Akkermansia muciniphila is a promising probiotic

Panax notoginseng saponins prevent colitis-associated colorectal cancer development: the role of gut microbiota

Gut microbiota dysbiosis is a risk factor for colorectal cancer (CRC) in inflammatory bowel disease (IBD). In this study, the effects of Panax notoginseng saponins (PNS) on colitis-associated CRC progression were evaluated on an azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model. In vivo, PNS significantly relieved AOM/DSS-induced colon tumorigenesis and development by reducing the disease activity index (DAI) scores and colon tumor load. The 16S rRNA data of fecal samples showed that the microbiome community was obviously destructed, while PNS could recover the richness and diversity of gut microbiota. Especially, PNS could increase the abundance of Akkermansia spp. which was significantly decreased in model group and negatively correlated with the progression of CRC. Moreover, ginsenoside compound K (GC-K) was evaluated on the effects of human CRC cells, which was the main bio-transformed metabolite of PNS by gut microbiota. Our data showed that PNS played important role in the prevention of the progression of CRC, due to their regulation on the microbiome balance and microbial bio-converted product with anti-CRC activity.

Tea polyphenols regulate gut microbiota dysbiosis induced by antibiotic in mice

Tea polyphenols (TPs) are now widely used in foods for various biological activities. However, they are rarely used in foods to regulate gut microbiota dysbiosis induced by antibiotics. We assessed the regulation of TPs on gut microbiota with an antibiotic-induced intestinal flora disorder mouse model. The mice were orally administered with cefixime for 8 days, then received TPs for 28 days. We found that the antibiotic had a profound impact on the gut microbiota. Compared with the normal group, significant decreases in the species richness and diversity and the production of short-chain fatty acids (SCFAs) were still observed 28 days after the antibiotic treatment, although there was no significant difference in the colonic mucosa. TPs significantly alleviated the decrease of the richness and diversity of gut microbiota caused by the antibiotic treatment, and significantly increased the relative abundance of beneficial microbes such as Lactobacillus, Akkermansia, Blautia, Roseburia, and Eubacterium. The function prediction showed that TPs significantly decreased the relative abundance of genes related to human diseases, yet significantly increased the relative abundance of genes related to cell growth and death, cell motility, and energy metabolism. These showed that TPs could regulate the gut microbiota dysbiosis induced by antibiotics, thus decreasing the risk of diseases such as obesity, cancer, and diabetes. These suggest that TPs have a great potential to be used as a functional food ingredient to prevent or reduce adverse effects of antibiotics.

A review of the impact of xenobiotics from dietary sources on infant health: Early life exposures and the role of the microbiota

Xenobiotics are worldwide distributed and humans are unavoidably exposed to multiple chemical compounds during life, from preconception to adulthood. The human microbiota is mainly settled during early life and modulate host health and fitness. One of the main routes for chemical exposure is by intake of contaminated food and water. Thus, the interplay between diet-xenobiotics-microbiota during pregnancy and perinatal period may have relevant consequences for infant and adult health. Maternal exposure to metal(oid)s, persistent organic pollutants, and some food additives can modify the infant's microbiota with unknown consequences for child or adult health. Toxicants' exposure may also modulate the maternal transfer of microorganisms to the progeny during birth and breastfeeding; however, scarce information is available. The rapid increase in releasing novel chemicals to the environment, the exposure to chemical mixtures, the chronic/low dose scenario, and the delay in science-stakeholders action call for novel and groundbreaking approaches to improve a comprehensive risk assessment in sensitive population groups like pregnant women and neonates, with emphasis on microbiota as modulating factor and target-organ of xenobiotic's toxicity.

Effect of a Traditional Chinese Medicine Formula (CoTOL) on Serum Uric Acid and Intestinal Flora in Obese Hyperuricemic Mice Inoculated with Intestinal Bacteria

CoTOL is a traditional Chinese medicine (TCM) formula in clinics for treating gout and hyperuricemia, especially in obese patients with recurrent attacks. However, fewer studies have investigated how CoTOL impacts the intestinal flora in reducing uric acid. In the present, we analyze the bacteria targeted by ingredients of CoTOL and evaluate the effects of CoTOL on uric acid and intestinal flora in a mice model of obese hyperuricemia inoculated with xanthine dehydrogenase- (XOD-) producing bacteria, Streptococcus faecalis. Firstly, ingredients of herbs in CoTOL and gene target by these ingredients were retrieved from TCMID 2.0, and these genes were screened by DAVID Bioinformatics Resources 6.8, deciphered to retrieve the bacteria. Then, 3-4-week-old male C57bl/6j mice were randomly divided into 6 groups and fed with high fat diet for 8 weeks up to obesity standard. The mice were inoculated intragastrically with 5 × 10⁹ CFU Streptococcus faecalis 3 times at the 5^th, 6^th, and 7^th week and intragastrically administrated with uricase inhibitor, potassium-oxonate (PO, 250 mg/kg), to induce hyperuricemia at the 8^th week, once a day for 7 consecutive days, respectively (IB model). IB model plus CoTOL (0.4 ml/20g) and allopurinol (40 mg/kg) were administrated by gavage at the 5^th week, once a day for 4 weeks. The feces and blood in each group were sampled at the 4^th and 8^th week. With no bacteria inoculation, CoTOL, allopurinol, and blank group were treated with CoTOL and allopurinol or water, respectively. 44 species of bacteria (i.e., Enterococcus faecalis, Streptococcus, etc.) genes were targeted by 6 ingredients of 6 herbs in CoTOL. Inoculation with Streptococcus faecalis significantly caused the elevation of uric acid and the change of intestinal flora structure, whereas treatment with CoTOL significantly increased the abundance of Akkermansia and those of Bacteroides and Alloprevotella decreased. Furthermore, CoTOL exhibited a unique effect on reducing weight unobserved in allopurinol intervention. The present study, for the first time, demonstrated that CoTOL has beneficial effects on hyperuricemia and overweight, which may be attributed to regulating material metabolism and improving the structure or function of intestinal flora. Thus, CoTOL may be a promising therapy for hyperuricemia and overweight in chronic gout management and can be integrated with conventional treatments.

Akkermansia muciniphila: A potential novel mechanism of nuciferine to improve hyperlipidemia

BACKGROUND

Intestinal microbiota is a novel drug target of metabolic diseases, especially for those with poor oral bioavailability. Nuciferine, with poor bioavailability, has an anti-hyperlipidemic effect at low dosages.

PURPOSE

In the present study, we aimed to explore the role of intestinal microbiota in the anti-hyperlipidemic function of nuciferine and identify the key bacterial targets that might confer the therapeutic actions.

METHODS

The contribution of gut microbes in the anti-hyperlipidemic effect of nuciferine was evaluated by conventional and antibiotic-established pseudo-sterile mice. Whole-metagenome shotgun sequencing was used to characterize the changes in microbial communities by various agents.

RESULTS

Nuciferine exhibited potent anti-hyperlipidemic and liver steatosis-alleviating effects at the doses of 7.5-30 mg/kg. The beneficial effects of nuciferine were substantially abolished when combined with antibiotics. Metagenomic analysis showed that nuciferine significantly shifted the microbial structure, and the enrichment of Akkermansia muciniphila was closely related to the therapeutic effect of nuciferine.

CONCLUSIONS

Our results revealed that gut microbiota played an essential role in the anti-hyperlipidemic effect of nuciferine, and enrichment of Akkermansia muciniphila represented a key mechanism through which nuciferine exerted its therapeutic effects.

