Antiviral Effects of Fructans

Infectious diseases of viral origin have never received so much interest globally since the emergence of the COVID-19 pandemic disease. In contrast to bacterial infections, antibiotic treatments do not have any effect on viral infections, requiring alternative solutions to reduce the impact of viral spread on animal populations. More important than curing, preventing viral replication before disease development is probably the best strategy to minimalize the negative effects of viruses on a global scale. Fructans, known to stimulate the immune system (by either interacting directly or indirectly with the immune system), may be interesting candidates as part of this broader prevention strategy. This chapter discusses the potential antiviral properties of fructans in relation to their well-described immunomodulating, antioxidant and prebiotic attributes, as well as a possible role as protein binders which may disturb the proper function of viral proteins, and thus reduce the infection ability of certain viral strains. © 2023 Elsevier Inc. All rights reserved.

Food for thought: the importance of nutritional well-being during COVID-19.

Individuals with mental illness have poorer physical health, nutritional status, and lowered life expectancy. Optimising their physical and nutritional status has become an increasingly important therapeutic goal. Current experience with COVID-19 has further emphasised the susceptibility to physical illness and poorer outcomes amongst individuals with mental illness and those who are nutritionally compromised. Although life as we knew it has been suspended until the widespread roll-out of a vaccine, individuals can take immediate action to improve physical and mental health by attending to and optimising their nutritional well-being. Clinicians within mental health services have a crucial role to play in assisting such change, and reminding their patients of the importance of pursuing a healthy and balanced diet.

How Toll-like receptors influence Parkinson's disease in the microbiome-gut-brain axis.

Recently, a large number of experimenters have found that the pathogenesis of Parkinson's disease may be related to the gut microbiome and proposed the microbiome-gut-brain axis. Studies have shown that Toll-like receptors, especially Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4), are key mediators of gut homeostasis. In addition to their established role in innate immunity throughout the body, research is increasingly showing that the Toll-like receptor 2 and Toll-like receptor 4 signaling pathways shape the development and function of the gut and enteric nervous system. Notably, Toll-like receptor 2 and Toll-like receptor 4 are dysregulated in Parkinson's disease patients and may therefore be identified as the core of early gut dysfunction in Parkinson's disease. To better understand the contribution of Toll-like receptor 2 and Toll-like receptor 4 dysfunction in the gut to early α-synuclein aggregation, we discussed the structural function of Toll-like receptor 2 and Toll-like receptor 4 and signal transduction of Toll-like receptor 2 and Toll-like receptor 4 in Parkinson's disease by reviewing clinical, animal models, and in vitro studies. We also present a conceptual model of the pathogenesis of Parkinson's disease, in which microbial dysbiosis alters the gut barrier as well as the Toll-like receptor 2 and Toll-like receptor 4 signaling pathways, ultimately leading to a positive feedback loop for chronic gut dysfunction, promoting α-synuclein aggregation in the gut and vagus nerve.

Mild SARS-CoV-2 infection results in long-lasting microbiota instability.

