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While new species of termites are described every year, the description of species distant from every known termite species is rare. In this paper, we describe one such species, Engelitermes zambosp.n., an African Termitidae belonging to an entirely new lineage of termites for which we create a new subfamily, Engelitermitinae subfam.n. The subfamily status of Engelitermitinae was supported by termite phylogenetic trees, including sequences from the four existing samples of E. zambosp.n., which, albeit with low bootstrap supports, placed Engelitermesgen.n. on a long branch sister to Forficulitermes, the two of which formed the sister group of a clade comprising Cubitermitinae, Nasutitermitinae, Syntermitinae and all other Termitinae. The sister relationship between Engelitermesgen.n. and Forficulitermes is further supported by the similar gut structure of their workers. In contrast, the soldiers of Engelitermesgen.n. resemble those of Cephalotermes. Our phylogenetic analyses, including all clades of Termitinae, call for a global taxonomic revision of the Termitinae subfamily names. Finally, our study highlights that new unique termite lineages are still awaiting to be described. [ABSTRACT FROM AUTHOR]

This paper argues for the sociological relevance of contemporary research from 'relational' or 'systems' biology on the microbiome‐gut‐brain (MGB) axis. I review research on the MGB from microbial neuroendocrinology, nutritional psychiatry and other fields with a specific focus on nutrition as a critical element of the social environment influencing gene‐environment interactions and a range of social behaviors. I discuss two plausible causal pathways from nutritional factors such as dietary inflammatory potential and hypocholesterolemia to social bonding, violence, and political extremism, and conclude with a discussion of the theoretical, methodological, and epistemological implications of these pathways, and of MGB research and relational biology generally, for social science. [ABSTRACT FROM AUTHOR]

Summary: Two commercial promising probiotic strains (Propionibacterium jensenii and Propionibacterium freudenreichii) were studied to evaluate two basic probiotic requisites (adhesion and survival during the transit into the gut); two commercial starter cultures (Lactobacillus plantarum and Lactobacillus delbrueckii subsp. bulgaricus) were used as references. As an additional goal, the technological robustness was evaluated as growth as a function of pH, temperature and salt. Adhesion was studied as biofilm formation and hydrophobicity, whereas a simplified protocol was used to simulate the transit into the gut, along with the assessment of survival at pH 2.5 and in the presence of 0.3% bile salts. Propionibacteria were hydrophobic and form biofilm on glass slides, thus confirming the correlation of these properties and with the ability to adhere. None of the strains survived after the simulation of the transit into the gut, but this property could be induced in propionibacteria using a simple protocol of adaptive evolution. This paper suggests the possibility of using hydrophobicity as a screening tool to assess adhesion in propionibacteria and highlights the necessity of using a complete protocol of simulation of the gut to study the resistance to the conditions of stomach and intestine to avoid false‐positive results. [ABSTRACT FROM AUTHOR]

High copper feed has been widely used as an inexpensive and highly effective feed additive to promote growth performance of pigs. However, long‐term feeding of high copper feed may reduce the growth‐promoting effects of copper, time‐dependent accumulation of copper in animal tissues and organs, and copper toxicity thereby reducing the growth performance of pigs. Due to the widespread effects of high copper supplementation in animals' diets, the benefits and drawbacks of high copper feeding in pigs have been reported in several studies. Meanwhile, few of these studies have systematically described the mechanism by which high copper diets restrain pig growth. Therefore, to address the concerns and give a better understanding of the mechanism of high copper diet in restraining pig growth in different systems, this paper reviews the research progress of long‐term supplementation of high copper on the growth of pigs and provides some suggestions and further research directions. [ABSTRACT FROM AUTHOR]

Prebiotic and probiotic products continue to experience strong consumer growth while gastroenterological researchers work behind the scenes to understand the effects of specific bacterial strains on study participants' feelings of mind‐body healthfulness. Correlations are achieved through the use of psychometric questionnaires, which aim to measure affect states like stress, anxiety, and depression. In this paper, we turn to qualitative textual analysis to examine two commonly employed psychometric questionnaires (HAM‐D and HADS) used in studies of the same probiotic formulation. We show how concepts of social deviance and norms of behavior (e.g., sleep patterns, social life, and work productivity) inform such questionnaires, thus inserting normative ethical imperatives into clinical findings. After demonstrating several key disjunctions across these questionnaires, we develop recommendations for gastroenterological researchers. In particular, we recommend that researchers give more focused attention to aligning psychometric questionnaires and more carefully enact their qualitative assessment requirements. In like manner, we recommend that ethical reviewers and science policy reviewers consider how psychometric questionnaires embed social assumptions into clinical trials, which can affect determinations of healthfulness. [ABSTRACT FROM AUTHOR]

Summary: Food contamination by toxins (both mycotoxins and bacterial toxins) represents a great challenge for their implications on health. Toxins could be removed during production, but many times, they enter the gut and act on the host. To some extents, a benefit of probiotics could be the removal/neutralisation of harmful compounds in the gut with an indirect health effect on the host. Some authors addressed the ability of yeasts and bacteria to remove mycotoxins and other toxins; however, to the best of our knowledge, there is not an overview on how and when mycotoxins and some other bacterial toxins (like cyanotoxins) can be removed by probiotics into the gut. Therefore, this topic is addressed in this paper. The manuscript is organised with an initial overview of the literature about probiotics, mycotoxins and cyanotoxins followed by a section on the ability of probiotics to remove toxins in vitro and in vivo. [ABSTRACT FROM AUTHOR]

