IU Indianapolis ScholarWorks :: Browsing by Subject "Gut microbiome"

Browsing by Subject "Gut microbiome"

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Adolescent alcohol drinking interaction with the gut microbiome: implications for adult alcohol use disorder
(Frontiers Media, 2024) Getachew, Bruk; Hauser, Sheketha R.; Bennani, Samia; El Kouhen, Nacer; Sari, Youssef; Tizabi, Yousef; Psychiatry, School of Medicine
Reciprocal communication between the gut microbiota and the brain, commonly referred to as the “gut-brain-axis” is crucial in maintaining overall physiological homeostasis. Gut microbiota development and brain maturation (neuronal connectivity and plasticity) appear to be synchronized and to follow the same timeline during childhood (immature), adolescence (expansion) and adulthood (completion). It is important to note that the mesolimbic reward circuitry develops early on, whereas the maturation of the inhibitory frontal cortical neurons is delayed. This imbalance can lead to increased acquirement of reward-seeking and risk-taking behaviors during adolescence, and consequently eventuate in heightened risk for substance abuse. Thus, there is high initiation of alcohol drinking in early adolescence that significantly increases the risk of alcohol use disorder (AUD) in adulthood. The underlying causes for heightened AUD risk are not well understood. It is suggested that alcohol-associated gut microbiota impairment during adolescence plays a key role in AUD neurodevelopment in adulthood. Furthermore, alcohol-induced dysregulation of microglia, either directly or indirectly through interaction with gut microbiota, may be a critical neuroinflammatory pathway leading to neurodevelopmental impairments and AUD. In this review article, we highlight the influence of adolescent alcohol drinking on gut microbiota, gut-brain axis and microglia, and eventual manifestation of AUD. Furthermore, novel therapeutic interventions via gut microbiota manipulations are discussed briefly.
Altered bile acid profile associates with cognitive impairment in Alzheimer's disease—An emerging role for gut microbiome
(Elsevier, 2019-01) MahmoudianDehkordi, Siamak; Arnold, Matthias; Nho, Kwangsik; Ahmad, Shahzad; Jia, Wei; Xie, Guoxiang; Louie, Gregory; Kueider‐Paisley, Alexandra; Moseley, M. Arthur; Thompson, J. Will; St John Williams, Lisa; Tenenbaum, Jessica D.; Blach, Colette; Baillie, Rebecca; Han, Xianlin; Bhattacharyya, Sudeepa; Toledo, Jon B.; Schafferer, Simon; Klein, Sebastian; Koal, Therese; Risacher, Shannon L.; Kling, Mitchel Allan; Motsinger‐Reif, Alison; Rotroff, Daniel M.; Jack, John; Hankemeier, Thomas; Bennett, David A.; De Jager, Philip L.; Trojanowski, John Q.; Shaw, Leslie M.; Weiner, Michael W.; Doraiswamy, P. Murali; van Duijn, Cornelia M.; Saykin, Andrew J.; Kastenmüller, Gabi; Kaddurah‐Daouk, Rima; Radiology and Imaging Sciences, School of Medicine
Introduction Increasing evidence suggests a role for the gut microbiome in central nervous system disorders and a specific role for the gut‐brain axis in neurodegeneration. Bile acids (BAs), products of cholesterol metabolism and clearance, are produced in the liver and are further metabolized by gut bacteria. They have major regulatory and signaling functions and seem dysregulated in Alzheimer's disease (AD). Methods Serum levels of 15 primary and secondary BAs and their conjugated forms were measured in 1464 subjects including 370 cognitively normal older adults, 284 with early mild cognitive impairment, 505 with late mild cognitive impairment, and 305 AD cases enrolled in the AD Neuroimaging Initiative. We assessed associations of BA profiles including selected ratios with diagnosis, cognition, and AD‐related genetic variants, adjusting for confounders and multiple testing. Results In AD compared to cognitively normal older adults, we observed significantly lower serum concentrations of a primary BA (cholic acid [CA]) and increased levels of the bacterially produced, secondary BA, deoxycholic acid, and its glycine and taurine conjugated forms. An increased ratio of deoxycholic acid:CA, which reflects 7α‐dehydroxylation of CA by gut bacteria, strongly associated with cognitive decline, a finding replicated in serum and brain samples in the Rush Religious Orders and Memory and Aging Project. Several genetic variants in immune response–related genes implicated in AD showed associations with BA profiles. Discussion We report for the first time an association between altered BA profile, genetic variants implicated in AD, and cognitive changes in disease using a large multicenter study. These findings warrant further investigation of gut dysbiosis and possible role of gut‐liver‐brain axis in the pathogenesis of AD.