Viruses targeting mammalian cells can indirectly alter the gut microbiota, potentially compounding their phenotypic effects. Multiple studies have observed a disrupted gut microbiota in severe cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that require hospitalization. Yet, despite demographic shifts in disease severity resulting in a large and continuing burden of non-hospitalized infections, we still know very little about the impact of mild SARS-CoV-2 infection on the gut microbiota in the outpatient setting. To address this knowledge gap, we longitudinally sampled 14 SARS-CoV-2-positive subjects who remained outpatient and 4 household controls. SARS-CoV-2 cases exhibited a significantly less stable gut microbiota relative to controls. These results were confirmed and extended in the K18-humanized angiotensin-converting enzyme 2 mouse model, which is susceptible to SARS-CoV-2 infection. All of the tested SARS-CoV-2 variants significantly disrupted the mouse gut microbiota, including USA-WA1/2020 (the original variant detected in the USA), Delta, and Omicron. Surprisingly, despite the fact that the Omicron variant caused the least severe symptoms in mice, it destabilized the gut microbiota and led to a significant depletion in Akkermansia muciniphila. Furthermore, exposure of wild-type C57BL/6J mice to SARS-CoV-2 disrupted the gut microbiota in the absence of severe lung pathology.IMPORTANCETaken together, our results demonstrate that even mild cases of SARS-CoV-2 can disrupt gut microbial ecology. Our findings in non-hospitalized individuals are consistent with studies of hospitalized patients, in that reproducible shifts in gut microbial taxonomic abundance in response to SARS-CoV-2 have been difficult to identify. Instead, we report a long-lasting instability in the gut microbiota. Surprisingly, our mouse experiments revealed an impact of the Omicron variant, despite producing the least severe symptoms in genetically susceptible mice, suggesting that despite the continued evolution of SARS-CoV-2, it has retained its ability to perturb the intestinal mucosa. These results will hopefully renew efforts to study the mechanisms through which Omicron and future SARS-CoV-2 variants alter gastrointestinal physiology, while also considering the potentially broad consequences of SARS-CoV-2-induced microbiota instability for host health and disease.

Deducing the Interplay Between Gut Flora and Respiratory Diseases: A New Therapeutic Strategy?

The gastrointestinal system, also referred to as the gut, is a universe that colonizes trillions of microbes. In addition to its digestive functions, the gut represents a biosystem that determines all the health vectors. It is now recognized as one of the body's defense systems, and good gut health regulates the body's immune responses. Disturbance of this barrier can trigger many diseases, including respiratory tract infections, as there is a close correlation between the gut microbiome and the chances of triggering illness. This review investigates the various factors affecting the gut microbiome, the diseases that can result from the dysregulation of the same, and their molecular mechanisms. The most basic solution to tackle this problem is to maintain the gut microbiome at the desired level. Timely diagnosis and interventions are needed for the proper management of the ensuing conditions. It is important to address the effects of factors on the gut microbiome and thereby regulate this level. The study also found that dysregulation in the system can lead to various diseases such as asthma, COPD, lung cancer following their respective pathways. In short, this paper reinforces the importance of the gut microbiome, the need to maintain its average level, and the need for proper interventions to treat the consequences. The manuscript posit that medications, diet as well and good physiological conditions of the human body can alter the microbiome and can ward off respiratory infections.

HLA-II immunopeptidome profiling and deep learning reveal features of antigenicity to inform antigen discovery.

CD4+ T cell responses are exquisitely antigen specific and directed toward peptide epitopes displayed by human leukocyte antigen class II (HLA-II) on antigen-presenting cells. Underrepresentation of diverse alleles in ligand databases and an incomplete understanding of factors affecting antigen presentation in vivo have limited progress in defining principles of peptide immunogenicity. Here, we employed monoallelic immunopeptidomics to identify 358,024 HLA-II binders, with a particular focus on HLA-DQ and HLA-DP. We uncovered peptide-binding patterns across a spectrum of binding affinities and enrichment of structural antigen features. These aspects underpinned the development of context-aware predictor of T cell antigens (CAPTAn), a deep learning model that predicts peptide antigens based on their affinity to HLA-II and full sequence of their source proteins. CAPTAn was instrumental in discovering prevalent T cell epitopes from bacteria in the human microbiome and a pan-variant epitope from SARS-CoV-2. Together CAPTAn and associated datasets present a resource for antigen discovery and the unraveling genetic associations of HLA alleles with immunopathologies.

A systematic review of gut microbiota profile in COVID-19 patients and among those who have recovered from COVID-19.

