Characterizations of gut bacteriome, mycobiome, and virome of healthy individuals living in sea-level and high-altitude areas.

BACKGROUND: The contribution of gut microbiota to human high-altitude adaptation remains inadequately understood. METHODS: Here a comparative analysis of gut microbiota was conducted between healthy individuals living at sea level and high altitude using deep whole-metagenome shotgun sequencing, to investigate the adaptive mechanisms of gut microbiota in plateau inhabitants. RESULTS: The results showed the gut bacteriomes in high-altitude individuals exhibited greater within-sample diversity and significant alterations in both bacterial compositional and functional profiles when compared to those of sea-level individuals, indicating the potential selection of unique bacteria associated with high-altitude environments. The strain-level investigation revealed enrichment of Collinsella aerofaciens and Akkermansia muciniphila in high-altitude populations. The characteristics of gut virome and gut mycobiome were also investigated. Compared to sea-level subjects, high-altitude subjects exhibited a greater diversity in their gut virome, with an increased number of viral operational taxonomic units (vOTUs) and unique annotated genes. Finally, correlation analyses revealed 819 significant correlations between 42 bacterial species and 375 vOTUs, while no significant correlations were observed between bacteria and fungi or between fungi and viruses. CONCLUSION: The findings have significantly contributed to an enhanced comprehension of the mechanisms underlying the high-altitude geographic adaptation of the human gut microbiota.

Health status of the population in Naqu, Tibet and its latent class analysis: a cross-sectional survey.

Background: Through a survey and analysis of the population's present state of health, it is possible to give data support for improving the health status of inhabitants in Naqu, Tibet. Additionally, it is possible to provide specific recommendations for the development of medical and healthcare facilities in Tibet. Methods: The health scores of the participants were based on their responses to the four main sections of the questionnaire: dietary habits, living habits, health knowledge, and clinical disease history, and the variability of health status among groups with different characteristics was analyzed based on the scores. The four major sections were used to create classes of participants using latent class analysis (LCA). Using logistic regression, the factors influencing the classification of latent classes of health status were investigated. Results: A total of 995 residents from 10 counties in Naqu were selected as the study subjects. And their demographic characteristics were described. The mean health score of residents after standardization was 81.59 ± 4.68. With the exception of gender, health scores differed between groups by age, education level, different occupations, marital status, and monthly income. The health status in Naqu, Tibet, was divided into two groups (entropy = 0.29, BLRT = 0.001, LMRT = 0.001) defined as the "good health group" and the "general health group." A monthly income of more than ¥5000 adverse to good health in Naqu, Tibet. Discussion: Single, well-educated young adults in Naqu, Tibet, have outstanding health. The vast majority of people in Tibet's Naqu region were in good health. Furthermore, the population's latent health status was divided into two classes, each with good dietary and living habits choices, low health knowledge, and a history of several clinical diseases. Univariate and multivariate logistic regression analysis showed that monthly income more than ¥5000 was an independent risk factor for poor health status.

Term breech presentation vaginal births in Tibet: A retrospective analysis of 451 cases.