Angiotensin Converting Enzyme 2 in Cardiopulmonary Diseases: Ramifications for the Control of SARS-CoV-2
(American Heart Association, 2020-09) Sharma, Ravindra K.; Stevens, Bruce R.; Obukhov, Alexander G.; Grant, Maria B.; Oudit, Gavin Y.; Li, Qiuhong; Richards, Elaine M.; Pepine, Carl J.; Raizada, Mohan K.; Anatomy and Cell Biology, School of Medicine
Discovery of angiotensin converting enzyme 2 (ACE2) revealed that the renin angiotensin system (RAS) has two counterbalancing arms. ACE2 is a major player in the protective arm, highly expressed in lungs and gut with the ability to mitigate cardiopulmonary diseases such as inflammatory lung disease. ACE2 also exhibits activities involving gut microbiome, nutrition, and as a chaperone stabilizing the neutral amino acid transporter, B0AT1, in gut. But the current interest in ACE2 arises because it is the cell surface receptor for the novel coronavirus, SARS-CoV-2, to infect host cells, similar to SARS-CoV. This suggests that ACE2 be considered harmful, however because of its important other roles, it is paradoxically a potential therapeutic target for cardiopulmonary diseases including COVID-19, caused by SARS-CoV-2. This review describes the discovery of ACE2, its physiological functions, and its place in the RAS. It illustrates new analyses of the structure of ACE2 that provides better understanding of its actions particularly in lung and gut, shedding of ACE2 by ADAM17 and role of TMPRSS2 in SARS-CoV-2 entry into host cells. Cardiopulmonary diseases are associated with decreased ACE2 activity and the mitigation by increasing ACE2 activity along with its therapeutic relevance are addressed. Finally, the potential use of ACE2 as a treatment target in COVID-19, despite its role to allow viral entry into host cells, is suggested.
Characterization of intratumor microbiome in cancer immunotherapy
(Elsevier, 2023-07-12) Zhang, Zhao; Gao, Qian; Ren, Xiangmei; Luo, Mei; Liu, Yuan; Liu, Peilin; Liu, Yun; Ye, Youqiong; Che, Xiang; Liu, Hong; Han, Leng; Biostatistics and Health Data Science, School of Medicine
Circulating trimethylamine N-oxide levels following fish or seafood consumption
(Springer, 2022) Wang, Zeneng; Tang, W. H. Wilson; O’Connell, Thomas; Garcia, Erwin; Jeyarajah, Elias J.; Li, Xinmin S.; Jia, Xun; Weeks, Taylor L.; Hazen, Stanley L.; Otolaryngology -- Head and Neck Surgery, School of Medicine
Purpose: Some species of fish and seafood are high in trimethylamine N-oxide (TMAO), which accumulates in muscle where it protects against pressure and cold. Trimethylamine (TMA), the metabolic precursor to TMAO, is formed in fish during bacterial spoilage. Fish intake is promoted for its potential cardioprotective effects. However, numerous studies show TMAO has pro-atherothrombotic properties. Here, we determined the effects of fish or seafood consumption on circulating TMAO levels in participants with normal renal function. Methods: TMAO and omega-3 fatty acid content were quantified across multiple different fish or seafood species by mass spectrometry. Healthy volunteers (n = 50) were recruited for three studies. Participants in the first study consented to 5 consecutive weekly blood draws and provided dietary recall for the 24 h preceding each draw. In the second study, TMAO levels were determined following defined low and high TMAO diets. Finally, participants consumed test meals containing shrimp, tuna, fish sticks, salmon or cod. TMAO levels were quantified by mass spectrometry in blood collected before and after dietary challenge. Results: TMAO + TMA content varied widely across fish and seafood species. Consumption of fish sticks, cod, and to a lesser extent salmon led to significant increases in circulating TMAO levels. Within 1 day, circulating TMAO concentrations in all participants returned to baseline levels. Conclusions: We conclude that some fish and seafood contain high levels of TMAO, and may induce a transient elevation in TMAO levels in some individuals. Selection of low TMAO content fish is prudent for subjects with elevated TMAO, cardiovascular disease or impaired renal function.