OBJECTIVES: Given the scale and persistence of coronavirus disease 2019 (COVID-19), significant attention has been devoted to understanding the relationship between human gut microbiota and COVID-19. In this systematic review we aimed to comprehensively assess the gut microbiota composition in patients infected with COVID-19 and those recovered from COVID-19 in comparison to healthy controls (HCs). METHODS: Peer-reviewed articles and preprints published up to September 1, 2022, were searched in Ovid MEDLINE, Ovid EMBASE, and SCOPUS. Observational studies reporting the gut microbiota profile in adult (≥18 years) COVID-19 patients or those recovered from COVID-19 compared to HCs were eligible for inclusion in this systematic review. The quality assessment of studies was performed using the Newcastle-Ottawa scale. RESULTS: We identified 27 studies comprising 18 studies that compared COVID-19 patients and six that compared recovered COVID-19 patients to HCs, while the other three studies compared both COVID-19 and recovered COVID-19 patients to HCs. Compared to HCs, decreased gut microbial diversity and richness and a distinctive microbial composition were reported in COVID-19 patients and recovered COVID-19 patients. In COVID-19 patients, Bacteroidetes were found to be enriched, and Firmicutes depleted. Decreased short-chain fatty acid (SCFA)-producing bacteria, such as Faecalibacterium, Ruminococcus, and Bifidobacterium, among others, were also observed in COVID-19 patients, which were not restored to normal levels in those who recovered. CONCLUSION: Gut dysbiosis was evident in COVID-19, and available data suggested that dysbiosis persisted even in recovered COVID-19 patients, with decreased Firmicutes and SCFA-producing bacteria.

BBIBP-CorV Vaccination against the SARS-CoV-2 Virus Affects the Gut Microbiome.

Several observational studies have confirmed that the severe acute respiratory syndrome coronavirus2 (SARS-CoV-2) might substantially affect the gastrointestinal (GI) system by replicating in human small intestine enterocytes. Yet, so far, no study has reported the effects of inactivated SARS-CoV-2 virus vaccines on gut microbiota alterations. In this study, we examined the effects of the BBIBP-CorV vaccine (ChiCTR2000032459, sponsored by the Beijing Institute of Biological Products/Sinopharm), on gut microbiota. Fecal samples were collected from individuals whoreceived two doses of intramuscular injection of BBIBP-CorV and matched unvaccinated controls. DNA extracted from fecal samples was subjected to 16S ribosomal RNA sequencing analysis. The composition and biological functions of the microbiota between vaccinated and unvaccinated individuals were compared. Compared with unvaccinated controls, vaccinated subjects exhibited significantly reduced bacterial diversity, elevated firmicutes/bacteroidetes (F/B) ratios, a tendency towards Faecalibacterium-predominant enterotypes, and altered gut microbial compositions and functional potentials. Specifically, the intestinal microbiota in vaccine recipients was enriched with Faecalibacterium and Mollicutes and with a lower abundance of Prevotella, Enterococcus, Leuconostocaceae, and Weissella. Microbial function prediction by phylogenetic investigation of communities using reconstruction of unobserved states (PICRUSt) analysis further indicated that Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways involved in carbohydrate metabolism and transcription were positively associated with vaccine inoculation, whereas capacities in neurodegenerative diseases, cardiovascular diseases, and cancers were negatively affected by vaccines. Vaccine inoculation was particularly associated with gut microbiota alterations, as was demonstrated by the improved composition and functional capacities of gut microbiota.

COVID-19 associated oral and oropharyngeal microbiome: Systematic review and meta-analysis.

Three years into the coronavirus disease 2019 (COVID-19) pandemic, there are still growing concerns with the emergence of different variants, unknown long- and short-term effects of the virus, and potential biological mechanisms underlying etiopathogenesis and increased risk for morbidity and mortality. The role of the microbiome in human physiology and the initiation and progression of several oral and systemic diseases have been actively studied in the past decade. With the proof of viral transmission, carriage, and a potential role in etiopathogenesis, saliva and the oral environment have been a focus of COVID-19 research beyond diagnostic purposes. The oral environment hosts diverse microbial communities and contributes to human oral and systemic health. Several investigations have identified disruptions in the oral microbiome in COVID-19 patients. However, all these studies are cross-sectional in nature and present heterogeneity in study design, techniques, and analysis. Therefore, in this undertaking, we (a) systematically reviewed the current literature associating COVID-19 with changes in the microbiome; (b) performed a re-analysis of publicly available data as a means to standardize the analysis, and (c) reported alterations in the microbial characteristics in COVID-19 patients compared to negative controls. Overall, we identified that COVID-19 is associated with oral microbial dysbiosis with significant reduction in diversity. However, alterations in specific bacterial members differed across the study. Re-analysis from our pipeline shed light on Neisseria as the potential key microbial member associated with COVID-19.

