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Advancements in Research on Necrotizing Enterocolitis Pathogenesis and Prevention Using PIGS
Published in David J. Hackam, Necrotizing Enterocolitis, 2021
Douglas Burrin, Juan Marini, Murali Premkumar, Barbara Stoll, Per Torp Sangild
The role of the microbiota in the development and function of the infant is one of the most rapidly advancing areas of research due to the development of genomic sequencing approaches to identify microbes in body sites and fluids. Recent reports of microbial DNA in the placenta, amniotic fluid, and meconium samples from preterm infants have challenged the idea that the fetal environment is sterile (124, 125). However, subsequent studies have found no DNA sequence–based evidence for bacterial colonization in the placenta, amniotic fluid, or fetus (126). The presence of milk-associated microbiota also has been implicated as another factor in the protective effects of breastfeeding in the human infant. In the context of NEC, there is evidence that the microbiota communities are characterized by high levels of facultative anaerobes and abundance of Proteobacteria and decreased relative abundances of Firmicutes and Bacteroidetes (127–129). Another study found an overrepresentation of gram-negative facultative bacilli and potentially pathogenic organisms, such as Escherichia coli, Enterobacter, and Klebsiella and the underrepresentation of obligate anaerobic bacteria, in particular Negativicutes and Clostridia, in infants' guts before NEC developed (130). A consistent finding from several large cohort studies including healthy preterm infants and those with NEC is that there is not one specific pathogenic bacterial species linked to NEC, but recent studies have narrowed the possibilities to some genera present prior to the onset of disease.
Inorganic Chemical Pollutants
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
In the absence of genome sequences for all Hg-methylating organisms, the generality of the present findings cannot yet be ascertained. However, their interpretation is in agreement with all currently available sequence information for methylating bacteria and archaea. The presence of the hgcAB cluster in the genomes of several sequenced, but so far untested, microorganisms leads them to hypothesize that these organisms are also capable of methylating mercury. The gene cluster appears to be quite sporadically distributed across two phyla of bacteria (Proteobacteria and Firmicutes) and one phylum of archaea (Euryarchaeota). Organisms possessing the two-gene cluster include 24 strains of Deltaproteobacteria, 16 Clostridia, 1 Negativicutes, and 11 Methanomicrobia. Interestingly, they also found these genes in a psychrophile,583 in a thermophile,584 and in a human commensal methanogen.585 The sporadic distribution of these genes and the lack of an obvious selective advantage related to mercury toxicity raise important questions regarding their physiological roles. Identification of these genes is a critical step linking specific microorganisms and environmental factors that influence microbial Hg methylation in aquatic ecosystems.
Religious Aspects and Medicinal Uses of Salvadora persica (Miswak)
Published in Mehwish Iqbal, Complementary and Alternative Medicinal Approaches for Enhancing Immunity, 2023
Furthermore, contemporary approaches have demonstrated some microbial infectious agents are closely related to periodontitis, for instance, the classes of microorganisms, i.e. Erysipelotrichia, Negativicutes and Clostridia (Griffen et al., 2012), Prevotella, Fusobacterium (Costalonga & Herzberg, 2014) and Synergistes (Vartoukian et al., 2009); similarly the species Aggregatibacter actinomycetemcomitans (Ardila & Bedoya-García, 2020), Methanosarcina mazeii, Methanobrevibacter oralis, Methanobacterium curvum/congolense (Lepp et al., 2004; Matarazzo et al., 2011; Willis & Gabaldón, 2020) and Filifactor alocis (Griffen et al., 2012). Several studies have explained the antibacterial effects of Salvadora persica on different kinds of microbes (Al Bratty et al., 2020; Arshad et al., 2021; Khalil et al., 2019). The products and extracts of miswak have been demonstrated to have considerable bacteria-killing activity against gram-negative and gram-positive microbes, as well as subduing microbial biofilms, in a lot of research experiments that encourage the usage of miswak as an antibacterial medicine in a range of ailments (Mekhemar et al., 2021). One of the suggested mechanisms of the miswak-facilitated bacterial killing function was focusing on the microbial membranes by BITC (benzyl isothiocyanate), which is one of the dynamic constituents of miswak extracts. Micrographs of periodontal infectious agents showed that complexes of benzyl isothiocyanate and miswak extracts might give rise to the membrane protuberances of bacteria like antimicrobial peptides (Socransky et al., 1998). By means of the disintegration of the external membrane of bacteria, bioactive complexes of Salvadora persica will invade the microbial cell and interrelate with the redox systems of the microbes, weakening the capability of the microbes to preserve their membrane potential. Such a method of benzyl isothiocyanate has also been documented for membranes of mitochondria (Socransky et al., 1998).