The ecological and genetic changes that underlie the evolution of host–microbe interactions remain elusive, primarily due to challenges in disentangling the variables that alter microbiome composition. To understand the impact of host habitat, host genetics, and evolutionary history on microbial community structure, we examined gut microbiomes of river‐ and three cave‐adapted morphotypes of the Mexican tetra, Astyanax mexicanus, in their natural environments and under controlled laboratory conditions. Field‐collected samples were dominated by very few taxa and showed considerable interindividual variation. We found that lab‐reared fish exhibited increased microbiome richness and distinct composition compared to their wild counterparts, underscoring the significant influence of habitat. Most notably, however, we found that morphotypes reared on the same diet throughout life developed distinct microbiomes suggesting that genetic loci resulting from cavefish evolution shape microbiome composition. We observed stable differences in Fusobacteriota abundance between morphotypes and demonstrated that this could be used as a trait for quantitative trait loci mapping to uncover the genetic basis of microbial community structure. [ABSTRACT FROM AUTHOR]

The human gastrointestinal microbiota and its unique metabolites regulate a diverse array of physiological processes with substantial implications for human health and performance. Chronic exercise training positively modulates the gut microbiota and its metabolic output. The benefits of chronic exercise for the gut microbiota may be influenced by acute changes in microbial community structure and function that follow a single exercise bout (i.e., acute exercise). Thus, an improved understanding of changes in the gut microbiota that occur with acute exercise could aid in the development of evidence‐based exercise training strategies to target the gut microbiota more effectively. In this review, we provide a comprehensive summary of the existing literature on the acute and very short‐term (<3 weeks) exercise responses of the gut microbiota and faecal metabolites in humans. We conclude by highlighting gaps in the literature and providing recommendations for future research in this area. New Findings: What is the topic of this review?The chronic benefits of exercise for the gut microbiota are likely influenced by acute changes in microbial community structure and function that follow a single exercise bout. This review provides a summary of the existing literature on acute exercise responses of the gut microbiota and its metabolic output in humans.What advances does it highlight?Acute aerobic exercise appears to have limited effects on diversity of the gut microbiota, variable effects on specific microbial taxa, and numerous effects on the metabolic activity of gut microbes with possible implications for host health and performance. [ABSTRACT FROM AUTHOR]

The development of nanotechnology is becoming a major trend nowadays. Nanoparticles (NPs) have been widely used in fields including food, biomedicine, and cosmetics, endowing NPs more opportunities to enter the human body. It is well‐known that the gut microbiome plays a key role in human health, and the exposure of intestines to NPs is unavoidable. Accordingly, the toxicity of NPs has attracted more attention than before. This review mainly highlights recent advances in the evaluation of NPs' toxicity in the gastrointestinal system from the existing cell‐based experimental models, such as the original mono‐culture models, co‐culture models, three‐dimensional (3D) culture models, and the models established on microfluidic chips, to those in vivo experiments, such as mice models, Caenorhabditis elegans models, zebrafish models, human volunteers, as well as computer‐simulated toxicity models. Owing to these models, especially those more biomimetic models, the outcome of the toxicity of NPs acting in the gastrointestinal tract can get results closer to what happened inside the real human microenvironment. The toxicity of nanoparticles (NPs) has raised concerns recently because the exposure of intestines to NPs is unavoidable. Therefore, in this review, the recent evaluation models of NPs' toxicity in the gastrointestinal system have been highlighted, from mono‐culture, co‐culture, three‐dimensional (3D) culture, and the models established on microfluidic chips in vitro, to mice, Caenorhabditis elegans, zebrafish, and humans in vivo, as well as computer‐simulated toxicity models. In summary, the developments of these models facilitate the further applications of NPs. [ABSTRACT FROM AUTHOR]

Objectives: To extract the microbiological and immunological evidence underpinning the association between periodontitis and inflammatory bowel disease (IBD). Methods: Relevant articles were sorted through a systematic search on PubMed, Embase, Scopus and Web of Science up to October 2020. Available evidence was grouped in three different clusters: (a) studies that examined oral microbial alterations in IBD patients; (b) studies that investigated intestinal dysbiosis in patients with periodontitis; and (c) evidence for a shared immunological pattern between the two conditions. Results: A total of 15 studies involving 1,171 patients were included. Oral microbiome, either subgingival or salivary, was consistently altered in patients with IBD compared to healthy subjects (a) Additionally, gut dysbiotic microbiota of IBD patients was colonized by pathobionts from oral origin, either via haematogenous or enteric route. Suffering from periodontitis is associated with lower alpha diversity in the gut microbiome (b) Lastly, both IBD and periodontitis are characterized by similar expression patterns of inflammatory cytokines at the gingival and gut levels that are exacerbated when both diseases are present (c). Conclusions: Periodontitis and IBD share common dysbiotic and immunological traits. Well‐designed preclinical models and longitudinal cohort studies are required to better explore the causal pathways between the two conditions (PROSPERO CRD42020194379). [ABSTRACT FROM AUTHOR]