Neurodegenerative and Neurodevelopmental Diseases and the Gut-Brain Axis: The Potential of Therapeutic Targeting of the Microbiome.

The human gut microbiome contains the largest number of bacteria in the body and has the potential to greatly influence metabolism, not only locally but also systemically. There is an established link between a healthy, balanced, and diverse microbiome and overall health. When the gut microbiome becomes unbalanced (dysbiosis) through dietary changes, medication use, lifestyle choices, environmental factors, and ageing, this has a profound effect on our health and is linked to many diseases, including lifestyle diseases, metabolic diseases, inflammatory diseases, and neurological diseases. While this link in humans is largely an association of dysbiosis with disease, in animal models, a causative link can be demonstrated. The link between the gut and the brain is particularly important in maintaining brain health, with a strong association between dysbiosis in the gut and neurodegenerative and neurodevelopmental diseases. This link suggests not only that the gut microbiota composition can be used to make an early diagnosis of neurodegenerative and neurodevelopmental diseases but also that modifying the gut microbiome to influence the microbiome-gut-brain axis might present a therapeutic target for diseases that have proved intractable, with the aim of altering the trajectory of neurodegenerative and neurodevelopmental diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, autism spectrum disorder, and attention-deficit hyperactivity disorder, among others. There is also a microbiome-gut-brain link to other potentially reversible neurological diseases, such as migraine, post-operative cognitive dysfunction, and long COVID, which might be considered models of therapy for neurodegenerative disease. The role of traditional methods in altering the microbiome, as well as newer, more novel treatments such as faecal microbiome transplants and photobiomodulation, are discussed.

The contributions of parental lactation on offspring development: It's not udder nonsense!

The Developmental Origins of Health and Disease (DOHaD) hypothesis describes how maternal stress exposures experienced during critical periods of perinatal life are linked to altered developmental trajectories in offspring. Perinatal stress also induces changes in lactogenesis, milk volume, maternal care, and the nutritive and non-nutritive components of milk, affecting short and long-term developmental outcomes in offspring. For instance, selective early life stressors shape the contents of milk, including macro/micronutrients, immune components, microbiota, enzymes, hormones, milk-derived extracellular vesicles, and milk microRNAs. In this review, we highlight the contributions of parental lactation to offspring development by examining changes in the composition of breast milk in response to three well-characterized maternal stressors: nutritive stress, immune stress, and psychological stress. We discuss recent findings in human, animal, and in vitro models, their clinical relevance, study limitations, and potential therapeutic significance to improving human health and infant survival. We also discuss the benefits of enrichment methods and support tools that can be used to improve milk quality and volume as well as related developmental outcomes in offspring. Lastly, we use evidence-based primary literature to convey that even though select maternal stressors may modulate lactation biology (by influencing milk composition) depending on the severity and length of exposure, exclusive and/or prolonged milk feeding may attenuate the negative in utero effects of early life stressors and promote healthy developmental trajectories. Overall, scientific evidence supports lactation to be protective against nutritive and immune stressors, but the benefits of lactation in response to psychological stressors need further investigation.

Resiliency among Older Adults Receiving (Roar) Lung Cancer Treatment: A Feasibility Study

