Gut Microbial Activity Research Articles

Bacillus licheniformis and phytase combination in broiler chicken diets: Effects on growth performance, digestibility coefficients, gut microbiome activities, and bone quality

In the present study, B. licheniformis was added to broiler chicken diets alone or in combination with 6-phytase and the effects on growth performance, coefficients of ileal nutrient digestibility, morphometrical measurements of selected internal organs, gut microbial activity, and bone quality were determined. Four hundred 1-day-old female birds (Ross 308) were randomly allotted to 4 dietary treatments (10 replicate pens, 10 birds each). The trial was set up as follows: negative control (NC), basal diet without any feed additive; NC+Pro, basal diet with B. licheniformis (500 g/t of diet); NC+Phy, basal diet with 6-phytase (400 g/t of diet); and NC+Pro+Phy, basal diet in which both experimental factors were added at the same levels as above. The interaction between treatments was noted in each evaluated period regarding BWG and FI. In the entire experiment, an increased body weight gain (P < 0.001) was observed in the NC+Pro+Phy treatment compared to the other groups. The birds that received both feed additives combined were characterized by an increased feed intake (P < 0.001), contrary to NC+Pro and NC+Phy. Moreover, in terms of microenvironment modulations, interactions (P < 0.05) were observed in the jejunal and cecal digesta pH, short-chain fatty acid (SCFA) level, and microbial enzyme activities. However, the impacts of B. licheniformis and phytase on cecal SCFA concentrations and bacterial enzymes were mainly opposite. There were no interactions (P < 0.05) in terms of geometrical, mechanical, and structural selected tibia and femur indices. However, 6-phytase addition improved bone structure, stiffness, and elasticity. In conclusion, the interactions between 6-phytase and B. licheniformis positively affect growth performance via microbial activity changes; however, the supportive bone quality maintenance properties are only connected to 6-phytase supplementation.

Gut microbiome and bladder cancer: A new link through nitrosamine metabolism

A recent Nature paper1 reveals that gut microbes metabolize N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) into the bladder carcinogen N-n-butyl-N-(3-carboxypropyl)-nitrosamine (BCPN) in the intestines, establishing a direct link between gut microbial activity and the development of bladder cancer.

Combined Supplementation of Inulin and Bacillus coagulans Lactospore Demonstrates Synbiotic Potential in the Mucosal Simulator of the Human Intestinal Microbial Ecosystem (M-SHIME®) Model

Prebiotic and probiotic combinations may lead to a synbiotic effect, demonstrating superior health benefits over either component alone. Using the Mucosal Simulator of the Human Intestinal Microbial Ecosystem (M-SHIME®) model, the effects of repeated supplementation with inulin (prebiotic, which is expected to provide a source of nutrition for the live microorganisms in the gut to potentially support optimal digestive health), Bacillus coagulans lactospore (probiotic), and a low and high dose of a synbiotic combination of the two on the gut microbial community activity and composition were evaluated. Test product supplementation increased the health-promoting short-chain fatty acids acetate and butyrate compared with levels recorded during the control period, demonstrating a stimulation of saccharolytic fermentation. This was likely the result of the increased abundance of several saccharolytic bacterial groups, including Megamonas, Bifidobacterium, and Faecalibacterium, following test product supplementation. The stimulation of acetate and butyrate production, as well as the increased abundance of saccharolytic bacterial groups were more evident in treatment week 3 compared with treatment week 1, demonstrating the value of repeated product administration. Further, the synbiotic formulations tended to result in greater changes compared with prebiotic or probiotic alone. Overall, the findings demonstrate a synbiotic potential for inulin and B. coagulans lactospore and support repeated administration of these products, indicating a potential for promoting gut health.

