Tranexamic acid as a therapeutic option for melasma management: meta-analysis and systematic review of randomized controlled trials.

Purpose: This study aimed to evaluate the efficacy of tranexamic acid (TXA) in treating melasma through a meta-analysis and systematic review of randomized controlled trials (RCTs). The study focused on identifying associated adverse effects and comparing TXA's effectiveness with other melasma treatments.Materials and methods: Following PROSPERO and PRISMA guidelines, an extensive electronic search was conducted across four databases for RCTs on TXA use in melasma. Inclusion criteria encompassed full-text English articles with specific outcome measures, while studies with high bias risk or non-English publications were excluded. Data were extracted from 22 relevant studies and analyzed using the RevMan software, with heterogeneity identified using I² statistics and forest plots.Results: A total of 22 studies with 1280 patients were included. TXA was administered orally, topically, or via injection, with treatment durations ranging from 8 weeks to nearly 2 years. TXA significantly reduced melasma severity, evidenced by reductions in MASI, mMASI, MI, and hemi-MASI scores. Oral TXA showed the most substantial decrease in MASI scores, followed by injections and topical applications. However, studies exhibited high heterogeneity, particularly in combined treatments. Adverse effects included gastrointestinal discomfort, skin irritation, and menstrual irregularities.Conclusions: TXA is effective in treating melasma, either alone or combined with other treatments. Despite significant reductions in melasma severity, further research is necessary to standardize TXA administration methods and address long-term effects. The high heterogeneity observed suggests a need for more consistent treatment protocols.

Preclinical Safety Assessment of Lepidium sativum L. Seed Extract and its Nanoparticles via Acute and Subacute Oral Administration.

BACKGROUND: Lepidium sativum (LS) seed extract has various pharmacological properties, such as antioxidant, hepatoprotective, and anticancer activities. However, the translation of L. sativum seed extract to the clinical phase is still tedious due to its bioavailability and stability issues. This problem can be solved by encapsulating it in a nanodelivery system to improve its therapeutic potency. METHODS: In this study, we have determined and compared the in vivo toxicity of ethanolic extracts of L. sativum seeds (EELS) and solid lipid nanoparticles (SLNs). To conduct toxicity (acute and subacute toxicity) assessments, EELS and SLNs were orally administered to Swiss albino mice. Animal survival, body weight, the weight of vital organs in relation to body weight, haematological profile, biochemistry profile, and histopathological alterations were examined. RESULTS: Animals administered with 2000 mg/kg and 5000 mg/kg in an acute toxicity study exhibited no toxicological symptoms regarding behaviour, gross pathology, and body weight. As per a study on acute toxicity, the LD50 (lethal dose) for SLNs and EELS was over 400 mg/kg and over 5000 mg/kg, respectively. When animals were given SLNs (50 and 100 mg/kg, orally) and EELS (250, 500, and 1000 mg/kg, orally) for 28 days, subacute toxicity study did not exhibit any clinical changes. There were no differences in weight gain, haematological parameters, or biochemical parameters compared to the control groups (p > 0.05). The organs of the treated animals showed no abnormalities in the histological analysis (liver, heart, kidney, and spleen). CONCLUSION: The result confirms ethanolic extracts of L. sativum seeds and their SLNs to not have harmful effects following acute and subacute administration to mice. For further studies, patents available on Lepidium may be referred for its preclinical and clinical applications.

Oral curcumin ameliorates acute murine campylobacteriosis.

