Division of Molecular Genetics and Biochemistry, Molecular Biology Group, ICMR-National Institute of Cancer Prevention and Research, Noida, Uttar Pradesh, India.
Division of Biomedical Informatics, Indian Council of Medical Researchgrid.19096.37 (ICMR), New Delhi, India.
Microbiol Spectr. 2022 Aug 31;10(4):e0227321. doi: 10.1128/spectrum.02273-21. Epub 2022 Jun 13.
The microbial communities present in smokeless tobacco products (STPs) perform critical steps in the synthesis of carcinogens, mainly tobacco-specific nitrosamines (TSNAs). Most studies emphasize the bacterial component, and the mycobiome of STPs has not been well characterized. In this study, we investigated the fungal communities in the different categories of STPs by sequencing the internal transcribed spacer (ITS) rRNA region of the fungal genome. The ecological character of the fungal community associated with STPs was determined by using FUNGuild. Our results indicated that and were the most abundant fungal phyla across all STPs. The predominant fungal genera in STPs were Pichia, Sterigmatomyces, and Mortierella. The α-diversity varied significantly across the STPs based on observed, Fisher, and Shannon indices. Using SparCC cooccurrence network analysis, significant positive correlations of 58.5% and negative connections of 41.5% were obtained among fungal genera identified in STPs. Furthermore, the functional predictions by FUNGuild determined that STPs possessed high abundances of saprotroph and pathotroph-saprotroph-symbiotroph fungal trophic groups. At the functional guild level, the qiwam samples contained high abundances of soil saprotrophs, while plant pathogens were prevalent in pan-masala samples. These results suggest that various fungal populations reside in STPs and interrelate with each other and can contribute to the synthesis of TSNAs. This study has established the basis for future large-scale investigations of STP-associated mycobiota and the impact of such mycobiota in oral carcinogenesis in STP users via inflammation and carcinogens (TSNAs and mycotoxins). Smokeless tobacco products (STPs) contain complex microbial communities that influence the synthesis of carcinogens, such as tobacco-specific nitrosamines (TSNAs). Research on STP-associated bacterial populations revealed connections between bacterial metabolism and TSNA synthesis. The abundance of the fungal population may also have an impact on the production of TSNAs. This study examined STPs popularly used in India, and diverse fungal communities were identified in these STPs. Pichia, Sterigmatomyces, and Mortierella were the predominant fungal genera in the STPs. High abundances of saprotroph and pathotroph-saprotroph-symbiotroph trophic groups in STPs could affect the degradation of tobacco products and the synthesis of TSNAs.
无烟气烟草制品 (STP) 中的微生物群落参与了致癌物质，主要是烟草特异性亚硝胺 (TSNA) 的合成的关键步骤。大多数研究强调细菌成分，而 STP 的真菌组尚未得到很好的描述。在这项研究中，我们通过测序真菌基因组的内部转录间隔区 (ITS) rRNA 区域来研究不同类别 STP 中的真菌群落。通过使用 FUNGuild 来确定与 STP 相关的真菌群落的生态特征。我们的结果表明，在所有 STP 中， 和 是最丰富的真菌门。STP 中的主要真菌属为毕赤酵母属、曲霉属和枝孢霉属。基于观察到的、Fisher 和 Shannon 指数，STP 中的真菌多样性差异显著。使用 SparCC 共现网络分析，在 STP 中鉴定的真菌属之间获得了 58.5%的显著正相关和 41.5%的负连接。此外，通过 FUNGuild 进行的功能预测确定，STP 具有高丰度的腐生和病原-腐生-共生营养真菌营养群。在功能类群水平上，qiwam 样本中含有丰富的土壤腐生菌，而泛马沙拉样本中则普遍存在植物病原体。这些结果表明，各种真菌种群存在于 STP 中并相互关联，并有助于 TSNAs 的合成。这项研究为未来大规模研究 STP 相关真菌群以及通过炎症和致癌物质 (TSNAs 和真菌毒素) 在 STP 用户中口腔致癌作用对这种真菌群的影响奠定了基础。无烟气烟草制品 (STP) 含有复杂的微生物群落，这些群落影响致癌物质的合成，如烟草特异性亚硝胺 (TSNAs)。研究 STP 相关的细菌种群揭示了细菌代谢与 TSNA 合成之间的联系。真菌种群的丰度也可能对 TSNAs 的产生产生影响。本研究检查了在印度流行的 STP，并在这些 STP 中鉴定出了不同的真菌群落。在 STP 中，毕赤酵母属、曲霉属和枝孢霉属是主要的真菌属。STP 中高丰度的腐生和病原-腐生-共生营养组可能会影响烟草制品的降解和 TSNAs 的合成。
