consumption of a high-caloric, western-style diet induces gut dysbiosis and inflammation resulting in leaky gut. Translocation of gut-derived bacterial content promotes hepatic inflammation and ER stress, and when either or both of these are combined with steatosis, it can cause NASH. Here, we review the metabolic links between diet-induced changes in the gut and NASH. Furthermore, therapeutic interventions for the treatment of obesity and liver metabolic diseases are also discussed with a focus on restoring the gut-liver axis.

Effects of oat (Avena sativa L.) hay diet supplementation on the intestinal microbiome and metabolome of Small-tail Han sheep

Supplementation of the sheep diet with oats (Avena sativa L.) improves animal growth and meat quality, however effects on intestinal microbes and their metabolites was not clear. This study aimed to establish the effect of dietary oat supplementation on rumen and colonic microbial abundance and explore the relationship with subsequent changes in digesta metabolites. Twenty Small-tail Han sheep were randomly assigned to a diet containing 30 g/100 g of maize straw (Control) or oat hay (Oat). After 90-days on experimental diets, rumen and colon digesta were collected and microbial diversity was determined by 16S rRNA gene Illumina NovaSeq sequencing and metabolomics was conducted using Ultra-high performance liquid chromatography Q-Exactive mass spectrometry (UHPLC-QE-MS). Compared to Control group, oat hay increased the abundance of Bacteroidetes and Fibrobacteres as well as known short-chain fatty acid (SCFA) producers Prevotellaceae, Ruminococcaceae and Fibrobacteraceae in rumen (p < 0.05). In rumen digesta, the Oat group showed had higher levels of (3Z,6Z)-3,6-nonadienal, Limonene-1,2-epoxide, P-tolualdehyde, and Salicylaldehyde compared to Control (p < 0.05) and these metabolites were positively correlated with the abundance of cecal Prevotellaceae NK3B31. In conclusion, supplementation of the sheep diet with oat hay improved desirable microbes and metabolites in the rumen, providing insight into mechanisms whereby meat quality can be improved by oat hay supplementation.

Impact of Dietary Arachidonic Acid on Gut Microbiota Composition and Gut-Brain Axis in Male BALB/C Mice

Although arachidonic acid (ARA) is the precursor of the majority of eicosanoids, its influence as a food component on health is not well known. Therefore, we investigated its impact on the gut microbiota and gut-brain axis. Groups of male BALB/c mice were fed either a standard diet containing 5% lipids (Std-ARA) or 15%-lipid diets without ARA (HL-ARA) or with 1% ARA (HL + ARA) for 9 weeks. Fatty acid profiles of all three diets were the same. The HL-ARA diet favored the growth of Bifidobacterium pseudolongum contrary to the HL + ARA diet that favored the pro-inflammatory Escherichia-Shigella genus in fecal microbiota. Dietary ARA intake induced 4- and 15-fold colic overexpression of the pro-inflammatory markers IL-1β and CD40, respectively, without affecting those of TNFα and adiponectin. In the brain, dietary ARA intake led to moderate overexpression of GFAP in the hippocampus and cortex. Both the hyperlipidic diets reduced IL-6 and IL-12 in the brain. For the first time, it was shown that dietary ARA altered the gut microbiota, led to low-grade colic inflammation, and induced astrogliosis in the brain. Further work is necessary to determine the involved mechanisms.

Relative contributions of the host genome, microbiome, and environment to the metabolic profile

BACKGROUND

Metabolic syndrome is as a well-known risk factor for cardiovascular disease, which is associated with both genetic and environmental factors. Recently, the microbiome composition has been shown to affect the development of metabolic syndrome. Thus, it is expected that the complex interplay among host genetics, the microbiome, and environmental factors could affect metabolic syndrome.

OBJECTIVE

To evaluate the relative contributions of genetic, microbiome, and environmental factors to metabolic syndrome using statistical approaches.

METHODS

Data from the prospective Korean Association REsource project cohort (N = 8476) were used in this study, including single-nucleotide polymorphisms, phenotypes and lifestyle factors, and the urine-derived microbial composition. The effect of each data source on metabolic phenotypes was evaluated using a heritability estimation approach and a prediction model separately. We further experimented with various types of metagenomic relationship matrices to estimate the phenotypic variance explained by the microbiome.

RESULTS

With the heritability estimation, five of the 11 metabolic phenotypes were significantly associated with metagenome-wide similarity. We found significant heritability for fasting glucose (4.8%), high-density lipoprotein cholesterol (4.9%), waist-hip ratio (7.7%), and waist circumference (5.6%). Microbiome compositions provided more accurate estimations than genetic factors for the same sample size. In the prediction model, the contribution of each source to the prediction accuracy varied for each phenotype.

CONCLUSION

The effects of host genetics, the metagenome, and environmental factors on metabolic syndrome were minimal. Our statistical analysis suffers from a small sample size, and the measurement error is expected to be substantial. Further analysis is necessary to quantify the effects with better accuracy.