Lactiplantibacillus argentoratensis AGMB00912 alleviates salmonellosis and modulates gut microbiota in weaned piglets: a pilot study

This study aimed to evaluate the efficacy of Lactiplantibacillus argentoratensis AGMB00912 (LA) in reducing Salmonella Typhimurium infection in weaned piglets. The investigation focused on the influence of LA on the gut microbiota composition, growth performance, and Salmonella fecal shedding. The results indicated that LA supplementation significantly improved average daily gain and reduced the prevalence and severity of diarrhea. Fecal analysis revealed reduced Salmonella shedding in the LA-supplemented group. Furthermore, LA notably altered the composition of the gut microbiota, increasing the levels of beneficial Bacillus and decreasing those of harmful Proteobacteria and Spirochaetes. Histopathological examination showed less intestinal damage in LA-treated piglets than in the controls. The study also observed that LA affected metabolic functions related to carbohydrate, amino acid, and fatty acid metabolism, thereby enhancing gut health and resilience against infection. Short-chain fatty acid concentrations in the feces were higher in the LA group, suggesting improved gut microbial activity. LA supplementation enriched the population of beneficial bacteria, including Streptococcus, Clostridium, and Bifidobacterium, while reducing the number of harmful bacteria, such as Escherichia and Campylobacter. These findings indicate the potential of LA as a probiotic alternative for swine nutrition, offering protective effects to the gut microbiota against Salmonella infection.

A gut microbiota-independent mechanism shapes the bile acid pool in mice with MASH

Background & AimsAn imbalance between primary and secondary bile acids contributes to the development of metabolic dysfunction-associated steatohepatitis (MASH). The precise mechanisms underlying changes in the bile acid pool in MASH remain to be identified. As gut bacteria convert primary bile acids to secondary bile acids, we investigated the contribution of the gut microbiota and its metabolizing activities to bile acid alterations in MASH. MethodsTo disentangle the influence of MASH from environmental and dietary factors, high fat diet fed foz/foz mice were compared to their high fat diet fed wildtype littermates. We developed functional assays (stable isotope labeling and in vitro experiments) to extend the analyses beyond a mere study of gut microbiota composition (16S rRNA gene sequencing). Key findings were confirmed in C57BL/6J mice were fed a western and high fructose diet, as an independent mouse model of MASH. ResultsWhile mice with MASH exhibited lower levels of secondary 7α-dehydroxylated bile acids (3.5-fold lower, p=0.0008), the gut microbial composition was similar in mice with and without MASH. Similar gut microbial bile salt hydrolase and 7α-dehydroxylating activities could not explain the low levels of secondary 7α-dehydroxylated bile acids. Furthermore, the 7α-dehydroxylating activity was unaffected by Clostridium scindens administration in mice with a non-standardized gut microbiota.By exploring alternative mechanisms, we identified an increased bile acid 7α-rehydroxylation mediated by liver CYP2A12 and CYP2A22 enzymes (4.0-fold higher, p<0.0001), that reduces secondary 7α-dehydroxylated bile acid levels in MASH. ConclusionsThis study reveals a gut microbiota-independent mechanism that alters the level of secondary bile acids and contributes to the development of MASH in mice. Impact and implicationsWhile changes in bile acid levels are implicated in the development of metabolic dysfunction-associated steatohepatitis (MASH), the precise mechanisms underpinning these alterations remain elusive. In this study, we investigated the mechanisms responsible for the changes in bile acid levels in mouse models of MASH. Our results support that neither the composition nor the metabolic activity of the gut microbiota can account for the alterations in the bile acid pool. Instead, we identified hepatic 7α-rehydroxylation of secondary bile acids as a gut microbiota-independent factor contributing to the reduced levels of secondary bile acids in mice with MASH. Further investigation is warranted to understand bile acid metabolism and its physiological implications in clinical MASH. Nonetheless, our findings hold promise for exploring novel therapeutic interventions for MASH.

Workplace food purchases, dietary intake, and gut microbial metabolites in a secondary analysis of the ChooseWell 365 study