The difference of regulatory effect of two Inonotus obliquus extracts on high-fat diet mice in relation to the fatty acid elongation function of gut microbiota

Obesity is a disease that causes metabolic disorders in the human body and is closely related to intestinal microbes. This experiment compares the therapeutic effects of two Inonotus obliquus extracts on high-fat diet (HFD) mice and explores the effects and mechanisms of intestinal flora and its metabolites. The energy intake (EI), weight gain (BWG), fecal flora diversity, fecal and urine metabolites, and fecal triglycerides (TG) of mice were measured at 4 temporal points. We found that due to the difference in energy intake between the two groups in the early stage of the experiment, the ethanol extract of Inonotus obliquus (IOE) had a stronger effect on the accumulated BWG than the polysaccharide (IOP) of Inonotus obliquus at the end of the experiment. Moreover, the difference caused by IOE and IOP intake was the largest in the second week, in four temporal points. Compared with IOP, IOE in the second week can reduce EI, fecal short-chain fatty acids (SCFA) and TG, reduce host metabolism, increase fecal Akkermansia and fatty acid elongation, and increase host substrate phosphorylation. The change trend of the fatty acid elongation P value from 2 to 14 weeks is consistent with the overall difference trend between the two groups. The difference in the regulating effect of the two Inonotus obliquus extracts on HFD mice is related to the fatty acid elongation function of the intestinal flora, which leads to the reduction of IOE and the effect of BWG is better than IOP. It provides a theoretical reference for the development of functional food using the extract of Inonotus obliquus.

Association Between Gut Akkermansia and Metabolic Syndrome is Dose-Dependent and Affected by Microbial Interactions: A Cross-Sectional Study

OBJECTIVE

Akkermansia muciniphila is among the most abundant bacterial species in the human intestine; however, its relationship to metabolic syndrome (MetS)-which is linked to gut dysbiosis-is not known. In this study, we investigated the association between Akkermansia abundance and risk of MetS and its components, as well as dose-response effects and the influence of microbial interactions on the association.

METHODS

This cross-sectional study included 6896 Chinese participants aged 18 to 97 years from the Guangdong Gut Microbiome Project. MetS was defined according to Joint Committee for Developing Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults criteria. The abundance of Akkermansia was assessed by 16S rRNA sequencing. Logistic regression analysis with adjustment for common confounders was performed to evaluate the association between Akkermansia and MetS and its components. Models with restricted cubic splines and interaction terms were used to examine the dose-response association and microbial interactions, respectively.

RESULTS

The prevalence of MetS was 20.4%, and the median abundance of Akkermansia was 0.08% (interquartile range: 0.04-0.93%). Increased Akkermansia abundance was associated with decreased risk of MetS (P _nonlinear<0.05), but this effect was not observed until the Akkermansia level was 0.2% of the total gut microbiota abundance (odds ratio=0.96, 95% confidence interval: 0.94-0.98). Of the 5 MetS components, obesity and hypertriglyceridemia showed the strongest association with Akkermansia, followed by reduced high-density lipoprotein cholesterol, hypertension, and hyperglycemia. Microbial interaction analyses showed that Ruminococcaceae and Lachnospiraceae were the predominant bacterial families and were not only correlated with Akkermansia abundance but also influenced the Akkermansia-MetS association.

CONCLUSION

There is a dose-response association between reduced risk of MetS and increased abundance of Akkermansia. The association between Akkermansia and 5 MetS components is variable and affected by microbial interactions.

Gut Akkermansia muciniphila ameliorates metabolic dysfunction-associated fatty liver disease by regulating the metabolism of L-aspartate via gut-liver axis

The gut bacterium Akkermansia muciniphila has been increasingly recognized for its therapeutic potential in treating metabolic disorders, including obesity, diabetes, and metabolicdysfunction-associated fatty liver disease (MAFLD). However, its underlying mechanism involved in its well-known metabolic actions needs further evaluation. The present study explored the therapeutic effect and mechanism of A. muciniphila in intervening MAFLD by using a high-fat and high-cholesterol (HFC) diet induced obese mice model. Mice treated with A. muciniphila efficiently reversed MAFLD in the liver, such as hepatic steatosis, inflammatory, and liver injury. These therapeutic effects persisted after long-term drug withdrawal and were slightly weakened in the antibiotics-treated obese mice. A. muciniphila treatment efficiently increased mitochondrial oxidation and bile acid metabolism in the gut-liver axis, ameliorated oxidative stress-induced cell apoptosis in gut, leading to the reshaping of the gut microbiota composition. These metabolic improvements occurred with increased L-aspartate levels in the liver that transported from the gut. The administration of L-aspartate in vitro or in mice displayed the similar beneficial metabolic effects mentioned above and efficiently ameliorated MAFLD. Together, these data indicate that the anti-MAFLD activity of A. muciniphila correlated with lipid oxidation and improved gut-liver interactions through regulating the metabolism of L-aspartate. A. muciniphila could be a potential agent for clinical intervention in MAFLD.

Effects of Smoking on Inflammatory Markers in a Healthy Population as Analyzed via the Gut Microbiota

The number of people who smoke has increased in recent years, and the incidence of smoking-related diseases increases annually. This study was conducted to explore whether smoking affects diseases via changes in the gut microbiota. We enrolled 33 smokers and 121 non-smokers. We collected fecal samples from all participants and performed whole-genome sequencing. Smoking significantly affected the gut microbiota. At the phylum through genus levels, the smokers' microbiotas showed slight changes compared with those of the non-smokers. The α- and β-diversities differed significantly between the smokers and non-smokers, and the smokers' gut microbiota compositions differed significantly from those of the non-smokers. At the species level, the relative abundances of Ruminococcus gnavus (P=0.00197) and Bacteroides vulgatus (P=0.0468) were significantly greater in the smokers than in the non-smokers, while the relative abundances of Faecalibacterium prausnitzii (P=0.0000052) and Akkermansia muciniphila (P=0.0057) were significantly lower in the smokers. Smoking increases inflammation in the body by inducing an increased abundance of proinflammatory bacteria. Non-smokers had higher abundances of anti-inflammatory microorganisms than did smokers; these microorganisms can produce short-chain fatty acids, which inhibit inflammation.

Oyster polysaccharides ameliorate intestinal mucositis and improve metabolism in 5-fluorouracil-treated S180 tumour-bearing mice

The purpose of this study was to investigated the potential role of gut microbiota in protecting the intestinal barrier and improving nutritional metabolism in 5-FU-treated S180 tumour-bearing mice after treatment with oyster polysaccharide (CHP). CHP, with an α-(1→4) d-linked glucose backbone and (→4,6)-α-d-Glc-(1→) branches every 4.7 residues on average, increased the villus height, crypt depth, mucosa thickness, villus surface area and V/C ratio; decreased the expression of IL-1β, IL-6, and TNF-α; and even restored the TP, ALB, PA, TRF, IgA, IgM and IgG levels to normal levels. All these factors are related to CHP increasing the propionic acid- and butyric acid-producing microorganisms and decreasing the production of Bacteroides, Prevotellaceae_UCG-001 and Rikenellaceae_RC9_gut_group, thus affecting the TLRs signalling pathway. In conclusion, CHP attenuates 5-FU-induced intestinal mucositis and malnutrition by regulating gut microbiota, and can improve the prognosis of patients receiving chemotherapy.

SARS-CoV-2 infection, gut dysbiosis, and heterogeneous clinical results of hydroxychloroquine on COVID-19 therapy-Is there a link?

Clinical manifestations of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can include gastrointestinal signals and symptoms. Individuals with previous clinical conditions that usually enroll gut dysbiosis have been identified as being at high risk to develop more severe infectious phenotypes. Actually, intestinal dysbiosis has been observed in infected patients and potentially linked to systemic hyperinflammation. These observations suggest that a previous gut dysbiosis may be aggravated by SARS-CoV-2 infection and related to progression of the coronavirus disease 2019 (COVID-19) into more severe stages. While COVID-19’s pathophysiology is not fully understood, it seems relevant to consider the interactions of candidate therapeutic drugs with the host, gut microbiota, and SARS-CoV-2. Here we summarize scientific evidence supporting the potential relevance of these interactions and suggest that unfavorable clinical data on hydroxychloroquine administration in COVID-19 may have been influenced by the dose provided and its impact on gut dysbiosis. The proposition is based on preliminary data on gut microbiota composition from individuals with inactive systemic lupus erythematosus under exclusive continuous hydroxychloroquine treatment, displaying a direct correlation between drug doses and markers typically associated with gut dysbiosis.

