Gut bacterial microbiota and obesity

Preparation technologies, structural characteristics and biological activities of polysaccharides from bee pollen: A review

Bee pollen, a natural honeybee product, is hailed as a treasure trove of human nutrition. Among the nourishing substances of bee pollen, the constituents with a low molecular weight (such as phenolic acids and flavonoid glycosides) have been extensively studied in the past decades, whereas the polysaccharides with a relatively high molecular weight have received much less attention. To deepen our understanding of bee pollen polysaccharides, this review summarizes the published findings related to their preparation technologies, structural characteristics and biological activities. Among the preparation technologies, ultrasonic-assisted extraction is currently the most effective technology for the recovery of polysaccharides from bee pollen, because ultrasound can crack the pollen exine into fragments and facilitate the release of polysaccharides present in the pollen intine. The preliminary structures, including the molecular weight and monosaccharide composition, of bee pollen polysaccharides have been widely reported, but their fine structures have not fully elucidated. Moreover, bee pollen polysaccharides have antioxidant, immunomodulatory, and antitumor activities, exhibiting potential application in functional foods. Furthermore, bee pollen polysaccharides can modulate the composition of gut microbiota and promote the production of short-chain fatty acids. It is expected that this review can provide inspiration for the development and utilization of bee pollen polysaccharides.

IL-5-producing Group 2 innate lymphoid cells promote T cell-independent IgA production in cooperation with eosinophils

Intestinal bacteria play a critical role in the regulation of the host immune system and an imbalance in the intestinal bacterial composition induces various host diseases. Therefore, maintaining a balance in the intestinal bacterial composition is crucial for health. Immunoglobulin A (IgA), produced through T cell-dependent and T cell-independent (TI) pathways, is essential for host defense against pathogen invasion and maintaining the balance of intestinal symbiotic bacteria. Interleukin (IL)-5 is constitutively produced by Group 2 innate lymphoid cells (ILC2s) and plays a critical role in the survival and proliferation of B cells and eosinophils. Here, we show the role of IL-5-producing ILC2s in intestinal TI IgA production at steady state using T cell receptor α deficient mice. In this mouse model, ILC2s increased fecal TI IgA levels in a non-inflammatory state in an IL-5-dependent manner. The administration of recombinant IL-33 (rIL-33) increased the amount of TI IgA production, accompanied by an increase in the number of IL-5-producing ILC2s in the large intestine. In addition, rIL-33 treatment increased IL-5-dependent IgA+ cells in isolated lymphoid follicles, the site of TI IgA production. Furthermore, eosinophils recruited by ILC2s were required for the maximal production of IgA in the TI pathway. Moreover, IL-5 increased the frequency of TI IgA-binding intestinal bacteria and was involved in the maintenance of intestinal bacterial composition. These findings indicate that IL-5-producing ILC2s together with eosinophils contribute to TI IgA production. In addition to their role in TI IgA production, IL-5-producing ILC2s may contribute to the homeostasis of intestinal commensal bacteria.

Seleno-chitooligosaccharide-induced modulation of intestinal barrier function: Role of inflammatory cytokines, tight junction proteins, and gut microbiota in mice

This study aimed to explore the function of Seleno-chitooligosaccharide (SOA) on the intestinal barrier through regulation of inflammatory cytokines, tight junction protein, and gut microbiota in mice. The results of ELISA assay demonstrated that SOA significantly increased the levels of IL-2, IL-10, and IFN-γ in serum and ileum. Meanwhile, SOA increased the levels of IL-4 in the ileum (p < 0.05). In addition, Diamine Oxidase (DAO) concentration was decreased in ileum by SOA treatments (p < 0.05). The administration of SOA significantly upregulated the expression of ZO-1 and Occludin in the ileum (p < 0.05). By 16S rDNA sequencing, reduced ratio of Bacillota/Bacteroidota was observed in SOA treated mice. Within the phylum of Bacteroidota, SOA increased the relative abundance of Deferribacterota, uncultured Bacteroidales bacterium, and Bacteroides. Within the phylum of Bacillota, increased relative abundance of Erysipelatoclostridium and Lachnoclostridium, and reduced relative abundance of Ruminococcaceae UCG-010 were observed with SOA supplement. In summary, SOA has the potential to modulate the function of intestinal barrier function and prevent intestinal diseases.

Fabrication of Rubus chingii Hu ellagitannins-loaded W/O and O/W emulsion gels: Structure, stability, in vitro digestion and in vivo metabolism

Tannin is the main naturally occurring phytochemicals in Rubus chingii Hu with poor digestive stability and low bioavailability. In this study, oil-in-water (O/W) and water-in-oil (W/O) emulsion gels encapsulating Rubus chingii Hu ellagitannins (RCHT) were fabricated and their structure, rheology, stability, in vitro digestion and in vivo metabolism were characterized. The W/O emulsion gel showed smaller particle size, better pH stability, thermal stability, centrifugal stability and storage stability. Regarding rheology, two emulsion gels exhibited characteristics of non-Newtonian fluids. The encapsulation efficiency of W/O emulsion gel was higher, reaching 95.46 %. The lower release rate and higher bioaccessibility of RCHT were also observed in the W/O emulsion gel. In vitro fermentation results indicated that W/O emulsion gel could promote the growth of intestinal beneficial bacteria and inhibit the growth of harmful bacteria. Metabolic kinetics in rats showed that the embedding of W/O emulsion gel greatly promoted the absorption and transformation of ellagitannins to urolithins in vivo. Thus, the W/O emulsion gel was quite suitable for the delivery of RCHT.

Effect of Dietary Oils with Different Fatty Acid Compositions on Serum Lipid and Gut Microbiota of Rats

The effects of three dietary oils (rapeseed oil, camellia oil, linseed oil) with different fatty acid compositions on the growth performance, digestion and gut microbiota of SD rats after 8 weeks of feeding were studied. The serum metabolic index and liver histomorphology of rats were measured using an automatic biochemical analyzer and light microscope. Furthermore, 16S rDNA amplicon sequencing technology was used to analyze the gut microbiota. It was found that these differences in fatty acid composition had no significant effect on body fat and liver tissue. However, after digestion, the rapeseed oil group showed lowest triglyceride content (1.22 ± 0.15) and a lower LDL/HDL ratio (0.41 ± 0.02). For gut microbiota distribution, the linseed oil group showed a higher Firmicutes/Bacteroides ratio (6.11 ± 0.54) and a high proportion of Lactobacillus. These data indicate that both the unsaturated fatty acid content and n-3 unsaturated fatty acids collectively had an effect on digestion metabolism, and the influence order may be n-3 unsaturated fatty acids > unsaturated fatty acid content.

Lincomycin as a growth-promoting antibiotic induces metabolic and immune dysregulation in animals

Since animal growth promoters (AGPs) are used in large quantities and commonly released to the environment from animal farms, it is necessary to determine whether such agents should be regarded as an environmental toxin that poses a threat to the ecosystem and health risk to wildlife. In this study, a multi-omics approach was employed to explore the effects of a representative AGP, lincomycin, on key metabolic and physiological functions of animals, using a mouse model. The results indicated that exposure to lincomycin resulted in a significant increase in growth rate of mice (50.11 %) over an 8 weeks period, during which significant decrease (61.94 %) and increase (68.64 %) in the relative abundance of Firmicutes and Escherichia coli, respectively, was observed in the gut microbiota, indicating that the gut microbiota structure has been altered. Moreover, the mice exhibited altered lipid profiles and liver damage suggestive of early-stage non-alcoholic fatty liver disease (NAFLD). Disruptions in blood glucose and insulin levels associated with type 2 diabetes mellitus (T2DM) were also observed. Furthermore, lincomycin was found to cause suppression in inflammatory responses, as evidenced by the downregulation of related genes and elevated inflammatory mediators, potentially resulting in increased susceptibility to microbial infection. Our findings underscore the detrimental effects of lincomycin on animal health and highlight the necessity for comprehensive toxicological assessments of lincomycin and other AGPs before their environmental release.