BackgroundDietary choices can affect human health through alterations in gut microbial metabolism, and gut microbial metabolites could serve as biomarkers for disease risk conferred by dietary intake. However, self-reported dietary intake may not reflect true intake. ObjectivesWe identified circulating metabolites, including gut microbiome-related metabolites, associated with adherence to a healthy diet in the ChooseWell 365 study. In this randomized clinical trial, the dietary choices of hospital employees were assessed over 24 mo using not only 24-h dietary recalls but also electronic records of hospital cafeteria purchases. MethodsPlasma metabolites were profiled from 470 participants. Two targeted metabolomics methods were developed and implemented to expand detection coverage for metabolites related to gut microbial activity. Linear regression models were used to associate metabolites with Healthy Purchasing Scores (HPSs) derived from cafeteria purchases and Healthy Eating Index-2015 (HEI-15) scores derived from dietary recalls. ResultsFourteen metabolites were concordantly associated with the HPS and HEI-15 scores in multivariable models adjusted for age, gender, and race, including the gut microbiome-related metabolites indole-3-propionic acid (HPS, β: 0.16, 95% CI: 0.07, 0.26, P = 7.32 × 10−4; HEI-15, β: 0.16, 95% CI: 0.07, 0.25, P = 6.79 × 10−4), hippuric acid (HPS, β: 0.11, 95% CI: 0.02, 0.21, P = 1.97 × 10−2; HEI-15, β: 0.10, 95% CI: 0.01, 0.19, P = 3.14 × 10−2), and indoxyl sulfate (HPS, β = −0.13, 95% CI: −0.23, −0.03, P = 8.21 × 10−3; HEI-15, β: −0.12, 95% CI: −0.22, −0.03, P = 8.50 × 10−3). These gut microbial metabolites were associated with the intake of specific food groups, such as whole fruits. These metabolites were also associated with clinical variables, including blood pressure, diabetes or prediabetes, and body mass index. ConclusionsIn a secondary analysis of the ChooseWell 365 study, associations between circulating gut microbiome–related metabolites and a healthy diet were confirmed using both objective and subjective measures of consumption. Accurate identification of diet-associated metabolites may help guide dietary or microbiome-based interventions aimed at disease prevention.

Bile Salt Hydrolase Activity-Based Probes for Monitoring Gut Microbial Bile Acid Metabolism.

Bile acids are bioactive metabolites that are biotransformed into secondary bile acids by the gut microbiota, a vast consortium of microbes that inhabit the intestines. The first step in intestinal secondary bile acid metabolism is carried out by a critical enzyme, bile salt hydrolase (BSH), that catalyzes the gateway reaction that precedes all subsequent microbial metabolism of these important metabolites. As gut microbial metabolic activity is difficult to probe due to the complex nature of the gut microbiome, approaches are needed to profile gut microbiota-associated enzymes such as BSH. Here, we develop a panel of BSH activity-based probes (ABPs) to determine how changes in diurnal rhythmicity of gut microbiota-associated metabolism affects BSH activity and substrate preference. This panel of covalent probes enables determination of BSH activity and substrate specificity from multiple gut anerobic bacteria derived from the human and mouse gut microbiome. We found that both gut microbiota-associated BSH activity and substrate preference is rhythmic, likely due to feeding patterns of the mice. These results indicate that this ABP-based approach can be used to profile changes in BSH activity in physiological and disease states that are regulated by circadian rhythms.

Short-Term Dietary Restriction Potentiates an Anti-Inflammatory Circulating Mucosal-Associated Invariant T-Cell Response.

Short-term protein-calorie dietary restriction (StDR) is a promising preoperative strategy for modulating postoperative inflammation. We have previously shown marked gut microbial activity during StDR, but relationships between StDR, the gut microbiome, and systemic immunity remain poorly understood. Mucosal-associated invariant T-cells (MAITs) are enriched on mucosal surfaces and in circulation, bridge innate and adaptive immunity, are sensitive to gut microbial changes, and may mediate systemic responses to StDR. Herein, we characterized the MAIT transcriptomic response to StDR using single-cell RNA sequencing of human PBMCs and evaluated gut microbial species-level changes through sequencing of stool samples. Healthy volunteers underwent 4 days of DR during which blood and stool samples were collected before, during, and after DR. MAITs composed 2.4% of PBMCs. More MAIT genes were differentially downregulated during DR, particularly genes associated with MAIT activation (CD69), regulation of pro-inflammatory signaling (IL1, IL6, IL10, TNFα), and T-cell co-stimulation (CD40/CD40L, CD28), whereas genes associated with anti-inflammatory IL10 signaling were upregulated. Stool analysis showed a decreased abundance of multiple MAIT-stimulating Bacteroides species during DR. The analyses suggest that StDR potentiates an anti-inflammatory MAIT immunophenotype through modulation of TCR-dependent signaling, potentially secondary to gut microbial species-level changes.

Dysbiosis of the gut microbiota and its effect on α-synuclein and prion protein misfolding: consequences for neurodegeneration.