Effects of intestinal flora on pharmacokinetics and pharmacodynamics of drugs
Published in Drug Metabolism Reviews, 2023
Amina Džidić-Krivić, Jasna Kusturica, Emina Karahmet Sher, Nejra Selak, Nejra Osmančević, Esma Karahmet Farhat, Farooq Sher
Epilepsy is one of the most emerging health problems in the modern world and quite often, the standard therapy protocols that are being used in clinical practice do not have the effect that is expected. In addition, one of the main issues is the development of drug-resistant epilepsy. Recent studies proposed that the gut microbiota composition, affected by an unhealthy diet is one of the important reasons for increased resistance to anti-epileptic drugs. A group of scientists evaluated feces samples taken from a group of patients that have epilepsy and respond to antiepileptic drugs. These feces samples were compared to the feces samples taken from the group of patients that do not respond to the therapy. Statistical analysis showed that the composition of the gut microbiota was different in both groups. Patients who responded to the treatment had a relative abundance of Bacteroides finegoldii and Bifidobacterium sp., as opposed to the patients did not respond to the therapy and had a relative abundance of Negativicutes sp. (Whang et al. 2019). This is the potential marker for detecting the group of patients that will not respond well to the antiepileptic drug therapy as shown in Figure 4.
Short-term supplementation with ω-3 polyunsaturated fatty acids modulates primarily mucolytic species from the gut luminal mucin niche in a human fermentation system
Published in Gut Microbes, 2022
Charlène Roussel, Sara Anunciação Braga Guebara, Pier-Luc Plante, Yves Desjardins, Vincenzo Di Marzo, Cristoforo Silvestri
Finally, to identify associations between bacterial abundance and SCFA concentration, a Spearman correlation matrix was generated, and significant associations were illustrated in a network format (Figure 7). The low microbiota diversity in the ileum (Figure 7a) showed limited associations between SCFA and taxa at the class level, though ω-3 PUFA supplementation (Ileum-T) modified the matrix, splitting it up into 2 distinct groups; acetate alone, on the one hand, and butyrate and propionate, which are positively associated (in blue) with the same taxa. More strikingly, in the descending colon, the significant increase of Verrucomicrobiae (Akkermansia muciniphila) and Desulfovibrionia (Desulfovibrio) observed under ω-3 PUFA supplementation (Descending colon-T), correlated positively with the observed rise of propionate (in blue, Figure 7b). The increase of Negativicutes members (Veillonella, Dialister, Megasphaera) was however correlated negatively (in red) with propionate production. The important decline of Clostridia members under ω-3 PUFA supplementation was not associated to the increase of propionate or decrease of butyrate, which instead correlated positively only with acetate (in blue). Therefore, Spearman correlations analysis displayed remarkable associations between metataxonomic traits and SCFA concentrations in a treatment and habitat-dependent fashion (Figure 7).
Dietary manipulation of the gut microbiome in inflammatory bowel disease patients: Pilot study
Published in Gut Microbes, 2022
Barbara Olendzki, Vanni Bucci, Caitlin Cawley, Rene Maserati, Margaret McManus, Effie Olednzki, Camilla Madziar, David Chiang, Doyle V. Ward, Randall Pellish, Christine Foley, Shakti Bhattarai, Beth A. McCormick, Ana Maldonado-Contreras
We then investigated whether different species could be enriched by disease phenotype during the intervention (Supplementary Table S5). In patients with CD, the top bacteria with significantly increased abundance during the intervention were mostly species members of the Clostridia, Bacteroidia, and Coriobacteriia classes, and two Firmicutes species (Figure 3). Bacterial species significantly reduced during the intervention belonged not only to Gammaproteobacteria and Negativicutes classes, but also to Clostridia, Bacteroidia, and Coriobacteriia classes (Figure 3). Despite the overlap of bacterial classes as being positively or negatively affected during the IBD-AID intervention, there were specific species within those classes that seemed to be directionally altered by the intervention. These results suggest that specific foods affect the abundance of bacteria at the species level and are consistent with previous studies.33,48,49