The Dynamic Changes of Gut Microbiota during the Perinatal Period in Sows

Simple Summary

The gut microbiota in sows is important for the health of the host, and potential benefits may also be transferred to piglets during pregnancy. Therefore, systematic studies investigating the changes in the gut microbiota of sows are needed to elucidate the microbial compositions and functions. This study was conducted at 12 time points to investigate the temporal variations in the gut microbiota of sows using 16S rRNA sequencing. The results provided important information for the gut microbiota of sows during different perinatal periods.

Abstract

The gut microbiota in sows is important for the health of the host, and potential benefits may also be transferred to piglets during pregnancy. Therefore, systematic studies investigating the changes in the gut microbiota of sows are needed to elucidate the microbial compositions and functions. This study was conducted at 12 time points to investigate the temporal variations in gut microbiota on Days 27, 46, 64, 81, 100, and 113 during gestation (G) and Days 3, 5, 7, 10, 14, and 21 during lactation (L). Results suggested that the gut microbiota changed across the perinatal period with microbial function and abundance varying between the prenatal and postnatal periods. The alpha diversity was higher in the postnatal period than in the prenatal period. Thirty-eight genera were distributed between the two periods with Methanobrevibacter, Desulfovibrio, Akkermansia, and Turicibacter being enriched in the prenatal period while Eubacterium, Actinobacillus, Paludibacter, Butyricimonas, Megasphaera, Succiniclasticum, Acidaminococcus, and Rummeliibacillus were enriched in the postnatal period. Analysis done at the different time points of the prenatal period suggested that Days 27 and 113 had more microbial biomarkers than other days. Bacteroidales, Bacteroidia, and Prevotella were enriched on the 27th day, while bacteria belonging to the Clostridium and Ruminococcaceae were enriched on the 113th day. On the other hand, Clostridiales, Ruminococcaceae, Clostridia, and unclassified Christensenellaceae were enriched three days after delivery. Predicted microbial KO functions were also more enriched on Day 27 of the gestation period and Day 3 of the lactation period. Random forest, a machine learning method, was used to identify the top five important genera of Megasphaera, Stenotrophomonas, Phyllobacterium, Catenibacterium, and Turicibacter, while the most important function was arginine and proline metabolism. These systematic results provide important information for the gut microbiota of sows.

Therapeutic avenues for restoring the gut microbiome in HIV infection

The interplay between the gut microbiota, the intestinal barrier and the mucosal immune system is profoundly altered in Human Immunodeficiency Virus (HIV) infection. An HIV-associated microbial dysbiotic signature has been difficult to define due to the strong impact of confounders that are intimately linked with HIV infection, namely HIV risk behaviors. When controlling for sexual preference and gender, HIV-associated microbial dysbiotic signatures are characterized by an increase in deleterious taxa and a decrease in beneficial bacteria and their respective metabolic end-products. First attempts to restore the gut microbiota of HIV subjects on Antiretroviral Therapy using Fecal Microbiota Transplantation proved to be safe and reported mild transient engraftment of donor microbiota and no effect on markers of HIV disease progression. This review focuses on the current evidence supporting a role for microbial dysbiosis in HIV pathogenesis, and reviews current microbiome-based therapeutics for restoring the gut microbiota in HIV infection.

Gut Microbiome Contributes to Liver Fibrosis Impact on T Cell Receptor Immune Repertoire

Gut microbiota (GM) modifies the intrahepatic immune microenvironment, but the underlying mechanisms remain poorly understood. Liver fibrosis-associated imprinting is predicted to be reflected in GM. This study investigated the link between GM and the intrahepatic T cell receptor (TCR) immune repertoire (IR), and whether GM modulates the intrahepatic immune microenvironment via TCR IR during liver fibrosis. We analyzed the correlation between GM and TCR IR during liver fibrogenesis. Accordingly, 16S rRNA gene sequencing (16S-seq) and bulk immune repertoire sequencing (IR-seq) were performed to characterize GM and intrahepatic TCR IR. Fecal microbial transplant (FMT) and TCRβ knockout (Tcrb^KO) mouse models were employed to determine the biological link between GM and TCR IR in liver fibrosis. We found that GM and intrahepatic TCR IR are highly correlated, with both showing reduced diversity and centralized distribution during liver fibrosis. The restoration of normal intestinal microbiota may reshape intrahepatic TCR IR and delay liver fibrosis. Interestingly, TCR IR ablation abrogated the impact of GM on liver fibrogenesis. Furthermore, GM modulated hepatic stellate cell (HSC) activation via TCR IR-mediated intrahepatic immune milieu. Our study demonstrates that GM, which exhibits cross-talk with the intrahepatic TCR IR, influences the intrahepatic immune microenvironment and liver fibrosis progression.

Gut microbiota and the human gut physiological changes

Background

The human gut can be colonized by number of microorganisms. The most studied are bacteria, which changes from birth to newborn born into adult-like gut microbiota. Much is known about the effects of dietary, medications, and lifestyles on the bacterial composition. However, the host physiological changes influencing the gut microbiota, the immediate consequences, and the possible gut microbiota therapy are not studied at length. This review is based profoundly on animal model studies through experimentation and some human clinical trials for the past 20 years.

Forward

The physiological factors studied to influences gut microbiota are bacterial mucosal receptors, mucin glycosylation, mucus, epithelial microvilli, and tight junction. Host secretions and immune response such as immunity, secretory A (sIgA), inflammasome, innate immunity, immune response, glycans, bile acids, peristalsis, microRNA, and adhesion to intestinal glycans are as well found to confer variety of alterations on gut microbial flora.

Conclusion

Despite the resilience of the gut microbiota in response to changes, chain of events causes the imbalance microbiota. Increased pro-inflammatory potential with the help of cell barriers, host secretions, and immune response mediate gut recovery.

A purified membrane protein from Akkermansia muciniphila or the pasteurised bacterium blunts colitis associated tumourigenesis by modulation of CD8+ T cells in mice

OBJECTIVE

Gut microbiota have been linked to inflammatory bowel disease (IBD) and colorectal cancer (CRC). Akkermansia muciniphila (A. muciniphila) is a gram-negative anaerobic bacterium that is selectively decreased in the faecal microbiota of patients with IBD, but its causative role and molecular mechanism in blunting colitis-associated colorectal cancer (CAC) remain inconclusive. This study investigates how A. muciniphila engages the immune response in CAC.

DESIGN

Mice were given dextran sulfate sodium to induce colitis, followed by azoxymethane to establish CAC with or without pasteurised A. muciniphila or a specific outer membrane protein (Amuc_1100) treatment. Faeces from mice and patients with IBD or CRC were collected for 16S rRNA sequencing. The effects of A. muciniphila or Amuc_1100 on the immune response in acute colitis and CAC were investigated.

RESULTS

A. muciniphila was significantly reduced in patients with IBD and mice with colitis or CAC. A. muciniphila or Amuc_1100 could improve colitis, with a reduction in infiltrating macrophages and CD8⁺ cytotoxic T lymphocytes (CTLs) in the colon. Their treatment also decreased CD16/32⁺ macrophages in the spleen and mesenteric lymph nodes (MLN) of colitis mice. Amuc_1100 elevated PD-1⁺ CTLs in the spleen. Moreover, A. muciniphila and Amuc_1100 blunted tumourigenesis by expanding CTLs in the colon and MLN. Remarkably, they activated CTLs in the MLN, as indicated by TNF-α induction and PD-1downregulation. Amuc_1100 could stimulate and activate CTLs from splenocytes in CT26 cell conditioned medium.