Introduction: Human infections with the food-borne enteropathogen Campylobacter jejuni are responsible for increasing incidences of acute campylobacteriosis cases worldwide. Since antibiotic treatment is usually not indicated and the severity of the enteritis directly correlates with the risk of developing serious autoimmune disease later-on, novel antibiotics-independent intervention strategies with non-toxic compounds to ameliorate and even prevent campylobacteriosis are utmost wanted. Given its known pleiotropic health-promoting properties, curcumin constitutes such a promising candidate molecule. In our actual preclinical placebo-controlled intervention trial, we tested the anti-microbial and anti-inflammatory effects of oral curcumin pretreatment during acute experimental campylobacteriosis. Methods: Therefore, secondary abiotic IL-10-/- mice were challenged with synthetic curcumin via the drinking water starting a week prior oral C. jejuni infection. To assess anti-pathogenic, clinical, immune-modulatory, and functional effects of curcumin prophylaxis, gastrointestinal C. jejuni bacteria were cultured, clinical signs and colonic histopathological changes quantitated, pro-inflammatory immune cell responses determined by in situ immunohistochemistry and intestinal, extra-intestinal and systemic pro-inflammatory mediator measurements, and finally, intestinal epithelial barrier function tested by electrophysiological resistance analysis of colonic ex vivo biopsies in the Ussing chamber. Results and discussion: Whereas placebo counterparts were suffering from severe enterocolitis characterized by wasting symptoms and bloody diarrhea on day 6 post-infection, curcumin pretreated mice, however, were clinically far less compromised and displayed less severe microscopic inflammatory sequelae such as histopathological changes and epithelial cell apoptosis in the colon. In addition, curcumin pretreatment could mitigate pro-inflammatory innate and adaptive immune responses in the intestinal tract and importantly, rescue colonic epithelial barrier integrity upon C. jejuni infection. Remarkably, the disease-mitigating effects of exogenous curcumin was also observed in organs beyond the infected intestines and strikingly, even systemically given basal hepatic, renal, and serum concentrations of pro-inflammatory mediators measured in curcumin pretreated mice on day 6 post-infection. In conclusion, the anti-Campylobacter and disease-mitigating including anti-inflammatory effects upon oral curcumin application observed here highlight the polyphenolic compound as a promising antibiotics-independent option for the prevention from severe acute campylobacteriosis and its potential post-infectious complications.

Population Dementia Incidence and Direct Oral Anticoagulant Use in a Representative Population With Atrial Fibrillation.

BACKGROUND AND OBJECTIVES: Incidence and prevalence of atrial fibrillation (AF), a risk factor of dementia, have been increasing over time. Oral anticoagulation reduces risk of stroke and other negative outcomes of AF and may reduce dementia health inequities. The objective of this study was to estimate dementia incidence in patients with newly-diagnosed AF and taking an anticoagulant as use of direct oral anticoagulants (DOACs) increased. METHODS: We used a retrospective cohort design with annual incident AF cohorts of community-dwelling Medicare Fee-for-Service beneficiaries, enrolled in Parts A, B, and D from 2007 to 2017. The sample was limited to beneficiaries aged 67 years and older with incident AF; no prior dementia; and use of anticoagulants warfarin, dabigatran, rivaroxaban, apixaban, or edoxaban in year t. RESULTS: A total of 1,083,338 beneficiaries were included in the study, 58.5% female, with mean (SD) age 77.2 (6.75) years. Among anticoagulated, incident AF cohorts, use of DOACs increased from 10.6% in their first year of availability (2011) to 41.4% in 2017. Among incident AF cohorts taking any oral anticoagulant, 3-year dementia incidence did not change significantly over the cohorts after adjusting for confounders. For example, incidence was 9.1% (95% CI 8.9-9.4) among White persons diagnosed with AF in 2007 and 2008 and 8.9% (95% CI 8.7-9.1) in 2017. Across cohorts, dementia incidence was consistently highest for Black persons, followed by American Indian/Alaska Native and White persons, and lowest for Asian persons. In 2017, 10.9% (95% CI 10.4-11.3) of Black persons in the cohort developed dementia within 3 years, 9.4% (95% CI 8.0-10.9) of American Indian/Alaska Native, 8.9% (95% CI 8.7-9.1) of White, 8.7% (95% CI 8.2-9.1) of Hispanic, and 6.9% (95% CI 6.4-7.4) of Asian persons. Across race/ethnicity, 3-year stroke risk decreased consistently over time; however, the increasing availability of DOACs did not alter the trend. DISCUSSION: Increased use of DOACs among incident AF cohorts from 2007 to 2017 was not associated with significant declines in dementia or stroke risk. Consideration of similar stroke and dementia risk, as well as differences in cost, is warranted when weighing the risks and benefits of available oral anticoagulants.

Optimising the oral midazolam dose for premedication in people with intellectual disabilities and/or autism spectrum disorder.

BACKGROUND: In people with intellectual disabilities and/or autism spectrum disorder, oral midazolam (OM) is very effective as premedication for facilitating medical treatment. In this retrospective study, we investigated the optimal dosage of OM for premedication. METHODS: Patients with intellectual disability and/or autism spectrum disorder who were given OM as a premedication were selected from anaesthesia records. The primary outcome variable was the dose of OM (mg/kg) required to produce an adequate sedation. RESULTS: The mean OM dose required was 0.32 ± 0.10 mg/kg. The required OM dose decreased significantly as age and weight increased, and age and weight were also shown to be significantly associated with the dose of OM in the multivariate linear regression analysis. CONCLUSION: The dosage of OM to achieve adequate sedation should decrease as the patient ages. Furthermore, adequate sedation can be achieved with even lower doses of OM in obese people.