Gut Microbiota Regulate Pancreatic Growth, Exocrine Function, and Gut Hormones

Growing evidence indicates an important link between gut microbiota, obesity, and metabolic syndrome. Alterations in exocrine pancreatic function are also widely present in patients with diabetes and obesity. To examine this interaction, C57BL/6J mice were fed a chow diet, a high-fat diet (HFD), or an HFD plus oral vancomycin or metronidazole to modify the gut microbiome. HFD alone leads to a 40% increase in pancreas weight, decreased glucagon-like peptide 1 and peptide YY levels, and increased glucose-dependent insulinotropic peptide in the plasma. Quantitative proteomics identified 138 host proteins in fecal samples of these mice, of which 32 were significantly changed by the HFD. The most significant of these were the pancreatic enzymes. These changes in amylase and elastase were reversed by antibiotic treatment. These alterations could be reproduced by transferring gut microbiota from donor C57BL/6J mice to germ-free mice. By contrast, antibiotics had no effect on pancreatic size or exocrine function in C57BL/6J mice fed the chow diet. Further, 1 week vancomycin administration significantly increased amylase and elastase levels in obese men with prediabetes. Thus, the alterations in gut microbiota in obesity can alter pancreatic growth, exocrine function, and gut endocrine function and may contribute to the alterations observed in patients with obesity and diabetes.

Radix Puerariae thomsonii polysaccharide (RPP) improves inflammation and lipid peroxidation in alcohol and high-fat diet mice by regulating gut microbiota

Polysaccharides are the important active constituents of Radix Puerariae thomsonii. Numerous studies have shown that polysaccharides can regulate gut microbiota, repair intestinal barrier, and affect the microbiota-intestine-liver axis, thereby showing therapeutic effects on metabolic disorders. In this study, Radix Puerariae thomsonii polysaccharide (RPP) was extracted from Radix Puerariae thomsonii. The average Mw of RPP was determined to be 1.09 × 10⁵ Da and the monosaccharide composition showed it consisted of glucose. The effects and underlying mechanisms of RPP on fatty liver were studied using C57/BL6J mice induced by alcohol and high-fat diet. The results showed that the oral supplementation of RPP could alleviate alcohol and high-fat diet-induced hepatic injury and steatosis. RPP also promoted intestinal barrier integrity and reduced inflammation through NF-κB signaling pathway. RPP could ameliorate the lipid peroxidation by AMPK/NADPH oxidase signaling pathway. Additionally, these improvements might be related to the enrichment of intestinal bacteria Parabacteroides (promote intestinal barrier integrity) and Prevotellaceae UCG 001 (activation of AMPK signaling pathway). These results demonstrated that RPP could improve inflammation and lipid peroxidation in the alcohol and high-fat diet mouse by restoring the intestinal barrier integrity and regulating the gut microbiota. This suggested that RPP was a potential food supplement for the treatment of fatty liver disease.

Effects of micronized bamboo powder on growth performance, serum biochemical indexes, cecal chyme microflora and metabolism of broilers aged 1-22 days

Adding insoluble fiber to diet of broilers has been reported to improve intestinal health and promote growth performance. Bamboo powder is a cheap raw material with rich insoluble fiber. This study aims to explore the effects of feeding micronized bamboo powder (MBP) on growth performance, serum biochemical indexes, intestinal microflora, and metabolism of broilers. A total of 1440 1-day-old slow-growing Ephedra chickens were randomly divided into three groups considering gender and body weight: (1) Group D: feeding with basal diet without antibiotics; (2) Group E: feeding with basal diet supplemented with 5% rice bran (RB); (3) Group F: feeding with basal diet supplemented with 1% MBP. Each group involved 8 replicates feeding for 22 days, with 60 chickens per replicate. Various indexes were detected. For the growth performance, the weight gain and feed consumption ratio (G: F) of Group F supplemented with MBP is 0.57 ± 0.04, which is significantly higher than that of E group supplemented with RB (0.52 ± 0.01, P < 0.05). For the serum biochemical indexes, the glutathione peroxidase activity in Group F is significantly higher than that of Group D, while the malondialdehyde content is significantly lower than that of Group D and Group E (P < 0.05 for all). The fresh cecal chyme is taken for determination. In Group F, the α diversity index Faith_pd is significantly lower in Group F than that of Group D. The microorganism species in cecal chyme of Group F and Group E are also different. The metabolic pathways of Group F, mainly in fatty acid metabolism, amino acid metabolism and intestinal immune IgA production, were different from those of Group D and Group E. Adding 1% MBP to broiler diet can enhance the anti-oxidant capacity, improve chyme microflora, regulate the metabolism pathways responsible for intestinal fatty acids, amino acids, and immunity.

The Relationship between Physical Activity, Physical Exercise, and Human Gut Microbiota in Healthy and Unhealthy Subjects: A Systematic Review