PURPOSE/HYPOTHESIS: Poor physical performance and negative mood are two risk factors for functional decline among older adults with lung cancer. Yet, targeted interventions to maintain independence prevent functional decline are not well studied. Our primary objective was to assess the feasibility of a novel virtual health physical therapy (PT) plus progressive muscle relaxation (PMR) intervention with longitudinal microbiome biospecimen collection delivered to older adults with advanced lung cancer. Secondary objectives were to characterize functional status and clinical factors pre and post-study intervention. NUMBER OF SUBJECTS: We accrued adults aged >=60 years with advanced non-small cell or extensive-stage small cell lung cancer receiving treatment at The Ohio State University James Comprehensive Cancer Center (OSU-JCCC) in the Thoracic Oncology department (N=22). There were no exclusion criteria pertaining to Eastern Cooperative Oncology Group (ECOG) performance status, laboratory values, prior cancer diagnoses, presence of comorbidities, or brain metastases. MATERIALS AND METHODS: Participants were asked about functional status, symptoms, mood through the PHQ-9, GAD-7, POMS, and acceptability questions about the program. PT evaluation and assessment included SPPB and 2- or 6-minute walk test outcomes. The study sought to collect gut microbiome samples for every in-person visit and activity monitoring data (Actigraph) on a subset. Feasibility was defined as successfully collecting specimens, wearing an Actigraph activity monitor, and adhering to the intervention. PT and psychologists evaluated participants in-person at the first and final visit. The rest of the 12-week intervention was conducted via virtual health. Physical therapy intervention consisted of endurance, strength, and flexibility exercises. RESULT(S): In total, 22 patients consented and 18 started the intervention (81.8%). Seven microbiome samples were collected from four participants. Six patients collected activity monitoring data. Among the 18 participants, 11 participants (61.1%) completed 70% or more of all the intervention visits. The SPPB data show a moderate effect size (Cohen's d=0.24) from pre- to post-data. On average patients improved by 1.8 total points on the SPPB. Patients demonstrated improvement on timed walk tests throughout intervention from an average of 108 feet pre-intervention to an average of 138.4 feet post intervention. CONCLUSION(S): Despite the challenges of the COVID-19 pandemic, longitudinal biospecimen and correlative data collection were feasible in the context of PT and PMR intervention among older adults with advanced lung cancer. Virtual physical therapy interventions can be safely delivered to improve physical performance as demonstrated by a moderate effect size for the SPPB in this patient population. CLINICAL RELEVANCE: Based on the feasibility study results, delivering a virtual PT intervention to older patients with lung cancer can improve SPPB score leading to decreased frailty and improve quality of life among patients.

Loss of Bifidobacteria in Lyme Disease: Cause or Effect

Introduction: Lyme disease is a poorly understood condition which starts with a rash but may continue with chronic fatigue and neurological symptoms. Approximately 1 in 5 early Lyme disease patients have GI symptoms, such as nausea, anorexia, abdominal pain, or diarrhea. Lyme disease is thought to be cased by microbes in the spirochetes phylum transmitted by black legged ticks. Lyme-related healthcare costs in America exceed 1.3 billion dollars annually. Bifidobacteria are known for their beneficial probiotic actions within the human gut microbiome. Their numbers are reduced in severe COVID-19, Clostridioides difficile infection and Inflammatory Bowel Disease. To our knowledge Bifidobacteria levels have not been studied in Lyme disease patients. Given the importance of Bifidobacterium abundance in other diseases, we focused on relative abundance of Bifidobacterium in fecal samples of patients with Lyme disease compared to controls. Method(s): Fecal samples were assessed for relative abundance of Bifidobacterium in Healthy Control subjects without Lyme disease (n=20) compared to patients with Lyme disease (n=39). The average symptom duration in patients with Lyme disease was 5 years and none were on antibiotics 2 weeks prior to sample collection (range of symptoms from 1 month to 20 years, all treated initially with antibiotics).Metagenomics Next Generation sequencing was performed on fecal samples, where DNA samples were extracted and normalized for library downstream analysis using Shotgun Methodology. Mann- Whitney Statistical test was used for comparison. This study was IRB approved. Result(s): Relative Abundance of bifidobacteria was significantly decreased (p< 0.0001) in patients with Lyme disease. Median and interquartile range (IQR) were: Control (Median:4.175%;IQR:1.72-10.27%) and Lyme disease (Median:0.0014%;IQR:0.00%-0.96%)(Figure). 30/39 Lyme disease patients (77%) were found to possess < 1% relative abundance of Bifidobacterium in their stool sample. Of interest only 1/39 samples showed presence of Spirochetes in stool samples. Conclusion(s): This is the first study that demonstrates low levels of Bifidobacteria in patients with chronic Lyme disease. These results raise three questions;whether the disease was caused by 1. the original microbe creating loss of Bifidobacterium 2. baseline low Bifidobacteria due likely to either diet or medications or 3. excessive treatment. Given Lyme disease comprises a gut dysbiosis issue, therapies should also aim at restoration of depleted Bifidobacteria. (Figure Presented).