A pharmacist-led interprofessional medication adherence program improved adherence to oral anticancer therapies: The OpTAT randomized controlled trial.

BACKGROUND: Oral anticancer therapies such as protein kinase inhibitors (PKIs) are increasingly prescribed in cancer care. We aimed to evaluate the impact of a pharmacist-led interprofessional medication adherence program (IMAP) on patient implementation (dosing history), persistence (time until premature cessation of the treatment) and adherence to 27 PKIs prescribed for various solid cancers, as well as the impact on patients' beliefs about medicines (BAM) and quality of life (QoL). METHODS: Patients (n = 118) were randomized 1:1 into two arms. In the intervention arm, pharmacists supported patient adherence through monthly electronic and motivational feedback, including educational, behavioral and affective components, for 12 months. The control arm received standard care plus EM without intervention. All PKIs were delivered in electronic monitors (EMs). Medication implementation and adherence were compared between groups using generalized estimating equation models, in which relevant covariables were included; persistence was compared with Kaplan‒Meier curves. Information on all treatment interruptions was compiled for the analysis. Questionnaires to evaluate BAM and QoL were completed among patients who refused and those who accepted to participate at inclusion, 6 and 12 months post-inclusion or at study exit. RESULTS: Day-by-day PKI implementation was consistently higher and statistically significant in the intervention arm (n = 58) than in the control arm (n = 60), with 98.1% and 95.0% (Δ3.1%, 95% confidence interval (CI) of the difference 2.5%; 3.7%) implementation at 6 months, respectively. The probabilities of persistence and adherence were not different between groups, and no difference was found between groups for BAM and QoL scores. No difference in BAM or QoL was found among patients who refused versus those who participated. The intervention benefited mostly men (at 6 months, Δ4.7%, 95% CI 3.4%; 6.0%), those younger than 60 years (Δ4.0%, 95% CI 3.1%; 4.9%), those who had initiated PKI more than 60 days ago before inclusion (Δ4.5%, 95% CI 3.6%; 5.4%), patients without metastasis (Δ4.5%, 95% CI 3.4%; 5.7%), those who were diagnosed with metastasis more than 2 years ago (Δ5.3%, 95% CI 4.3%; 6.4%) and those who had never used any adherence tool before inclusion (Δ3.8%, 95% CI 3.1%; 4.5%). CONCLUSIONS: The IMAP, led by pharmacists in the context of an interprofessional collaborative practice, supported adherence, specifically implementation, to PKIs among patients with solid cancers. To manage adverse drug events, PKI transient interruptions are often mandated as part of a strategy for treatment and adherence optimization according to guidelines. Implementation of longer-term medication adherence interventions in the daily clinic may contribute to the improvement of progression-free survival. TRIAL REGISTRATION: ClinicalTrials.gov NCT04484064.

The effect of pre-emptive oral pregabalin on opioid consumption in patients undergoing laparoscopic sleeve gastrectomy with an analysis of intraoperative hemodynamic stability and quality of recovery: study protocol for a randomized, prospective, double-blind study.

BACKGROUND: Obese patients undergoing laparoscopic sleeve gastrectomy (LSG) are particularly at risk of opioid-related side effects. To reduce patient exposure to opioids, multimodal analgesia, which involves the use of drugs of different classes, may be utilized. One of the drugs under consideration is pregabalin. Despite an opioid-sparing potential, few studies assess the role of pregabalin as an element of multimodal analgesia in LSG. Considering the limited number and inconsistent results of available studies, we decided to conduct a randomized, prospective study on the effect of preemptive pregabalin administration in obese patients on opioid consumption, pain scores, the incidence of opioid side effects, and hemodynamical stability. METHODS: The study is designed as a prospective randomized controlled trial with double-blinding. Randomization will be performed in a block with a parallel 1:1 allocation. The intervention will involve receiving a pregabalin 150 mg capsule 1-2 h before the surgery, whereas the control group will receive an identically looking placebo. The primary outcome measure will be total oxycodone consumption in the first 24 h following surgery. Secondary outcome measures will be pain severity assessed using the Numerical Rating Scale (NRS) 1, 6, 12, and 24 h after surgery, postoperative sedation on the Ramsay scale, PONV impact scale, the incidence of desaturation episodes < 94%, and episodes of blurred vision at 1, 6, 12, and 24 h after surgery, intraoperative hemodynamic parameters such as heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), total fluid volume, and total ephedrine dose. Patient comfort will be additionally assessed using the QoR-40 questionnaire at discharge. DISCUSSION: The study will explore the efficacy and safety of preemptive pregabalin in a dose of 150 mg as a co-analgesic used in multimodal analgesia for LSG. As studies on opioid-sparing regimes concern the safety of obese patients, we aim to contribute objective data with a relatively large study sample size. The result of the present clinical trial may support the reassessment of recommendations to use pregabalin in the studied population. TRIAL REGISTRATION: ClinicalTrials.gov NCT05804591. Registered on 07.04.2023.