Several studies have been conducted to find at least an association between physical activity (PA)/ physical exercise (PE) and the possibility to modulate the gut microbiome (GM). However, the specific effects produced on the human GM by different types of PA/PE, different training modalities, and their age-related effects are not yet fully understood. Therefore, this systematic review aims to evaluate and summarize the current scientific evidence investigating the bi-directional relationship between PA/PE and the human GM, with a specific focus on the different types/variables of PA/PE and age-related effects, in healthy and unhealthy people. A systematic search was conducted across four databases (Web of Science, Medline (PubMed), Google Scholar, and Cochrane Library). Information was extracted using the populations, exposure, intervention, comparison, outcomes (PICOS) format. The Oxford Quality Scoring System Scale, the Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-I) tool, and the JBI Critical Appraisal Checklist for Analytical Cross-Sectional Studies were used as a qualitative measure of the review. The protocol was registered in PROSPERO (code: CRD42022302725). The following data items were extracted: author, year of publication, study design, number and age of participants, type of PA/PE carried out, protocol/workload and diet assessment, duration of intervention, measurement tools used, and main outcomes. Two team authors reviewed 694 abstracts for inclusion and at the end of the screening process, only 76 full texts were analyzed. Lastly, only 25 research articles met the eligibility criteria. The synthesis of these findings suggests that GM diversity is associated with aerobic exercise contrary to resistance training; abundance of Prevotella genus seems to be correlated with training duration; no significant change in GM richness and diversity are detected when exercising according to the minimum dose recommended by the World Health Organizations; intense and prolonged PE can induce a higher abundance of pro-inflammatory bacteria; PA does not lead to significant GM α/β-diversity in elderly people (60+ years). The heterogeneity of the training parameters used in the studies, diet control, and different sequencing methods are the main confounders. Thus, this systematic review can provide an in-depth overview of the relationship between PA/PE and the human intestinal microbiota and, at the same time, provide indications from the athletic and health perspective.

Role of Dietary Supplements and Probiotics in Modulating Microbiota and Bone Health: The Gut-Bone Axis

Osteoporosis is characterized by an alteration of bone microstructure with a decreased bone mineral density, leading to the incidence of fragility fractures. Around 200 million people are affected by osteoporosis, representing a major health burden worldwide. Several factors are involved in the pathogenesis of osteoporosis. Today, altered intestinal homeostasis is being investigated as a potential additional risk factor for reduced bone health and, therefore, as a novel potential therapeutic target. The intestinal microflora influences osteoclasts’ activity by regulating the serum levels of IGF-1, while also acting on the intestinal absorption of calcium. It is therefore not surprising that gut dysbiosis impacts bone health. Microbiota alterations affect the OPG/RANKL pathway in osteoclasts, and are correlated with reduced bone strength and quality. In this context, it has been hypothesized that dietary supplements, prebiotics, and probiotics contribute to the intestinal microecological balance that is important for bone health. The aim of the present comprehensive review is to describe the state of the art on the role of dietary supplements and probiotics as therapeutic agents for bone health regulation and osteoporosis, through gut microbiota modulation.

Multi-Omics Association Reveals the Effects of Intestinal Microbiome-Host Interactions on Fat Deposition in Broilers

Growing evidence indicates that gut microbiota factors cannot be viewed as independent in the occurrence of obesity. Because the gut microbiome is highly dimensional and complex, studies on interactions between gut microbiome and host in obesity are still rare. To explore the relationship of gut microbiome-host interactions with obesity, we performed multi-omics associations of gut metagenome, intestinal transcriptome, and host obesity phenotypes in divergently selected obese-lean broiler lines. Metagenomic shotgun sequencing generated a total of 450 gigabases of clean data from 80 intestinal segment contents of 20 broilers (10 of each line). The microbiome comparison showed that microbial diversity and composition in the duodenum, jejunum, ileum, and ceca were altered variously between the lean- and fat-line broilers. We identified two jejunal microbes (Escherichia coli and Candidatus Acetothermia bacterium) and four cecal microbes (Alistipes sp. CHKCI003, Ruminococcaceae bacterium CPB6, Clostridiales bacterium, and Anaeromassilibacillus sp. An200), which were significantly different between the two lines (FDR < 0.05). When comparing functional metagenome, the fat-line broilers had an intensive microbial metabolism in the duodenum and jejunum but degenerative microbial activities in the ileum and ceca. mRNA-sequencing identified a total of 1,667 differentially expressed genes (DEG) in the four intestinal compartments between the two lines (| log2FC| > 1.5 and FDR < 0.05). Multi-omics associations showed that the 14 microbial species with abundances that were significantly related with abdominal fat relevant traits (AFRT) also have significant correlations with 155 AFRT-correlated DEG (p < 0.05). These DEG were mainly involved in lipid metabolism, immune system, transport and catabolism, and cell growth-related pathways. The present study constructed a gut microbial gene catalog of the obese-lean broiler lines. Intestinal transcriptome and metagenome comparison between the two lines identified candidate DEG and differential microbes for obesity, respectively. Multi-omics associations suggest that abdominal fat deposition may be influenced by the interactions of specific gut microbiota abundance and the expression of host genes in the intestinal compartments in which the microbes reside. Our study explored the interactions between gut microbiome and host intestinal gene expression in lean and obese broilers, which may expand knowledge on the relationships between obesity and gut microbiome.

Differential effects of lung inflammation on insulin resistance in humans and mice

BACKGROUND

The rates of obesity, its associated diseases, and allergies are raising at alarming rates in most countries. House dust mites (HDM) are highly allergenic and exposure often associates with an urban sedentary indoor lifestyle, also resulting in obesity. The aim of this study was to investigate the epidemiological association and physiological impact of lung inflammation on obesity and glucose homeostasis.