Compositional and Temporal Changes in the Gut Microbiome of Pediatric Ulcerative Colitis Patients Are Linked to Disease Course
(Elsevier, 2018-10-10) Schirmer, Melanie; Denson, Lee; Vlamakis, Hera; Franzosa, Eric A.; Thomas, Sonia; Gotman, Nathan M.; Rufo, Paul; Baker, Susan S.; Sauer, Cary; Markowitz, James; Pfefferkorn, Marian; Oliva-Hemker, Maria; Rosh, Joel; Otley, Anthony; Boyle, Brendan; Mack, David; Baldassano, Robert; Keljo, David; LeLeiko, Neal; Heyman, Melvin; Griffiths, Anne; Patel, Ashish S.; Noe, Joshua; Kugathasan, Subra; Walters, Thomas; Huttenhower, Curtis; Hyams, Jeffrey; Xavier, Ramnik J.; Medicine, School of Medicine
Evaluating progression risk and determining optimal therapy for ulcerative colitis (UC) is challenging as many patients exhibit incomplete responses to treatment. As part of the PROTECT (Predicting Response to Standardized Colitis Therapy) Study, we evaluated the role of the gut microbiome in disease course for 405 pediatric, new-onset, treatment-naive UC patients. Patients were monitored for 1 year upon treatment initiation, and microbial taxonomic composition was analyzed from fecal samples and rectal biopsies. Depletion of core gut microbes and expansion of bacteria typical of the oral cavity were associated with baseline disease severity. Remission and refractory disease were linked to species-specific temporal changes that may be implicative of therapy efficacy, and a pronounced increase in microbiome variability was observed prior to colectomy. Finally, microbial associations with disease-associated serological markers suggest host-microbial interactions in UC. These insights will help improve existing treatments and develop therapeutic approaches guiding optimal medical care
The critical role of dietary foliage in maintaining the gut microbiome and metabolome of folivorous sifakas
(Springer Nature, 2018-09-27) Greene, Lydia K.; McKenney, Erin A.; O'Connell, Thomas M.; Drea, Christine M.; Otolaryngology -- Head and Neck Surgery, School of Medicine
The gut microbiome (GMB) of folivores metabolizes dietary fiber into nutrients, including short-chain fatty acids (SCFAs); however, experiments probing the consequences of foliage quality on host GMBs are lacking. We therefore examined GMB structure and function via amplicon sequencing and Nuclear Magnetic Resonance spectroscopy in 31 captive sifakas (Propithecus coquereli) during dietary manipulations associated with husbandry. Supplementing standard diets with diverse foliage blends, versus with a single plant species, promoted more diverse GMBs, enriched for taxa implicated in plant-fiber metabolism, but depleted in taxa implicated in starch metabolism and bile tolerance. The consumption of diverse blends was associated with greater concentrations of colonic SCFAs. Abundant foliage, via forest access, promoted compositionally distinct and more stable GMBs, but reduced concentrations of SCFAs, possibly reflecting selection of high-quality leaves. In 11 subjects denied forest access, we examined the temporal pace of microbial shifts when supplemental foliage was abruptly switched between diverse blends and single species. The sifaka GMB responded within days, with community diversity and composition closely tracking foliage diversity. By providing experimental evidence that the folivore GMB is sensitive to minor changes in dietary foliage, we reveal the fragility of specialist GMBs, with implications for managing the wellbeing of endangered wildlife.