Digestive characteristics of extracellular polysaccharide from Lactiplantibacillus plantarum T1 and its regulation of intestinal microbiota

This study assessed the potential prebiotic characteristics of the previously reported Lactiplantibacillus plantarum extracellular polysaccharide (EPS-T1) with immunological activity. EPS-T1 was a novel heteropolysaccharide composed of glucose and galactose (1.00:1.21), with a molecular weight of 1.41 × 106 Da. The monosaccharide composition, molecular weight, fourier transform infrared, and 1H NMR analysis showed that EPS-T1 was well tolerated in the simulated oral cavity, gastric fluid, and small intestinal fluid environments, and was not easily degraded. Meanwhile, EPS-T1 could effectively be used as a carbon source to promote the growth of beneficial Lactobacillus species (Lactobacillus delbrueckii ssp. Bulgaricus, Streptococcus thermophilus, Lacticaseibacillus rhamnose GG, Lactiplantibacillus plantarum, Lacticaseibacillus paracasei and Lactobacillus reuteri). After 24 h of fecal fermentation, EPS-T1(5 mg/mL) effectively reduced the relative abundance of harmful bacteria such as the Escherichia-Shigella, Citrobacter, Fusobacterium, Parasutterella, and Lachnoclostridium. While, the level content of beneficial flora (Bacteroides, Blautia, Phascolarctobacterium, Bifidobacterium, Parabacteroides, and Subdoligranulum) were significantly increased. In addition, EPS-T1 was able to significantly promote the enrichment of short-chain fatty acids such as acetic acid, propionic acid and butyric acid. These results provide some basis for the functional application of EPS-T1 as a potential prebiotic.

The opportunistic nature of gut commensal microbiota

The abundance of gut commensals has historically been associated with health-promoting effects despite the fact that the definition of good or bad microbiota remains condition-specific. The beneficial or pathogenic nature of microbiota is generally dictated by the dimensions of host-microbiota and microbe-microbe interactions. With the increasing popularity of gut microbiota in human health and disease, emerging evidence suggests opportunistic infections promoted by those gut bacteria that are generally considered beneficial. Therefore, the current review deals with the opportunistic nature of the gut commensals and aims to summarise the concepts behind the occasional commensal-to-pathogenic transformation of the gut microbes. Specifically, relevant clinical and experimental studies have been discussed on the overgrowth and bacteraemia caused by commensals. Three key processes and their underlying mechanisms have been summarised to be responsible for the opportunistic nature of commensals, viz. improved colonisation fitness that is dictated by commensal-pathogen interactions and availability of preferred nutrients; pathoadaptive mutations that can trigger the commensal-to-pathogen transformation; and evasion of host immune response as a survival and proliferation strategy of the microbes. Collectively, this review provides an updated concept summary on the underlying mechanisms of disease causative events driven by gut commensal bacteria.

Immunological mechanisms of inflammatory diseases caused by gut microbiota dysbiosis: A review

The gut microbiota is indispensable for maintaining host health by enhancing the host's digestive capacity, safeguarding the intestinal epithelial barrier, and preventing pathogen invasion. Additionally, the gut microbiota exhibits a bidirectional interaction with the host immune system and promotes the immune system of the host to mature. Dysbiosis of the gut microbiota, primarily caused by factors such as host genetic susceptibility, age, BMI, diet, and drug abuse, is a significant contributor to inflammatory diseases. However, the mechanisms underlying inflammatory diseases resulting from gut microbiota dysbiosis lack systematic categorization. In this study, we summarize the normal physiological functions of symbiotic microbiota in a healthy state and demonstrate that when dysbiosis occurs due to various external factors, the normal physiological functions of the gut microbiota are lost, leading to pathological damage to the intestinal lining, metabolic disorders, and intestinal barrier damage. This, in turn, triggers immune system disorders and eventually causes inflammatory diseases in various systems. These discoveries provide fresh perspectives on how to diagnose and treat inflammatory diseases. However, the unrecognized variables that might affect the link between inflammatory illnesses and gut microbiota, need further studies and extensive basic and clinical research will still be required to investigate this relationship in the future.

Gut colonization with an obesity-associated enteropathogenic microbe modulates the premetastatic niches to promote breast cancer lung and liver metastasis

Introduction

Obesity, an independent risk factor for breast cancer growth and metastatic progression, is also closely intertwined with gut dysbiosis; and both obese state and dysbiosis promote each other. Enteric abundance of Bacteroides fragilis is strongly linked with obesity, and we recently discovered the presence of B. fragilis in malignant breast cancer. Given that enterotoxigenic B. fragilis or ETBF, which secretes B. fragilis toxin (BFT), has been identified as a procarcinogenic microbe in breast cancer, it is necessary to examine its impact on distant metastasis and underlying systemic and localized alterations promoting metastatic progression of breast cancer.

Methods

We used syngeneic mammary intraductal (MIND) model harboring gut colonization with ETBF to query distant metastasis of breast cancer cells. Alterations in the immune network and cytokines/chemokines in the tumor microenvironment and distant metastatic sites were examined using flow cytometry, immunohistochemistry, and multiplex arrays.

Results

ETBF infection initiates a systemic inflammation aiding in the establishment of the premetastatic niche formation in vital organs via increased proinflammatory and protumorigenic cytokines like IL17A, IL17E, IL27p28, IL17A/F, IL6, and IL10 in addition to creating a prometastatic immunosuppressive environment in the liver and lungs rich in myeloid cells, macrophages, and T regulatory cells. It induces remodeling of the tumor microenvironment via immune cell and stroma infiltration, increased vasculogenesis, and an EMT-like response, thereby encouraging early metastatic dissemination ready to colonize the conducive environment in liver and lungs of the breast tumor-bearing mice.

Discussion

In this study, we show that enteric ETBF infection concomitantly induces systemic inflammation, reshapes the tumor immune microenvironment, and creates conducive metastatic niches to potentiate early dissemination and seeding of metastases to liver and lung tissues in agreement with the "seed and soil hypothesis." Our results also support the ETBF-induced "parallel model" of metastasis that advocates for an early dissemination of tumor cells that form metastatic lesions independent of the primary tumor load.

Exploring breast tissue microbial composition and the association with breast cancer risk factors

BACKGROUND

Microbial dysbiosis has emerged as an important element in the development and progression of various cancers, including breast cancer. However, the microbial composition of the breast from healthy individuals, even relative to risk of developing breast cancer, remains unclear. Here, we performed a comprehensive analysis of the microbiota of the normal breast tissue, which was analyzed in relation to the microbial composition of the tumor and adjacent normal tissue.

METHODS

The study cohorts included 403 cancer-free women (who donated normal breast tissue cores) and 76 breast cancer patients (who donated tumor and/or adjacent normal tissue samples). Microbiome profiling was obtained by sequencing the nine hypervariable regions of the 16S rRNA gene (V1V2, V2V3, V3V4, V4V5, V5V7, and V7V9). Transcriptome analysis was also performed on 190 normal breast tissue samples. Breast cancer risk score was assessed using the Tyrer-Cuzick risk model.

RESULTS

The V1V2 amplicon sequencing resulted more suitable for the analysis of the normal breast microbiome and identified Lactobacillaceae (Firmicutes phylum), Acetobacterraceae, and Xanthomonadaceae (both Proteobacteria phylum) as the most abundant families in the normal breast. However, Ralstonia (Proteobacteria phylum) was more abundant in both breast tumors and histologically normal tissues adjacent to malignant tumors. We also conducted a correlation analysis between the microbiome and known breast cancer risk factors. Abundances of the bacterial taxa Acetotobacter aceti, Lactobacillus vini, Lactobacillus paracasei, and Xanthonomas sp. were associated with age (p < 0.0001), racial background (p < 0.0001), and parity (p < 0.0001). Finally, transcriptome analysis of normal breast tissues showed an enrichment in metabolism- and immune-related genes in the tissues with abundant Acetotobacter aceti, Lactobacillus vini, Lactobacillus paracasei, and Xanthonomas sp., whereas the presence of Ralstonia in the normal tissue was linked to dysregulation of genes involved in the carbohydrate metabolic pathway.

CONCLUSIONS

This study defines the microbial features of normal breast tissue, thus providing a basis to understand cancer-related dysbiosis. Moreover, the findings reveal that lifestyle factors can significantly affect the normal breast microbial composition.

Plasma short-chain fatty acid changes after bariatric surgery in patients with severe obesity

BACKGROUND

Obesity has reached epidemic dimensions in recent decades. Bariatric surgery (BS) is one of the most effective interventions for weight loss and metabolic improvement in patients with obesity. Short-chain fatty acids (SCFA) are gut microbiota-derived metabolites with a key role in body weight control and insulin sensitivity. Although BS is known to induce significant changes in the gut microbiota composition, its impact on the circulating levels of certain metabolites produced by the gut microbiota such as SCFA remains poorly understood.