METHODS

Epidemiological data from 2207 adults of the population-based KORA FF4 cohort were used to test associations between asthma and rhinitis with metrics of body weight and insulin sensitivity. To obtain functional insights, C57BL/6J mice were intranasally sensitized and challenged with HDM and simultaneously fed with either low-fat or high-fat diet for 12 weeks followed by a detailed metabolic and biochemical phenotyping of the lung, liver, and adipose tissues.

RESULTS

We found a direct association of asthma with insulin resistance but not body weight in humans. In mice, co-development of obesity and HDM-induced lung inflammation attenuated inflammation in lung and perigonadal fat, with little impact on body weight, but small shifts in the composition of gut microbiota. Exposure to HDM improved glucose tolerance, reduced hepatosteatosis, and increased energy expenditure and basal metabolic rate. These effects associate with increased activity of thermogenic adipose tissues independent of uncoupling protein 1.

CONCLUSIONS

Asthma associates with insulin resistance in humans, but HDM challenge results in opposing effects on glucose homeostasis in mice due to increased energy expenditure, reduced adipose inflammation, and hepatosteatosis.

Promising Indicators in Probiotic-recommendations in COVID-19 and its Accompanying Diseases

Scientific data suggests the possible beneficial role of probiotics in treatments for COVID-19, but the species/strains-specificity and disease-specificity of probiotics need high attention in choosing the appropriate probiotic in diseases, in particularly in the COVID-19. We hope this review will raise awareness of the COVID-19 probiotic recommendations, highlighting the latest scientific information about virus/hydrogen peroxide/probiotics and the importance of finding out of a specific “criterion” for the probiotics’ recommendation in this disease.

Cross-Talk Between Gut Microbiota and Adipose Tissues in Obesity and Related Metabolic Diseases

The rapid increase of obesity and associated diseases has become a major global health problem. Adipose tissues are critical for whole-body homeostasis. The gut microbiota has been recognized as a significant environmental factor in the maintenance of energy homeostasis and host immunity. A growing body of evidence suggests that the gut microbiota regulates host metabolism through a close cross-talk with adipose tissues. It modulates energy expenditure and alleviates obesity by promoting energy expenditure, but it also produces specific metabolites and structural components that may act as the central factors in the pathogenesis of inflammation, insulin resistance, and obesity. Understanding the relationship between gut microbiota and adipose tissues may provide potential intervention strategies to treat obesity and associated diseases. In this review, we focus on recent advances in the gut microbiota and its actions on adipose tissues and highlight the joint actions of the gut microbiota and adipose tissue with each other in the regulation of energy metabolism.

Sanghuangporus vaninii mixture ameliorated type 2 diabetes mellitus and altered intestinal microbiota in mice

Sanghuangporus vaninii mixture ameliorated type 2 diabetes mellitus through improving body weight, fasting blood glucose, insulin-related indicators, lipid indexes, inflammatory factors, histological pathology, and intestinal microbiota.

Vaccine Hyporesponse Induced by Individual Antibiotic Treatment in Mice and Non-Human Primates Is Diminished upon Recovery of the Gut Microbiome

Emerging evidence demonstrates a connection between microbiome composition and suboptimal response to vaccines (vaccine hyporesponse). Harnessing the interaction between microbes and the immune system could provide novel therapeutic strategies for improving vaccine response. Currently we do not fully understand the mechanisms and dynamics by which the microbiome influences vaccine response. Using both mouse and non-human primate models, we report that short-term oral treatment with a single antibiotic (vancomycin) results in the disruption of the gut microbiome and this correlates with a decrease in systemic levels of antigen-specific IgG upon subsequent parenteral vaccination. We further show that recovery of microbial diversity before vaccination prevents antibiotic-induced vaccine hyporesponse, and that the antigen specific IgG response correlates with the recovery of microbiome diversity. RNA sequencing analysis of small intestine, spleen, whole blood, and secondary lymphoid organs from antibiotic treated mice revealed a dramatic impact on the immune system, and a muted inflammatory signature is correlated with loss of bacteria from Lachnospiraceae, Ruminococcaceae, and Clostridiaceae. These results suggest that microbially modulated immune pathways may be leveraged to promote vaccine response and will inform future vaccine design and development strategies.

Alteration and the Function of Intestinal Microbiota in High-Fat-Diet- or Genetics-Induced Lipid Accumulation

Diet and host genetics influence the composition of intestinal microbiota, yet few studies have compared the function of intestinal microbiota in the diet- or genotype-induced lipid deposition, which limits our understanding of the role of intestinal bacteria in metabolic disorders. The lipid accumulation in wild-type zebrafish fed with control (CON) or high-fat (HF) diet and two gene-knockout zebrafish lines (cpt1b^–/– or pparab^–/–) fed with control diet was measured after a 4-week feeding experiment. The intestinal microbiota composition of these groups was investigated using 16S ribosomal RNA (rRNA) gene sequencing (DNA-based) and 16S rRNA sequencing (RNA-based). The HF diet or deficiency of two genes induced more weight gain and higher triglyceride content in the liver compared with their control group. 16S rRNA gene sequencing (DNA-based) indicated the decreased abundance of Proteobacteria in the HF group compared with CON, but there was no significant difference in bacterial α diversity among treatments. 16S rRNA sequencing (RNA-based) confirmed the decreased abundance of Proteobacteria and the bacterial α diversity in the HF group compared with CON. Deficiency of cpt1b or pparab showed less change in microbiota composition compared with their wild-type group. Intestinal microbiota of each group was transferred to germ-free zebrafish, and the quantification of Nile red staining indicated that the intestinal microbiota of the HF group induced more lipid accumulation compared with CON, whereas intestinal microbiota of cpt1b^–/– and pparab^–/– zebrafish did not. The results showed that RNA-based bacterial sequencing revealed more bacterial alteration than DNA-based bacterial sequencing. HF diet had a more dominant role in shaping gut microbiota composition to induce lipid accumulation compared with the gene-knockout of cpt1b or pparab in zebrafish, and the transplant of intestinal microbiota from HF-fed fish induced more lipid deposition in germ-free zebrafish. Together, these data suggested that a high-fat diet exerted a more dominant role over the deletion of cpt1b or pparab on the intestinal bacterial composition, which corresponded to lipid accumulation.