Case report of SARS-CoV-2 with secondary Clostridioides difficile infection

There has been an overuse of antibiotics in most patients suffering from COVID-19 which predisposes patients to hospital acquired C. difficile Infection (CDI). Also, COVID infection of the gastrointestinal tract also predisposes the patient to CDI. We here present a fatal case of SARS-CoV-2 coinfection with CDI.

The Association Between Stool Shedding of SARS-Cov-2 Microbiome Diversity and Intestinal Inflammation

Introduction: The transmission of the etiologic virus of COVID-19 (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) is thought to occur mainly via respiratory droplets even though limited evidence has shown the virus can be found in feces and involve the gastrointestinal (GI) tract. The aim of this study was to assess if patients with COVID-19 present with fecal shedding of SARS-CoV-2, intestinal inflammation or changes in their microbiota. Method(s): This was a prospective cohort study that included outpatients that presented with symptoms of COVID-19 and were tested using a nasopharyngeal PCR test (NPT). Two cohorts were selected: one with a (1) NPT and a control group with a (-) NPT. Stool and a clinical data were collected at baseline and then, days 14, 28 and 42. SARS-CoV-2 viral loads were measured in stool using PCR and stool microbiome was analyzed using 16S rRNA gene sequencing (V3/V4 region). Fecal calprotectin levels were also measured on each sample and used as a surrogate marker of intestinal inflammation. Result(s): 101 patients were recruited (410 total samples). Of those, 55 had a (1) COVID-19 NPT. Most patients with a (1) COVID-19 NPT PCR had a detectable fecal viral load (71%). Among these patients, 23 (55%) had detectable viral stool loads only at baseline, 12 through day 14, 6 through day 28 and 1 through day 42. One patient had a (-) NPT but detectable SARS-CoV-2 in the baseline stool sample. Subjects with (1) NPT presented more commonly with myalgias (p=0.02), dysgeusia (p=0.019) and anosmia (p=0.03) when compared to those with (-) NPT but there were no differences in any other symptoms including GI manifestations.Within the group with a (1) NPT, those patient with detectable SARS-CoV-2 in the stool were younger but no differences were seen in demographic, symptoms, or fecal calprotectin levels (Table). There was no correlation between fecal SARS-CoV-2 loads and fecal calprotectin levels (rho: 0.007 [p=0.95]). Patients with a (1) NPT PCR had higher evenness when compared to those that tested (-) for a NPT PCR. However, no differences were seen in other alpha or beta diversity (Figures 1A and 1B, respectively). Conclusion(s): Even though intestinal viral shedding of SARS-CoV-2 in patients with COVID-19 is common, these patients do not present with evidence of inflammation of the GI tract, a significantly disrupted gut microbiome or a higher incidence of GI symptoms when compared to patients with respiratory symptoms and no COVID-19.

Early Enteral Feeding With Prebiotic-Containing Formula in Critically Ill Mechanically Ventilated Covid-19 Patients