CONCLUSIONS

These data indicate that pasteurised A. muciniphila or Amuc_1100 can blunt colitis and CAC through the modulation of CTLs.

State of the Art in the Culture of the Human Microbiota: New Interests and Strategies

The last 5 years have seen a turning point in the study of the gut microbiota with a rebirth of culture-dependent approaches to study the gut microbiota. High-throughput methods have been developed to study bacterial diversity with culture conditions aimed at mimicking the gut environment by using rich media such as YCFA (yeast extract, casein hydrolysate, fatty acids) and Gifu anaerobic medium in an anaerobic workstation, as well as media enriched with rumen and blood and coculture, to mimic the symbiosis of the gut microbiota. Other culture conditions target phenotypic and metabolic features of bacterial species to facilitate their isolation. Preexisting technologies such as next-generation sequencing and flow cytometry have also been utilized to develop innovative methods to isolate previously uncultured bacteria or explore viability in samples of interest. These techniques have been applied to isolate CPR (Candidate Phyla Radiation) among other, more classic approaches. Methanogenic archaeal and fungal cultures present different challenges than bacterial cultures. Efforts to improve the available systems to grow archaea have been successful through coculture systems. For fungi that are more easily isolated from the human microbiota, the challenge resides in the identification of the isolates, which has been approached by applying matrix-assisted laser desorption ionization-time of flight mass spectrometry technology to fungi. Bacteriotherapy represents a nonnegligible avenue in the future of medicine to correct dysbiosis and improve health or response to therapy. Although great strides have been achieved in the last 5 years, efforts in bacterial culture need to be sustained to continue deciphering the dark matter of metagenomics, particularly CPR, and extend these methods to archaea and fungi.

Gut bacteria Akkermansia is associated with reduced risk of obesity: evidence from the American Gut Project

Background

Gut bacteria Akkermansia has been shown an anti-obesity protective effect in previous studies and may be used as promising probiotics. However, the above effect may be confounded by common factors, such as sex, age and diets, which should be verified in a generalized population.

Methods

We used datasets from the American Gut Project to strictly reassess the association and further examined the effect of aging on it. A total of 10,534 participants aged 20 to 99 years from the United States and the United Kingdom were included. The relative abundance of Akkermansia was assessed based on 16S rRNA sequencing data. Obesity (body mass index, BMI ≥ 30 kg/m²) risks were compared across Akkermansia quintiles in logistic models with adjustment for common confounders. Restricted cubic splines were used to examine dose response effects between Akkermansia, obesity and age. A sliding-windows-based algorithm was used to investigate the effect of aging on Akkermansia-obesity associations.

Results

The median abundance of Akkermansia was 0.08% (interquartile range: 0.006-0.93%), and the prevalence of obesity was 11.03%. Nonlinear association was detected between Akkermansia and obesity risk (P = 0.01). The odds ratios (95% confidence interval) for obesity across the increasing Akkermansia quintiles (referencing to the first quintile) were 1.14 (0.94-1.39), 0.94 (0.77-1.15), 0.70 (0.56-0.85) and 0.79 (0.64-0.96) after adjusting for age and sex (P for trend < 0.001). This association remained unchanged after further controlling for smoking, alcohol drinking, diet, and country. The odds ratios (95% CI) of Akkermansia were 0.19 (0.03-0.62) and 0.77 (0.64-0.91) before and over 40 years, respectively, indicating that the protective effect of Akkermansia against obesity was not stable with aging.

Conclusion

High relative abundance of Akkermansia is associated with low risk of obesity and the association declines with aging.

Alterations of Akkermansia muciniphila in the inflammatory bowel disease patients with washed microbiota transplantation

Akkermansia muciniphila is a promising probiotic in the gut. This study aimed to determine the presence and abundance of Akkermansia in patients with inflammatory bowel disease (IBD) who underwent washed microbiota transplantation (WMT) in order to elucidate the relationship between its level and patients' clinical data and outcomes. A cohort of Chinese volunteers including 80 healthy controls (HC), 43 patients with ulcerative colitis (UC), and 57 patients with Crohn's disease (CD) were recruited. Akkermansia presented a low colonization rate of 48.8% and a relative abundance of 0.07% in a healthy Chinese population. Compared with HC, significantly lower colonization and abundance of Akkermansia were found in UC and CD (p < 0.01, p < 0.001, respectively). The combination of Akkermansia and twelve other gut commensal bacteria significantly enriched in healthy individuals could be conductive to discriminate IBD from HC. Co-occurrence of Akkermansia-Faecalibacterium prausnitzii was at a lower level in IBD. Patients' age could affect the abundance of Akkermansia in CD. After WMT, 53.7% of patients achieved clinical response, and the colonization rate of Akkermansia increased significantly than that pre-WMT (p < 0.01). There was a positive correlation between patients and donors in the abundance of Akkermansia after WMT. Different from Europeans, the healthy Chinese population is characterized by a low presence of intestinal Akkermansia. Compared with healthy people, its colonization and abundance in IBD decreased more significantly. The efficacy of WMT for IBD was closely correlated with Akkermansia. ClinicalTrials.gov , pooled registered trials, NCT01790061, NCT01793831. Registered February 13, 2013, 18 February 2013. KEY POINTS: • Akkermansia showed a lower colonization and abundance in Chinese than Europeans. • Akkermansia could distinguish IBD from healthy people with a reduced abundance. • IBD patients achieved response from WMT through an increased Akkermansia level. Graphical abstract.

Fish Oil, Cannabidiol and the Gut Microbiota: An Investigation in a Murine Model of Colitis

Inflammatory bowel disorders can be associated with alterations in gut microbiota (dysbiosis) and behavioral disturbances. In experimental colitis, administration of fish oil (FO) or cannabinoids, such as cannabidiol (CBD), reduce inflammation. We investigated the effect of combined FO/CBD administration on inflammation and dysbiosis in the dextran sulphate sodium (DSS) model of mouse colitis, which also causes behavioral disturbances. Colitis was induced in CD1 mice by 4% w/v DSS in drinking water for five consecutive days followed by normal drinking water. FO (20–75 mg/mouse) was administered once a day starting two days after DSS, whereas CBD (0.3–30 mg/kg), alone or after FO administration, was administered once a day starting 3 days after DSS, until day 8 (d8) or day 14 (d14). Inflammation was assessed at d8 and d14 (resolution phase; RP) by measuring the Disease Activity Index (DAI) score, change in body weight, colon weight/length ratio, myeloperoxidase activity and colonic interleukin (IL)-1β (IL-1β), IL-10, and IL-6 concentrations. Intestinal permeability was measured with the fluorescein isothiocyanate-dextran. Behavioral tests (novel object recognition (NOR) and light/dark box test) were performed at d8. Fecal microbiota composition was determined by ribosomal 16S DNA sequencing of faecal pellets at d8 and d14. DSS-induced inflammation was stronger at d8 and accompanied by anxiety-like behavior and impaired recognition memory. FO (35, 50, 75 mg/mouse) alone reduced inflammation at d8, whereas CBD alone produced no effect at any of the doses tested; however, when CBD (3, 10 mg/kg) was co-administered with FO (75 mg/mouse) inflammation was attenuated. FO (20 mg/mouse) and CBD (1 mg/kg) were ineffective when given alone, but when co-administered reduced all inflammatory markers and the increased intestinal permeability at both d8 and d14, but not the behavioral impairments. FO, CBD, and their combination affected gut bacteria taxa that were not affected by DSS per se. Akkermansia muciniphila, a species suggested to afford anti-inflammatory action in colitis, was increased by DSS only at d14, but its levels were significantly elevated by all treatments at d8. FO and CBD co-administered at per se ineffective doses reduce colon inflammation, in a manner potentially strengthened by their independent elevation of Akkermansia muciniphila.

