Gut Flora Research Articles

Gut system of chitinivorous insect Chrysomya megacephala was purposefully targeted to find unexplored microbial resources based on the rationale of their usual food habits. A phytobeneficial bacterial strain Aeromonas veronii CMF was successfully isolated and characterized up to genomic approaches. The gut isolate A. veronii CMF is a non-pathogenic strain, as proven by the negative results from the hemolysis and DNase tests. Antifungal enzyme production by the CMF exhibited 22.14 ± 2.12, 16.09 ± 0.476, and 1.89 ± 0.46 U/mL chitinase, protease, and β-1,3-glucanase production, respectively. Further, in vitro and in vivo studies also elucidate the effective utilization of such gut bacterial attributes against as many as nine plant pathogenic fungi, demonstrating plant growth-promoting (PGP) and root-colonizing activities with Cicer arietinum and Oryza sativa IR36, as well as heavy metal(loid)s (HMs) resistance, removal, and bioaccumulation potential. Hence, the current study revealed the potential of the gut symbiont CMF to respond against both the biotic and abiotic stresses with PGP attributes for sustainable agriculture.IMPORTANCEGut symbiont A. veronii CMF, with integrated antifungal (chitinase, protease, and β-1,3-glucanase activity), plant growth-promoting (including plant root colonizing potential), and bioremediational attributes can be harnessed as a biotechnological tool for sustainable agriculture and human welfare by fulfilling several sustainable developmental goals. On the basis of such multidimensional gut symbiotic attributes which are validated through genomic-phenotypic observations during this study, it can be suggested that this gut symbiont can perform the host beneficial attributes in the plant rhizosphere, i.e., the "plant gut system" and consequently act as "plant gut symbionts."

Resistant starch (RS), a major category of dietary fiber, promotes healthy lipid and glucose metabolism. These effects are partly mediated by gut microbes. RS is known to influence microbial bile acid metabolism and, in turn, can lower serum cholesterol. We hypothesized that RS may promote another microbial process that affects serum cholesterol levels – the cholesterol:coprostanol transformation pathway, which has not been fully characterized. Individuals who harbor gut microbes encoding a recently identified gene in the pathway, intestinal sterol metabolism A (ismA), can transform cholesterol to less absorbable coprostanol. Individuals with microbial ismA genes have lower serum cholesterol than people without microbial ismA genes. We conducted a seven-week crossover study with 59 individuals completing three treatments: dietary supplementation with RS type 2, RS type 4, and a digestible starch, for ten days each with five-day washout periods in between. We collected fecal samples at the beginning and end of each treatment and extracted DNA to generate a shotgun metagenomics dataset from the gut microbiomes. We also measured the concentrations of bile acids and the sterols, cholesterol and coprostanol, in the stool. RS supplementation caused interindividual variability in gut microbiome response. Also, during the RS type 2 treatment, we observed a decrease in taurocholic acid, a bile acid that may promote colon cancer (q < 0.05). RS supplementation did not universally affect sterol levels. However, we observed consistent correlations between the abundances of some microbes, or species level genome bins (SGBs), and sterol concentrations longitudinally within subjects. We identified 24 SGBs, including three Oscillibacter species, which were negatively correlated with cholesterol and positively correlated with coprostanol (Spearman's rho ≥ 0.4). In addition to its ability to transform cholesterol, Oscillibacter has previously been implicated as benefiting lipid metabolism and cardiovascular health. We also identified 12 unclassified SGBs that may be involved in the transformation of cholesterol to coprostanol in the human gut. These SGBs may represent previously undiscovered species that participate in the cholesterol:coprostanol transformation pathway, and these species may possess unknown genes in the pathway. Comprehensive characterization of this pathway could lead to novel microbiome-based therapeutics to treat hypercholesterolemia.

Introduction: Parvimonas is a part of the oral and gastrointestinal flora. It is a rare cause of purulent pericarditis and liver abscess. The literature has reported isolated cases of pericardial abscesses and liver abscesses caused by other anaerobes and E. coli. We report a rare case of concomitant pericardial and liver abscess caused by Parvimonas micra. Case Report: Our case is a 51-year-old male with a past medical history of multiple sclerosis who presented to the emergency department with vomiting, chest pain, and shortness of breath. The EKG on admission was concerning for ST elevation in the inferolateral leads, but it resolved without any intervention. He had normal troponins. 2-D echocardiogram showed moderate to large circumferential pericardial effusion with mobile echodensities along the RV without evidence of cardiac tamponade physiology. CT of the abdomen and pelvis also revealed low attenuation in the left hepatic lobe that was concerning for liver abscess with free fluid in the pelvis. Pericardiocentesis was done and yielded 500 ml of straw-colored fluid. An ultrasound-guided pigtail catheter was inserted for the liver abscess, which drained 70 ml of purulent fluid. Cultures from the pericardial fluid yielded Parvimonas mica. The patient was treated empirically with piperacillin-tazobactam and was later switched to ceftriaxone. However, a repeat echocardiogram done a few days later showed reaccumulation of purulent pericardial effusion, which required a pericardial window. The patient also developed bilateral pleural effusions after the pericardial window. Drainage of right pleural fluid yielded 950 ml of neutrophilic predominant fluid. Afterwards, he improved clinically and was discharged with a four-week course of IV ceftriaxone followed by PO Augmentin for another four weeks. Discussion: In our case, the patient initially presented with chest pain and electrocardiographic findings of inferolateral ST elevation and was found to have purulent pericarditis and a liver abscess. Literature reports rare cases of liver abscess and purulent pericarditis in isolation caused by Parvimonas micra; however, in our case, the patient had concomitant pericardial and liver abscess from Parvimonas micra. One case reported both abscesses in the same patient caused by B. fragilis, Hungatella hathewayi, and Fusobacterium nucleatum. Our patient also had reaccumulation of pericardial abscess requiring creation of a pericardial window during the hospital course.