Adherence, health care utilization, and costs between long-acting injectable and oral antipsychotic medications in South Carolina Medicaid beneficiaries with schizophrenia.

BACKGROUND: Schizophrenia and schizoaffective disorder require long-term antipsychotic treatment with antipsychotic medications, but poor medication adherence can lead to increased health care utilization and costs. Long-acting injectable antipsychotics (LAIs) offer potential therapeutic advantages in that they require less frequent dosing and improved medication adherence. South Carolina has the highest adoption of LAIs among US states, making it an ideal population for comparing the effectiveness of LAIs vs oral antipsychotics (OAPs) in treating schizophrenia or schizoaffective disorder. OBJECTIVE: To evaluate the effect of LAIs compared with OAPs on medication adherence, health care resource utilization, and costs among South Carolina Medicaid beneficiaries with schizophrenia or schizoaffective disorder. METHODS: South Carolina Medicaid beneficiaries with at least 1 claim for an LAI or OAP between January 1, 2015, and December 31, 2018, aged 18 to 65, with at least 2 claims with diagnoses of schizophrenia or schizoaffective disorder were included. Propensity scores (PSs) were calculated using logistic regression adjusting for confounders and predictors of the outcome. We estimated the "average treatment effect on the treated" by employing PS-weighted t-tests and chi-square tests. RESULTS: A total of 3,531 patients met the inclusion criteria, with 1,537 (44.5%) treated with LAIs and 1,994 (56.5%) treated with OAPs. In PS-weighted analyses, the LAI cohort had a greater proportion of days covered than the OAP cohort with a 365-day fixed denominator (69% vs 64%; P < 0.0001), higher medication possession ratio with a variable denominator while on therapy (85% vs 80%; P < 0.0001), and higher persistence (82% vs 64%; P < 0.0001). The average number of inpatient visits and emergency department visits did not significantly differ between cohorts (0.28 hospitalizations, P = 0.90; 3.68 vs 2.96 emergency department visits, P = 0.19). The number of outpatient visits, including visits for medication administration, were greater in the LAI cohort (23.1 [SD 24.2]) vs OAP (16.9 [SD 21.2]; P < 0.0001); however, including the costs for medication administration visits, outpatient costs (per member) were approximately $2,500 lower in the LAI cohort (P < 0.0001). The number of pharmacy visits was greater in the OAP cohort (LAI 21.0 [SD 17.0] vs OAP 23.0 [SD 15.0]; P = 0.006). All-cause total costs were greater in the LAI cohort ($26,025 [SD $29,909]) vs the OAP cohort ($17,291 [SD $25,261]; P < 0.0001) and were driven by the difference in pharmaceutical costs (LAI $15,273 [SD $16,183] vs OAP $4,696 [SD $10,371]; P < 0.0001). CONCLUSIONS: Among South Carolina Medicaid beneficiaries, treatment with LAIs for schizophrenia or schizoaffective disorder was associated with greater medication adherence rates. Patients using LAIs had higher drug costs and total costs, but lower outpatient and total nondrug costs compared with those using OAPs.

Sunproofing from within: A deep dive into oral photoprotection strategies in dermatology.

BACKGROUND: Photoprotection is the first measure in the prevention and treatment of the deleterious effects that sunlight can cause on the skin. It is well known that prolonged exposure to solar radiation leads to acute and chronic complications, such as erythema, accelerated skin aging, proinflammatory and procarcinogenic effects, and eye damage, among others. METHODS: A better understanding of the molecules that can protect against ultraviolet radiation and their effects will lead to improvements in skin health. RESULTS: Most of these effects of the sunlight are modulated by oxidative stress and proinflammatory mechanisms, therefore, the supplementation of substances that can regulate and neutralize reactive oxygen species would be beneficial for skin protection. Current evidence indicates that systemic photoprotection should be used as an adjunctive measure to topical photoprotection. CONCLUSION: Oral photoprotectors are a promising option in improving protection against damage induced by UVR, as they contain active ingredients that increase the antioxidant effects of the body, complementing other photoprotection measures. We present a review of oral photoprotectors and their effects.