Abnormal behavior of α-synuclein and prion proteins is the hallmark of Parkinson's disease (PD) and prion illnesses, respectively, being complex neurological disorders. A primary cause of protein aggregation, brain injury, and cognitive loss in prion illnesses is the misfolding of normal cellular prion proteins (PrPC) into an infectious form (PrPSc). Aggregation of α-synuclein causes disruptions in cellular processes in Parkinson's disease (PD), leading to loss of dopamine-producing neurons and motor symptoms. Alteration in the composition or activity of gut microbes may weaken the intestinal barrier and make it possible for prions to go from the gut to the brain. The gut-brain axis is linked to neuroinflammation; the metabolites produced by the gut microbiota affect the aggregation of α-synuclein, regulate inflammation and immunological responses, and may influence the course of the disease and neurotoxicity of proteins, even if their primary targets are distinct proteins. This thorough analysis explores the complex interactions that exist between the gut microbiota and neurodegenerative illnesses, particularly Parkinson's disease (PD) and prion disorders. The involvement of the gut microbiota, a complex collection of bacteria, archaea, fungi, viruses etc., in various neurological illnesses is becoming increasingly recognized. The gut microbiome influences neuroinflammation, neurotransmitter synthesis, mitochondrial function, and intestinal barrier integrity through the gut-brain axis, which contributes to the development and progression of disease. The review delves into the molecular mechanisms that underlie these relationships, emphasizing the effects of microbial metabolites such as bacterial lipopolysaccharides (LPS), and short-chain fatty acids (SCFAs) in regulating brain functioning. Additionally, it looks at how environmental influences and dietary decisions affect the gut microbiome and whether they could be risk factors for neurodegenerative illnesses. This study concludes by highlighting the critical role that the gut microbiota plays in the development of Parkinson's disease (PD) and prion disease. It also provides a promising direction for future research and possible treatment approaches. People afflicted by these difficult ailments may find hope in new preventive and therapeutic approaches if the role of the gut microbiota in these diseases is better understood.

Unveiling the therapeutic symphony of probiotics, prebiotics, and postbiotics in gut-immune harmony.

The gut microbiota and immune system interaction play a crucial role in maintaining overall health. Probiotics, prebiotics, and postbiotics have emerged as promising therapeutic approaches to positively influence this complex axis and enhance health outcomes. Probiotics, as live bacteria, promote the growth of immune cells, shape immune responses, and maintain gut barrier integrity. They modify the gut microbiota by fostering beneficial bacteria while suppressing harmful ones. Additionally, probiotics interact with the immune system, increasing immune cell activity and anti-inflammatory cytokine production. Prebiotics, as indigestible fibers, selectively nourish beneficial microorganisms in the gut, enhancing gut microbial diversity and activity. This, in turn, improves gut health and boosts immune responses while controlling inflammation through its immunomodulatory properties. Postbiotics, produced during probiotic fermentation, such as short-chain fatty acids and antimicrobial peptides, positively impact gut health and modulate immune responses. Ensuring quality control and standardization will be essential for successful clinical implementation of these interventions. Overall, understanding and harnessing the gut microbiota-immune system interplay offer promising avenues for improving digestive and immunological health.

Effect of protein modification in synbiotic infant formula on probiotic metabolic activity and bacterial composition in an infant gut-model.

Aim: Microbial colonization of the neonatal gut is pivotal in priming the infant's immune system. Human milk (HM) is the best nutrition for infants and supports the development of the microbiota due to prebiotic compounds and probiotic microorganisms. When exclusive breastfeeding is not possible, infant formula (IF) with probiotics is a strategy to support the infant's microbiome development. However, knowledge about the effects of the infant gut microbiota and different compounds in IF on individual probiotic strains is limited, as strain-level detection in a complex ecosystem is challenging. The aim of the present study was to show the effects of IF with different protein forms on the metabolic activity of two probiotic strains isolated from HM in a complex ecosystem. Methods: By using an ex-vivo infant gut model containing infant donor-microbiota, the effects of IF with either intact or extensively hydrolyzed protein on the metabolic activity of the donor microbiota, as well as two probiotic strains [Limosilactobacillus fermentum (L. fermentum) CECT 5716 (Lf) and Bifidobacterium breve (B. breve) DSM 32583 (Bb)], were analyzed. A new bioinformatic pipeline combined with a specific infant microbiome database was used to explore shotgun metagenome datasets (1200 Megabases) for taxonomic identification and strain-level tracking. Results: Both protein forms (i.e., intact or extensively hydrolyzed protein) in IF supported infant gut microbial metabolic activity equally, as evidenced by similar levels of short-chain fatty acids (SCFAs). Interestingly, gut microbial metabolic activity was found to be differently activated in a strain-dependent manner. Taxonomic profiling of the microbiome at the strain level enabled monitoring of the prevalence and abundance of both probiotic strains, even in a complex ecosystem. Conclusion: Food matrix and host microbiota interactions should be considered when evaluating strain-specific probiotic effects in the future.