Cancer and immunotherapy: a role for microbiota composition

Human microbiota plays a key role in preserving homeostasis; therefore, alteration in its composition is associated with susceptibility to various diseases. Recent findings suggest that gut microbiota may influence response to cancer treatment, especially immune checkpoint blockers (ICBs). The development of ICBs has changed outcomes of patients with cancer and has allowed sustained recovery. Unfortunately, some patients do not respond to ICBs, and microbiota may be a promising new biomarker to identify patients who will have benefit from ICBs. This review presents relationship between microbiome composition or microbiota-derived metabolites and response to ICBs or immune-related adverse events. Furthermore, we will present different strategies to modulate microbiota composition in patients to enhance ICB efficacy or dampen their toxicities which could lead to the emergence of interesting complementary treatments.

Arc1 and the microbiota together modulate growth and metabolic traits in Drosophila

Perturbations to animal-associated microbial communities (the microbiota) have deleterious effects on various aspects of host fitness, but the molecular processes underlying these impacts are poorly understood. Here, we identify a connection between the microbiota and the neuronal factor Arc1 that affects growth and metabolism in Drosophila. We find that Arc1 exhibits tissue-specific microbiota-dependent expression changes, and that germ-free flies bearing a null mutation of Arc1 exhibit delayed and stunted larval growth, along with a variety of molecular, cellular and organismal traits indicative of metabolic dysregulation. Remarkably, we show that the majority of these phenotypes can be fully suppressed by mono-association with a single Acetobacter sp. isolate, through mechanisms involving both bacterial diet modification and live bacteria. Additionally, we provide evidence that Arc1 function in key neuroendocrine cells of the larval brain modulates growth and metabolic homeostasis under germ-free conditions. Our results reveal a role for Arc1 in modulating physiological responses to the microbial environment, and highlight how host-microbe interactions can profoundly impact the phenotypic consequences of genetic mutations in an animal host.

Oral infection with a periodontal pathogen alters oral and gut microbiomes

Periodontal disease, an inflammatory bone disease of the oral cavity, affects more than 50% of the United States population over the age of 30. The Gram-negative, anaerobic bacterium Porphyromonas gingivalis, the etiological agent of periodontal disease, is known to induce dysbiosis of the oral microbiome while promoting inflammatory bone loss. We have recently reported that P. gingivalis can also alter the gut microbiota of mice prone to develop inflammatory atherosclerosis. However, it is still unknown whether P. gingivalis induces similar changes to the gut microbiome as it does to oral microbiome. In this study, we demonstrate that P. gingivalis infection increases the diversity of the oral microbiome, allowing for colonization of potentially opportunistic species in the oral microbiome and overgrowth of commensal species in both the oral and gut microbiomes. Since periodontal disease treatment in humans typically involves antibiotic treatment, we also examined the combined effect of P. gingivalis infection on mice pretreated with oral antibiotics. By correlating the oral and cecal microbiota of P. gingivalis-infected mice fed a normal chow diet, we identified blooms of the Gram-negative genera Barnesiella and Bacteroides and imbalances of mucin-degrading bacteria. These disrupted community structures were predicted to have increased detrimental functional capacities including increased flavonoid degradation and l-histidine fermentation. Though antibiotic pretreatment (without P. gingivlais) had a dominant impact on the cecal microbiome, P. gingivalis infection of mice with or without antibiotic pretreatment increased the abundance of the phylum Firmicutes and the Porphyromonadaceae family in the cecum. Collectively, our study demonstrates that P. gingivalis oral infection disrupted the oral and cecal microbiomes of otherwise unperturbed mice, altering their community membership and functional potential.

Insulin action at a molecular level - 100 years of progress

The discovery of insulin 100 years ago and its application to the treatment of human disease in the years since have marked a major turning point in the history of medicine. The availability of purified insulin allowed for the establishment of its physiological role in the regulation of blood glucose and ketones, the determination of its amino acid sequence, and the solving of its structure. Over the last 50 years, the function of insulin has been applied into the discovery of the insulin receptor and its signaling cascade to reveal the role of impaired insulin signaling-or resistance-in the progression of type 2 diabetes. It has also become clear that insulin signaling can impact not only classical insulin-sensitive tissues, but all tissues of the body, and that in many of these tissues the insulin signaling cascade regulates unexpected physiological functions. Despite these remarkable advances, much remains to be learned about both insulin signaling and how to use this molecular knowledge to advance the treatment of type 2 diabetes and other insulin-resistant states.