OBJECTIVE

To determine the impact of BS on the circulating SCFA levels in patients with severe obesity.

SETTING

University hospital.

METHODS

An observational, prospective study was performed on 51 patients undergoing Roux-en-Y gastric bypass. Plasma samples were collected at baseline (1 day before surgery) and at 6 and 12 months after BS. Plasma SCFA levels were determined by liquid chromatography-mass spectrometry.

RESULTS

The results revealed significant changes in the circulating levels of SCFA after BS. A marked increase in propionate, butyrate, isobutyrate, and isovalerate levels and a decrease in acetate, valerate, hexanoate, and heptanoate levels were observed 12 months after BS. Furthermore, the changes in the levels of propionate, butyrate, and isobutyrate negatively correlated with changes in body mass index, while those of isobutyrate correlated negatively with changes in the homeostatic model assessment for insulin resistance index.

CONCLUSION

These results suggest that propionate, butyrate, and isobutyrate levels could be related to weight loss and improved insulin sensitivity in patients with severe obesity after BS.

Dietary Supplementation of Inulin Contributes to the Prevention of Estrogen Receptor-Negative Mammary Cancer by Alteration of Gut Microbial Communities and Epigenetic Regulations

Breast cancer (BC) is among the most frequently diagnosed malignant cancers in women in the United States. Diet and nutrition supplementation are closely related to BC onset and progression, and inulin is commercially available as a health supplement to improve gut health. However, little is known with respect to inulin intake for BC prevention. We investigated the effect of an inulin-supplemented diet on the prevention of estrogen receptor-negative mammary carcinoma in a transgenic mouse model. Plasma short-chain fatty acids were measured, the gut microbial composition was analyzed, and the expression of proteins related to cell cycle and epigenetics-related genes was measured. Inulin supplementation greatly inhibited tumor growth and significantly delayed tumor latency. The mice that consumed inulin had a distinct microbiome and higher diversity of gut microbial composition compared to the control. The concentration of propionic acid in plasma was significantly higher in the inulin-supplemented group. The protein expression of epigenetic-modulating histone deacetylase 2 (Hdac2), Hdac8, and DNA methyltransferase 3b decreased. The protein expression of factors related to tumor cell proliferation and survival, such as Akt, phospho-PI3K, and NF-kB, also decreased with inulin administration. Furthermore, sodium propionate showed BC prevention effect in vivo through epigenetic regulations. These studies suggest that modulating microbial composition through inulin consumption may be a promising strategy for BC prevention.

Structural, in vitro digestion, and fermentation characteristics of lotus leaf flavonoids

Bioaccessibility and bioactivity of flavonoids in lotus leaves are related to their characteristics in gastrointestinal digestion and colonic fermentation. The aim of this study is to investigate the stability of lotus leaf flavonoids (LLF) in simulated gastrointestinal digestion, and its modulation on gut microbiota in vitro fermentation. Results showed that LLF mainly consisted of quercetin-3-O-galactoside, quercetin-3-O-glucuronide, quercetin-3-O-glucoside, and kaempferol-3-O-glucoside. These flavonoids kept stability with only a small fraction degraded in simulated gastric and intestinal fluids. In vitro fermentation, LLF stimulated the growth of Actinobacteria and Firmicutes, inhibited the growth of Proteobacteria, and induced the production of fermentation gases and short-chain fatty acids. Interestingly, supplementation of soluble starch significantly improved the utilization of LLF by the intestinal flora. These results revealed that LLF shaped a unique biological web with Lactobacillus and Bifidobacterium spp. as the core of the biological network, which would be more beneficial to gut health.

Gut Microbiome in Post-COVID-19 Patients Is Linked to Immune and Cardiovascular Health Status but Not COVID-19 Severity

The composition of the gut microbiome stores the imprints of prior infections and other impacts. COVID-19 can cause changes in inflammatory status that persist for a considerable time after infection ends. As the gut microbiome is closely associated with immunity and inflammation, the infection severity might be linked to its community structure dynamics. Using 16S rRNA sequencing of stool samples, we investigated the microbiome three months after the end of the disease/infection or SARS-CoV-2 contact in 178 post-COVID-19 patients and those who contacted SARS-CoV-2 but were not infected. The cohort included 3 groups: asymptomatic subjects (n = 48), subjects who contacted COVID-19 patients with no further infection (n = 46), and severe patients (n = 86). Using a novel compositional statistical algorithm (nearest balance) and the concept of bacterial co-occurrence clusters (coops), we compared microbiome compositions between the groups as well as with multiple categories of clinical parameters including: immunity, cardiovascular parameters and markers of endothelial dysfunction, and blood metabolites. Although a number of clinical indicators varied drastically across the three groups, no differences in microbiome features were identified between them at this follow-up point. However, there were multiple associations between the microbiome features and clinical data. Among the immunity parameters, the relative lymphocyte number was linked to a balance including 14 genera. Cardiovascular parameters were associated with up to four bacterial cooperatives. Intercellular adhesion molecule 1 was linked to a balance including ten genera and one cooperative. Among the blood biochemistry parameters, calcium was the only parameter associated with the microbiome via a balance of 16 genera. Our results suggest comparable recovery of the gut community structure in the post-COVID-19 period, independently of severity or infection status. The multiple identified associations of clinical analysis data with the microbiome provide hypotheses about the participation of specific taxa in regulating immunity and homeostasis of cardiovascular and other body systems in health, as well as their disruption in SARS-CoV-2 infections and other diseases.

Exploring body weight-influencing gut microbiota by elucidating the association with diet and host gene expression

We aimed to identify gut microbiota that influences body weight by elucidating the association with diets and host genes. Germ-free (GF) mice with and without fecal microbiota transplant (FMT) were fed a normal, high-carbohydrate, or high-fat diet. FMT mice exhibited greater total body weight; adipose tissue and liver weights; blood glucose, insulin, and total cholesterol levels; and oil droplet size than the GF mice, regardless of diet. However, the extent of weight gain and metabolic parameter levels associated with gut microbiota depended on the nutrients ingested. For example, a disaccharide- or polysaccharide-rich diet caused more weight gain than a monosaccharide-rich diet. An unsaturated fatty acid-rich diet had a greater microbial insulin-increasing effect than a saturated fatty acid-rich diet. Perhaps the difference in microbial metabolites produced from substances taken up by the host created metabolic differences. Therefore, we analyzed such dietary influences on gut microbiota, differentially expressed genes between GF and FMT mice, and metabolic factors, including body weight. The results revealed a correlation between increased weight gain, a fat-rich diet, increased Ruminococcaceae abundance, and decreased claudin 22 gene expression. These findings suggest that weight regulation might be possible through the manipulation of the gut microbiota metabolism using the host's diet.

Effects of synbiotic supplementation on anthropometric indices and body composition in overweight or obese children and adolescents: a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Recently, beneficial effects of probiotics and/or prebiotics on cardio-metabolic risk factors in adults have been shown. However, existing evidence has not been fully established for pediatric age groups. This study aimed to assess the effect of synbiotic on anthropometric indices and body composition in overweight or obese children and adolescents.

METHODS

This randomized double-blind, placebo-controlled trial was conducted among 60 participants aged 8-18 years with a body mass index (BMI) equal to or higher than the 85th percentile. Participants were randomly divided into two groups that received either a synbiotic capsule containing 6 × 109 colony forming units (CFU) Lactobacillus coagulans SC-208, 6 × 109 CFU Lactobacillus indicus HU36 and fructooligosaccharide as a prebiotic (n = 30) or a placebo (n = 30) twice a day for eight weeks. Anthropometric indices and body composition were measured at baseline and after the intervention.

RESULTS

The mean (standard deviation, SD) age was 11.07 (2.00) years and 11.23 (2.37) years for the placebo and synbiotic groups, respectively (P = 0.770). The waist-height ratio (WHtR) decreased significantly at the end of the intervention in comparison with baseline in the synbiotic group (0.54 ± 0.05 vs. 0.55 ± 0.05, P = 0.05). No significant changes were demonstrated in other anthropometric indices or body composition between groups.

CONCLUSIONS

Synbiotic supplementation might be associated with a reduction in WHtR. There were no significant changes in other anthropometric indices or body composition.