EAAS AND WHEY PROTEIN MAY IMPROVE PHYSICAL FUNCTION OF OLDER ADULTS INDEPENDENTLY OF GUT MICROBIOME

Abstract Essential amino acids (EAAs) and dietary proteins are major nutritional supplements that support the growth and activity of gut microbes, contributing to the wellbeing of their host. We hypothesized that daily ingestion of EAAs or whey proteins for twelve weeks would improve the gut microbiome of older adults and thereby have a positive impact on their physical functioning. The stool samples were collected from the 40 subjects before and after consuming EAAs or whey proteins for twelve weeks and subjected to Illumina based 16S rRNA gene sequencing. In both groups, the most abundant families in order of relative abundance included: Bacteroidaceae, Ruminococcaceae, Lachnospiraceae, Rikenellaceae, and Prevotellaceae, which indicated that these subjects were able to maintain a dominant consortium of microbes in their guts that have been associated with healthy aging. Individual gut microbiome samples analysis with nonmetric multidimensional space (NMDS) showed that each individual was associated with its unique microbiome. The key finding of this study was a significant reduction of plasma Interleukin-18 binding protein (IL-18) in EAAs vs whey group (p &amp;lt; 0.003). It is plausible that the reduced level of inflammatory IL-18 contributed to improved intestinal immunity. Moreover, the reduced inflammation might have resulted in better muscle performance in the EAAs group vs whey as evidenced by six-minute walking distance (EAAs 92.55 ± 4.16 ft vs whey 47.46 ± 4.99 ft, p&amp;lt; 0.0001) at the completion of study. Future studies will need to explore the role of EAAs on gut microbiome mediated reduction of immune inflammation on physical function and aging.

The prebiotic potential of RS-3 preparations for pre- and post-weaning piglets

Piglets undergo stress during the weaning period, resulting in an imbalance in gut microbial composition and activity, and potentially post-weaning diarrhoea. Supporting maturation of gut microbiota is a strategy preparing piglets for weaning, and could be achieved by providing dietary fibres such as resistant starch (RS) in the creep feed. We investigated the prebiotic potential of four well-characterised retrograded starches (RS-3 preparations) for pre- and post-weaning piglets. These RS-3 preparations were in vitro fermented using pooled faecal inoculum of 3-week-old (pre-weaning) and 7-week-old (post-weaning) piglets. RS-3 preparations containing a high amount of digestible starch (≥ 75 %) were fully fermented by both faecal inocula within 48 h. Such substrates generated mostly butyrate when fermented by pre-weaning piglet faecal inoculum, whereas mostly propionate was found during fermentation by post-weaning inoculum. Bacterial genera Prevotella and Megasphaera increased in relative abundance after fermentation by both inocula, whereas Streptococcus and Selenomonas increased in relative abundance only when fermented by pre-weaning or post-weaning piglet faecal inocula, respectively. Highly resistant or so-called intrinsic RS-3 (≥ 80 % RS) was hardly degraded by pre-weaning inoculum, whereas it was slowly fermented by post-weaning piglet faecal microbiota, leading to an increase in relative abundance of specific Prevotella and Roseburia phylotypes (amplicon sequence variants). This study shows that partially resistant RS-3 preparations might be beneficial dietary fibres for pre-weaning piglets by promoting short-chain fatty acids production, while intrinsic RS-3 was hardly fermentable. Intrinsic RS-3 substrates might have prebiotic potential for post-weaning piglets by stimulating potential health-beneficial Prevotella and Roseburia.

Prebiotic potential of green banana flour: impact on gut microbiota modulation and microbial metabolic activity in a murine model.