Background: Optimal supportive care which includes adequate nutrient delivery remains the cornerstone in managing critically ill patients with COVID-19. Nutrition guiding principles for critically ill patients with COVID-19 strongly recommend providing early enteral nutrition (EEN) within 24-36 hours of admission to the intensive care unit (ICU) or within 12 hours of placement on mechanical ventilation (MV). Moreover, data show critically ill COVID-19 patients have negative alterations in their gut microbiome which is attributed to many factors including insufficient EN and fiber provision. The success and tolerance of EEN with a prebiotic formula in patients with COVID 19 is unknown. Here we aimed to assess, before and after implementation of an enteral feeding protocol, the achievement of EEN, estimated energy goals, and tolerance of a prebiotic formula in MV patients with COVID-19. Method(s): Data were collected and analyzed retrospectively from June 2020-May 2021 and prospectively from June 2021-January 2022. A protocol to promote EEN and improve nutrition delivery with a prebiotic-containing formula to patients within the seven days of ICU admission was created and implemented in June 2021 in the Medical ICU. Time to start EEN following invasive MV was assessed. Feeding adequacy over the first seven days of ICU admission was calculated by dividing the mean total calories of formula infused over the first seven ICU days by the estimated goal calories/day. The average number of bowel movements (BM) over the first seven ICU days was used to evaluate feeding tolerance. To determine the impact of inflammation and co-morbid conditions on feeding adequacy and tolerance, admission C-reactive protein (CRP) and Charlson Comorbidity Index (CCI) were trended with feeding adequacy. The Institutional Review Board approved the study. Result(s): A total of 343 patient records were analyzed with 203 patients in retrospective (R) and 140 patients in prospective groups (P). The post- MV feeding initiation time was shorter after implementing the feeding protocol (Mean 45.2 vs 33.8 hrs, and Interquartile Range (IQR) of Median (hrs) (18, 51) vs (16, 43) for the R and P groups, respectively (p = 0.04). Achievement of feeding goal rates were similar between groups (30.0 % vs 29.5%) (p >0.05). A prebiotic-containing formula was received in 36.2 % of patients in the R group versus 43.4 % in the P group. Providing a prebiotic formula had no impact on achieving goal nutrition in either period. In the R group, patients receiving the non-prebiotic formula had a higher total 7-days BM occurrence compared to the prebiotic formula group (8 vs 5.9 BMs/7 days, p = 0.03). In the P group there were no differences in the number of BMs between non-prebiotic and prebiotic formula groups (5.3 vs 5.0 BMs/7 days, p >0.05). Higher admission CRP and CCI values trended with higher incidence of inadequate feeding. Mean CCI was 4.42 and 4.17 for patients who received less than 25% goal feeding compared to those who received >80% of their goal feeds, respectively. Mean CRP was 12.3 and 11.4 for patients who received < 25% goal feeds compared to those who received >80% of goal feeds, respectively (p > 0.05). There were no differences in overall ICU length of stay between the R (11.7 days) and P (11.1 days) groups. (p = 0.34) Conclusion(s): EEN protocol implementation decreased time to EEN initiation in mechanically ventilated COVID-19 patients but did not affect patients in achieving goal nutrition in the first week of their ICU stay. Furthermore, COVID-19 patients tolerated EEN with prebiotic containing formulas. Further research is warranted to determine the impact of EEN with a prebiotic formula on the gut microbiome in critically ill MV patients with COVID-19.

Emerging applications of phage therapy and fecal virome transplantation for treatment of Clostridioides difficile infection: challenges and perspectives.

Clostridioides difficile, which causes life-threatening diarrheal disease, is considered an urgent threat to healthcare setting worldwide. The current standards of care solely rely on conventional antibiotic treatment, however, there is a risk of promoting recurrent C. difficile infection (rCDI) because of the emergence of antibiotic-resistant strains. Globally, the alarming spread of antibiotic-resistant strains of C. difficile has resulted in a quest for alternative therapeutics. The use of fecal microbiota transplantation (FMT), which involves direct infusion of fecal suspension from a healthy donor into a diseased recipient, has been approved as a highly efficient therapeutic option for patients with rCDI. Bacteriophages or phages are a group of viruses that can infect and destroy bacterial hosts, and are recognized as the dominant viral component of the human gut microbiome. Accumulating data has demonstrated that phages play a vital role in microbial balance of the human gut microbiome. Recently, phage therapy and fecal virome transplantation (FVT) have been introduced as promising alternatives for the treatment of C. difficile -related infections, in particular drug-resistant CDI. Herein, we review the latest updates on C. difficile- specific phages, and phage-mediated treatments, and highlight the current and future prospects of phage therapy in the management of CDI.