Dysbiosis in gastrointestinal pathophysiology: Role of the gut microbiome in Gulf War Illness
(Wiley, 2023) Slevin, Elise; Koyama, Sachiko; Harrison, Kelly; Wan, Ying; Klaunig, James E.; Wu, Chaodong; Shetty, Ashok K.; Meng, Fanyin; Medicine, School of Medicine
Gulf War Illness (GWI) has been reported in 25%-35% of veterans returned from the Gulf war. Symptoms of GWI are varied and include both neurological and gastrointestinal symptoms as well as chronic fatigue. Development of GWI has been associated with chemical exposure particularly with exposure to pyridostigmine bromide (PB) and permethrin. Recent studies have found that the pathology of GWI is connected to changes in the gut microbiota, that is the gut dysbiosis. In studies using animal models, the exposure to PB and permethrin resulted in similar changes in the gut microbiome as these found in GW veterans with GWI. Studies using animal models have also shown that phytochemicals like curcumin are beneficial in reducing the symptoms and that the extracellular vesicles (EV) released from gut bacteria and from the intestinal epithelium can both promote diseases and suppress diseases through the intercellular communication mechanisms. The intestinal epithelium cells produce EVs and these EVs of intestinal epithelium origin are found to suppress inflammatory bowel disease severity, suggesting the benefits of utilizing EV in treatments. On the contrary, EV from the plasma of septic mice enhanced the level of proinflammatory cytokines in vitro and neutrophils and macrophages in vivo, suggesting differences in the EV depending on the types of cells they were originated and/or influences of environmental changes. These studies suggest that targeting the EV that specifically have positive influences may become a new therapeutic strategy in the treatment of veterans with GWI.
Engaging Adolescent and Young Adults in Microbiome Sample Self-Collection: Strategies for Success
(Sage, 2021) Chen, Chen X.; Carpenter, Janet S.; Murphy, Tabitha; Brooks, Patricia; Fortenberry, J. Dennis; School of Nursing
Human microbiome research provides rich opportunities to elucidate factors influencing health, uncover novel biomarkers, and expand disease treatment options. A well-conducted microbiome study depends not only on a rigorous design but also on successfully engaging participants in collecting quality samples. In this paper, we aim to describe (1) strategies our team used to engage adolescents and young adults in vaginal and gut microbiome sample self-collection and (2) their effectiveness. In our prospective, longitudinal, feasibility study of 20 female adolescents and young adults, research participants self-collected vaginal and gut microbiome samples at home. Using a participatory and iterative process, we developed strategies to engage participants in sample self-collection, including (1) providing clear instructions to ensure comprehension and buy-in, (2) providing a user-friendly take-home package, (3) minimizing disgust/embarrassment associated with sample collection, and (4) follow-up communications to facilitate sample collections and return. With these strategies, we achieved 100% participant retention and 100% sample return rates. All samples (n = 80, 100%) were usable for downstream 16s rRNA gene sequencing and analysis. All participants rated the study procedures as acceptable, and qualitative data showed that strategies were well received by participants. This study suggests that carefully planning and implementing strategies to engage participants in sample self-collection can result in high degrees of participant compliance, sample quality, and participant satisfaction in microbiome research.
The gut microbiome, immunity, and Plasmodium severity
(Elsevier, 2020-12) Waide, Morgan L.; Schmidt, Nathan W.; Pediatrics, School of Medicine
Malaria continues to pose a severe threat to over half of the world's population each year. With no long-term, effective vaccine available and a growing resistance to antimalarials, there is a need for innovative methods of Plasmodium treatment. Recent evidence has pointed to a role of the composition of the gut microbiota in the severity of Plasmodium infection in both animal models and human studies. Further evidence has shown that the gut microbiota influences the adaptive immune response of the host, the arm of the immune system necessary for Plasmodium clearance, sustained Plasmodium immunity, and vaccine efficacy. Together, this illustrates the future potential of gut microbiota modulation as a novel method of preventing severe malaria.

Browsing by Subject "Gut microbiome"

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