Comparative Analysis of the Microbiota Between Rumen and Duodenum of Twin Lambs Based on Diets of Ceratoides or Alfalfa

In our previous study, diet directly impacted the microbiota of the rumen in twin lambs. The duodenum is the first part of the small intestine, so we seek to determine whether there is a difference in the digesta between the two feed groups HFLP (high fiber, low protein) and LFHP (low fiber, high protein), and its impact on the biodiversity and metabolism of the duodenum. Results showed that the number of Operational Taxonomic Units (OTUs) in the duodenum (2,373 OTUs) was more than those in the rumen (1,230 OTUs), and 143 OTUs were significantly different in the duodenum between the two groups. The two most predominant phyla were Bacteriodetes and Firmicutes, but this ratio was reversed between the rumen and duodenum of lambs fed different feedstuffs. The difference in the digesta that greatly changed the biodiversity of the rumen and duodenum could affect the microbial community in the gastrointestinal tract (GIT). Sixteen metabolites were significantly different in the duodenum between the two groups based on the metabolome analysis. The relationships were built between the microbiome and the metabolome based on the correlation analysis. Some metabolites have a potential role in influencing meat quality, which indicated that the diet could affect the microbiota community and finally change meat quality. This study could explain how the diet affects the rumen and duodenum’s microbiota, lay a theoretical basis for controlling feed intake, and determine the relationship between the duodenum’s microbiota and metabolism.

The Effectiveness of Potential Probiotics Lactobacillus rhamnosus Vahe and Lactobacillus delbrueckii IAHAHI in Irradiated Rats Depends on the Nutritional Stage of the Host

Several species of eukaryotic organisms living in the high mountain areas of Armenia with naturally occurring levels of radiation have high adaptive responses to radiation. We speculate on the role of the gastrointestinal microbiota in this protection against radiation. Therefore, seventeen microorganisms with high antagonistic activities against several multi-drug-resistant pathogens were isolated from the human and animal gut microbiota, as well as from traditional Armenian fermented products. These strains were tested in vivo on Wistar rats to determine their ability to protect the eukaryotic host against radiation damages. The efficiency of the probiotics' application and the dependence on pre- and post-radiation nutrition of rats were described. The effects of Lactobacillus rhamnosus Vahe, isolated from a healthy breastfed infant, and Lactobacillus delbrueckii IAHAHI, isolated from the fermented dairy product matsuni, on the survival of irradiated rats, and their blood leucocyte and glucose levels, were considered to be the most promising, based on this study's results.

Profiling system of oral microbiota utilizing polymerase chain reaction-restriction fragment length polymorphism analysis

OBJECTIVES

Profiling of oral microbiota has traditionally been performed using conventional methods. These methods are relatively time-consuming and labor-intensive. Metagenomic analysis of oral microbiota using high-speed next-generation sequencing is a highly promising technology. However, it is expensive. This study sought to develop a simple and cost-effective profiling method for oral microbiota using 16S rRNA gene polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of PCR-amplified 16S ribosomal RNA genes.

METHODS

Oral isolates of 59 bacterial species from human saliva, including Streptococcus, Actinomyces, and Veillonella, were cultured anaerobically on CDC Anaerobe 5% sheep blood agar plates. Genomic DNA was extracted from single colonies and 16S rRNA genes were PCR-amplified using the 27F and 1492R universal primers. The PCR products were purified and characterized by single digestion with HpaII restriction endonuclease. 16S rRNA gene sequences were obtained from the GenBank database, and the expected restriction profiles were compared with the RFLP patterns obtained from agarose gel electrophoresis.

RESULTS

Sixty-five RFLP patterns were obtained from 27 genera and 59 species. The expected fragment sizes of these species were calculated based on GenBank 16S rRNA gene sequences. Fifty-nine patterns were obtained from the analysis of GenBank sequences. The RFLP patterns produced with HpaII distinguished many oral bacterial species. RFLP patterns enabling identification of oral bacteria were generated. The 16S rRNA gene PCR-RFLP analysis did not require expensive equipment and reagents and was cost-effective.

CONCLUSION

PCR-RFLP analysis based on 16S rRNA genes could be an alternative method for oral microbiota analysis in smaller laboratories.

Adequacy of calcium and vitamin D reduces inflammation, β-catenin signaling, and dysbiotic Parasutterela bacteria in the colon of C57BL/6 mice fed a western-style diet

