Background Heavy tobacco smoking, a hallmark feature of lung cancer, is drastically predominant in Middle Eastern populations. The precise links between nicotine dependence and the functional contribution of the oral microbiota remain unknown in these populations. Methods We evaluated the composition and functional capabilities of oral microbiota with relation to cigarette smoking in 105 adults through shotgun metagenomics using buccal swabs. Results The oral microbiota composition in our study subjects was dominated by the phyla Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes, in addition to the genera Prevotella and Veillonella, similar to previously described westernized cohorts. Furthermore, the smoker's oral microbiota represented a significant abundance of Veillonella dispar, Leptotrichia spp. and Prevotella pleuritidis when compared to non-smokers. Within the smoking groups, differential relative abundance testing unveiled relative abundance of Streptobacillus hongkongensis, Fusobacterium massiliense, Prevotella bivia in high nicotine dependent compared to low nicotine dependent profiles based on Fagerström Test for Nicotine Dependence. Functional profiling showed marked differences between smokers and non-smokers. Smokers exhibited an enrichment of Tricarballylate utilization and Lactate racemization when compared to the non-smokers. According to their nicotine dependence, enrichment of Xanthosine utilization, p-Aminobenzoyl-Glutamate utilization, and multidrug efflux pump in Campylobacter jejuni biosynthesis modules were detected in the high nicotine dependent group. Conclusions These compositional and functional differences may provide critical insight on how variations in the oral microbiota could predispose to respiratory illnesses and smoke cessation relapse in cigarette smokers. In particular, the observed enrichment of Fusobacterium and Prevotella in the oral microbiota possibly suggests an intriguing linkage to gut and lung cancers.

Radiation therapy (RT) has dramatically improved cancer survival, leading to several inevitable complications. Unintentional irradiation of the heart can lead to radiation-induced heart disease (RIHD), including cardiomyopathy, pericarditis, coronary artery disease, valvular heart disease, and conduction system abnormalities. Furthermore, the development of RIHD is aggravated with the addition of chemotherapy. The screening, diagnosis, and follow-up for RIHD in patients who have undergone RT are described by the consensus guidelines from the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE). There is compelling evidence that chest RT can increase the risk of heart disease. Although the prevalence and severity of RIHD are likely to be reduced with modern RT techniques, the incidence of RIHD is expected to rise in cancer survivors who have been treated with old RT regimens. However, there remains a gap between guidelines and clinical practice. Currently, therapeutic modalities followed in the treatment of RIHD are similar to the non-irradiated population. Preventive measures mainly reduce the radiation dose and radiation volume of the heart. There is no concrete evidence to endorse the preventive role of statins, angiotensin-converting enzyme inhibitors, and antioxidants. This review summarizes the current evidence of RIHD subtypes and risk factors and suggests screening regimens, diagnosis, treatment, and preventive approaches.

Background: Heavy tobacco smoking, a hallmark feature of lung cancer is drastically predominant in Middle Eastern populations. The precise links between nicotine dependence and the functional contribution of the oral microbiota remain unknown in these populations. Methods: We evaluated the functional capabilities of the oral microbiota with relation to cigarette smoking in 105 adults through shotgun metagenomics. Results: The four major enterotypes initially described in westernized cohorts were retrieved in this population. Differential relative abundance testing unveiled relative abundance of Streptobacillus hongkongensis (Log2FoldChange 4.78, P. adjusted value < 0.00004), Fusobacterium massiliense (Log2FoldChange 4.63, P. adjusted value < 0.00000004), Prevotella bivia (Log2FoldChange 2.46, P. adjusted value < 0.00024) in high nicotine dependent compared to low nicotine dependent profiles based on Fagerström test for Nicotine Dependence. Functional profiling showed marked differences between smokers and non-smokers controls with an enrichment of Tricarballylate utilization (Log2FoldChange 2.52, P. adjusted value < 0.0013) and Lactate racemization (Log2FoldChange 1.003, P. adjusted value < 0.0001) among others in smokers vs . non-smokers group. According to nicotine dependence, we detected enrichment of Xanthosine utilization (Log2FoldChange 3.38, P. adjusted value < 0.00007), p-Aminobenzoyl-Glutamate utilization (Log2FoldChange 1.33, P. adjusted value < 0.00056), and Multidrug efflux pump in Campylobacter jejuni (Log2FoldChange 1.14, P. adjusted value < 0.00007) biosynthesis modules in the high nicotine dependent group. Conclusions: These differences provide a critical insight on how variations in the oral microbiota may predispose to smoke cessation relapse, serious respiratory illnesses, and lung cancer in heavy cigarette smokers. The observed enrichment of Fusobacterium and Prevotella suggest an intriguing linkage to lung and gut cancers. This information may eventually lead to the development of screening biomarkers to predict early cancer development.

Background: Heavy tobacco smoking, a hallmark feature of lung cancer, is drastically predominant in Middle Eastern populations. The precise links between nicotine dependence and the functional contribution of the oral microbiota remain unknown in these populations.Methods: We evaluated the composition and functional capabilities of oral microbiota with relation to cigarette smoking in 105 adults through shotgun metagenomics using buccal swabs. Results: The oral microbiota composition in our study subjects was dominated by the phyla Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes, in addition to the genera Prevotella and Veillonella, similar to previously described westernized cohorts. Furthermore, the smoker's oral microbiota represented a significant abundance of Veillonella dispar, Leptotrichia spp., and Prevotella pleuritidis when compared to non-smokers. Within the smoking groups, differential relative abundance testing unveiled relative abundance of Streptobacillus hongkongensis, Fusobacterium massiliense, Prevotella bivia in high nicotine dependent compared to low nicotine dependent profiles based on Fagerström Test for Nicotine Dependence. Functional profiling showed marked differences between smokers and non-smokers. Smokers exhibited an enrichment of Tricarballylate utilization and Lactate racemization when compared to the non-smokers. According to their nicotine dependence, enrichment of Xanthosine utilization, p-Aminobenzoyl-Glutamate utilization, and multidrug efflux pump in Campylobacter jejuni biosynthesis modules were detected in the high nicotine dependent group. Conclusions: These compositional and functional differences may provide critical insight on how variations in the oral microbiota could predispose to respiratory illnesses and smoke cessation relapse in cigarette smokers. In particular, the observed enrichment of Fusobacterium and Prevotella in the oral microbiota possibly suggests an intriguing linkage to gut and lung cancers.