Beneficial Effects of Newly Isolated Akkermansia muciniphila Strains from the Human Gut on Obesity and Metabolic Dysregulation

The identification of new probiotics with anti-obesity properties has attracted considerable interest. In the present study, the anti-obesity activities of Akkermansia muciniphila (A. muciniphila) strains isolated from human stool samples and their relationship with the gut microbiota were evaluated using a high fat-diet (HFD)-fed mice model. Three strains of A. muciniphila were chosen from 27 isolates selected based on their anti-lipogenic activity in 3T3-L1 cells. The anti-lipogenic, anti-adipogenic and anti-obesity properties of these three strains were evaluated further in HFD-induced obese mice. The animals were administered these strains six times per week for 12 weeks. The treatment improved the HFD-induced metabolic disorders in mice in terms of the prevention of body weight gain, caloric intake and reduction in the weights of the major adipose tissues and total fat. In addition, it improved glucose homeostasis and insulin sensitivity. These effects were also associated with the inhibition of low-grade intestinal inflammation and restoration of damaged gut integrity, prevention of liver steatosis and improvement of hepatic function. These results revealed a difference in the distribution pattern of the gut microbial communities between groups. Therefore, the gut microbial population modulation, at least in part, might contribute to the beneficial impact of the selected A. muciniphila strains against metabolic disorders.

Akkermansia muciniphila is Negatively Correlated with Hemoglobin A1c in Refractory Diabetes

Patients with refractory diabetes are defined as type 2 diabetes (T2D) patients; they cannot achieve optimal glycemic control and exhibit persistent elevations of hemoglobin A1c (HbA1c) ≥8% while on appropriate therapy. Hyperglycemia can lead to severe microvascular/macrovascular complications. However, in contrast to T2D, few studies have focused specifically on the gut microbiota in refractory diabetes. To examine this issue, we recruited 79 subjects with T2D and refractory diabetes (RT2D), and all subjects received standard therapy with Metformin or other hypoglycemic agents with or without insulin for at least one year. The α-diversity displayed no significant difference, whereas the β-diversity showed a marginal significance (p = 0.054) between T2D and RT2D. The evaluation of taxonomic indices revealed reductions in both Akkermansia muciniphila and Fusobacterium and a corresponding enrichment of Bacteroides vulgatus, Veillonella denticariosi among those with RT2D. These microbial markers distinguished RT2D from T2D with an acceptable degree of discrimination (area under the curve (AUC) = 0.719, p < 0.01) and were involved in several glucose-related functional pathways. Furthermore, the relative abundance of Akkermansia muciniphila was negatively correlated with HbA1c. Our combined results reveal unique features of the gut microbiota in RT2D and suggest that the evaluation of the gut microbiota could provide insights into the mechanisms underlying glycemic control and the impact of therapeutic modalities in patients with RT2D.

Contributions of Lactobacillus plantarum PC170 administration on the recovery of gut microbiota after short-term ceftriaxone exposure in mice

This study aimed to determine the impact of Lactobacillus plantarum PC170 concurrent with antibiotic treatment and/or during the recovery phase after antibiotic treatment on the body weight, faecal bacterial composition, short-chain fatty acids (SCFAs) concentration, and splenic cytokine mRNA expression of mice. Orally administrated ceftriaxone quantitatively and significantly decreased body weight, faecal total bacteria, Akkermansia muciniphila, and Lactobacillus plantarum, and faecal SCFAs concentration. Ceftriaxone treatment also dramatically altered the faecal microbiota with an increased Chao1 index, decreased species diversities and Bacteroidetes, and more Firmicutes and Proteobacteria. After ceftriaxone intervention, these changes all gradually started to recover. However, faecal microbiota diversities were still totally different from control by significantly increased α- and β-diversities. Bacteroidetes all flourished and became dominant during the recovery process. However, mice treated with PC170 both in parallel with and after ceftriaxone treatment encouraged more Bacteroidetes, Verrucomicrobia, and Actinobacteria, and the diversity by which to make faecal microbiota was very much closer to control. Furthermore, the expression of splenic pro-inflammatory cytokine tumour necrosis factor-α mRNA in mice supplemented with PC170 during the recovery phase was significantly lower than natural recovery. These results indicated that antibiotics, such as ceftriaxone, even with short-term intervention, could dramatically damage the structure of gut microbiota and their abilities to produce SCFAs with loss of body weight. Although such damages could be partly recovered with the cessation of antibiotics, the implication of antibiotics to gut microbiota might remain even after antibiotic treatment. The selected strain PC170 might be a potential probiotic because of its contributions in helping the host animal to remodel or stabilise its gut microbiome and enhancing the anti-inflammatory response as protection from the side effects of antibiotic therapy when it was administered in parallel with and after antibiotic treatment.

Diversity in the Extracellular Vesicle-Derived Microbiome of Tissues According to Tumor Progression in Pancreatic Cancer

This study was conducted to identify the composition and diversity of the microbiome in tissues of pancreatic cancer and to determine its role. First, extracellular vesicles (EVs) were obtained from the paired tumor and normal tissues, and 16s rRNA gene sequencing was performed. We identified the microbiomes, compared the diversity between groups, and found that Tepidimonas was more abundant in tumors. Second, larger tumors resulted in lower levels of Leuconostoc and Sutterella, and increased lymph node metastasis resulted in higher levels of Comamonas and Turicibacter in tumor tissues. Moreover, in the case of tumor recurrence, the levels of Streptococcus and Akkermansia were decreased in tumor tissues. Finally, with the supernatant of Tepidimonasfonticaldi, proliferation and migration of cells increased, and epithelial-mesenchymal transition and the Tricarboxylic Acid (TCA) cycle-related metabolites were enhanced. The composition and diversity of EV-derived microbiomes are important for providing novel insights into theragnostic approaches in pancreatic cancer.

Effects of Gut Microbiome and Short-Chain Fatty Acids (SCFAs) on Finishing Weight of Meat Rabbits

Understanding how the gut microbiome and short-chain fatty acids (SCFAs) affect finishing weight is beneficial to improve meat production in the meat rabbit industry. In this study, we identified 15 OTUs and 23 microbial species associated with finishing weight using 16S rRNA gene and metagenomic sequencing analysis, respectively. Among these, butyrate-producing bacteria of the family Ruminococcaceae were positively associated with finishing weight, whereas the microbial taxa related to intestinal damage and inflammation showed opposite effects. Furthermore, interactions of these microbial taxa were firstly found to be associated with finishing weight. Gut microbial functional capacity analysis revealed that CAZymes, such as galactosidase, xylanase, and glucosidase, could significantly affect finishing weight, given their roles in regulating nutrient digestibility. GOs related to the metabolism of several carbohydrates and amino acids also showed important effects on finishing weight. Additionally, both KOs and KEGG pathways related to the membrane transportation system and involved in aminoacyl-tRNA biosynthesis and butanoate metabolism could act as key factors in modulating finishing weight. Importantly, gut microbiome explained nearly 11% of the variation in finishing weight, and our findings revealed that a subset of metagenomic species could act as predictors of finishing weight. SCFAs levels, especially butyrate level, had critical impacts on finishing weight, and several finishing weight-associated species were potentially contributed to the shift in butyrate level. Thus, our results should give deep insights into how gut microbiome and SCFAs influence finishing weight of meat rabbits and provide essential knowledge for improving finishing weight by manipulating gut microbiome.