Adoption of an obesogenic diet low in calcium and vitamin D (CaD) leads to increased obesity, colonic inflammation, and cancer. However, the underlying mechanisms remain to be elucidated. We tested the hypothesis that CaD supplementation (from inadequacy to adequacy) may reduce colonic inflammation, oncogenic signaling, and dysbiosis in the colon of C57BL/6 mice fed a Western diet. Male C57/BL6 mice (4-weeks old) were assigned to 3 dietary groups for 36 weeks: (1) AIN76A as a control diet (AIN); (2) a defined rodent "new Western diet" (NWD); or (3) NWD with CaD supplementation (NWD/CaD). Compared to the AIN, mice receiving the NWD or NWD/CaD exhibited more than 0.2-fold increase in the levels of plasma leptin, tumor necrosis factor α (TNF-α) and body weight. The levels of plasma interleukin 6 (IL-6), inflammatory cell infiltration, and β-catenin/Ki67 protein (oncogenic signaling) were increased more than 0.8-fold in the NWD (but not NWD/CaD) group compared to the AIN group. Consistent with the inflammatory phenotype, colonic secondary bile acid (inflammatory bacterial metabolite) levels increased more than 0.4-fold in the NWD group compared to the NWD/CaD and AIN groups. Furthermore, the abundance of colonic Proteobacteria (e.g., Parasutterela), considered signatures of dysbiosis, was increased more than four-fold; and the α diversity of colonic bacterial species, indicative of health, was decreased by 30% in the NWD group compared to the AIN and NWD/CaD groups. Collectively, CaD adequacy reduces colonic inflammation, β-catenin oncogenic signaling, secondary bile acids, and bacterial dysbiosis in mice fed with a Western diet.

Genetic and environmental factors influencing the interaction between the gut microbiota and the human host: implications for gastrointestinal disorders and treatment approaches

The growing knowledge on the microbiota hosted in the human intestine has allowed researchers and clinicians to discover a critical role for these microorganisms in the pathogenesis of several human disorders. In particular, perturbation in the microbiotic strains populating the gastrointestinal tract has been associated with several conditions affecting the digestive system. The composition of the human gut microbiota is influenced by both genetic factors, like the human and the microbiotic genomes, and environmental ones, such as diet or drugs. Alteration of the interaction between the gut microbiota and the human host has been proven to be associated with several gastrointestinal disorders as well as potential effects on pharmacological therapies.

The beneficial effects of polysaccharide obtained from persimmon (Diospyros kaki L.) on the proliferation of Lactobacillus and gut microbiota

The objective of this study was to investigate the effect of polysaccharide extracts from persimmon (PPE) on the proliferation of Lactobacillus and the gut microbiota of mice. Lactobacillus strains were cultured in medium containing PPE, and differential gene expression was evaluated using transcriptomics. In addition, 16S rDNA was employed to analyze the abundance and diversity of fecal colonies in mice, and the influence of PPE on the intestinal flora in mice was further examined. The results showed that Lactobacillus acidophilus NCFM and Lactobacillus acidophilus CICC 6075 could proliferate in PPE medium. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomics (KEGG) pathway analysis indicated that glucose metabolism-related genes, such as phosphoyruvate hydratase (eno) and PTS mannose transporter subunit IIAB (manX), were up-regulated. The metabolic pathways of fructose and mannose were also significantly up-regulated. After gavage of mice with PPE, 16S rDNA sequencing of mouse feces indicated that the beneficial bacteria in the intestines proliferated and the abundance of harmful bacteria was reduced. PPE can maintain the balance of intestinal microorganisms in mice. Therefore, PPE has a significant positive effect on both Lactobacillus proliferation and gut microbiota of mice.

The Role of Neutrophil Extracellular Traps in Periodontitis

Periodontitis is a chronic, destructive disease of periodontal tissues caused by multifaceted, dynamic interactions. Periodontal bacteria and host immunity jointly contribute to the pathological processes of the disease. The dysbiotic microbial communities elicit an excessive immune response, mainly by polymorphonuclear neutrophils (PMNs). As one of the main mechanisms of PMN immune response in the oral cavity, neutrophil extracellular traps (NETs) play a crucial role in the initiation and progression of late-onset periodontitis. NETs are generated and released by neutrophils stimulated by various irritants, such as pathogens, host-derived mediators, and drugs. Chromatin and proteins are the main components of NETs. Depending on the characteristics of the processes, three main pathways of NET formation have been described. NETs can trap and kill pathogens by increased expression of antibacterial components and identifying and trapping bacteria to restrict their spread. Moreover, NETs can promote and reduce inflammation, inflicting injuries on the tissues during the pro-inflammation process. During their long-term encounter with NETs, periodontal bacteria have developed various mechanisms, including breaking down DNA of NETs, degrading antibacterial proteins, and impacting NET levels in the pocket environment to resist the antibacterial function of NETs. In addition, periodontal pathogens can secrete pro-inflammatory factors to perpetuate the inflammatory environment and a friendly growth environment, which are responsible for the progressive tissue damage. By learning the strategies of pathogens, regulating the periodontal concentration of NETs becomes possible. Some practical ways to treat late-onset periodontitis are reducing the concentration of NETs, administering anti-inflammatory therapy, and prescribing broad-spectrum and specific antibacterial agents. This review mainly focuses on the mechanism of NETs, pathogenesis of periodontitis, and potential therapeutic approaches based on interactions between NETs and periodontal pathogens.