Vacuolar ATPase (vATPase) is an important proton pump in insect tissues including gut and Malpighian tubule. Subunit F, one of the 16 subunits of the vATPase holoenzyme, is not well characterized. Here, we found that two HvvATPaseF isoforms were highly expressed in the hindgut and Malpighian tubules (MT) in the 28‐spotted lady‐beetle Henosepilachna vigintioctopunctata, an agricultural pest that feeds on Solanaceae and Cucurbitaceae. Knockdown of both HvvATPaseF variants by RNA interference (RNAi) delayed larval growth and negatively affected ecdysis and adult emergence. In the midgut, RNAi treatment resulted in the disappearance of peritrophic membrane, the reduction in the size and the impaired integrity of the gut, which was associated with sparse principle cells and an increase in TUNEL‐ and EdU‐positive cells. Whereas the MT were opaque and the tubule lumens were full of urine in dsegfp‐fed larvae, the tubules were clear and the tubule lumens were empty in the dsvATPaseF‐fed larvae. HvvATPaseF knockdown was also associated with a decrease in the abundance of the fat body and the levels of glucose, trehalose, triglyceride, total soluble amino acids and proteins, and an increase in glycogen. Consistent with the known effects of sugars on chitin formation, both the expression level of a chitin biosynthesis gene and the thickness of the head capsule cuticle were reduced in the HvvATPaseF‐depleted beetles. Our results demonstrated that subunit F plays an essential role in H. vigintioctopunctata development. [ABSTRACT FROM AUTHOR]

Sizeable scientific evidence indicates the health benefits related to phenolic compounds and dietary fiber. Various phenolic compounds‐rich foods or ingredients are also rich in dietary fiber, and these two health components may interrelate via noncovalent (reversible) and covalent (mostly irreversible) interactions. Notwithstanding, these interactions are responsible for the carrier effect ascribed to fiber toward the digestive system and can modulate the bioaccessibility of phenolics, thus shaping health‐promoting effects in vivo. On this basis, the present review focuses on the nature, occurrence, and implications of the interactions between phenolics and food components. Covalent and noncovalent interactions are presented, their occurrence discussed, and the effect of food processing introduced. Once reaching the large intestine, fiber‐bound phenolics undergo an intense transformation by the microbial community therein, encompassing reactions such as deglycosylation, dehydroxylation, α‐ and β‐oxidation, dehydrogenation, demethylation, decarboxylation, C‐ring fission, and cleavage to lower molecular weight phenolics. Comparatively less information is still available on the consequences on gut microbiota. So far, the very most of the information on the ability of bound phenolics to modulate gut microbiota relates to in vitro models and single strains in culture medium. Despite offering promising information, such models provide limited information about the effect on gut microbes, and future research is deemed in this field. [ABSTRACT FROM AUTHOR]

The gut wall houses mast cells that are anatomically situated near enteric neuronal fibers. Roles of specific neuropeptides in modulating function of immune components like mast cells in response to challenge with bacterial components are relatively unknown. Investigating such interactions requires models that include diverse cellular elements in native anatomic arrangements. Using an organotypic slice model that maintains gut wall cellular diversity ex vivo, the present study compared responses between tissues derived from male and female mice to examine neural‐immune signaling in the gut wall after selected treatments. Ileum slices were treated with pharmacological reagents that block neuronal function (e.g., tetrodotoxin) or vasoactive intestinal peptide (VIP) receptors prior to challenge with lipopolysaccharide (LPS) to assess their influence on anatomic plasticity of VIP fibers and activation of mast cells. Sex differences were observed in the number of mucosal mast cells (c‐kit/ACK2 immunoreactive) at baseline, regardless of treatment, with female ileum tissue having 46% more ACK2‐IR mast cells than males. After challenge with LPS, male mast cell counts rose to female levels. Furthermore, sex differences were observed in the percentage of ACK2‐IR cells within 1 µm of a VIP+ neuronal fiber, and mast cell size, a metric previously tied to activation, with females having larger cells at baseline. Male mast cell sizes reached female levels after LPS challenge. This study suggests sex differences in neural‐immune plasticity and in mast cell activation both basally and in response to challenge with LPS. These sex differences could potentially impact functional neuroimmune response to pathogens. [ABSTRACT FROM AUTHOR]

Background: Ips is a bark beetle genus of 45 species, many of which are pests of conifer forests and plantations under stress. Twelve Ips species are recorded from China and presumably native there. From 2016 to 2018, specimens suspected to be Ips calligraphus and Ips grandicollis, were collected from traps with ethanol as a sole lure in Zhuhai, Guangdong, China. Both species originate in North America and infest various species of native or introduced pines. Since Ips species are known to cause or exacerbate problems in pine plantations, and a regional survey using traps baited with attractants were implemented in this study to investigate the extent of the introduction. Results: Both I. calligraphus and I. grandicollis have been collected repeatedly from several traps with Ips attractants in Zhuhai, Guangdong, China since 2016. Potential distributions of these two species in Asia, inferred using MaxEnt, is extensive, given the high projected environmental suitability in North America, South America, Mediterranean Europe, Northern Africa, and Eastern Asia. The host plant of I. calligraphus from Zhuhai was identified as slash pine Pinus elliottii using DNA barcoding of gut contents from trapped individuals. Conclusion: This is the first report of the establishment of two American pine bark beetles, I. calligraphus and I. grandicollis in continental Asia. The gut content of both species suggests that these pest feeds on a non‐native host. Whether the two species present high‐risk to Asian forests will become clear with more research on their interactions with native pines. [ABSTRACT FROM AUTHOR]