Effects of Probiotics on Intermediate Cardiovascular Outcomes in Patients with Overweight or Obesity: A Systematic Review and Meta-Analysis

Background: Clinical trials evaluating the effect of probiotics on cardiovascular intermediate outcomes have been scarce in recent years. We systematically evaluated the efficacy of probiotics on intermediate cardiovascular outcomes in patients with overweight or obesity. Methods: We searched for randomized controlled trials (RCTs) in four databases (until August 2021) that evaluated the effects of probiotics versus controls on intermediate cardiovascular outcomes. The outcomes were body mass index (BMI), weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), glucose, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels. Inverse variance random effects meta-analyses were used. The effects were reported as mean difference (MD), with their 95% confidence intervals (95% CI). The quality of evidence (QoE) was assessed with GRADE (grading of recommendations, assessment, development and evaluations) methodology. Results: A total of 25 RCTs were included (n = 2170), with a range of follow-up from two to six months. Probiotics likely reduced BMI (MD −0.27 kg/m2, 95%CI: −0.35 to −0.19; 17 RCTs; I2 = 26%, QoE: moderate), as well as likely reduced weight (MD −0.61 kg, 95%CI: −0.89 to −0.34; 15 RCTs; I2 = 0%, QoE: moderate), and may have slightly reduce LDL (MD −4.08 mg/dL; 95%CI: −6.99 to −1.17; 9 RCTs; I2 = 87%, QoE: low) in comparison to the controls. However, probiotics had no effect on SBP (MD −0.40 mmHg; 95%CI: −5.04 to 4.25; 7 RCTs; I2 = 100%, QoE: very low), DBP (MD −1.73 mmHg; 95%CI: −5.29 to 1.82; 5 RCTs; I2 = 98%, QoE: very low), glucose (MD −0.07 mg/dL; 95%CI −0.89 to 0.75; I2 = 96%, QoE: very low), HDL (MD −1.83 mg/dL; 95%CI: −4.14 to 2.47; 14 RCTs; I2 = 98%, QoE: very low), or triglycerides (MD −3.29 mg/dL, 95%CI −17.03 to 10.45; 14 RCTs, I2 = 95%, QoE: very low) compared to control arms, and the evidence was very uncertain. Conclusions: In obese or overweight patients, BMI, weight, and LDL were lower in patients who received probiotics compared to those who received controls. Other lipids, glucose, and blood pressure were not affected by the probiotics.

Microbial changes from bariatric surgery alters glucose-dependent insulinotropic polypeptide and prevents fatty liver disease

Bariatric surgery remains a potent therapy for nonalcoholic fatty liver disease (NAFLD), but its inherent risk and eligibility requirement limit its adoption. Therefore, understanding how bariatric surgery improves NAFLD is paramount to developing novel therapeutics. Here, we show that the microbiome changes induced by sleeve gastrectomy (SG) reduce glucose-dependent insulinotropic polypeptide (GIP) signaling and confer resistance against diet-induced obesity (DIO) and NAFLD. We examined a cohort of NALFD patients undergoing SG and evaluated their microbiome, serum metabolites, and GI hormones. We observed significant changes in Bacteroides, lipid-related metabolites, and reduction in GIP. To examine if the changes in the microbiome were causally related to NAFLD, we performed fecal microbial transplants in antibiotic-treated mice from patients before and after their surgery who had significant weight loss and improvement of their NAFLD. Mice transplanted with the microbiome of patients after bariatric surgery were more resistant to DIO and NAFLD development compared to mice transplanted with the microbiome of patients before surgery. This resistance to DIO and NAFLD was also associated with a reduction in GIP levels in mice with post-bariatric microbiome. We further show that the reduction in GIP was related to higher levels of Akkermansia and differing levels of indolepropionate, bacteria-derived tryptophan-related metabolite. Overall, this is one of the few studies showing that GIP signaling is altered by the gut microbiome, and it supports that the positive effect of bariatric surgery on NAFLD is in part due to microbiome changes.

How is gut microbiome of patients with familial adenomatous polyposis different from healthy people?

The gut microbiome has been increasingly suggested as an underlying cause of various human diseases. In this study, we hypothesized that the gut microbiomes of patients with familial adenomatous polyposis (FAP) are different from those of healthy people and attempted to identify the associations between gut microbiome characteristics and FAP. We collected fecal samples from patients with FAP and healthy volunteers and evaluated the diversity, composition, and distribution of the gut microbiome between the 2 groups via 16S rRNA-based taxonomic profiling of the fecal samples. Fecal samples were collected from 10 patients with FAP (4 men and 6 women, mean age 39.2 ± 13.8 years) and 10 healthy volunteers (4 men and 6 women, mean age 40.9 ± 9.8 years). The microbial richness in patients with FAP was significantly lower than that in healthy people. Regarding microbial composition, the Firmicutes/Bacteroidetes ratio in patients with FAP was higher than that in healthy people, especially in those with a lower proportion of Bacteroidetes and a higher proportion of Proteobacteria. We also found 7 specific abundant strains in fecal samples of patients with FAP. Patients with FAP had different Firmicutes/Bacteroidetes ratios and Proteobacteria abundance compared to healthy people and showed the presence of specific bacteria. These findings suggest a promising role of the gut microbiome in patients with FAP, although further studies are needed.

Response of Intestinal Microbiota to the Variation in Diets in Grass Carp (Ctenopharyngodon idella)

The intestinal microbiota is important for the nutrient metabolism of fish and is significantly influenced by the host’s diet. The effect of ryegrass and commercial diets on the intestinal microbiota of grass carp was compared in this study. In comparison to ryegrass, artificial feed significantly reduced the microbial diversity in the intestine, which was measured by a decrease in the observed OTUs, ACE, Shannon, and the InvSimpson index. Although grass carp fed with ryegrass and artificial feed shared a dominant phyla Firmicutes and Proteobacteria, the microbial composition was clearly distinguishable between the two groups. In grass carp fed with ryegrass, Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria predominated, whereas Bacilli was significantly higher in the artificial feed group due to an increase in Weissella and an unassigned Bacillales bacteria, as well as a significant increase in a potential pathogen: Aeromonas australiensis. Grass carp fed with ryegrass exhibited a more complex ecological network performed by the intestinal bacterial community, which was dominated by cooperative interactions; this was also observed in grass carp fed with artificial feed. Despite this, the increase in A. australiensis increased the competitive interaction within this ecological network, which contributed to the vulnerable perturbation of the intestinal microbiota. The alteration of the microbial composition through diet can further affect microbial function. The intestinal microbial function in grass carp fed with ryegrass was rich in amino acids and exhibited an increased energy metabolism in order to compensate for a low-nutrient diet intake, while the artificial feed elevated the microbial lipid metabolism through the promotion of its synthesis in the primary and secondary bile acids, together with a notable enhancement of fatty acid biosynthesis. These results indicated that diet can affect the homeostasis of the intestinal microbiota by altering the microbial composition and the interspecific interactions, whilst microbial function can respond to a variation in diet.

Gut microbiota profiling in aged dogs after feeding pet food contained Hericium erinaceus

Health concern of dogs is the most important issue for pet owners. People who have companied the dogs long-term provide the utmost cares for their well-being and healthy life. Recently, it was revealed that the population and types of gut microbiota affect the metabolism and immunity of the host. However, there is little information on the gut microbiome of dogs. Hericium erinaceus (H. erinaceus; HE) is one of the well-known medicinal mushrooms and has multiple bioactive components including polyphenol, β-glucan, polysaccharides, ergothioneine, hericerin, erinacines, etc. Here we tested a pet food that contained H. erinaceus for improvement in the gut microbiota environment of aged dogs. A total of 18 dogs, each 11 years old, were utilized. For sixteen weeks, the dogs were fed with 0.4 g of H. erinaceus (HE-L), or 0.8 g (HE-H), or without H. erinaceus (CON) per body weight (kg) with daily diets (n = 6 per group). Taxonomic analysis was performed using metagenomics to investigate the difference in the gut microbiome. Resulting from principal coordinates analysis (PCoA) to confirm the distance difference between the groups, there was a significant difference between HE-H and CON due to weighted Unique fraction metric (Unifrac) distance (p = 0.047), but HE-L did not have a statistical difference compared to that of CON. Additionally, the result of Linear discriminate analysis of effect size (LEfSe) showed that phylum Bacteroidetes in HE-H and its order Bacteroidales increased, compared to that of CON, Additionally, phylum Firmicutes in HE-H, and its genera (Streptococcus, Tyzzerella) were reduced. Furthermore, at the family level, Campylobacteraceae and its genus Campylobacter in HE-H was decreased compared to that of CON. Summarily, our data demonstrated that the intake of H. erinaceus can regulate the gut microbial community in aged dogs, and an adequate supply of HE on pet diets would possibly improve immunity and anti-obesity on gut-microbiota in dogs.