Green banana flour can be used as a prebiotic due to its ability to promote gut health and provide several health benefits. In this study, we investigated whether feeding mice green banana flour at different doses would alter intestinal microbiota composition. We fed C57BL/6N mice either a Low-dose (500 mg/kg/day) or High-dose (2000 mg/kg/day) of green banana flour daily for 3 weeks, and fecal samples were collected on days 0, 14, and 21 for microbiota analysis. Our results showed that the composition of intestinal microbiota was significantly altered by day 21, regardless of the dose. Notably, the consumption of green banana flour increased the presence of beneficial bacteria, including Coriobacteriaceae_UCG-002, Turicibacter, Parasutterella, Gastranaerophilales_ge, and RF39_ge. These changes in the intestinal microorganisms were accompanied by increased biological processes such as amino acid biosynthesis and secondary metabolite biosynthesis. Conversely, the consumption of green banana flour resulted in a decrease in biological processes related to carbohydrate degradation, glycerol degradation, and similar functions. These results emphasize the potential of green banana flour as a prebiotic that can benefit the gut microbiome.

Growth performance and physiological responses of striped catfish (Pangasianodon hypophthalmus) under different carbohydrates supplemented biofloc aquaculture systems

Biofloc technology is booming in inland aquaculture sector across the world especially in the places where water scarcity is high and land cost is expensive. Currently, the lack of appropriate selection and application feasibility of suitable carbohydrate in water quality management and fish health in biofloc aquaculture system are the major concern for wider adaptability of the technology. Therefore, the present experiment investigated the effect of different carbohydrate sources on overall wellbeing of striped catfish (Pangasianodon hypophthalmus) fingerlings. The experiment was randomly designed in four treatments (T1, T2, T3 and T4) and one control in triplicates in indoor tanks (1.0 m3). T1, T2, T3 and T4 groups supplemented with tapioca flour, sugarcane bagasse, molasses and jaggery, respectively under biofloc system at C:N ratio of 15:1, whereas the control group was not supplemented with carbohydrate source. Pre-acclimatized 525 fingerlings (7.2 ± 0.03 cm, 7.4 ± 0.003 g) were randomly stocked (35 nos. m−3) in the tanks and reared for 90 days. Overall, better water quality, fish performance and health status were observed in all the carbohydrates supplemented treatments than the control. Higher abundance of heterotrophic bacteria (5.88–118.18%) and biofloc associated microorganisms in jaggery supplemented biofloc, significantly (P ≤ 0.05) reduced total ammonia nitrogen, nitrite‑nitrogen, and increased nitrate‑nitrogen concentrations than other treatments. In the T4 treatment, jaggery supplementation enhanced biofloc volume, which influenced enhancement of fish body weight gain, specific growth rate, and improvement of feed conversion ratio than other biofloc treatments. Enhanced gut microbial population and digestive enzymes activity in fish significantly enhanced protein efficiency ratio, apparent net protein utilization, and flesh protein content in the T4 treatment. Fish showed significantly (P ≤ 0.05) higher haematological, immunological, and improved antioxidative responses in the T4 treatment than other treatments. Consumption of biofloc significantly (P ≤ 0.05) improved intestinal villi microarchitecture as higher villi surface area, width and height were detected in the T4 treatment. Collectively, the findings suggested that jaggery was the suitable carbohydrate source in terms of overall improvement of the culture system including growth performance and health status of P. hypophthalmus, if applied appropriately in biofloc aquaculture system. The present study comprehensively addressed carbohydrate sources, biofloc formation, total ammonia nitrogen management, fish growth and health resulting in better adoptability of biofloc technology by farmers in aquaculture.

A Metabolite Perspective on the Involvement of the Gut Microbiota in Type 2 Diabetes.

Type 2 diabetes (T2D) is a commonly diagnosed condition that has been extensively studied. The composition and activity of gut microbes, as well as the metabolites they produce (such as short-chain fatty acids, lipopolysaccharides, trimethylamine N-oxide, and bile acids) can significantly impact diabetes development. Treatment options, including medication, can enhance the gut microbiome and its metabolites, and even reverse intestinal epithelial dysfunction. Both animal and human studies have demonstrated the role of microbiota metabolites in influencing diabetes, as well as their complex chemical interactions with signaling molecules. This article focuses on the importance of microbiota metabolites in type 2 diabetes and provides an overview of various pharmacological and dietary components that can serve as therapeutic tools for reducing the risk of developing diabetes. A deeper understanding of the link between gut microbial metabolites and T2D will enhance our knowledge of the disease and may offer new treatment approaches. Although many animal studies have investigated the palliative and attenuating effects of gut microbial metabolites on T2D, few have established a complete cure. Therefore, conducting more systematic studies in the future is necessary.