Background: A high proportion of COVID‐19 patients have cardiac involvement, even those without known cardiac disease. Downregulation of angiotensin converting enzyme 2 (ACE2), a receptor for SARS‐CoV‐2 and the renin‐angiotensin system, as well as inflammatory mechanisms have been suggested to play a role. ACE2 is abundant in the gut and associated with gut microbiota composition. We hypothesized that gut leakage of microbial products, and subsequent inflammasome activation could contribute to cardiac involvement in COVID‐19 patients. Methods: Plasma levels of a gut leakage marker (LPS‐binding protein, LBP), a marker of enterocyte damage (intestinal fatty acid binding protein, IFABP), a gut homing marker (CCL25, ligand for chemokine receptor CCR9) and markers of inflammasome activation (IL‐1β, IL‐18 and their regulatory proteins) were measured at three time points (day 1, 3–5 and 7–10) in 39 hospitalized COVID‐19 patients and related to cardiac involvement. Results: Compared to controls, COVID‐19 patients had elevated plasma levels of LBP and CCL25 but not IFABP, suggesting impaired gut barrier function and accentuated gut homing of T cells without excessive enterocyte damage. Levels of LBP were twice as high at baseline in patients with elevated cardiac markers compared with those without and remained elevated during hospitalization. Also, markers of inflammasome activation were moderately elevated in patients with cardiac involvement. LBP was associated with higher NT‐pro‐BNP levels, whereas IL‐18, IL‐18BP and IL‐1Ra were associated with higher troponin levels. Conclusion: Patients with cardiac involvement had elevated markers of gut leakage and inflammasome activation, suggestive of a potential gut‐heart axis in COVID‐19. [ABSTRACT FROM AUTHOR]

As they age, adult stem cells become more prone to functional decline, which is responsible for aging‐associated tissue degeneration and diseases. One goal of aging research is to identify drugs that can repair age‐associated tissue degeneration. Multiple organ development‐related signaling pathways have recently been demonstrated to have functions in tissue homeostasis and aging process. Therefore, in this study, we tested several chemicals that are essential for organ development to assess their ability to delay intestinal stem cell (ISC) aging and promote gut function in adult Drosophila. We found that taurine, a free amino acid that supports neurological development and tissue metabolism in humans, represses ISC hyperproliferation and restrains the intestinal functional decline seen in aged animals. We found that taurine represses age‐associated ISC hyperproliferation through a mechanism that eliminated endoplasmic reticulum (ER) stress by upregulation of the target genes of unfolded protein response in the ER (UPRER) and inhibiting the c‐Jun N‐terminal kinase (JNK) signaling. Our findings show that taurine plays a critical role in delaying the aging process in stem cells and suggest that it may be used as a natural compound for the treatment of age‐associated, or damage‐induced intestinal dysfunction in humans. [ABSTRACT FROM AUTHOR]

Not getting enough sleep is a common problem in our society and contributes to numerous health problems, including high blood pressure, diabetes and obesity. Related to these observations, a wealth of studies has underscored the negative impact of both acute and chronic sleep deprivation on cognitive function. More recently it has become apparent that the gut microbiota composition can be rapidly altered, modulates brain function and is affected by the aforementioned health problems. As such, changes in the microbiota composition may contribute to the behavioural and physiological phenotypes associated with sleep deprivation. It is unclear, however, whether a brief period of sleep deprivation can also negatively impact the gut microbiota. Here, we examined the impact of 5 hr of sleep deprivation on gut microbiota composition of male C57Bl6/J mice. Despite the fact that the overall microbial composition did not change between the control‐ and sleep‐deprived groups, the relative abundance of the Clostridiaceae and Lachnospiraceae were slightly altered in sleep‐deprived animals compared to controls. Together, these data suggest that depriving mice of sleep for 5 hr leads to subtle changes in the gut microbiota composition. [ABSTRACT FROM AUTHOR]

Objectives: Obstetric demands have long been considered in the evolution of the pelvis, yet consideration of the interaction of pregnancy, the pelvis, and the gastrointestinal tract (gut) is lacking. Here, we explore sex differences in the relationship of gut volume with body size and pelvic dimensions. Materials and Methods: Computed tomography (CT) scans of living adult Homo sapiens (46 females and 42 males) were obtained to measure in vivo gut volume (GV) and to extract 3D models of the pelvis. We collected 19 3D landmarks from each pelvis model to acquire pelvic measurements. We used ordinary least squares regression to explore relationships between GV and body weight, stature, and linear pelvic dimensions. Results: The gut‐pelvis relationship differs between males and females. Females do not exhibit significant statistical correlations between GV and any variable tested. GV correlates with body size and pelvic outlet size in males. GV scales with negative allometry relative to body weight, stature, maximum bi‐iliac breadth, inferior transverse outlet breadth, and bispinous distance in males. Discussion: The lack of association between GV and body size in females may be due to limits imposed by the anticipation of accommodating a gravid uterus and/or the increased plasticity of the pelvis. The pattern of relationship between GV and the pelvic outlet suggests the role of the bony pelvis in supporting the adominal viscera in females may be small relative to its role in childbirth. We conclude that gut size inference in fossil hominins from skeletal proxies is limited and confounded by sexual dimorphism. [ABSTRACT FROM AUTHOR]