Probiotic Mechanisms Affecting Glucose Homeostasis: A Scoping Review

The maintenance of a healthy status depends on the coexistence between the host organism and the microbiota. Early studies have already focused on the nutritional properties of probiotics, which may also contribute to the structural changes in the gut microbiota, thereby affecting host metabolism and homeostasis. Maintaining homeostasis in the body is therefore crucial and is reflected at all levels, including that of glucose, a simple sugar molecule that is an essential fuel for normal cellular function. Despite numerous clinical studies that have shown the effect of various probiotics on glucose and its homeostasis, knowledge about the exact function of their mechanism is still scarce. The aim of our review was to select in vivo and in vitro studies in English published in the last eleven years dealing with the effects of probiotics on glucose metabolism and its homeostasis. In this context, diverse probiotic effects at different organ levels were highlighted, summarizing their potential mechanisms to influence glucose metabolism and its homeostasis. Variations in results due to different methodological approaches were discussed, as well as limitations, especially in in vivo studies. Further studies on the interactions between probiotics, host microorganisms and their immunity are needed.

Gut microbiota: Role and Association with Tumorigenesis in Different Malignancies

The microbiota has been associated with different cancer and may vary from patient to patient. A specific microbial strain can alter the progression of cancer and therapeutic outcome in response to anti-cancer therapy. The variations in microbiota contributed due to the individual microbiome of the microorganism are responsible for diverse clinical outcomes. The expansion of microbiota subpopulation during dysbiosis can lead to toxin production, inducing inflammation and cancer. The microbiota can be a dual-edged sword because it can be tumor-suppressive or oncogenic in the case of the gut. The transition of cancer cells from early to late-stage also impacts the composition of the microbiota, and this alteration could change the behavior of cancer. Multi-omics platforms derived data from an individual's multi-dimensional data (DNA, mRNA, microRNA, protein, metabolite, microbiota, and microbiome), i.e., individualome, to exploit it for personalized tailored treatment for different cancers in a precise manner. A number of studies suggest the importance of microbiota and its add-in suitability to existing treatment options for different malignancies. Furthermore, in vitro, and in vivo studies and cancer clinical trials suggest that probiotics have driven modulation of gut microbiota and other sites discourage the aggressive behavior and progression of different cancers.

Fecal Microbiota Transplantation During Lactation Programs the Metabolism of Adult Wistar Rats in a Sex-specific Way

BACKGROUND

The intestinal microbiota is involved in many physiological processes. However, the effects of microbiota in metabolic programming still unknow. We evaluated whether the transplantation of fecal microbiota during early life can program health or disease during adulthood in a model of lean and obese male and female Wistar rats.

METHODS

Parental obesity were induced using a small litter (SL, 3 pups/dam) model. At 90 d old, normal litter (NL, 9 pups/dam) and SL males and females (parents) from different litters were mated: NL male vs. NL female; SL male vs. SL female. After birth, male and female offspring rats were also standardized in normal litters or small litters . From the 10^th until 25^th d of life, the NL and SL male and female offspring received via gavage of a solution containing the diluted feces of the opposite dam (fecal microbiota, M) or saline solution (S). At 90 d of age, biometric and biochemical parameters were assessed.

RESULTS

NLM male rats transplanted with obese microbiota showed increased body weight, and fat pad deposition, hyperinsulinemia, glucose intolerance and dyslipidemia. SLM male rats transplanted with lean microbiota had decreased retroperitoneal and mesenteric fat, triglycerides and VLDL levels and improvement of glucose tolerance. Despite SLM female rats showed higher visceral fat, microbiota transplantation in female rats caused no changes in these parameters compared with control groups.

CONCLUSION

Fecal microbiota transplantation during lactation induces long-term effects on the metabolism of male Wistar rats. However, female rats were resistant to metabolic alterations caused by the treatment.

Bacteriocin-Producing Probiotic Lactic Acid Bacteria in Controlling Dysbiosis of the Gut Microbiota

Several strains of lactic acid bacteria are potent probiotics and can cure a variety of diseases using different modes of actions. These bacteria produce antimicrobial peptides, bacteriocins, which inhibit or kill generally closely related bacterial strains and other pathogenic bacteria such as Listeria, Clostridium, and Salmonella. Bacteriocins are cationic peptides that kill the target cells by pore formation and the dissipation of cytosolic contents, leading to cell death. Bacteriocins are also known to modulate native microbiota and host immunity, affecting several health-promoting functions of the host. In this review, we have discussed the ability of bacteriocin-producing probiotic lactic acid bacteria in the modulation of gut microbiota correcting dysbiosis and treatment/maintenance of a few important human disorders such as chronic infections, inflammatory bowel diseases, obesity, and cancer.

Oligosaccharides derived from Lycium barbarum ameliorate glycolipid metabolism and modulate the gut microbiota community and the faecal metabolites in a type 2 diabetes mouse model: metabolomic bioinformatic analysis

Herein, we assessed the effects of Lycium barbarum oligosaccharides (LBO) on the intestinal microenvironment of a type 2 diabetes (T2D) mouse model through gut microbiome and metabolomics analysis. We set high (300 mg kg^-1), medium (200 mg kg^-1), and low (100 mg kg^-1) doses of LBO for intervention once a day for 4 weeks. The results showed that the intervention effect of the medium-dose group was the most significant. It reduced the symptoms of hyperglycemia, inflammation, insulin resistance, and lipid accumulation in the T2D mouse model. It restored the structure of damaged tissues and cells, such as the pancreas, liver, and kidneys. LBO increased the relative abundance of beneficial bacteria, such as Lactobacillus, Bacteroides, Prevotella, and Akkermansia, and maintained intestinal barrier integrity. The faecal metabolic map showed that the contents of glycogen amino acids, such as proline, serine, and leucine, increased. The contents of cholic, capric, and dodecanoic acid decreased. In summary, we may suggest that LBO can be used as a prebiotic for treating T2D.

Effects of early-life cecal microbiota transplantation from divergently selected inbred chicken lines on growth, gut serotonin, and immune parameters in recipient chickens

Recent studies have revealed that fecal microbiota transplantation exerts beneficial effects on modulating stress-related inflammation and gastrointestinal health of the host. The aim of this study was to examine if cecal microbiota transplantation (CMT) presents similar efficiency in improving the health status of egg-laying strain chickens. Chicken lines 6₃ and 7₂ divergently selected for resistance or susceptibility to Marek's disease were used as CMT donors. Eighty-four d-old male recipient chicks (a commercial DeKalb XL layer strain) were randomly assigned into 3 treatments with 7 replicates per treatment and 4 birds per replicate (n = 7): saline (control, CTRL), cecal solution of line 6₃ (6₃-CMT), and cecal solution of line 7₂ (7₂-CMT) for a 16-wk trial. Cecal transplant gavage was conducted once daily from d 1 to d 10, then boosted once weekly from wk 3 to wk 5. The results indicated that 7₂-CMT birds had the highest body weight and ileal villus/crypt ratio among the treatments at wk 5 (P ≤ 0.05); and higher heterophil/lymphocyte ratios than that of 6₃-CMT birds at wk 16 (P < 0.05). 7₂-CMT birds also had higher levels of plasma natural IgG and Interleukin (IL)-6 at wk 16, while 6₃-CMT birds had higher concentrations of ileal mucosal secretory IgA at wk 5 and plasma IL-10 at wk 16 (P < 0.05), with a tendency for lower mRNA abundance of splenic IL-6 and tumor necrosis factor (TNF)-α at wk 16 (P = 0.08 and 0.07, respectively). In addition, 7₂-CMT birds tended to have the lowest serotonin concentrations (P = 0.07) with the highest serotonin turnover in the ileum at wk 5 (P < 0.05). There were no treatment effects on the levels of plasma corticosterone and testosterone at wk 16 (P > 0.05). In conclusion, early postnatal CMT from different donors led to different patterns of growth and health status through the regulation of ileal morphological structures, gut-derived serotonergic activities, peripheral cytokines, and antibody production in recipient chickens.

