Alzheimer’s disease (AD), a prevalent neurodegenerative disorder in the aging population, remains without definitive therapeutic solutions. Emerging insights into the gut microbiota (GM) and its bidirectional communication with the central nervous system(CNS) through the microbiota–gut–brain axis (MGBA) have unveiled potential correlative mechanisms that may contribute to AD pathogenesis, though causal evidence remains limited. Dysregulation of GM composition (dysbiosis) exacerbates AD progression via neuroinflammation, amyloid-β (Aβ) deposition, and tau hyperphosphorylation (p-tau), while restoring microbial homeostasis presents a promising therapeutic strategy. Fecal microbiota transplantation (FMT), a technique to reconstitute gut ecology by transferring processed fecal matter from healthy donors, has demonstrated efficacy in ameliorating cognitive deficits and neuropathology in AD animal models. Preclinical studies reveal that FMT reduces Aβ plaques, normalizes tau phosphorylation, suppresses inflammasome activation, and restores microglial homeostasis through modulation of microbial metabolites and immune pathways. Although clinical evidence remains limited to case reports and small-scale trials showing potential therapeutic effect, safety concerns regarding long-term effects and protocol standardization necessitate further investigation. This review synthesizes current knowledge on GM–AD interactions, evaluates FMT’s mechanistic potential, and discusses challenges in translating this ancient practice into a cutting-edge AD therapy. Rigorous randomized controlled trials and personalized microbiota-based interventions are imperative to advance FMT from bench to bedside.

Background: The association between soy product consumption and cancer risk varies among studies. Therefore, this comprehensive meta-analysis of observational studies examines the association between soy product consumption and total cancer risk. Methods: This study was conducted following the PRISMA guidelines. Up to October 2023, all eligible published studies were searched through PubMed and Web of Science databases. Results: A total of 52 studies on soy product consumption were included in this meta-analysis (17 cohort studies and 35 case–control studies). High consumption of total soy products (RR: 0.69; 95% CI: 0.60, 0.80), tofu (RR: 0.78; 95% CI: 0.70, 0.86), and soymilk (RR: 0.75; 95% CI: 0.60, 0.93) were associated with reduced total cancer risk. No association was found between high consumption of fermented soy products (RR: 1.18; 95% CI: 0.95, 1.47), non-fermented soy products (RR: 0.95; 95% CI: 0.77, 1.18), soy paste (RR: 1.00; 95% CI: 0.88, 1.14), miso soup (RR: 0.99; 95% CI: 0.87, 1.12), or natto (RR: 0.96; 95% CI: 0.82, 1.11) and cancer risk. A 54 g per day increment of total soy products reduced cancer risk by 11%, a 61 g per day increment of tofu reduced cancer risk by 12%, and a 23 g per day increment of soymilk reduced cancer risk by 28%, while none of the other soy products were associated with cancer risk. Conclusion: Our findings suggest that high total soy product consumption, especially soymilk and tofu, is associated with lower cancer risk. More prospective cohort studies are still needed to confirm the causal relationship between soy product consumption and cancer risk.

Heavy metals and per- and polyfluoroalkyl substances (PFASs) have become particularly important when studying the development of depression, a common illness that severely restricts psychosocial functioning and diminishes quality of life. Therefore, the potential joint effects of heavy metal and PFAS exposure on depression, as well as the underlying mechanisms involved, were investigated by using integrated epidemiological and bioinformatic approaches in the present study. A thorough analysis of 7301 samples from the National Health and Nutrition Examination Survey (NHANES) cycles that occurred between 2005 and 2018 was performed. Single-exposure studies have shown that cadmium exposure is positively associated with depression, whereas perfluorooctanesulfonic acid (PFOS) exposure and perfluorodecanoic acid (PFDE) exposure are negatively associated with depression. Furthermore, the Bayesian kernel machine regression (BKMR) and quantile g-computation (QGcomp) models were employed to investigate the collective impact of exposure to mixed metals on depression. Cadmium emerged as the principal contributor to depression. Moreover, the addition of PFAS to the metal mixture had an antagonistic effect on depression, with PFOS having the most prominent influence. Analysis of the effects of co-exposure to cadmium and PFOS confirmed the presence of an antagonistic effect. The inflection points of cadmium and PFOS were determined to be -1.11 and 2.27, respectively. Additionally, exposure to cadmium and PFOS had the opposite effects on two crucial pathways, namely, the rap1 and calcium signaling pathways, which involve core genes related to depression such as ADORA2A, FGF2, and FGFR1. These findings have significant implications for future studies and provide new strategies for exploring the mechanisms underlying co-exposure effects.

Background: Sexual transmission among men who have sex with men (MSM) has become the major HIV transmission route. However, limited research has been conducted to investigate the association between transactional sex (TS) and HIV incidence in China. Objective: This study aims to investigate HIV incidence and distinguish sociodemographic and sexual behavioral risk factors associated with HIV incidence among MSM who engage in TS (MSM-TS) in China. Methods: We conducted a prospective cohort study using a WeChat-based platform to evaluate HIV incidence among Chinese MSM, including MSM-TS in Ningbo, recruited from July 2019 until June 2022. At each visit, participants completed a questionnaire and scheduled an appointment for HIV counseling and testing on the WeChat-based platform before undergoing offline HIV tests. HIV incidence density was calculated as the number of HIV seroconversions divided by person-years (PYs) of follow-up, and univariate and multivariate Cox proportional hazards regression was conducted to identify factors associated with HIV incidence. Results: A total of 932 participants contributed 630.9 PYs of follow-up, and 25 HIV seroconversions were observed during the study period, resulting in an estimated HIV incidence of 4.0 (95% CI 2.7-5.8) per 100 PYs. The HIV incidence among MSM-TS was 18.4 (95% CI 8.7-34.7) per 100 PYs, which was significantly higher than the incidence of 3.2 (95% CI 2.1-5.0) per 100 PYs among MSM who do not engage in TS. After adjusting for sociodemographic characteristics, factors associated with HIV acquisition were MSM-TS (adjusted hazard ratio [aHR] 3.93, 95% CI 1.29-11.93), having unprotected sex with men (aHR 10.35, 95% CI 2.25-47.69), and having multiple male sex partners (aHR 3.43, 95% CI 1.22-9.64) in the past 6 months. Conclusions: This study found a high incidence of HIV among MSM-TS in Ningbo, China. The risk factors associated with HIV incidence include TS, having unprotected sex with men, and having multiple male sex partners. These findings emphasize the need for developing targeted interventions and providing comprehensive medical care, HIV testing, and preexposure prophylaxis for MSM, particularly those who engage in TS.