The Mekong Delta is host to a large number of freshwater species, including a unique group of facultative air‐breathing Anabantiforms. Of these, the striped snakehead (Channa striata), the climbing perch (Anabas testudineus), the giant gourami (Osphronemus goramy) and the snakeskin gourami (Trichogaster pectoralis) are major contributors to aquaculture production in Vietnam. The gastrointestinal responses to feeding in these four species are detailed here. Relative intestinal length was lowest in the snakehead, indicating carnivory, and 5.5‐fold greater in the snakeskin, indicating herbivory; climbing perch and giant gourami were intermediate, indicating omnivory. N‐waste excretion (ammonia‐N + urea‐N) was greatest in the carnivorous snakehead and least in the herbivorous snakeskin, whereas the opposite trend was observed for net K+ excretion. Similarly, the more carnivorous species had a greater stomach acidity than the more herbivorous species. Measurements of acid–base flux to water indicated that the greatest postprandial alkaline tide occurred in the snakehead and a potential acidic tide in the snakeskin. Additional findings of interest were high levels of both PCO2 (up to 40 mmHg) and HCO3− (up to 33 mM) in the intestinal chyme of all four of these air‐breathing species. Using in vitro gut sac preparations of the climbing perch, it was shown that the intestinal net absorption of fluid, Na+ and HCO3− was upregulated by feeding but not net Cl− uptake, glucose uptake or K+ secretion. Upregulated net absorption of HCO3− suggests that the high chyme (HCO3−) does not result from secretion by the intestinal epithelium. The possibility of ventilatory control of PCO2 to regulate postprandial acid–base balance in these air‐breathing fish is discussed. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the potential impact of intrapartum antibiotics, and their specific classes, on the infant gut microbiota in the first year of life.Design: Prospective study of infants in the New Hampshire Birth Cohort Study (NHBCS).Settings: Rural New Hampshire, USA.Population or Sample: Two hundred and sixty-six full-term infants from the NHBCS.Methods: Intrapartum antibiotic use during labour and delivery was abstracted from medical records. Faecal samples collected at 6 weeks and 1 year of age were characterised by 16S rRNA sequencing, and metagenomics analysis in a subset of samples.Exposures: Maternal exposure to antibiotics during labour and delivery.Main Outcome Measure: Taxonomic and functional profiles of faecal samples.Results: Infant exposure to intrapartum antibiotics, particularly to two or more antibiotic classes, was independently associated with lower microbial diversity scores as well as a unique bacterial community at 6 weeks (GUnifrac, P = 0.02). At 1 year, infants in the penicillin-only group had significantly lower α diversity scores than infants not exposed to intrapartum antibiotics. Within the first year of life, intrapartum exposure to penicillins was related to a significantly lower increase in several taxa including Bacteroides, use of cephalosporins was associated with a significantly lower rise over time in Bifidobacterium and infants in the multi-class group experienced a significantly higher increase in Veillonella dispar.Conclusions: Our findings suggest that intrapartum antibiotics alter the developmental trajectory of the infant gut microbiome, and specific antibiotic types may impact community composition, diversity and keystone immune training taxa.Tweetable Abstract: Class of intrapartum antibiotics administered during delivery relates to maturation of infant gut microbiota. [ABSTRACT FROM AUTHOR]

Harpellales fungi associated with larval black flies were studied for the first time in Korea. They are a common, widespread group of filamentous fungi that, as obligate symbionts, inhabit the digestive tracts of many terrestrial and aquatic arthropods. Total of 842 ultimate/penultimate instar larvae of black flies from 53 stream were dissected to detect trichomycetes colonization. As a result of the study, seven species of Harpellales including single undetermined Pennella species was found from eight species of black fly hosts: Harpella melusinae, Pennella angustispora, Pennella hovassi, Pennella KNU‐1, Simuliomyces microsporus, Smittium simulii, and Smittium megazygosporum. Descriptions for general features including size and shape of trichospore and zygospores (if available) of each species and their host larval black flies were provided. A key to all known Harpellales fungi found in larval black flies from Korea was also provided. [ABSTRACT FROM AUTHOR]

Spread of α-synuclein pathology from the peripheral to central nervous system may be an important etiological factor in Parkinson's disease, although there are some unanswered questions about its correlation with neuronal loss. Experimental evidence has highlighted the gastrointestinal tract as a potential starting point for aggregated α-synuclein, with the vagus nerve acting as a "highway" by which pathology may be transmitted to the lower brain stem. This review begins by highlighting the key studies demonstrating that α-synuclein pathology has the ability to spread from certain sites in the gastrointestinal tract to the brain (and vice versa). We go on to assess the recent epidemiological studies that have shown that vagotomy and appendectomy may have the potential to reduce the risk of developing Parkinson's disease. Finally, we discuss the factors in the gastrointestinal tract (such as dysbiosis of the gut microbiota, infection, and inflammation) that may trigger α-synuclein aggregation in the first place, as well as other potential mechanisms underlying the distribution of α-synuclein pathology in the brain. © 2019 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Abstract: Leptin is an anorectic hormone secreted mainly by peripheral adipocytes but also by other central and peripheral tissues. It acts by means of a receptor called OB‐R, influencing not only appetite and body mass but being also involved in many fields like endocrinology, metabolism and reproduction. Immunohistochemistry and qRT‐PCR techniques were, respectively, used to demonstrate the presence of leptin and its receptor in the gut of adult zebrafish and to evaluate the leptin gene expression response to feeding and fasting. Immunoreactivity for the antibodies utilized was demonstrated in feeding but not in fasting fish, and the gene expression analysis corroborates the data obtained by immunohistochemistry. Therefore, all the obtained results support the hypothesis of the role of this hormone in food regulation in zebrafish. [ABSTRACT FROM AUTHOR]