The anti-obesity and gut microbiota modulating effects of taxifolin in C57BL/6J mice fed with a high-fat diet

BACKGROUND

Taxifolin is a natural dihydroflavonol found in many plants and health products. In the present study, its anti-obesity and gut microbiota modulating effects were studied. C57BL/6J mice were fed with a high-fat diet (HFD) supplemented with taxifolin (0, 0.5 and 1 mg mL-1 , respectively) in drinking water for 15 weeks.

RESULTS

Taxifolin supplementation showed no influence on food and water intake. However, it decreased body weight gain, inhibited fat accumulation, and decreased total cholesterol and triacylglycerol level in mice liver. Taxifolin enhanced superoxide dismutase (SOD) activity in mice liver, which in turn protected the liver from lipid peroxidation damage. It also improved insulin resistance in obese mice. Metagenomic analysis of bacterial 16S rRNA demonstrated that HFD decreased gut microbiota diversity and caused dysbiosis. However, taxifolin improved the gut microbiota diversity and decreased the Firmicutes/Bacteroidetes ratio. In particular, it inhibited Proteobacteria from blooming, this being a signature of dysbiosis in gut microbiota.

CONCLUSION

Taxifolin ameliorated the symptoms of obesity, hepatic steatosis, lipid peroxidation, insulin resistance, and gut microbiota dysbiosis in HFD fed C57BL/6J mice. © 2021 Society of Chemical Industry.

Lactobacillus acidophilus LA85 ameliorates cyclophosphamide-induced immunosuppression by modulating Notch and TLR4/NF-κB signal pathways and remodeling the gut microbiota

With the prevalence of coronavirus disease 2019 (COVID-19), we found that probiotics may be effective in organism immune recovery and remodeling of gut microbiota in their patients and recovered individuals....

Dietary Proteins Alter Fermentation Characteristics of Human Gut Microbiota In Vitro

The objective of this study was to evaluate the fermentation characteristics of proteins from diverse sources by human gut microbiota. Cereal proteins (rice and oat), red meat proteins (pork and beef), chicken protein and casein were selected as the substrates for simulated gastrointestinal digestion (SGID), and human faecal samples were collected from healthy donors as the inoculum of fermentation. In this study, we further analyzed the correlations of amino acids (AA) compositions, fermentation productions and gut microbiota. As the results, the animal protein groups had higher degree of hydrolysis (DH) after digestion and higher levels of ammonia nitrogen (NH₃-N) after fermentation than cereal proteins. The pH value of fermentation liquid declined as proteins were added during fermentation. Cereal protein groups promoted the gut microbiota to produce more short chain fatty acids (SCFAs) with the high proportion of acetate, propionate and butyrate by lowering the pH than red meat proteins. The abundance of Firmicutes at phylum level in cereal protein groups was lower than red meat proteins after fermentation. The cereal protein groups enhanced the growth of Bacteroides spp. and Bifidobacterium spp. while red meat proteins stimulated the growth of Peptoclostridium spp.. Taken together, our research implies that cereal proteins have better fermentation characters than red meat proteins.

Differential Effect of Light and Dark Period Sleep Fragmentation on Composition of Gut Microbiome and Inflammation in Mice

Bi-directional interactions amongst the gut microbiota, immune system, and brain function are thought to be critical mediators of health and disease. The role sleep plays in mediating these interactions is not known. We assessed the effects of sleep fragmentation (SF) on the microbiota–gut–brain axis. Male C57BL/6NCrl mice (4 to 5 per cage, fed standard lab chow) experienced SF via mechanical stimulation at 2 min intervals during the light (SF) and dark (DD, dark disturbances) periods. Home cage (HC) controls were undisturbed. After 10 days, fecal samples were collected at light onset, midday, light offset, and midnight. Samples were also collected after 10 days without SF. Subsequently, the mice were randomized across groups and allowed 20 additional days of recovery followed by 10 days of SF or DD. To assess effects on the microbiota, 16S rRNA sequencing was used, and mesenteric lymph nodes (MLNs) and cortex and medial prefrontal cortex were analyzed using cytokine arrays. SF and DD produced significant alterations in the microbiota compared to HC, and DD had greater impact than SF on some organisms. SF produced marked suppression in MLNs of chemokines that regulate inflammation (CCL3, CCL4 and their receptor CCR5) and maintain the immune mucosal barrier (Cxcl13) at the same time that cortical cytokines (IL-33) indicated neuroinflammation. DD effects on immune responses were similar to HC. These data suggest that SF alters the microbiome and suppresses mucosal immunity at the same time that mediators of brain inflammation are upregulated. The translational implications for potential application to clinical care are compelling.

The intestinal 3M (microbiota, metabolism, metabolome) zeitgeist - from fundamentals to future challenges

The role of the intestine in human health and disease has historically been neglected and was mostly attributed to digestive and absorptive functions. In the past two decades, however, discoveries related to human nutrition and intestinal host-microbe reciprocal interaction have established the essential role of intestinal health in the pathogenesis of chronic diseases and the overall wellbeing. That transfer of gut microbiota could be a means of disease phenotype transfer has revolutionized our understanding of chronic disease pathogenesis. This narrative review highlights the major concepts related to intestinal microbiota, metabolism, and metabolome (3M) that have facilitated our fundamental understanding of the association between the intestine, and human health and disease. In line with increased interest of microbiota-dependent modulation of human health by dietary phytochemicals, we have also discussed the emerging concepts beyond the phytochemical bioactivities which emphasizes the integral role of microbial metabolites of parent phytochemicals at extraintestinal tissues. Finally, this review concludes with challenges and future prospects in defining the 3M interactions and has emphasized the fact that, it takes 'guts' to stay healthy.

Clinical and Epidemiological Changes in French Soldiers After Deployment: Impact of Doxycycline Malaria Prophylaxis on Body Weight

BACKGROUND

Antibiotics are growth promotors used in animal farming. Doxycycline (DOXY) is a tetracycline antibiotic taken daily and continued 1 month after return to protect against malaria during travel and deployment in endemic areas. We evaluated DOXY impact on body weight in military international travelers.

MATERIEL AND METHODS

A prospective cohort analysis was conducted in 2016-2018, recruiting 170 French soldiers before a 4-month assignment overseas. Many clinical data including anthropometric measures by an investigator were collected before and after deployment. Weight gain was defined by an increase of 2% from baseline. The study protocol was supported by the French Armed Forces Health Services and approved by the French ethics committee (IRB no. 2015-A01961-48, ref promoter 2015RC0). Written, informed consent was obtained with signature from each volunteer before inclusion.

RESULTS

After deployment, 84 soldiers were followed up. Overall, 38/84 (45%) were deployed to Mali with DOXY malaria prophylaxis, and others were deployed to Iraq or Lebanon without malaria prophylaxis according to international recommendations. Body weight increased in 24/84 (30%), of whom 14/24 (58%) were exposed to DOXY. In bivariate analysis, DOXY had a positive but not significant effect on weight gain (P-value = .4). In the final logistic regression model (Fig. 3), weight gain after deployment positively correlated with an increase in waist circumference (odds ratio [OR] 1.23 with 95% CI [1.06-1.47]) suggesting fat gain; with sedentary work (OR 5.34; 95% CI [1.07-31.90]); and with probiotic intake (OR 5.27; 95% CI [1.51-20.40]). Weight impact of probiotics was more important when associated with DOXY intake (OR 6.86; 95% CI [1.52-38.1]; P-value = .016).

CONCLUSIONS

Doxycycline (DOXY) malaria prophylaxis during several months did not cause significant weight gain in soldiers. Further studies are required in older and less sportive traveling populations, and to investigate a cumulative effect over time and recurrent DOXY exposure. Doxycycline (DOXY) may enhance other growth-promoting factors including fatty food, sedentariness, and strain-specific probiotics contained in fermented dairy products which are also used as growth promotors.

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.