Dietary Supplementation of Foxtail Millet Ameliorates Colitis-Associated Colorectal Cancer in Mice via Activation of Gut Receptors and Suppression of the STAT3 Pathway

Coarse cereal intake has been reported to be associated with reduced risk of colorectal cancer. However, evidence from intervention studies is absent and the molecular basis of this phenomenon remains largely unexplored. This study sought to investigate the effects of foxtail millet and rice, two common staple grains in Asia, on the progression of colitis-associated colorectal cancer (CAC) and define the mechanism involved. In total, 40 BALB/c mice were randomized into four groups. The Normal and azoxymethane/dextran sodium sulfate (AOM/DSS) groups were supplied with an AIN-93G diet, while the millet- and rice-treated groups were supplied with a modified AIN-93G diet. Compared to the AOM/DSS-induced CAC mice supplemented with rice, an increased survival rate, suppressed tumor burden, and reduced disease activity index were observed in the millet-treated group. The levels of IL-6 and IL-17 were decreased in the millet-treated group compared to both the AOM/DSS and AOM/DSS + rice groups. Millet treatment inhibited the phosphorylation of STAT3 and the related signaling proteins involved in cell proliferation, survival and angiogenesis. These beneficial effects were mediated by the activation of gut receptors AHR and GPCRs via the microbial metabolites (indole derivates and short-chain fatty acids) of foxtail millet. Moreover, millet-treatment increased the abundance of Bifidobacterium and Bacteroidales_S24-7 compared to the rice-treated mice. This study could help researchers to develop better dietary patterns that work against inflammatory bowel disease (IBD) and for CAC patients.

Toxicological safety evaluation of pasteurized Akkermansia muciniphila

Gut microorganisms are vital for many aspects of human health, and the commensal bacterium Akkermansia muciniphila has repeatedly been identified as a key component of intestinal microbiota. Reductions in A. muciniphila abundance are associated with increased prevalence of metabolic disorders such as obesity and type 2 diabetes. It was recently discovered that administration of A. muciniphila has beneficial effects and that these are not diminished, but rather enhanced after pasteurization. Pasteurized A. muciniphila is proposed for use as a food ingredient, and was therefore subjected to a nonclinical safety assessment, comprising genotoxicity assays (bacterial reverse mutation and in vitro mammalian cell micronucleus tests) and a 90-day toxicity study. For the latter, Han Wistar rats were administered with the vehicle or pasteurized A. muciniphila at doses of 75, 375 or 1500 mg/kg body weight/day (equivalent to 4.8 × 10⁹ , 2.4 × 10¹⁰ , or 9.6 × 10¹⁰ A. muciniphila cells/kg body weight/day) by oral gavage for 90 consecutive days. The study assessed potential effects on clinical observations (including detailed arena observations and a modified Irwin test), body weight, food and water consumption, clinical pathology, organ weights, and macroscopic and microscopic pathology. The results of both in vitro genotoxicity studies were negative. No test item-related adverse effects were observed in the 90-day study; therefore, 1500 mg/kg body weight/day (the highest dose tested, equivalent to 9.6 × 10¹⁰ A. muciniphila cells/kg body weight/day) was established as the no-observed-adverse-effect-level. These results support that pasteurized A. muciniphila is safe for use as a food ingredient.

Host Akkermansia muciniphila Abundance Correlates With Gulf War Illness Symptom Persistence via NLRP3-Mediated Neuroinflammation and Decreased Brain-Derived Neurotrophic Factor

Neurological disorders are commonly reported among veterans who returned from the Gulf war. Veterans who suffer from Gulf War illness (GWI) complain of continued symptom persistence that includes neurological disorders, muscle weakness, headaches, and memory loss, that developed during or shortly after the war. Our recent research showed that chemical exposure associated microbial dysbiosis accompanied by a leaky gut connected the pathologies in the intestine, liver, and brain. However, the mechanisms that caused the symptoms to persist even 30 years after the war remained elusive to investigators. In this study, we used a rodent model of GWI to investigate the persistence of microbiome alterations, resultant chronic inflammation, and its effect on neurotrophic and synaptic plasticity marker BDNF. The results showed that exposure to GW chemicals (the pesticide permethrin and prophylactic drug pyridostigmine bromide) resulted in persistent pathology characterized by the low relative abundance of the probiotic bacteria Akkermansia muciniphila in the gut, which correlated with high circulatory HMGB1 levels, blood-brain barrier dysfunction, neuroinflammation and lowered neurotrophin BDNF levels. Mechanistically, we used mice lacking the NLRP3 gene to investigate this inflammasome's role in observed pathology. These mice had significantly decreased inflammation and a subsequent increase in BDNF in the frontal cortex. This suggests that a persistently low species abundance of Akkermansia muciniphila and associated chronic inflammation due to inflammasome activation might be playing a significant role in contributing to chronic neurological problems in GWI. A therapeutic approach with various small molecules that can target both the restoration of a healthy microbiome and decreasing inflammasome activation might have better outcomes in treating GWI symptom persistence.

The influence of the gut microbiome on obesity

Obesity is a disease with multiple environmental and genetic factors, which when combined contribute to the maintenance of an elevated body weight, thereby reducing long-term success of weight loss. The human gut microbiome is becoming a new potential contributor to obesity. Specifically, gut bacteria and their metabolites are known to affect dysbiosis, metabolism, endotoxemia, and inflammation. Many environmental and lifestyle factors can alter the gut microbiota affecting obesity. Potential therapies to alter the gut microbiota include supplementation with probiotic organisms and the use of fecal microbiota transplantation. This review will examine the growing evidence supporting the mechanisms with which the human gut microbiota may influence obesity, various influences on the microbiota, and potential therapies.

New insight into 20(S)-ginsenoside Rh2 against T-cell acute lymphoblastic leukemia associated with the gut microbiota and the immune system

T-cell acute lymphoblastic leukemia (T-ALL) is a hematopoietic malignancy associated with unfavorable factors including male gender and over nine years of age. Chemotherapy toxicity continues to present a major challenge. There is a need to develop novel natural agents to improve survival and quality of life in patients with T-ALL. 20(S)-ginsenoside Rh2 (GRh2) exhibits immune regulation and anti-tumor effects in both cellular and murine xenograft models. In the present study, the anti-cancer mechanisms of 20(S)-GRh2 involved in the immune system and intestinal microbiota were investigated in T-ALL mice. We revealed that 20(S)-Rh2 suppressed T-ALL by blocking the PI3K/Akt/mTOR signaling pathway, and enhanced immunity in the spleen by regulating immune factors. In addition, 20(S)-GRh2 altered the composition of the gut microbiota, and promoted intestinal homeostasis by elevating the levels of tight junction proteins, antimicrobial peptides and IgA. 20(S)-GRh2 ameliorated the LPS-induced inflammatory response in the intestine of T-ALL mice. Furthermore, Bacteroidetes, Verrucomicrobia, Akkermansia, Lactobacillus, and Lachnospiraceae_NK4A136_group were positively correlated with anti-tumor immune factors, intestinal barrier-related factors, and the anti-inflammatory response. Conversely, Firmicutes, Proteobacteria, Parabacteroides and Alistipes had the opposite correlation. Collectively, these results suggest that 20(S)-GRh2 is a safe and effective natural product, that shows promise for the prevention and treatment of T-ALL.

Update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA 12: suitability of taxonomic units notified to EFSA until March 2020

The qualified presumption of safety (QPS) was developed to provide a generic safety evaluation for biological agents to support EFSA's Scientific Panels. It is based on an assessment of the taxonomic identity, the body of knowledge, safety concerns and antimicrobial resistance. Safety concerns identified for a taxonomic unit (TU) are where possible to be confirmed at strain or product level, reflected by 'qualifications'. No new information was found that would change the previously recommended QPS TUs of the 39 microorganisms notified to EFSA between October 2019 and March 2020, 33 were excluded, including five filamentous fungi, five Escherichia coli, two Enterococcus faecium, two Streptomyces spp. and 19 TUs already evaluated. Six TUs were evaluated. Akkermansia muciniphila was not recommended for QPS status due to safety concerns. Clostridium butyricum was not recommended because some strains contain pathogenicity factors. This TU was excluded for further QPS evaluation. Galdieria sulphuraria and Pseudomonas chlororaphis were also rejected due to a lack of body of knowledge. The QPS status of Corynebacterium ammoniagenes (with the qualification 'for production purposes only') and of Komagataella pastoris (with the qualification 'for enzyme production') was confirmed. In relation to the taxonomic revision of the Lactobacillus genus, previously designated Lactobacillus species will be reassigned to the new species and both the old and new names will be retained in the QPS list.