Investigating the Crime Scene-Molecular Signatures in Inflammatory Bowel Disease.

Inflammatory bowel diseases (IBD) are without cure and troublesome to manage because of the considerable diversity between patients and the lack of reliable biomarkers. Several studies have demonstrated that diet, gut microbiota, genetics and other patient factors are essential for disease occurrence and progression. Understanding the link between these factors is crucial for identifying molecular signatures that identify biomarkers to advance the management of IBD. Recent technological breakthroughs and data integration have fuelled the intensity of this research. This research demonstrates that the effect of diet depends on patient factors and gut microbial activity. It also identifies a range of potential biomarkers for IBD management, including mucosa-derived cytokines, gasdermins and neutrophil extracellular traps, all of which need further evaluation before clinical translation. This review provides an update on cutting-edge research in IBD that aims to improve disease management and patient quality of life.

Predominant contribution of an endogenous cellulase (OlCel) to the cellulolysis in the digestive system of larvae of banana pseudostem weevil, Odoiporus longicollis (Coleoptera: Curculionidae).

Insects have evolved with effective strategies to utilize cellulose as an energy source by possessing cellulolytic enzymes which can be used as an optimal resource in the bioenergy sector. The study was aimed at evaluating the cellulolytic enzyme in the larval gut of the banana pseudostem weevil, Odoiporus longicollis Olivier (Coleoptera: Curculionidae). Primarily, cellulase activity was localized along the gut, in which the midgut showed the highest activity (2858 U/mg). The thermo-tolerance of cellulase activity was found to be up to 80°C (highest at 60°C), and the enzyme was stable at a pH between 5 and 6. Various concentrations of divalent cations (CaCl2 , MgCl2 , and CuCl2 ) have differential enhancing and inhibitory effects on cellulase activity. The cellulase (OlCel) was purified using anion exchange chromatography. The molecular weight of the cellulase was determined to be 47 kDa. The physicochemical parameters of the purified enzyme were similar to that of enzyme activity of whole gut extract. Mass spectrometry results identified sequence similarities of purified cellulase to the glycosyl hydrolase family 5 (GHF5) family. The gut microbial cellulase activity as exogenous source showed no competence compared with the endogenous activity.

Vitamin K and Hallmarks of Ageing: Focus on Diet and Gut Microbiome.

Vitamin K and vitamin K-dependent proteins have been reported to be associated with a large spectrum of age-related diseases. While most of these associations have been deduced from observational studies, solid evidence for the direct impact of vitamin K on cellular senescence remains to be proven. As vitamin K status reflects the complexity of interactions between dietary intake, gut microbiome activity and health, we will demonstrate the pivotal role of the diet-microbiome-health axis in human ageing and exemplify how vitamin K is implicated therein. We propose that food quality (i.e., food pattern) should be highlighted beyond the quantity of total vitamin K intake. Instead of focusing on a single nutrient, exploring a healthy diet containing vitamin K may be more strategic. As such, healthy eating patterns can be used to make dietary recommendations for the public. Emerging evidence suggests that dietary vitamin K is a modulator of the diet-microbiome-health axis, and this needs to be incorporated into the investigation of the impact of vitamin K on gut microbial composition and metabolic activities, along with host health outcomes. In addition, we highlight several critical caveats that need to be acknowledged regarding the interplay between diet, vitamin K, gut microbiome and host health that is pivotal for elucidating the role of vitamin K in ageing and responding to the urgent call of healthy eating concerning public health.

Targeting the human gut microbiome with small-molecule inhibitors.

The human gut microbiome is a complex microbial community that is strongly linked to both host health and disease. However, the detailed molecular mechanisms underlying the effects of these microorganisms on host biology remain largely uncharacterized. The development of non-lethal, small-molecule inhibitors that target specific gut microbial activities enables a powerful but underutilized approach to studying the gut microbiome and a promising therapeutic strategy. In this Review, we will discuss the challenges of studying this microbial community, the historic use of small-molecule inhibitors in microbial ecology, and recent applications of this strategy. We also discuss the evidence suggesting that host-targeted drugs canaffect the growth and metabolism of gut microbes. Finally, we address the issues of developing and implementing microbiome-targeted small-molecule inhibitors and define important future directions for this research.