Intestinal lymphatic transport of Smilax china L. pectic polysaccharide via Peyer's patches and its uptake and transport mechanisms in mononuclear phagocytes.

Recently, the intestinal lymphatic transport based on Peyer's patches (PPs) is emerging as a promising absorption pathway for natural polysaccharides. Herein, the aim of this study is to investigate the PP-based oral absorption of a pectic polysaccharide from Smilax china L. (SCLP), as well as its uptake and transport mechanisms in related immune cells. Taking advantages of the traceability of fluorescently labeled SCLP, we confirmed that SCLP could be absorbed into PPs and captured by their mononuclear phagocytes (dendritic cells and macrophages) following oral administration. Subsequently, the systematic in vitro study suggested that the endocytic mechanisms of SCLP by model mononuclear phagocytes (BMDCs and RAW264.7 cells) mainly involved caveolae-mediated endocytosis, macropinocytosis and phagocytosis. More importantly, SCLP directly binds and interacts with toll-like receptor 2 (TLR2) and galectin 3 (Gal-3) receptor, and was taken up by mononuclear phagocytes in receptor-mediated manner. After internalization, SCLP was intracellularly transported primarily through endolysosomal pathway and ultimately localized in lysosomes. In summary, this work reveals novel information and perspectives about the in vivo fate of SCLP, which will contribute to further research and utilization of SCLP and other pectic polysaccharides.

Consensus Statements on the Use of Novel Formulations of Isotretinoin: A Modified Delphi Process.

Oral isotretinoin remains a mainstay of treatment for severe, recalcitrant nodular acne. Novel formulations of isotretinoin have been developed over the past decade, including lidose isotretinoin and micronized isotretinoin. It is important to understand the differences between isotretinoin formulations to help guide clinical decision-making and selection of isotretinoin therapy. This study aims to provide evidence-based consensus statements regarding the use of novel formulations of isotretinoin for the treatment of moderate-to-severe acne. The Expert Consensus Group consisted of dermatologists with expertise in the treatment of acne. Voting members met in person to conduct a modified Delphi process; a maximum of 2 rounds of voting were conducted for each consensus statement. A total of 5 statements were generated regarding the use of novel formulations of isotretinoin, addressing the efficacy, tolerability, and side effects of novel isotretinoin formulations. All 5 statements achieved agreement with high consensus. The Expert Consensus Group agrees that individualized selection of isotretinoin therapy is important to maximize efficacy and minimize side effects. Compared to generic isotretinoin, micronized isotretinoin may require lower doses to achieve sufficient plasma concentrations. With the increased bioavailability of micronized formulation, there is no need to calculate cumulative dose; instead, the general recommendation with micronized isotretinoin is to treat for at least 5 months, or longer if needed to achieve clearance. Micronized isotretinoin can be taken in the fed or fasted state and has an acceptable safety profile. J Drugs Dermatol. 2024;23(6):429-432.     doi:10.36849/JDD.7971.

Robotic Pills as Innovative Personalized Medicine Tools: A Mini Review.

The most common route for drug administration is the oral route due to the various advantages offered by this route, such as ease of administration, controlled and sustained drug delivery, convenience, and non-invasiveness. In spite of this, oral drug absorption faces challenges due to various issues related to its stability, permeability and solubility in the GI tract. Biologic drugs generally face problems when administered by oral route as they are readily degradable and thus required to be injected. To overcome these issues in oral absorption, different approaches like novel drug delivery systems and newer pharmaceutical technologies have been adopted. With a combined knowledge of drug delivery and pharmaceutical technology, robotic pills can be designed and used successfully to enhance the adhesion and permeation of drugs through the mucus membrane of the GI tract to achieve drug delivery at the target site. The potential application of robotic pills in diagnosis and drug dispensing is also discussed. The review highlights recent developments in robotic pill drug-device technology and discusses its potential applications to solve the problems and challenges in oral drug delivery.

Oral administration of probiotic spore ghosts for efficient attenuation of radiation-induced intestinal injury.