Effects of prebiotic dietary fibers and probiotics on human health: With special focus on recent advancement in their encapsulated formulations

Background

Dietary fibers (DFs) are known as potential formulations in human health due to their beneficial effects in control of life-threatening chronic diseases including cardiovascular disease (CVD), diabetes mellitus, obesity and cancer. In recent decades scientists around the globe have shown tremendous interest to evaluate the interplay between DFs and gastrointestinal (GIT) microbiota. Evidences from various epidemiological and clinical trials have revealed that DFs modulate formation and metabolic activities of the microbial communities residing in the human GIT which in turn play significant roles in maintaining health and well-being. Furthermore, interestingly, a rapidly growing literature indicates success of DFs being prebiotics in immunomodulation, namely the stimulation of innate, cellular and humoral immune response, which could also be linked with their significant roles in modulation of the probiotics (live beneficial microorganisms).

Scope and approach

The main focus of the current review is to expressively highlight the importance of DFs being prebiotics in human health in association with their influence on gut microbiota. Now in order to significantly achieve the promising health benefits from these prebiotics, it is aimed to develop novel formulations to enhance and scale up their efficacy. Therefore, finally, herein unlike previously published articles, we highlighted different kinds of prebiotic and probiotic formulations which are being regarded as hot research topics among the scientific community now a days.

Conclusion

The information in this article will specifically provide a platform for the development of novel functional foods the demands for which has risen drastically in recent years.

Human Gut Microbiome Aging Clock Based on Taxonomic Profiling and Deep Learning

The human gut microbiome is a complex ecosystem that both affects and is affected by its host status. Previous metagenomic analyses of gut microflora revealed associations between specific microbes and host age. Nonetheless there was no reliable way to tell a host's age based on the gut community composition. Here we developed a method of predicting hosts' age based on microflora taxonomic profiles using a cross-study dataset and deep learning. Our best model has an architecture of a deep neural network that achieves the mean absolute error of 5.91 years when tested on external data. We further advance a procedure for inferring the role of particular microbes during human aging and defining them as potential aging biomarkers. The described intestinal clock represents a unique quantitative model of gut microflora aging and provides a starting point for building host aging and gut community succession into a single narrative.

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DNNs are the most appropriate model to predict host age from gut microflora profiles

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Our DNN models reach MAE of 5.9 years in independent verification

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Feature importance analysis gives a starting point for anti-aging intervention design

Fungal Gut Microbiota Dysbiosis and Its Role in Colorectal, Oral, and Pancreatic Carcinogenesis

The association between bacterial as well as viral gut microbiota imbalance and carcinogenesis has been intensively analysed in many studies; nevertheless, the role of fungal gut microbiota (mycobiota) in colorectal, oral, and pancreatic cancer development is relatively new and undiscovered field due to low abundance of intestinal fungi as well as lack of well-characterized reference genomes. Several specific fungi amounts are increased in colorectal cancer patients; moreover, it was observed that the disease stage is strongly related to the fungal microbiota profile; thus, it may be used as a potential diagnostic biomarker for adenomas. Candida albicans, which is the major microbe contributing to oral cancer development, may promote carcinogenesis via several mechanisms, mainly triggering inflammation. Early detection of pancreatic cancer provides the opportunity to improve survival rate, therefore, there is a need to conduct further studies regarding the role of fungal microbiota as a potential prognostic tool to diagnose this cancer at early stage. Additionally, growing attention towards the characterization of mycobiota may contribute to improve the efficiency of therapeutic methods used to alter the composition and activity of gut microbiota. The administration of Saccharomyces boulardii in oncology, mainly in immunocompromised and/or critically ill patients, is still controversial.

Akkermansia muciniphila Aspartic Protease Amuc_1434* Inhibits Human Colorectal Cancer LS174T Cell Viability via TRAIL-Mediated Apoptosis Pathway

Mucin2 (Muc2) is the main component of the intestinal mucosal layer and is highly expressed in mucous colorectal cancer. Previous studies conducted by our lab found that the recombinant protein Amuc_1434 (expressed in Escherichia coli prokaryote cell system, hereinafter termed Amuc_1434*), derived from Akkermansia muciniphila, can degrade Muc2. Thus, the main objective of this study was to explore the effects of Amuc_1434* on LS174T in colorectal cancer cells expressing Muc2. Results from this study demonstrated that Amuc_1434* inhibited the proliferation of LS174T cells, which was related to its ability to degrade Muc2. Amuc_1434* also blocked the G0/G1 phase of the cell cycle of LS174T cells and upregulated the expression of tumor protein 53 (p53), which is a cell cycle-related protein. In addition, Amuc_1434* promoted apoptosis of LS174T cells and increased mitochondrial ROS levels in LS174T cells. The mitochondrial membrane potential of LS174T cells was also downregulated by Amuc_1434*. Amuc_1434* can activate the death receptor pathway and mitochondrial pathway of apoptosis by upregulating tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL). In conclusion, our study was the first to demonstrate that the protein Amuc_1434* derived from Akkermansia muciniphila suppresses LS174T cell viability via TRAIL-mediated apoptosis pathway.

Amelioration of Alcohol Induced Gastric Ulcers Through the Administration of Lactobacillus plantarum APSulloc 331261 Isolated From Green Tea

Gastric inflammation is an indication of gastric ulcers and possible other underlying gastric malignancies. Epidemiological studies have revealed that several Asian countries, including South Korea, suffer from a high incidence of gastric diseases derived from high levels of stress, alcoholic consumption, pyloric infection and usage of non-steroidal anti-inflammatory drugs (NSAIDs). Clinical treatments of gastric ulcers are generally limited to proton pump inhibitors that neutralize the stomach acid, and the application of antibiotics for Helicobacter pylori eradication, both of which are known to have a negative effect on the gut microbiota. The potential of probiotics for alleviating gastrointestinal diseases such as intestinal bowel syndrome and intestinal bowel disease receives increasing scientific interest. Probiotics may support the amelioration of disease-related symptoms through modulation of the gut microbiota without causing dysbiosis. In this study the potential of Lactobacillus plantarum APSulloc 331261 (GTB1^TM), isolated from green tea, was investigated for alleviating gastric inflammation in an alcohol induced gastric ulcer murine model (positive control). Treatment with the test strain significantly influenced the expression of pro-inflammatory and anti-inflammatory biomarkers, interleukin 6 (IL6) and interleukin 10 (IL10), of which the former was down- and the latter up-regulated when the alcohol induced mice were treated with the test strain. This positive effect was also indicated by less severe gastric morphological changes and the histological score of the gastric tissues. A significant increase in the abundance of Akkermansia within the GTB1^TM treated group compared to the positive control group also correlated with a decrease in the ratio of acetate over propionate. The increased levels of propionate in the GTB1^TM group appear to result from the impact of the test strain on the microbial population and the resulting metabolic activities. Moreover, there was a significant increase in beta-diversity in the group that received GTB1^TM over that of the alcohol induced control group.

The impact of probiotics, prebiotics, and synbiotics on the biochemical, clinical, and immunological markers, as well as on the gut microbiota of obese hosts

Obesity is currently considered a global epidemic and it leads to several alterations on the human body and its metabolism. There are evidences showing that the intestinal microbiota can influence on the pathogenesis of obesity. Microbiota plays a vital role not only in the digestion and absorption of nutrients, but also in the homeostatic maintenance of host immunity, metabolism, and gut barrier. Its dietary alteration is an important target in the treatment of obesity. Emerging evidence suggests that modifying the composition of the gut microbiota through probiotic, prebiotic, and synbiotic supplementation may be a viable adjuvant treatment option for obese individuals. In this review, the impact of probiotics, prebiotics, and synbiotics on the anthropometric profile, biochemical regulation, clinical, and immunological markers, as well as on the gut microbiota of obese hosts is described. It also emphasizes how changes in the composition and/or metabolic activity of the gut microbiota through the administration of nutrients with probiotic, prebiotic, or synbiotic properties can modulate the host's gene expression and metabolism, and thereby positively influence on the host's adipose tissue development and related metabolic disorders. The beneficial effects on the host's metabolism promoted by prebiotics, probiotics, and synbiotics have been successfully demonstrated by several studies. However, further investigation is needed to fully explain the cellular mechanisms of action of probiotics and prebiotics on human health, and also to elucidate the relationship between microbiota and obesity etiology, using well-designed, long-term, and large-scale clinical interventions.