Summary: Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract, thought to at least in part reflect an aberrant immune response to gut bacteria. IBD is increasing in incidence, particularly in populations that have recently immigrated to western countries. This suggests that environmental factors are involved in its pathogenesis. We hypothesize that the increase in IBD rates might reflect the consumption of an unhealthy Western diet, containing excess calories and lacking in key nutritional factors, such as fibre and vitamin D. Several recent studies have determined that dietary factors can dramatically influence the activation of immune cells and the mediators they release through a process called immunonutrition. Moreover, dietary changes can profoundly affect the balance of beneficial versus pathogenic bacteria in the gut. This microbial imbalance can alter levels of microbiota‐derived metabolites that in turn can influence innate and adaptive intestinal immune responses. If the diet–gut microbiome disease axis does indeed underpin much of the ‘western’ influence on the onset and progression of IBD, then tremendous opportunity exists for therapeutic changes in lifestyle, to modulate the gut microbiome and to correct immune imbalances in individuals with IBD. This review highlights four such therapeutic strategies – probiotics, prebiotics, vitamin D and caloric restriction – that have the potential to improve and add to current IBD treatment regimens. [ABSTRACT FROM AUTHOR]

Summary: Endozoochory has been recognised as the most important dispersal mechanism in invasive Prosopis species, because their sugary, tasty pods attract animals and because some of their seeds remain intact after passing through some animals' digestive systems. In this study, we evaluated the role of the camel (Camelus dromedarius) as a potential disperser of the seeds of invasive tree Prosopis juliflora. Four camels of similar weight (ca. 400 kg) and age (ca. 2 years) were each fed with 70 fruits (1000 seeds approximately) of P. juliflora, which were retrieved from the camels' dung at 24‐h intervals for 4 days. The seeds retrieved were tested for germination and viability, along with seeds not eaten by the camels, with and without pericarp. Less than 3% of the seeds eaten were retrieved from the camels' dung. Most of the seeds (74%) were retrieved between 24 and 72 h after ingestion. The passage through the camel gut significantly accelerated and increased seed germination of P. juliflora in comparison with uneaten seeds covered with pericarp (48–75% and 15% respectively). While gut passage liberated P. juliflora seeds from the pericarp, increasing and accelerating their germination, the viability of seeds which had not germinated after germination trials were decreased (ca. ~20%) relative to uneaten seeds that had also not germinated. Our results show that, despite the low recorded seed recovery, camels can potentially disperse seeds of P. juliflora, which is in line with field observation showing P. juliflora expansion along the camels' routes in Gebel Elba National Park, south‐east Egypt. [ABSTRACT FROM AUTHOR]

The development of the enteric nervous system ( ENS) and intestinal smooth muscle occurs in a spatially and temporally correlated manner, but how they influence each other is unknown. In the developing mid-gut of the chick embryo, we find that α-smooth muscle actin expression, indicating early muscle differentiation, occurs after the arrival of migrating enteric neural crest-derived cells ( ENCCs). In contrast, hindgut smooth muscle develops prior to ENCC arrival. Smooth muscle development is normal in experimentally aganglionic hindguts, suggesting that proper development and patterning of the muscle layers does not rely on the ENS. However, inhibiting early smooth muscle development severely disrupts ENS patterning without affecting ENCC proliferation or apoptosis. Our results demonstrate that early intestinal smooth muscle differentiation is required for patterning the developing ENS. [ABSTRACT FROM AUTHOR]

Paratransgenesis targeting the gut protozoa is being developed as an alternative method for the control of the Formosan subterranean termite (FST). This method involves killing the cellulose-digesting gut protozoa using a previously developed antiprotozoal peptide consisting of a target specific ligand coupled to an antimicrobial peptide (Hecate). In the future, we intend to genetically engineer termite gut bacteria as 'Trojan Horses' to express and spread ligand-Hecate in the termite colony. The aim of this study was to assess the usefulness of bacteria strains isolated from the gut of FST as 'Trojan Horses.' We isolated 135 bacteria from the guts of workers from 3 termite colonies. Sequencing of the 16S rRNA gene identified 20 species. We tested 5 bacteria species that were previously described as part of the termite gut community for their tolerance against Hecate and ligand-Hecate. Results showed that the minimum concentration required to inhibit bacteria growth was always higher than the concentration required to kill the gut protozoa. Out of the 5 bacteria tested, we engineered Trabulsiella odontotermitis, a termite specific bacterium, to express green fluorescent protein as a proof of concept that the bacteria can be engineered to express foreign proteins. Engineered T. odontotermitis was fed to FST to study if the bacteria are ingested. This feeding experiment confirmed that engineered T. odontotermitis is ingested by termites and can survive in the gut for at least 48 h. Here we report that T. odontotermitis is a suitable delivery and expression system for paratransgenesis in a termite species. [ABSTRACT FROM AUTHOR]

The migratory locust, Locusta migratoria, is a serious agricultural pest and important insect model in the study of insect digestion and feeding behaviour. The gut is one of the primary interfaces between the insect and its environment. Nevertheless, knowledge on the gut transcriptome of L. migratoria is still very limited. Here, 48 802 expressed sequence tags were extracted from publicly available databases and their expression in larval gut and/or brain tissue was determined using microarray hybridization. Our data show 2765 transcripts predominantly or exclusively expressed in the gut. Many transcripts had putative functions closely related to the physiological functions of the gut as a muscular digestive organ and as the first barrier against microorganisms and a wide range of toxins. By means of a ranking procedure based on the relative signal intensity, we estimated 15% of the transcripts to show high expression levels, the highest belonging to diverse digestive enzymes and muscle-related proteins. We also found evidence for very high expression of an allergen protein, which could have important implications, as locusts form a traditional food source in various parts of the world, and were also recently added to the list of insects fit for human consumption in Europe. Interestingly, many highly expressed sequences have as yet unknown functions. Taken together, the present data provide significant insight into locust larval gut physiology, and will be valuable for future studies on the insect gut. [ABSTRACT FROM AUTHOR]