The Intestinal Microbiome Predicts Weight Loss on a Calorie-Restricted Diet and Is Associated With Improved Hepatic Steatosis

Background: The microbiome has been shown in pre-clinical and epidemiological studies to be important in both the development and treatment of obesity and metabolic associated fatty liver disease (MAFLD). However, few studies have examined the role of the microbiome in the clinical response to calorie restriction. To explore this area, we performed a prospective study examining the association of the intestinal microbiome with weight loss and change in hepatic steatosis on a calorie-restricted diet. Methods: A prospective dietary intervention study of 80 overweight and obese participants was performed at the Greater West Los Angeles Veterans Affair Hospital. Patients were placed on a macronutrient standardized diet for 16 weeks, including 14 weeks of calorie restriction (500 calorie deficit). Body composition analysis by impedance, plasma lipid measurements, and ultrasound elastography to measure hepatic steatosis were performed at baseline and week 16. Intestinal microbiome composition was assessed using 16S rRNA gene sequencing. A per protocol analysis was performed on all subjects completing the trial (n = 46). Results: Study completers showed significant reduction in weight, body mass index, total cholesterol, low density lipoprotein, and triglyceride. Subjects who lost at least 5% of their body weight had significantly greater reduction in serum triglyceride and hepatic steatosis than those with <5% body weight loss. Enterococcus and Klebsiella were reduced at the end of the trial while Coprococcus and Collinsella were increased. There were also significant baseline microbiome differences between patients who had at least 5% weight loss as compared to those that did not. Lachnoclostridium was positively associated with hepatic steatosis and Actinomyces was positively associated with hepatic steatosis and weight. Baseline microbiome profiles were able to predict which patients lost at least 5% of their body weight with an AUROC of 0.80. Conclusion: Calorie restriction alters the intestinal microbiome and improves hepatic steatosis in those who experience significant weight loss. Baseline microbiome differences predict weight loss on a calorie-restricted diet and are associated with improvement in hepatic steatosis, suggesting a role of the gut microbiome in mediating the clinical response to calorie restriction.

Effect of gut microbiome on minor complications after a colonoscopy

BACKGROUND/AIMS

Minor complications that might occur after colonoscopy, including abdominal discomfort, bloating, diarrhea, and constipation, could a barrier for patients to undergo a screening colonoscopy. In this study, we aimed to identify the effect of gut microbial diversity and composition on minor complications after colonoscopy.

METHODS

A total of 24 healthy subjects provided their stools before bowel preparation and on the 7th and 28th day after colonoscopy. On the 7th day after colonoscopy, the presence of minor complications was investigated using a questionnaire. We divided patients into 2 groups, the no complication group and complications group. The fecal microbial diversity, distribution, and composition were then compared between the groups.

RESULTS

Five of the 24 subjects reported that they had undergone minor complications after colonoscopy. Most of the symptoms were mild and self-limited, but 1 patient needed medication. Interestingly, the Firmicutes/Bacteroidetes ratio of the initial stool samples before bowel preparation in the complication group was significantly higher than that in no complication group. After bowel preparation, the Firmicutes/Bacteroidetes ratio of the complication group decreased, but not in the no complication group. The microbial diversity of the no complication group decreased after bowel preparation, but not in the complication group.

CONCLUSIONS

The gut microbial composition and diversity before and after bowel preparation could be considered as one of the causes of minor complications after colonoscopy. Further studies are needed to delineate the role of gut microbiota in the occurrence of minor complications after colonoscopy.

Gut Microbiota Prevents Sugar Alcohol-Induced Diarrhea

While poorly-absorbed sugar alcohols such as sorbitol are widely used as sweeteners, they may induce diarrhea in some individuals. However, the factors which determine an individual’s susceptibility to sugar alcohol-induced diarrhea remain unknown. Here, we show that specific gut bacteria are involved in the suppression of sorbitol-induced diarrhea. Based on 16S rDNA analysis, the abundance of Enterobacteriaceae bacteria increased in response to sorbitol consumption. We found that Escherichia coli of the family Enterobacteriaceae degraded sorbitol and suppressed sorbitol-induced diarrhea. Finally, we showed that the metabolism of sorbitol by the E. coli sugar phosphotransferase system helped suppress sorbitol-induced diarrhea. Therefore, gut microbiota prevented sugar alcohol-induced diarrhea by degrading sorbitol in the gut. The identification of the gut bacteria which respond to and degrade sugar alcohols in the intestine has implications for microbiome science, processed food science, and public health.

The interaction between tea polyphenols and host intestinal microorganisms: an effective way to prevent psychiatric disorders

Tea polyphenols (TP) are the most bioactive components in tea extracts. It has been reported that TP can regulate the composition and the function of the intestinal flora. Meanwhile, intestinal microorganisms improve the bioavailability of TP, and the corresponding metabolites of TP can regulate intestinal micro-ecology and promote human health more effectively. The dysfunction of the microbiota-gut-brain axis is the main pathological basis of depression, and its abnormality may be the direct cause and potential influencing factor of psychiatric disorders. The interrelationship between TP and intestinal microorganisms is discussed in this review, which will enable us to better evaluate the potential preventive effects of TP on psychiatric disorders by modulating host intestinal microorganisms.

The Influence of Gut Microbiota on the Cardiovascular System Under Conditions of Obesity and Chronic Stress

PURPOSE OF REVIEW

Based on the available data, it can be assumed that microbiota is an integral part of the human body. The most heavily colonized area of the human body is the gut, with bacterial accumulation ranging from 101-103 cells/g in the upper intestine to 1011-1012 cells/g in the colon. However, colonization of the gut is not the same throughout, as it was shown that there are differences between the composition of the microbiota in the intestine lumen and in the proximity of the mucus layer.

RECENT FINDINGS

Gut microbiota gradient can be differentially regulated by factors such as obesity and chronic stress. In particular, a high fat diet influences the gut microbial composition. It was also found that chronic stress may cause the development of obesity and thus change the organization of the intestinal barrier. Recent research has shown the significant effect of intestinal microflora on cardiovascular function. Enhanced absorption of bacterial fragments, such as lipopolysaccharide (LPS), promotes the onset of "metabolic endotoxemia," which could activate toll-like receptors, which mediates an inflammatory response and in severe cases could cause cardiovascular diseases. It is presumed that the intestinal microbiota, and especially its metabolites (LPS and trimethylamine N-oxide (TMAO)), may play an important role in the pathogenesis of arterial hypertension, atherosclerosis, and heart failure. This review focuses on how gut microbiota can change the morphological and functional activity of the cardiovascular system in the course of obesity and in conditions of chronic stress.

Health beneficial effects of resistant starch on diabetes and obesity via regulation of gut microbiota: a review

Resistant starch (RS) is well known to prevent type 2 diabetes mellitus (T2DM) and obesity. Recently, attention has been paid to gut microbiota which mediates the RS's impact on T2DM and obesity, while a mechanistic understanding of how RS prevents T2DM and obesity through gut microbiota is not clear yet. Therefore, this review aims at exploring the underlying mechanisms of it. RS prevents T2DM and obesity through gut microbiota by modifying selective microbial composition to produce starch-degrading enzymes, promoting the production of intestinal metabolites, and improving gut barrier function. Therefore, RS possessing good functional features can be used to increase the fiber content of healthier food. Furthermore, achieving highly selective effects on gut microbiota based on the slight differences of RS's chemical structure and focusing on the effects of RS on strain-levels are essential to manipulate the microbiota for human health.

Diet, adiposity, and the gut microbiota from infancy to adolescence: A systematic review

Early life gut microbiota are affected by several factors that make identification of microbial-adiposity relationships challenging. This review evaluates studies that have investigated the gut microbiota composition associated with adiposity in infants, children, and adolescents and provides evidence-based nutrition recommendations that address microbiota-adiposity links. Electronic databases were systematically searched through January 2020. Eligible studies were published in English and analyzed gut microbiota and adiposity among individuals aged birth to 18 years. Abstracts and full-text articles were reviewed by three independent reviewers. Of 45 full-text articles reviewed, 33 were included. No difference in abundance was found for Bacteroidetes (n = 7/15 articles), Firmicutes (n = 10/17), Actinobacteria (n = 8/12), Proteobacteria (n = 8/12), Tenericutes (n = 4/5), and Verrucomicrobia (n = 4/6) with adiposity. Lower abundance of Christensenellaceae (n = 3/5) and Rikenellaceae (n = 6/8) but higher abundance of F. prausnitzii (n = 3/5) and Prevotella (n = 5/7) were associated with adiposity. A lack of consensus exists for gut microbial composition associations with adiposity. A healthy gut microbiota is associated with a diet rich in fruits and vegetables with moderate consumption of animal fat and protein. Future research should use more robust sequencing technologies to identify all bacterial taxa associated with adiposity and evaluate how diet effects these adiposity-associated microbes.