The gut-brain axis is a highly complex, bidirectional communication link between the gut and the central nervous system (CNS), mainly through neural, endocrine, immunological, and metabolic pathways. This review outlines the growing contribution of gut microbiota in the remediation of neurological health and also emphasizes the controlling role of gut microbiota on the synthesis of neurotransmitters. Emerging evidence indicates that dysbiosis of the gut is related to a variety of neurodegenerative and neuropsychiatric diseases such as Parkinson's disease (PD), Alzheimer's disease (AD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), autism spectrum disorders (ASD), depression, and glioblastoma. Mechanistic understandings show that gut microbes critically contribute to neuroimmune and blood-brain barrier (BBB) signaling. The peripheral association of gut microflora, networked with inflammasome activation, nuclear factor kappa B (NF-κB), and type-I IFN pathways highlights their role in CNS inflammation. Microbiota-targeted interventions with probiotics, prebiotics, synbiotics, antibiotics, dietary modifications, and fecal microbiota transplantation are examined for their therapeutic potential. These strategies appear to be promising to reinstate microbial balance, enhance neuroplastic responses, and ameliorate the disease symptoms. The review highlights personalized microbiome-based algorithms, underpinned by integrated multi-omics technologies and machine-learning-driven diagnostics. Future research should address underlying microbial mechanisms and perform large, randomized controlled trials in order to establish microbiota-based therapies for neurological disorders.

The identification and functional characterization of Lactococcus lactis PRL2024 and Streptococcus thermophilus PRL2025 as human-adapted reference strains provide a valuable foundation for further in vivo experimentation. Given their ecological resilience, metabolic versatility, and interaction potential with beneficial gut microbes, these strains represent promising candidates as microbiota-targeted functional foods.

The relationship between obstructive sleep apnea (OSA) and the gut microbiota is increasingly recognized, yet the involvement of specific microbial taxa and the direction of causality remain unclear. This review synthesizes current evidence linking gut dysbiosis with disordered sleep, with a focus on OSA and its associated complications. Studies of alpha and beta microbial diversity in OSA patients, sampled at different sites, have had inconsistent results. Members of the genus Fusobacterium and family Lachnospiraceae are enriched in some studies of OSA and have been linked with gut barrier permeability and complications, such as hypertension. OSA treatments, including positive airway pressure and GLP-1 agonists, have varying effects on the microbiota. Microbiota-targeted therapies may reduce OSA-related complications, but these potential treatments require additional well designed trials to clarify the bidirectional relationship between gut microbes and sleep-related health.

Lycium barbarum polysaccharides alleviate experimental autoimmune prostatitis by putrescine/TRAF/JAK/STAT-mediated Th17 differentiation.

Integrated multi-omics reveals mechanistic impact of gut microbiota inhibition on lignocellulose biodegradation in Tenebrio molitor.

Synergistic mechanism of tetracycline degradation by poor-degrading microbe Serratia marcescens cooperated with insect during environmental decomposition cycle.

Gut microbiota - indole-3-acetic acid axis in cancer: dual functions, mechanistic insights, and therapeutic potential.

Optimizing mealworm rearing conditions and gut microbiome function for enhanced plastics biodegradation.

Liuwei Dihuang formula ameliorates perimenopausal atherosclerosis by modulating the microbiota-dependent TMA-TMAO metabolic axis.

Phytosterols as modulators of gut-brain axis and neuroinflammation in Alzheimer's disease: A novel therapeutic avenue in aging research.

Cognitive function and synaptic plasticity in the hippocampus exposed to stress respond similarly to different probiotic mixtures.

Trimethylamine N-Oxide (TMAO) and cancer risk: Insights into a possible link.

Advancing approaches to cultivate industrially and ecologically relevant microorganisms from termite guts.

Modified Xiaoyaosan rescues depression-like behavior via remodeling gut microbiota and leucine metabolism.

Antibiotic treatment improves gut dysbiosis and depression-like behavior induced by morphine withdrawal.

Varroa destructor infestation amplifies imidacloprid vulnerability in Apis mellifera.

Huangshui polysaccharide: A multifunctional additive for enhancing antioxidant activity, aroma profile, and gut health in baijiu.