Behavioural variation within a species is usually explained as the consequence of individual variation in physiology. However, new evidence suggests that the arrow of causality may well be in the reverse direction: behaviours such as diet preferences cause the differences in physiological and morphological traits., Recently, diet preferences were proposed to underlie consistent differences in digestive organ mass and movement patterns (patch residence times) in red knots ( Calidris canutus islandica). Red knots are molluscivorous and migrant shorebirds for which the size of the muscular stomach (gizzard) is critical for the food processing rate., In this study, red knots ( C. c. canutus, n = 46) were caught at Banc d'Arguin, an intertidal flat ecosystem in Mauritania, and released with radio-tags after the measurement of gizzard mass. Using a novel tracking system (time-of-arrival), patch residence times were measured over a period of three weeks. Whether or not gizzard mass determined patch residence times was tested experimentally by offering 12 of the 46 tagged red knots soft diets prior to release; this reduced an individual's gizzard mass by 20-60%. To validate whether the observed range of patch residence times would be expected from individual diet preferences, we simulated patch residence times as a function of diet preferences via a simple departure rule., Consistent with previous empirical studies, patch residence times in the field were positively correlated with gizzard mass. The slope of this correlation, as well as the observed range of patch residence times, was in accordance with the simulated values. The 12 birds with reduced gizzard masses did not decrease patch residence times in response to the reduction in gizzard mass., These findings suggest that diet preferences can indeed cause the observed among-individual variation in gizzard mass and patch residence times. We discuss how early diet experiences can have cascading effects on the individual expression of both behavioural and physiomorphic traits. This emphasizes that to understand the ecological consequences of individual differences, knowledge of the environment during development is required. [ABSTRACT FROM AUTHOR]

The prevalence of human and canine allergic diseases is commonly perceived to be increasing. Suggested predisposing factors in people and dogs include increased allergen load, increased exposure to pollutants, reduced family size, reduced microbial load and less exposure to infection at a young age, increasingly urbanised environment, and changes in dietary habits. Genetic make-up may provide a template for phenotypic predisposition which is strongly influenced by our diet and environment leading to constant regulation of gene expression. One way in which diet can alter gene expression is via its effects on the gut flora or microbiota, the collection of microbes residing in the gastrointestinal tract. The resident microbiota is important in maintaining structural and functional integrity of the gut and in immune system regulation. It is an important driver of host immunity, helps protect against invading enteropathogens, and provides nutritional benefits to the host. Disruption of the microbiota (dysbiosis) may lead to severe health problems, both in the gastrointestinal tract and extra-intestinal organ systems. The precise mechanisms by which the intestinal microbiota exerts its effects are only beginning to be unravelled but research is demonstrating close links between gut microflora and many factors involved in the pathogenesis of atopic dermatitis ( AD). AD and indeed any other 'skin disease', may be seen as a possible manifestation of a more systemic problem involving gut dysbiosis and increased intestinal permeability, which may occur even in the absence of gastrointestinal signs. Manipulation of the canine intestinal microbiota as a method for modifying atopy, may be attempted in many ways including avoidance of certain foods, supplementation with probiotics and prebiotics, optimising nutrient intake, minimising stress, antimicrobial therapy, correction and prevention of low stomach acid, and faecal microbiota transplantation ( FMT). [ABSTRACT FROM AUTHOR]

The most well-known mechanism of metformin action, one of the most commonly prescribed antidiabetic drugs, is adenosine monophosphate-activated protein kinase activation; however, recent investigations have shown that adenosine monophosphate-activated protein kinase-independent pathways can explain some of metformin's beneficial metabolic effects as well as undesirable side-effects. Such novel pathways include induction of mitochondrial stress, inhibition of mitochondrial shuttles, alteration of intestinal microbiota, suppression of glucagon signaling, activation of autophagy, attenuation of inflammasome activation, induction of incretin receptors and reduction of terminal endoplasmic reticulum stress. Together, these studies have broadened our understanding of the mechanisms of antidiabetic agents as well as the pathogenic mechanism of diabetes itself. The results of such investigations might help to identify new target molecules and pathways for treatment of diabetes and metabolic syndrome, and could also have broad implications in diseases other than diabetes. Accordingly, new antidiabetic drugs with better efficacy and fewer adverse effects will likely result from these studies. [ABSTRACT FROM AUTHOR]

ABSTRACT To enable microbial colonization of the gut mucosa, the intestinal immune system must not only react to danger signals but also recognize cues that indicate safety. Recognition of safety, paradoxically, is mediated by the same environmental sensors that are involved in signaling danger. Indeed, in addition to their well-established role in inducing inflammation in response to stress signals, pattern recognition receptors and a variety of metabolic sensors also promote gut-microbiota symbiosis by responding to 'microbial symbiosis factors', 'resolution-associated molecular patterns', markers of energy extraction and other signals indicating the absence of pathogenic infection and tissue damage. Here we focus on how the paradoxical roles of immune receptors and other environmental sensors define the microbiota signature of an individual. [ABSTRACT FROM AUTHOR]