Effects of vitamin D deficiency on the improvement of metabolic disorders in obese mice after vertical sleeve gastrectomy

Vertical sleeve gastrectomy (VSG) is one of the most commonly performed clinical bariatric surgeries for the remission of obesity and diabetes. Its effects include weight loss, improved insulin resistance, and the improvement of hepatic steatosis. Epidemiologic studies demonstrated that vitamin D deficiency (VDD) is associated with many diseases, including obesity. To explore the role of vitamin D in metabolic disorders for patients with obesity after VSG. We established a murine model of diet-induced obesity + VDD, and we performed VSGs to investigate VDD's effects on the improvement of metabolic disorders present in post-VSG obese mice. We observed that in HFD mice, the concentration of VitD3 is four fold of HFD + VDD one. In the post-VSG obese mice, VDD attenuated the improvements of hepatic steatosis, insulin resistance, intestinal inflammation and permeability, the maintenance of weight loss, the reduction of fat loss, and the restoration of intestinal flora that were weakened. Our results suggest that in post-VSG obese mice, maintaining a normal level of vitamin D plays an important role in maintaining the improvement of metabolic disorders.

Circulating exosomes and gut microbiome induced insulin resistance in mice exposed to intermittent hypoxia: Effects of physical activity

Background

Gut microbiota (GM) contribute to obesity and insulin resistance (IR). Obstructive sleep apnea (OSA), characterized by intermittent hypoxia (IH), promotes IR and alters GM. Since circulating exosomes are implicated in IR, we examined the effects of IH and physical activity (PA) in mice on GM, colonic epithelium permeability, systemic IR, and plasma exosome cargo, and exosome effects on visceral white adipose tissues (vWAT) IR.

Methods

C57BL/6 mice were exposed to IH or room air (RA) for 6 weeks with and without PA (n = 12/group), and GM and systemic IR changes were assessed, as well as the effects of plasma exosomes on naïve adipocyte insulin sensitivity. Fecal microbiota transfers (FMT) were performed in naïve mice (n = 5/group), followed by fecal 16S rRNA sequencing, and systemic IR and exosome-induced effects on adipocyte insulin sensitivity were evaluated.

Findings

Principal coordinate analysis (PCoA) ordinates revealed B-diversity among IH and FMT recipients that accounted for 64% principal component 1 (PC1) and 12.5% (PC2) of total variance. Dominant microbiota families and genera in IH-exposed and FMT-treated were preserved, and IH-exposed GM and IH-FMT induced increased gut permeability. Plasma exosomes from IH-exposed and IH-FMT mice decreased pAKT/AKT responses to exogenous insulin in adipocytes vs. IH+PA or RA FMT-treated mice (p = 0.001).

Interpretation

IH exposures mimicking OSA induce changes in GM, increase gut permeability, and alter plasma exosome cargo, the latter inducing adipocyte dysfunction (increased IR). Furthermore, these alterations improved with PA. Thus, IH leads to perturbations of a singular GM-circulating exosome pathway that disrupts adipocyte homeostasis resulting in metabolic dysfunction, as reflected by IR.

Funding

This study was supported by grants from the National Institutes of Health grants HL130984 and HL140548 and University of Missouri Tier 2 grant. The study has not received any funding or grants from pharmaceutical or other industrial corporations.

Protective effect of Ganoderma lucidum spore extract in trimethylamine-N-oxide-induced cardiac dysfunction in rats

Previous research has shown that the extracts from the Ganoderma lucidum spore (GS) have potentially cardioprotective effects, but there is still abundant room for development in determining its mechanism. In this study, the rat model of cardiac dysfunction was established by intraperitoneal injection of trimethylamine-N-oxide (TMAO), and the extracts of GS (oil, lipophilic components, and polysaccharides) were given intragastrically at a dose of 50 mg/kg/day to screen the pharmacological active components of GS. After 50 days of treatments, we found that the extraction from GS reduced the levels of total cholesterol, triglyceride, and low-density lipoprotein; increased the levels of high-density lipoprotein; and reduced the levels of serum TMAO when compared to the model group (P < 0.05); especially the GS polysaccharides (DT) and GS lipophilic components (XF) exhibited decreases in serum TMAO compared to TMAO-induced control. The results of 16S rRNA sequencing showed that GS could change the gut microbiota, increasing the abundance of Firmicutes and Proteobacteria in the DT-treated group and XF-treated group, while reducing the abundance of Actinobacteria and Tenericutes. Quantitative proteomics analysis showed that GS extracts (DT and XF) could regulate the expression of some related proteins, such as Ucp1 (XF-TMAO/M-TMAO ratio is 2.76), Mpz (8.52), Fasn (2.39), Nefl (1.85), Mtnd5 (0.83), Mtnd2 (0.36), S100a8 (0.69), S100a9 (0.70), and Bdh1 (0.72). The results showed that XF can maintain the metabolic balance and function of the heart by regulating the expression of some proteins related to cardiovascular disease, and DT can reduce the risk of cardiovascular diseases by targeting gut microbiota.

The microbiota-microglia axis in central nervous system disorders

The innate immune system in the central nervous system (CNS) is mainly represented by specialized tissue-resident macrophages, called microglia. In the past years, various species-, host- and tissue-specific as well as environmental factors were recognized that essentially affect microglial properties and functions in the healthy and diseased brain. Host microbiota are mostly residing in the gut and contribute to microglial activation states, for example, via short-chain fatty acids (SCFAs) or aryl hydrocarbon receptor (AhR) ligands. Thereby, the gut microorganisms are deemed to influence numerous CNS diseases mediated by microglia. In this review, we summarize recent findings of the interaction between the host microbiota and the CNS in health and disease, where we specifically highlight the resident gut microbiota as a crucial environmental factor for microglial function as what we coin "the microbiota-microglia axis."