Iron Reshapes the Gut Microbiome and Host Metabolism

Compelling studies have established that the gut microbiome is a modifier of metabolic health. Changes in the composition of the gut microbiome are influenced by genetics and the environment, including diet. Iron is a potential node of crosstalk between the host-microbe relationship and metabolic disease. Although iron is well characterized as a frequent traveling companion of metabolic disease, the role of iron is underappreciated because the mechanisms of iron's influence on host metabolism are poorly characterized. Both iron deficiency and excessive amounts leading to iron overload can have detrimental effects on cardiometabolic health. Optimal iron homeostasis is critical for regulation of host immunity and metabolism in addition to regulation of commensal and pathogenic enteric bacteria. In this article we review evidence to support the notion that altering composition of the gut microbiome may be an important route via which iron impacts cardiometabolic health. We discuss reshaping of the microbiome by iron, the physiological significance and the potential for therapeutic interventions.

Anti-Inflammatory and Immunomodulatory Properties of Fermented Plant Foods

Fermented plant foods are gaining wide interest worldwide as healthy foods due to their unique sensory features and their health-promoting potentials, such as antiobesity, antidiabetic, antihypertensive, and anticarcinogenic activities. Many fermented foods are a rich source of nutrients, phytochemicals, bioactive compounds, and probiotic microbes. The excellent biological activities of these functional foods, such as anti-inflammatory and immunomodulatory functions, are widely attributable to their high antioxidant content and lactic acid-producing bacteria (LAB). LAB contribute to the maintenance of a healthy gut microbiota composition and improvement of local and systemic immunity. Besides, antioxidant compounds are involved in several functional properties of fermented plant products by neutralizing free radicals, regulating antioxidant enzyme activities, reducing oxidative stress, ameliorating inflammatory responses, and enhancing immune system performance. Therefore, these products may protect against chronic inflammatory diseases, which are known as the leading cause of mortality worldwide. Given that a large body of evidence supports the role of fermented plant foods in health promotion and disease prevention, we aim to discuss the potential anti-inflammatory and immunomodulatory properties of selected fermented plant foods, including berries, cabbage, and soybean products, and their effects on gut microbiota.

Gardenia Jasminoides Ameliorates Antibiotic-Associated Aggravation of DNCB-Induced Atopic Dermatitis by Restoring the Intestinal Microbiome Profile

The intestinal microbiome is considered one of the key regulators of health. Accordingly, the severity of atopic dermatitis (AD) is mediated by the skin and intestinal microbiome environment. In this study, while evaluating the aggravation in AD symptoms by the antibiotics cocktail (ABX)-induced depletion of the intestinal microbiome, we sought to verify the effect of Gardenia jasminoides (GJ), a medicinal herb used for inflammatory diseases, on AD regarding its role on the intestinal microbiome. To verify the aggravation in AD symptoms induced by the depletion of the intestinal microbiome, we established a novel mouse model by administrating an ABX to create a microbiome-free environment in the intestine, and then applied 2,4-dinitrochlorobenzene (DNCB) to induce an AD-like skin inflammatory response. While ABX treatment aggravated AD-like symptoms, the 2-week administration of GJ improved these pathological changes. DNCB application upregulated immune cell count and serum cytokine expression, which were alleviated by GJ. Moreover, pathological alterations by antibiotics and DNCB, including histological damage of the intestine and the intestinal expression of IL-17, were recovered in GJ-treated mice. The beneficial effect of GJ was due to the restoration of the intestinal microbiome composition. Overall, we suggest GJ as a potential therapeutic agent for AD due to its regulation of the intestinal microbiome.

Chronic oral exposure to pesticides and their consequences on metabolic regulation: role of the microbiota

Pesticides have long been used in agriculture and household treatments. Pesticide residues can be found in biological samples for both the agriculture workers through direct exposure but also to the general population by indirect exposure. There is also evidence of pesticide contamination in utero and trans-generational impacts. Whilst acute exposure to pesticides has long been associated with endocrine perturbations, chronic exposure with low doses also increases the prevalence of metabolic disorders such as obesity or type 2 diabetes. Dysmetabolism is a low-grade inflammation disorder and as such the microbiota plays a role in its etiology. It is therefore important to fully understand the role of microbiota on the genesis of subsequent health effects. The digestive tract and mostly microbiota are the first organs of contact after oral exposure. The objective of this review is thus to better understand mechanisms that link pesticide exposure, dysmetabolism and microbiota. One of the key outcomes on the microbiota is the reduced Bacteroidetes and increased Firmicutes phyla, reflecting both pesticide exposure and risk factors of dysmetabolism. Other bacterial genders and metabolic activities are also involved. As for most pathologies impacting microbiota (including inflammatory disorders), the role of prebiotics can be suggested as a prevention strategy and some preliminary evidence reinforces this axis.

Research progress on the potential delaying skin aging effect and mechanism of tea for oral and external use

Skin aging is characterized by the gradual loss of elasticity, the formation of wrinkles and various color spots, the degradation of extracellular matrix proteins, and the structural changes of the dermis. With the increasingly prominent problems of environmental pollution, social pressure, ozone layer thinning and food safety, skin problems have become more and more complex. The skin can reflect the overall health of the body. Skincare products for external use alone cannot fundamentally solve skin problems; it needs to improve the overall health of the body. Based on the literature review in recent 20 years, this paper systematically reviewed the potential delaying effect of tea and its active ingredients on skin aging by oral and external use. Tea is the second-largest health drink after water. It is rich in tea polyphenols, l-theanine, tea pigments, caffeine, tea saponins, tea polysaccharides and other secondary metabolites. Tea and its active substances have whitening, nourishing, anti-wrinkle, removing spots and other skincare effects. Its mechanism of action is ultraviolet absorption, antioxidant, anti-inflammatory, inhibition of extracellular matrix aging, inhibiting the accumulation of melanin and toxic oxidation products, balancing intestinal and skin microorganisms, and improving mood and sleep, among other effects. At present, tea elements skincare products are deeply loved by consumers. This paper provides a scientific theoretical basis for tea-assisted beauty and the high-end application of tea in skincare products.

Comparative Analysis of Gut Microbiota in Captive and Wild Oriental White Storks: Implications for Conservation Biology

The oriental white stork (Ciconia boyciana) is considered an endangered species based on the International Union for Conservation of Nature (IUCN) Red List. This study presents the first evidence on comparative analysis of gut microbial diversity of C. boyciana from various breeding conditions. To determine the species composition and community structure of the gut microbiota, 24 fecal samples from Tianjin Zoo and Tianjin Qilihai Wetland were characterized by sequencing 16S rRNA gene amplicons using the Illumina MiSeq platform. Firmicutes was found to be the predominant phylum. Analysis of community structure revealed significant differences in the species diversity and richness between the populations of the two breeding conditions. The greatest α-diversity was found in wild C. boyciana, while artificial breeding storks from Tianjin Zoo had the least α-diversity. Principal coordinates analysis showed that the microbial communities were different between the two studied groups. In conclusion, this study reveals the species composition and structure of the gut microbiota of oriental white storks under two breeding conditions, and our findings could contribute to the integrative conservation of this endangered bird.

A Pilot Study for Metabolic Profiling of Obesity-Associated Microbial Gut Dysbiosis in Male Wistar Rats

Obesity is one of the most incident and concerning disease worldwide. Definite strategies to prevent obesity and related complications remain elusive. Among the risk factors of the onset of obesity, gut microbiota might play an important role in the pathogenesis of the disease, and it has received extensive attention because it affects the host metabolism. In this study, we aimed to define a metabolic profile of the segregated obesity-associated gut dysbiosis risk factor. The study of the metabolome, in an obesity-associated gut dysbiosis model, provides a relevant way for the discrimination on the different biomarkers in the obesity onset. Thus, we developed a model of this obesity risk factors through the transference of gut microbiota from obese to non-obese male Wistar rats and performed a subsequent metabolic analysis in the receptor rats. Our results showed alterations in the lipid metabolism in plasma and in the phenylalanine metabolism in urine. In consequence, we have identified metabolic changes characterized by: (1) an increase in DG:34:2 in plasma, a decrease in hippurate, (2) an increase in 3-HPPA, and (3) an increase in o-coumaric acid. Hereby, we propose these metabolites as a metabolic profile associated to a segregated dysbiosis state related to obesity disease.