Background: In high altitude areas, like Tibet, most fetuses in breech presentation at term are delivered vaginally owing to a variety of reasons, but this has not been published. Objective: This study aimed to provide references and evidence for the delivery of breach presentation term fetuses in high altitude areas, through comparing and analyzing the data of full-term singleton fetuses with breech or cephalic presentation in Naqu People's Hospital, Tibet. Study design: We retrospectively analyzed the clinical data of 451 breech presentation fetuses mentioned above over a period of 5 years (2016-2020). A total of 526 cephalic presentation fetuses' data within 3 months (1 June to 1 September 2020) of the same period were collected too. Statistics were compared and assembled on fetal mortality, Apgar scores, and severe neonatal complications for both planned cesarean section (CS) and vaginal delivery. In addition, we also analyzed the types of breech presentation, the second stage of labor, and damage to the maternal perineum during vaginal delivery. Results: Among the 451 cases of breech presentation fetuses, 22 cases (4.9%) elected for CS and 429 cases (95.1%) elected for vaginal delivery. Of the women who chose vaginal trial labor, 17 cases underwent emergency CSs. The perinatal and neonatal mortality rate was 4.2% in the planned vaginal delivery group and the incidence of severe neonatal complications was 11.7% in the transvaginal group, no deaths were detected in the CS group. Among the 526 cephalic control groups with planned vaginal delivery, the perinatal and neonatal mortality was 1.5% (p = 0.012), and the incidence of severe neonatal complications was 1.9%. Among vaginal breech deliveries, most of them were complete breech presentation (61.17%). Among the 364 cases, the proportion of intact perinea was 45.1%, and first degree lacerations accounted for 40.7%. Conclusion: In the Tibetan Plateau region, vaginal delivery was less safe than cephalic presentation fetuses for full-term breech presentation fetuses delivered in the lithotomy position. However, if dystocia or fetal distress can be identified in time and then encouraged to convert to cesarean, its safety will be greatly improved.

Association of dietary pattern and Tibetan featured foods with high-altitude polycythemia in Naqu, Tibet: A 1:2 individual-matched case-control study.

This study focused on the association of dietary patterns and Tibetan featured foods with high-altitude polycythemia (HAPC) in Naqu, Tibet, to explore the risk factors of HAPC in Naqu, Tibet, to raise awareness of the disease among the population and provide evidence for the development of prevention and treatment interventions. A 1:2 individual-matched case-control study design was used to select residents of three villages in the Naqu region of Tibet as the study population. During the health examination and questionnaire survey conducted from December 2020 to December 2021, a sample of 1,171 cases was collected. And after inclusion and exclusion criteria and energy intake correction, 100 patients diagnosed with HAPC using the "Qinghai criteria" were identified as the case group, while 1,059 patients without HAPC or HAPC -related diseases were identified as the control group. Individuals were matched by a 1:2 propensity score matching according to gender, age, body mass index (BMI), length of residence, working altitude, smoking status, and alcohol status. Dietary patterns were determined by a principal component analysis, and the scores of study subjects for each dietary pattern were calculated. The effect of dietary pattern scores and mean daily intake (g/day) of foods in the Tibetan specialty diet on the prevalence of HAPC was analyzed using conditional logistic regression. After propensity score matching, we found three main dietary patterns among residents in Naqu through principal component analysis, which were a "high protein pattern," "snack food pattern," and "vegetarian food pattern." All three dietary patterns showed a high linear association with HAPC (p < 0.05) and were risk factors for HAPC. In the analysis of the relationship between Tibetan featured foods and the prevalence of HAPC, the results of the multifactorial analysis following adjustment for other featured foods showed that there was a positive correlation between the average daily intake of tsampa and the presence of HAPC, which was a risk factor. Additionally, there was an inverse correlation between the average daily intake of ghee tea and the presence of HAPC, which was a protective factor.

Cervical cancer screening in high-altitude areas in China: A large cross-section study of 25,173 women in northern Tibet.