Radiation-induced intestinal injury is the most common side effect during radiotherapy of abdominal or pelvic solid tumors, significantly impacting patients' quality of life and even resulting in poor prognosis. Until now, oral application of conventional formulations for intestinal radioprotection remains challenging with no preferred method available to mitigate radiation toxicity in small intestine. Our previous study revealed that nanomaterials derived from spore coat of probiotics exhibit superior anti-inflammatory effect and even prevent the progression of cancer. The aim of this work is to determine the radioprotective effect of spore coat (denoted as spore ghosts, SGs) from three clinically approved probiotics (B.coagulans, B.subtilis and B.licheniformis). All the three SGs exhibit outstanding reactive oxygen species (ROS) scavenging ability and excellent anti-inflammatory effect. Moreover, these SGs can reverse the balance of intestinal flora by inhibiting harmful bacteria and increasing the abundance of Lactobacillus. Consequently, administration of SGs significantly reduce radiation-induced intestinal injury by alleviating diarrhea, preventing X-ray induced apoptosis of small intestinal epithelial cells and promoting restoration of barrier integrity in a prophylactic study. Notably, SGs markedly improve weight gain and survival of mice received total abdominal X-ray radiation. This work may provide promising radioprotectants for efficiently attenuating radiation-induced gastrointestinal syndrome and promote the development of new intestinal predilection.

Integrated oral microgel system ameliorates renal fibrosis by hitchhiking co-delivery and targeted gut flora modulation.

BACKGROUND: Renal fibrosis is a progressive process associated with chronic kidney disease (CKD), contributing to impaired kidney function. Active constituents in traditional Chinese herbs, such as emodin (EMO) and asiatic acid (AA), exhibit potent anti-fibrotic properties. However, the oral administration of EMO and AA results in low bioavailability and limited kidney accumulation. Additionally, while oral probiotics have been accepted for CKD treatment through gut microbiota modulation, a significant challenge lies in ensuring their viability upon administration. Therefore, our study aims to address both renal fibrosis and gut microbiota imbalance through innovative co-delivery strategies. RESULTS: In this study, we developed yeast cell wall particles (YCWPs) encapsulating EMO and AA self-assembled nanoparticles (NPYs) and embedded them, along with Lactobacillus casei Zhang, in chitosan/sodium alginate (CS/SA) microgels. The developed microgels showed significant controlled release properties for the loaded NPYs and prolonged the retention time of Lactobacillus casei Zhang (L. casei Zhang) in the intestine. Furthermore, in vivo biodistribution showed that the microgel-carried NPYs significantly accumulated in the obstructed kidneys of rats, thereby substantially increasing the accumulation of EMO and AA in the impaired kidneys. More importantly, through hitchhiking delivery based on yeast cell wall and positive modulation of gut microbiota, our microgels with this synergistic strategy of therapeutic and modulatory interactions could regulate the TGF-ß/Smad signaling pathway and thus effectively ameliorate renal fibrosis in unilateral ureteral obstruction (UUO) rats. CONCLUSION: In conclusion, our work provides a new strategy for the treatment of renal fibrosis based on hitchhiking co-delivery of nanodrugs and probiotics to achieve synergistic effects of disease treatment and targeted gut flora modulation.

Effect of oral tryptamines on the gut microbiome of rats-a preliminary study.

Background: Psilocybin and related tryptamines have come into the spotlight in recent years as potential therapeutics for depression. Research on the mechanisms of these effects has historically focused on the direct effects of these drugs on neural processes. However, in addition to such neural effects, alterations in peripheral physiology may also contribute to their therapeutic effects. In particular, substantial support exists for a gut microbiome-mediated pathway for the antidepressant efficacy of other drug classes, but no prior studies have determined the effects of tryptamines on microbiota. Methods: To address this gap, in this preliminary study, male Long Evans rats were treated with varying dosages of oral psilocybin (0.2 or 2 mg/kg), norbaeocystin (0.25 or 2.52 mg/kg), or vehicle and their fecal samples were collected 1 week and 3 weeks after exposure for microbiome analysis using integrated 16S ribosomal DNA sequencing to determine gut microbiome composition. Results: We found that although treatment with neither psilocybin nor norbaeocystin significantly affected overall microbiome diversity, it did cause significant dose- and time-dependent changes in bacterial abundance at the phylum level, including increases in Verrucomicrobia and Actinobacteria, and decreases in Proteobacteria. Conclusion and Implications: These preliminary findings support the idea that psilocybin and other tryptamines may act on the gut microbiome in a dose- and time-dependent manner, potentially identifying a novel peripheral mechanism for their antidepressant activity. The results from this preliminary study also suggest that norbaeocystin may warrant further investigation as a potential antidepressant, given the similarity of its effects to psilocybin.