Background Gastrointestinal ( GI) dysfunction is a major cause of morbidity in acquired immunodeficiency syndrome (AIDS). HIV-1-induced neuropathogenesis is significantly enhanced by opiate abuse, which increases proinflammatory chemokine/cytokine release, the production of reactive species, glial reactivity, and neuronal injury in the central nervous system. Despite marked interactions in the gut, little is known about the effects of HIV-1 in combination with opiate use on the enteric nervous system. Methods To explore HIV-opiate interactions in myenteric neurons, the effects of Tat ± morphine (0.03, 0.3, and 3 μM) were examined in isolated neurons from doxycycline- ( DOX-) inducible HIV-1 Tat1-86 transgenic mice or following in vitro Tat 100 nM exposure (>6 h). Key Results Current clamp recordings demonstrated increased neuronal excitability in neurons of inducible Tat(+) mice (Tat+/ DOX) compared to control Tat−/ DOX mice. In neurons from Tat+/ DOX, but not from Tat−/ DOX mice, 0.03 μM morphine significantly reduced neuronal excitability, fast transient and late long-lasting sodium currents. There was a significant leftward shift in V0.5 of inactivation following exposure to 0.03 μM morphine, with a 50% decrease in availability of sodium channels at −100 mV. Similar effects were noted with in vitro Tat exposure in the presence of 0.3 μM morphine. Additionally, GI motility was significantly more sensitive to morphine in Tat(+) mice than Tat(−) mice. Conclusions & Inferences Overall, these data suggest that the sensitivity of enteric neurons to morphine is enhanced in the presence of Tat. Opiates and HIV-1 may uniquely interact to exacerbate the deleterious effects of HIV-1-infection and opiate exposure on GI function. [ABSTRACT FROM AUTHOR]

Background Gastrointestinal ( GI) motor disorders often involve several regions of the GI tract. Therefore, easy and safe assessment of whole gut and regional motility is valuable for more precise diagnosis. 3D-Transit is a novel method for ambulatory evaluation of total and regional gastrointestinal transit times ( GITT) based on the anatomical localization of ingestible electromagnetic capsules. The main purpose of this study was to test the performance of the 3D-Transit system. Methods Twenty healthy volunteers each ingested three electromagnetic capsules over a period of two consecutive days. Standard radio-opaque markers (ROM) were also ingested to assess the agreement between total GITT obtained with both methods. Key Results Investigations were well-tolerated and three capsules could be tracked simultaneously with minimal data loss (Capsule 1: median: 0.2% of time (range 0-25.3%). Region specific contraction patterns were identified and used for computation of total and regional GITT in all subjects. Inter-observer agreement was 100% for total GITT (median variation 0%) but less for regional GITT. Day-to-day and diurnal variations were significant for total and regional GITT. Total GITT assessed by 3D-Transit capsules were moderately well-correlated to those assessed with standard ROM ( Spearman's rho = 0.7). Conclusions & Inferences 3D-transit is a well-tolerated and minimal invasive ambulatory method for assessment of GI motility. By providing both total and regional transit times, the 3D-Transit system holds great promise for future clinical studies of GI function in health and disease. [ABSTRACT FROM AUTHOR]

Non-neuronal acetylcholine ( ACh) is predicted to function as a local cell signaling molecule. However, the physiological significance of the synthesis of non-neuronal ACh in the intestine remains unclear. Here, experiments using crypt-villus organoids that lack nerve and immune cells in culture led us to suggest that endogenous ACh is synthesized in the intestinal epithelium to evoke growth and differentiation of the organoids through activation of muscarinic ACh receptors (m AChRs). The extracts of the cultured organoids showed a noticeable capacity for ACh synthesis that was sensitive to a potent inhibitor of choline acetyltransferase. Imaging MS revealed endogenous ACh localized in the epithelial layer in mouse small intestinal epithelium in vivo, suggesting that there are non-neuronal resources of ACh. Treatment of organoids with carbachol downregulated the growth of organoids and the expression of marker genes for epithelial cells. On the other hand, antagonists for m AChRs enhanced the growth and differentiation of organoids, indicating the involvement of m AChRs in regulating the proliferation and differentiation of Lgr5-positive stem cells. Collectively, our data provide evidence that endogenous ACh released from intestinal epithelium maintains homeostasis of intestinal epithelial cell growth and differentiation via m AChRs in mice. [ABSTRACT FROM AUTHOR]

The gut‐brain axis is a hot topic in Parkinson's disease. In an attempt to decipher its role in the disease pathogenesis, several animal models have been developed. Most of these models tried to reproduce Braak's hypothesis by showing that the pathological process could spread from the gut to the brain (bottom‐up scenario). Interestingly, others groups showed that a top‐down scenario could also occur and that 6‐hydroxydopamine‐induced nigrostriatal denervation was sufficient to induce significant changes in the gastrointestinal tract. Aside from this toxic approach, the article by O'Donovan and colleagues in this edition of Neurogastroenterology and Motility showed that bilateral nigral injection of adeno‐associated virus (AAV)‐alpha‐synuclein in rats was accompanied by changes in the enteric nervous system and the gut microbiota, which occurred without any apparent brain‐to‐gut spread of human injected alpha‐synuclein. Some changes observed in the gastrointestinal tract of animals injected with AAV‐alpha‐synuclein were in line with previous observations in Parkinson's disease patients, including increased expression of glial markers, swollen tyrosine hydroxylase‐positive varicosities in the submucosal plexus, and decreases in Faecalibacterium and Lachnospiraceae. These findings suggest that, in addition to gut‐brain pathways, the brain‐to‐gut communication may also be involved in Parkinson's disease pathophysiology. In this mini‐review, we describe the strengths and limitations of the existing studies on the gut‐brain axis in experimental models of parkinsonism and discuss an alternative hypothesis in which the central and enteric nervous system would evolve separately during disease progression. [ABSTRACT FROM AUTHOR]