Background: Cervical cancer has become a worldwide concern owing to its high incidence and mortality rates. To date, high-altitude areas of Tibet have not benefited from any large-scale cervical cancer screening programs. Therefore, we initiated a screening program to investigate the prevalence of human papilloma virus (HPV) and HPV genotype distribution to reveal cervical cancer and its precursor which lead to morbidity among women in the city of Nagqu in northern Tib3et. Methods: A total of 25,173 women were recruited to undergo HPV genotype tests between June and December 2019. Women infected with HPV 16 and/or 18 underwent colposcopy and histological examination. Women with other high-risk HPV type (hr-HPV) underwent cytological tests to determine whether to conduct further colposcopy and histological examination for diagnosis. HPV prevalence was calculated in the total population and further stratified according to various parameters, such as age group, area location (altitude level), and single or mixed infection status. The HPV genotype distribution was also investigated accordingly. Cervical lesions revealed by further colposcopic findings were also analyzed; high-grade and malignant lesion morbidities were calculated in total and in each county. Most data were collected and analyzed using descriptive and consistency check statistical methods, and a risk factor investigation for HPV infection was performed using logistic regression models. Results: The total HPV infection rate among women in Nagqu was 13.42%. Of the 25,173 women in the study, 999 (3.97%) were HPV 16/18 positive, 2,379 (9.45%) were other hr-HPV-positive, and 21,795 (86.58%) were HPV-negative. The five most common HPV genotypes, accounting for more than 60% of all HPV infections in Nagqu people, were HPV 16, 58, 31, 18, and 52. Tibetan women younger than 20 years and older than 60 years were the two age groups with the highest rates of HPV infection, 26.7% and 19.8%, respectively. Among the HPV-positive women, 2,656 (78.33%) were infected with a single strain and 732 (21.67%) were infected with multiple strains (more than two genotypes). HPV prevalence increased in high-altitude areas (positive rate highest in Nyima with an altitude of 5,000 m, 23.9%) and decreased in relatively low-altitude areas (positive rate lowest in Lhari with an altitude of 4,000 m, 6.6%). Multiple analyses showed that age, parity, age at first delivery, and altitude of residence were independent factors facilitating HPV infection in Tibetan women. High-grade and malignant cervical lesions revealed by histological findings were different among living locations, with the highest rates in Xainza, Baingoin, and Nyainrong, these being 2.019%, 1.820%, and 1.116%, respectively, among women in these areas. Conclusion: Our survey provides an overall perspective on HPV genotype infection and cervical lesions in women in northern Tibet. The data not only provide useful information for the treatment of cervical lesions but also has great value in terms of the primary and secondary prevention measures that can be taken for women living in these regions. Clinical Trial Registration: www.chictr.org.cn, indentifier ChiCTR2000035061.

Distinct Nutrient Intake Style in Inhabitants of Ultra-High-Altitude Areas in North of Tibet, China: A Cross-Sectional Study Based on Newly Developed Tibetan Food Frequency Questionnaires.

Dietary pattern is quite distinct among the inhabitants of high-altitude areas because of environmental and geographical uniqueness; hence, it is important to investigate this data as accurately as possible. However, very few data are related to these populations up to now. Based on the food frequency questionnaire (FFQ) used in the Chinese population, a revised Tibetan edition was developed with respect to the lifestyle in high-altitude areas. After assessment of validity and reproducibility, a nutrition intake survey was conducted among 1,071 randomly sampled Tibetan people. In addition, the Bland-Altman approach was used to compare the agreement between the two dietary tools. For the reproducibility analysis, intraclass correlation coefficients (ICC) were calculated to examine the agreement of food groups and nutrients from the two FFQs (FFQ1 and FFQ2). Nutrient intake was calculated using food composition tables. For the validity analysis, Pearson's correlation of food groups intakes varied from 0.22 to 0.91 (unadjusted). The correlations of nutrients ranged from 0.24 to 0.76 (unadjusted). In the analysis of reliability, the ICC of food groups varied from 0.27 to 0.70 (unadjusted). The ICC of nutrient intakes ranged from 0.22 to 0.87 (unadjusted). The results of nutritional analysis showed that ~25% of foods consumed frequently were traditional Tibetan foods. However, traditional Han foods were frequently consumed. In addition, the energy, iron, and protein intakes for male or female subjects were close to the Chinese Dietary Nutrient Reference Intake (Chinese DRIs); however, fat and sodium intakes were significantly higher than the Chinese DRIs. Interestingly, lower intakes of other types of nutrition, such as vitamin C were detected in people living in high-altitude areas. Our data indicated that excess consumption of fat and sodium and insufficient intake of vitamin C were common among Tibetan people, as compared with the most Chinese people living in the plateau areas. More investigations are needed to reveal the association between the food intake style and high-altitude endemic diseases.