Function of Akkermansia muciniphila in Obesity: Interactions With Lipid Metabolism, Immune Response and Gut Systems

Obesity and its metabolic syndrome, including liver disorders and type 2 diabetes, are a worldwide epidemic and are intimately linked to diet. The gut microbiota interaction has been pointed to as a hot topic of research in the treatment of obesity and related metabolic diseases by influencing energy metabolism and the immune system. In terms of the novel beneficial microbes identified, Akkermansia muciniphila (A. muciniphila) colonizes the mucosa layer of the gut and modulates basal metabolism. A. muciniphila is consistently correlated with obesity. The causal beneficial impact of A. muciniphila treatment on obesity is coming to light, having been proved by a variety of animal models and human studies. A. muciniphila has been characterized as a beneficial player in body metabolism and has great prospects for treatments of the metabolic disorders associated with obesity, as well as being considered for next-generation therapeutic agents. This paper aimed to investigate the basic mechanism underlying the relation of A. muciniphila to obesity and its host interactions, as identified in recent discoveries, facilitating the establishment of the causal relationship in A. muciniphila-associated therapeutic supplement in humans.

Preliminary Evaluation of the Safety and Probiotic Potential of Akkermansia muciniphila DSM 22959 in Comparison with Lactobacillus rhamnosus GG

In this study, for the first time, we examined some of the physico-chemical properties of the cell surface of Akkermansiamuciniphila DSM 22959, comparing it with those of Lactobacillusrhamnosus GG-one of the most extensively studied probiotic microorganisms. In particular, hydrophobicity, auto-aggregation, co-aggregation, and biofilm formation were investigated. In addition, antibiotic susceptibility, co-culture, and antimicrobial activity of the two strains were compared. Hydrophobicity was evaluated using xylene and toluene, showing that A. muciniphila DSM 22959 possessed moderate hydrophobicity. A. muciniphila showed a faster and higher auto-aggregation ability than Lb. rhamnosus GG, but a lower aptitude in biofilm formation. In the co-aggregation test, the best performance was obtained by Lb. rhamnosus GG. Regarding the susceptibility to antibiotics, the differences between the two strains were remarkable, with A. muciniphila DSM 22959 showing resistance to half of the antibiotic tested. Interesting results were also obtained with regard to the stimulating effect of Lb. rhamnosus GG on the growth of A. muciniphila when co-cultured.

Nondigestible Oligosaccharides with Anti-Obesity Effects

Obesity has an important influence on health conditions, causing a multitude of complications and comorbidities, and drug therapy is considered to be one of the treatment strategies. Nowadays, there is increasing interest in the study of intestinal microbiota regulation of obesity; also, an increasing number of agricultural and sideline products have been found to have anti-obesity potential. In the present review, we summarize an overview of current known and potential anti-obesity oligosaccharides and their molecular structures. We describe their anti-obesity potential activity and the molecular structure associated with this activity, the regulation of intestinal microbiota composition and its mechanism of action, including regulation of the short-chain fatty acid (SCFA) pathway and altering bile acid (BA) pathway. This review will provide new ideas for us to develop new anti-obesity functional foods.

Exploring the genetic diversity of the 16S rRNA gene of Akkermansia muciniphila in IBD and IBS

Aim: The human gastrointestinal tract harbors diverse, abundant microbiota and Akkermansia muciniphila is involved in this community. The aim of this study is to characterize 16 new A. muciniphila 16S ribosomal RNA sequences selected from a metagenomic database from stools of patients with irritable bowel syndrome (IBS), inflammatory bowel diseases and control (CTRLs) subjects by a phylogenetic approach. Materials & methods: A phylogenetic approach was used to study the genetic diversity and SNPs in 16 A. muciniphila 16S ribosomal RNA sequences from stools of 107 individuals, 36 of which were patients affected by IBS, 30 by inflammatory bowel disease and 41 were CTRLs. Results: Phylogenetic analysis confirmed the subdivision into different supported clusters. An increase of variability in IBS has been identified. Conclusion: The genetic variation combined to the relative abundance, contribute to the protective role of A. muciniphila. Phylogenesis represent an additional approach to investigate genetic variability.

Intestinal Flora Disruption and Novel Biomarkers Associated With Nasopharyngeal Carcinoma

Background: Nasopharyngeal carcinoma (NPC) is a malignant nasopharyngeal disease with a complicated etiology that occurs mostly in southern China. Intestinal flora imbalance is believed to be associated with a variety of organ malignancies. Current studies revealed that the destruction of intestinal flora is associated with NPC, and many studies have shown that intestinal flora can be used as a biomarker for many cancers and to predict cancer. Methods: To compare the differences in intestinal flora compositions and biological functions among 8 patients with familial NPC (NPC_F), 24 patients with sporadic NPC (NPC_S), and 27 healthy controls (NOR), we compared the intestinal flora DNA sequencing and hematological testing results between every two groups using bioinformatic methods. Results: Compared to the NOR group, the intestinal flora structures of the patients in the NPC_F and NPC_S groups showed significant changes. In NPC_F, Clostridium ramosum, Citrobacter spp., Veillonella spp., and Prevotella spp. were significantly increased, and Akkermansia muciniphila and Roseburia spp. were significantly reduced. In NPC_S, C. ramosum, Veillonella parvula, Veillonella dispar, and Klebsiella spp. were significantly increased, and Bifidobacterium adolescentis was significantly reduced. A beta diversity analysis showed significant difference compared NPC_F with NOR based on Bray Curtis (P = 0.012) and Unweighted UniFrac (P = 0.0045) index, respectively. The areas under the ROC curves plotted were all 1. Additionally, the concentrations of 5-hydroxytryptamine (5-HT) in NPC_F and NPC_S were significantly higher than those of NOR. C. ramosum was positively correlated with 5-HT (rcm: 0.85, P < 0.001). A functional analysis of the intestinal flora showed that NPC_F was associated with Neurodegenerative Diseases (P = 0.023) and that NPC_S was associated with Neurodegenerative Diseases (P = 0.045) as well. Conclusion: We found that NPC was associated with structural imbalances in the intestinal flora, with C. ramosum that promoted the elevation of 5-HT and opportunistic pathogens being significantly increased, while probiotics significantly decreased. C. ramosum can be used as a novel biomarker and disease prediction models should be established for NPC. The new biomarkers and disease prediction models may be used for disease risk prediction and the screening of high-risk populations, as well as for the early noninvasive diagnosis of NPC.

Importance of nutritional therapy in the management of intestinal diseases: beyond energy and nutrient supply

The gut is an immune-microbiome-epithelial complex. Gut microbiome-host interactions have widespread biological implications, and the role of this complex system extends beyond the digestion of food and nutrient absorption. Dietary nutrients can affect this complex and play a key role in determining gut homeostasis to maintain host health. In this article, we review various dietary nutrients and their contribution to the pathogenesis and treatment of various intestinal diseases including inflammatory bowel disease, irritable bowel syndrome, colorectal cancer, and diverticulitis, among other such disorders. A better understanding of diet-host-gut microbiome interactions is essential to provide beneficial nutrients for gut health and to limit nutritional hazards to ensure successful nutritional management of gastrointestinal conditions in clinical practice.